CAD designs by Ivan

Advises worth sharing

2012-02-15T13:25:00.001+01:00

Advises worth sharing, from Eng-Tips forum, published with approvals of author patprimmer.

original text is in this tread.

"As someone who worked in market development and business development for years, there are a few basic common sense rules and traps.

1) Never discuss their oppositions business. If they see you being indiscreet about someone else, they will expect you to be the same behind their back. It takes years to build a reputation and trust and seconds to blow it all.

2) Be very careful criticising previous or current work. If you say who was the idiot that did that (or even subtly imply it) the idiot may be the one facing you.

3) Keep in depth contacts at the major existing accounts. As David found out, your contacts do move on and you need second and third or more contacts to maintain the business long term.

4) Knock on doors and use the phone. Both forms are required, but show respect for their time and don't waste it.

5) Prospects who don't see reps will see you if you can tweak their interest. They need confidence that you won't be wasting their time and you will likely impart knowledge to them or have a deal to suit their needs. Start of brief and very to the point about your companies capabilities and their needs and where they might overlap.

6) If your product or service does not fit their needs, say so. Maybe then explore a bit deeper if they are happy to continue, but don't flog a dead horse. It wastes everyone's time.

7) If you can't offer a really suitable product, walk away gracefully. That way you are much more likely to get another chance when you do have something they can use. Overselling an unsuitable product usually ends up in a failed project down the line and lots of burned bridges and even law suits.

8) If it is going to be a difficult or experimental project and nobody has a suitable product, go in on a VERY clear understanding that you will work with them, but you are both going where no man has been before and the risks are high for both. Even then they may use you as a scape goat.

9) If you get business easy or only on price, you can lose it just as easy.

10) For any really good customers, you really don't win their business, there current supplier loses it. You just need to be there or in the front of their mind when the current supplier stuffs up bad. This takes patience and serenity.

11) Sometimes a customer won't deal with you if they think you might also be working with a competitor. It can be done at times, but you need to be very careful about it and don't even try if an existing loyal customer is likely to react badly. For that to work, the existing customer needs to trust you implicitly.

12) Never sell purely on price. Sell on value. That is quite often the lowest price, but on occasion can be the highest price if your product has a major advantage. Higher price, higher benefit is often a harder sell as the price is a concrete principle and the benefit might be abstract.

13) Never promise more than you can deliver, and always follow up and deliver what you promise.

14) Never go into an introductory or first visit with everything. No one does a real deal on the first visit. Show them enough to tweak interest, but also search for their needs. You will very likely find they are different to your original thoughts. When you come back, you have had time to think and prepare and are then much better prepared to really meet their needs.

15) Listen more than you talk. You do not need to talk them into something, you need to identify their needs and align your offer to match. That takes carefully though out questions, product knowledge and a willingness to listen and learn.

16) Never be shy to ask for the order. They only agreed to spend their valuable time with you because they expect to get something they need from you. Once you identify a match between your wares and their needs, always ask for the order, but never push.

17) Always have a clear objective in mind whenever you call. Saying things like I was in the area, so I thought I would just drop in really shows disrespect and disregard for their time. Saying things like "I have reason to think we might have something of interest to you and I would like to investigate that" or "we are a supplier to your industry and I would like to investigate to see if we have something that will meet your needs" are much better lines to request an interview or to start of a cold call.

18) Your objectives should never be carved in stone. If the customer has done a 180 for whatever reason, think about your objective and change to plan B post haste if apropriate. I can recite a real good real world example of this if you wish to be bored with a long detailed story."

Grabcad mobile office design

2012-01-10T21:35:00.000+01:00

Designed in Siemens NX8

Less then 5 hours for design, and one more for good render, and this is result.

It started with Grabcad challenge GrabCAD Office Mobile Meeting Room. As I have some practical experience with fairs/exhibitions and I know that good "portable" office is what most companies need in such cases. This "portable" or mobile office have all you need for meetings, short or long. This small office can make quiet and calm oasis in hurried and crowded halls or rooms/large offices. It is equipped with air conditioner that blow fresh air from back side of seats making good atmosphere for sparking, brainstorming session. It have power for portable devices, natural and artificial lighting, bis screen for presentations, can be equipped with video conference equipment, whiteboard, intercom etc.

office with door open

office with door closed

front view

left view

right view

top view

front section view

top section view

Birdhouse

2012-01-10T20:58:00.000+01:00

Designed in Siemens NX8

Last few days there is too many splines in my life :) so I had to make something simple to relax a little. For no special reason I designed this birdhouse... it is more like bird hotel then a house. I hope I will have house with yard someday so I can make this in real.
Model if free for download, please send me images if you make this birdhouse.

Download IGES model
Download STEP model

Wind turbine (free CAD download file)

2011-11-04T11:38:00.002+01:00

Designed in Siemens NX6

In the light of some recent events I just had to make this model of wind turbine. It does not have many details but it is good for rendering and maybe some simulations and analysis. Please note that this is not blade of real wind turbine, and that this design is not product of any math, this is just a shape that I found on internet and make it look little smoother, so any use of this model is on your own responsibility. If you find this model useful for some purpose other then making renderings please let me know, I will be truly grateful.

It is really hard to find this type of geometry on internet but after extended search I finally found turbine blade base geometry on this site: https://confluence.cornell.edu/display/SIMULATION/ANSYS+WB+-+Wind+Turbine+Blade+-+Geometry.
But blade was very much distorted and looked like this:

So i had to "iron" it a little before I used it in my model. Now it look like this:

blade as part of wind turbine assembly look like this after rendering:

STEP model download
IGES model download

Parametric plane wing using wave linking, tutorial

2011-11-02T21:17:00.000+01:00

Designed in Siemens NX6

This is tutorial for one of many ways to use WAVE linking in NX6. Idea was to make plane wing that can be changed with simple change of values in Tools>Expressions. I tried to make this from one part, but it is too complicated to be really useful, so I made it with assembly and wave linking to keep it simple and functional.
In video below you can see how wing geometry is changed with change of values in expressions:

Next set of images show how to make this kind of design. Keep in mind that WAVE linking have great potential in design, and that this is just one of many ways to use it. It is one of most impressive technologies I saw so far in NX.

Air profile is done by importing points of air profile (I used NACA 6412 profile) and then scale it do get full size root profile.

Same have to be done for tip profile. (tip profile can be same or different from root profile, for this tutorial I used same NACA 6412 profile but I imported them with different attack angle)

Save profiles in separate files.

Now make new file which will be used to parameterize our wing.

First make expressions in tools>expressions.

half span [length-mm =3000]
wing angle [angle-degrees =75]
dihedral angle [angle-degrees =5]
root attack angle [angle-degrees =7]
tip attack angle [angle-degrees =2]

Make first sketch, on XY plane, it is simple line with start in 0,0,0 with angle toward X axis of 'wing angle' and length of 'half span'.

Make a associative plane from line from previous sketch and Z axes. Make a new sketch on that plane. In this sketch make again onl one line from 0,0,0 this time with 'dihedral angle' toward first line, or if you expect negative "anhedral" angle make it from Z axes but as '=90-dihedral angle' (this is because in NX sketch you can not make negative angle dimension). If you want to have length of span as projection on XY plane then make vertical line from end of line from previous sketch to end of line in this sketch. To make it more simple for this example I just used 'half span' length as length of this line.

Two more sketches, one at XZ plane where you will place root profile with only one line (this one line thing become boring?) make angle from Z axes with '=90+root attack angle' value, so it can go both + and - way.

Make new plane for last sketch, have to be associative, parallel to XZ plane and to go through end point of line we draw in sketch with dihedral angle. Make a sketch on that plane. This time two lines, one vertical and one at '=90+tip attack angle' value from first line.

Part should look like picture below at this stage.

Now this part become assembly. Assembly> component> add component, add both profiles (root and tip profile parts).

Constrain tip profile: profile plane XZ parallel to assembly XZ plane, WCS origin of tip profile touch/align with end of line from sketch with 'dihedral angle' dimension, X axes of tip profile with line from sketch that have 'tip attack angle' dimension.

Constrain root profile: profile plane XZ touch/align with assembly plane XZ, profile Y axes touch/align with assembly Y axes, and profile X axes touch align with line from sketch that have 'root attack angle' dimension.

Now Insert> Associative copy> WAVE geometry linker, and add both profiles to our assembly part as associative WAVE geometry.

Use new WAVE geometry to make ruled surface.

Now you can play with expressions to see how wing update as you change expressions values.

For more interesting model i added one more level of WAVE linking. I made new part and added wing we got in last assembly as linked geometry and then I made a model of wing flaps area to see how it will update with changes of parameters in previous part. You can see it yourself in next few images.

Gummy Bear model

2011-11-01T23:59:00.000+01:00

Designed in Siemens NX6

Gummy Bear model. Designed as GRABCAD model request, using image below (brown bear on black background image). This is a model that would be much better if done in Rhino or 3D Studio MAX, but instead it come to me. I did my best to design it and it come out good but not perfect. I give up of fine tuning as some of surfaces I made for this model took more then 2 hours to update when edited, and that is just not a time I have to spend on this model.

Football ball, parametric model (free CAD download file)

2011-10-23T00:55:00.002+02:00

Designed in Siemens NX6

Lot of designs done in CAD softwares are parametric models. It mean that model is defined by relationships, constrains and formulas, and that by changing one part of model you will change all parts that are somehow connected to it. Some of challenging models are those who are made to depend on only one variable parameter. I like to make that kind of design because it challenging, at least for me it is.
Here is a ball, with only one variable parameter "a", which is diameter of ball. On video you can see how it works in NX window.

stp file of 281KB is just a ball with separated faces and 25cm diameter (image of black and white ball), and 1MB stp file is more realistic ball with 3d shaped faces and 22cm diameter (white blue and brown ball images).

model 25cm download
model 22cm download

If you are interested in NX file please contact me over "contact me form"

Egyptian pyramid (free CAD download file)

2011-10-18T19:54:00.003+02:00

Designed in Siemens NX6

This is a model of Egyptian pyramids, same proportions, but instead feet i used mm as measurement unit. I tried to make it with 200 levels of stone blocks, but it killed NX (i tried to subtract shape of all 200 levels of stone in one operation...) so I tried little modest variation with around 50 levels. hope that you will enjoy this model.

Download IGES model
Download STEP model

StarWars Jedi Ligtsaber (free CAD download file)

2011-10-15T20:00:00.000+02:00

Designed in Siemens NX6

From 19th century and flintlock weapons we jump to far future and present Jedi lightsaber. Well... as this is my first Jedi weapon I hope it look like lightsaber. I think that Star Wars have lot of interesting ideas for models, but i am not sure if I like to do that kind of design. I did this saber only because i was asked to make it...

Download STEP model
Download IGES model

Skate helmet (free CAD download file)

2011-10-14T20:00:00.000+02:00

Designed in Siemens NX6

One more helmet for my collection, this time it is Skate helmet. Skateboard helmets are one of those things that no one wants to spend too much money on. Most skaters don't even want to wear a helmet at all! But, hitting your head is all too easy in skateboarding, and for that time you DO slam your skull into the coping or curb, you will be glad you bought the best skateboard helmet you could!
For now enjoy my model.

Download STEP model
Download IGES model

Apple logo 3D (free CAD download file)

2011-10-13T20:00:00.000+02:00

Designed in Siemens NX6

3D model of Apple logo, once bitten apple... I was making iPhone5 model and when I put apple logo on it's back, I just couldn't resist to make that apple in 3D.

Download this model

Flintlock pistol (free CAD download file)

2011-10-03T11:41:00.000+02:00

Designed in Siemens NX6

Flintlock pistol model

This is second addition to my 19th century firearms collection. Same barrel and flintlock mechanism as flintlock longrifle model.
Flintlock pistols were used as self-defense weapons and as a military arm. Their effective range was short, and they were frequently used as an adjunct to sword or cutlass. Pistols were usually smoothbore although some rifled pistols were produced.

Future old weapons project I am working on will be with more precise mechanism and with (I hope) much more woodcut and and with engravings on metal parts of weapon.

More god news is that by courtesy of the staff of the Military Museum in Belgrade I will have access to original peaces of XVIII-XIX century weapons. I hope that my models from now on will be much more accurate representation of real weapons and will be designed with much more details.

download this model in STEP format
download this model in IGES format

And always remember:

THE FOUR RULES OF FIREARMS SAFETY

1. All guns are always loaded.

An unloaded gun is useless, and no one should ever assume that any piece he may see or touch is not ready to fire. Would that we would never again hear the plaintive wail, "I didn't know it was loaded!" Of course, it was loaded. That is why it exists. Treat it so!

2. Never let the muzzle cover anything that you are not willing to destroy.

When you point a weapon, you may not always actually intend to destroy, but you must be emotionally willing to do so. The fact that the piece is not loaded does not alter this. See Rule 1.

3. Keep your finger off the trigger until your sights are on the target.

Guns do not "go off" by themselves. Somebody fires them. The competent shooter keeps his finger straight and outside the trigger guard until he verifies his sight picture. Violation of Rule 3 is responsible for about 80 percent of firearms mishaps.

4. Be sure of your target.

Never shoot at anything that you have not identified. Never shoot at a shadow or a sound or a silhouette or anything that you cannot see clearly. Also make sure of what is behind and beyond your target that a bullet may penetrate completely.

These are the four general rules of gun safety. They apply always: while you are on and off the range, at home, in transit, hunting, or fighting. In studying them, you will see that if they were always observed by all people at all times there could be no such thing as a "firearms accident." As to that, it may be proper to insist that there is no such thing as a firearms accident - only negligence.

These rules were developed by weapons authority and author Jeff Cooper, Lt. Col. USMC (ret), and are considered by many to be the simplest and most useful rules for safe firearm handling. These rules were transcribed from his book, The Art of the Rifle, Paladin Press 1997.

iPhone 5 (free CAD download file)

2011-10-01T18:45:00.000+02:00

Designed in Siemens NX6

THIS IS NOT OFFICIAL IPHONE5 DESIGN, this is just my CAD interpretation of information from internet (page1 and page2).

Download links are at bottom of the page...

model STEP file
model IGES file

Poached egg (free CAD download file)

2011-09-27T22:34:00.000+02:00

Designed in Siemens NX6

Well what to say about this model. It was middle of the night and I was in funny mood so I made one unusual model. this is 5 minute model, actually it took me three times more time to make renders then to make a model.
My favorite comment about this model: "There is really not a limit for modeling! hahaha great one!"
As always link for model download is on bottom of the page.

download STEP file
download IGES file

Diamond, parametric model (free CAD download file)

2011-09-27T11:41:00.001+02:00

Designed in Siemens NX6

This is a model of diamond cut. Simple design, good for rendering. Model is parametric, main parameter is diameter size of diamond model.
Link on bottom of the page is for .zip file with 6 different size models, from 1 mm to 6 mm diameter. Models are in STEP format.

Model STEP files

Wrist chrono watch (free CAD download file)

2011-09-26T17:28:00.003+02:00

Designed in Siemens NX6

Watch is a small timepiece, typically worn either on the wrist or attached on a chain and carried in a pocket, with wristwatches being the most common type of watch used today. They evolved in the 17th century from spring powered clocks, which appeared in the 15th century.
The first watches were strictly mechanical. As technology progressed, the mechanisms used to measure time have, in some cases, been replaced by use of quartz vibrations or electromagnetic pulses and are called quartz movements.
Chronograph is a timepiece or watch with both timekeeping and stopwatch functions as well as other functions. Pocket watch chronographs were produced as early as the 18 th century but did not become popular until the 1820s. The term "chronograph" is often confused with the term "chronometer" which in some cases designates a watch that has received a precision certification. The Marine chronometer was an accurate timepiece used to enable celestial navigation." from wikipedia.

Download link is on bottom of the page. Model include stand and turntable base..

Model IGES file

Gold Canon, jewelry (free CAD download file)

2011-09-24T22:34:00.002+02:00

Designed in Siemens NX6

Few days ago I was in shopping and in one jewelry shop I saw small gold canon model, and I couldn't resist to make small gold model myself :)
At first I made only canon, and made one render of it, then I figured out that it would look interesting to make turntable animation, so I did, but it was not as good as I wanted it to be. So i get back to NX and made turntable with two steps and tried to make animation with that. That was much better but turntable was to empty with only canon on it. So as final step in designing of this model I put few canon balls next to canon and it get this nice looking animation.

Canon model STEP file
Canon model IGES file

Widowmaker robot, model

2011-09-17T00:04:00.000+02:00

Designed in Siemens NX6

This is the model i made for GrabCAD CAD job.
I started with client files: Widowmaker.ai shown below. It was a challenge to make it in less then two days (deadline was 72 hours but i lost whole work day to get additional informations so I can start making it). Main problem was that .ai file show only two projections, so it was hard to make some of details. But at the end I got this from client: "Wow! That looks amazing!"

widowmaker.ai client file

Relief map 3D (free CAD download file)

2011-09-16T23:50:00.000+02:00

Designed in Siemens NX6

Old model of island, something I done a while ago. and one more way to use CAD software, there is much better solutions for this but this was fun to make.

model IGES file

Beer mug models (free CAD download file)

2011-09-14T23:13:00.000+02:00

Designed in Siemens NX6

This was fun project! It took me less then hour to make models and more then three to find and set texture for this render. But at the end CHEERS!
I finally get how to make liquid look good in render. Both beer and beer foam are textured with images downloaded from internet, it just take time to position textures good so they cover all parts of model visible in rendering view.

Model download links are at bottom of page.

beer mug 1

beer mug 2

Beer mug 1
Beer mug 2

Jewelry - men rings (free CAD download file)

2011-09-10T22:07:00.003+02:00

Designed in Siemens NX6

I started ring design after I saw request for ring model on GrabCAD site. After few models found this modeling quite relaxing and quite challenging, as almost every design I can think is already made. So for now I will not care if my rings already exists and I will share my models with world, and maybe from time to time I will make some unique designs :)

I started with simplest designs of "flat wedding bands" and "half-round rings" or D-ring, as these are easy to design and good for practice and learning.

Few explanations about models:
01. flat ring with ECG signal line;
01b. half round ring with ECG signal line;
02. flat ring with "steps", it is just a circular array of three sided prisms;
03. "spidermen" ring, have spider web and some kind of stone in center;
04. flat ring with lot of small boll shapes ;
05. D-ring is first step to "multifaceted" ring design, but i found it interesting so I keep it as separate design;
06. this is "multifaceted" D-ring ring, with lot of hexagonal faces all over D shape;
07. have faces that keep D-shape in profile view, difference between 07, 07b and 07c model are in number of faces, and 07c have two types of faces;
08. D-ring with some kind of mechanical pattern on it

Thank You for visiting and there will be more rings soon.

Download links are at the bottom of this page.

Model 01
Model 01b
Model 02
Model 03
Model 04
Model 05
Model 06
Model 07
Model 07b
Model 07c
Model 08

DNA model (free CAD download file)

2011-09-05T12:26:00.002+02:00

Designed in Siemens NX6

Model of DNA, great for renderings.

1920x1080

model IGES file
model STEP file

Perfume bottle model 2 (free CAD download file)

2011-09-04T22:21:00.001+02:00

Designed in Siemens NX6

Second design of perfume bottle, this time it is some kind of ellipse type with "shoulders" and ball cap. This time perfume look little better as I added small ripples on top surface of "liquid", but still not good as I would like it.

model IGES file
model STEP file

Tennis ball (free CAD download file)

2011-09-04T22:01:00.002+02:00

Designed in Siemens NX6

I had to try to make that curve on tennis ball... and I almost did it. It is not perfect (so I will keep trying) but it is good enough for few good looking rendered images.
model download links are at bottom of page.

model STEP file
model IGES file

Perfume bottle model (free CAD download file)

2011-09-04T21:45:00.002+02:00

Designed in Siemens NX6

This is just a little excursion to glass design. I saw few nice renders of models like these so I had to try it myself. Thick glass look great but I do not know how to make liquid inside look like perfume?! So far it look like something between powder and colored mercury...
Base is twisted octagon inscribed in ellipse, then I added few more cuts, chamfers and blends and here it is. Links for models as usually at bottom of page.

model STEP file
model IGES file

Book holders (free CAD download file)

2011-08-29T23:05:00.001+02:00

Designed in Siemens NX6

Book holders, two models, completely different. Horse one is solid, look heavy and stable. Designed as metal plate with engraved horse head on it (horse head is not my model it is tribal .jpg I downloaded from internet). And second one is Fairy book holder, made of sheet metal. (fairy shape is not my model, it is tribal .jpg downloaded from internet)

Fairy book holder model download
Horse book holder model download

Dolphins in heart (free CAD download file)

2011-08-29T22:53:00.001+02:00

Designed in Siemens NX

Dolphins in heart model I made for my daughter :)
Point was that she was sitting next to me during whole process of design, she left when I stared to make edge blends, it was to boring for her.

download this model IGES file
download this model STEP file

3D tribal models (free CAD download file)

2011-08-29T22:42:00.002+02:00

Designed in Siemens NX6

download this model

This is just a exercise in transforming .jpg files in 3D. I used B&W tribal images from internet, then traced (vectorized) them in some of graphics software. then i exported file in some CAD format, most of these softwares can make .dxf (AutoCAD file format) file and it is good enough for this. Then I imported that file in NX, edited splines if needed and extruded splines to get this.

download this model

download this file

download this model

Daft Punk 3D model (free CAD download file)

2011-08-26T19:13:00.000+02:00

Designed in Siemens NX6

This is a model I designed for tutorial request. You can find tutorial here, and links for downloading a model are at bottom of this page. Please keep in mind that I made this model larger then it should be so if you download it before you use it it should be scaled down to 70-80% of original size, depending on head size of helmet user.

download STEP model
download IGES model

Daft Punk helmet design tutorial

2011-08-26T18:34:00.008+02:00

Designed in Siemens NX6

I was asked to maketutorial of design of DAFT PUNK helmet. Now i finished it and here it is, soyou can make this helmet too. Model is free for download from this page.

This tutorial do not cover electronics and assembly details, just how to model plastic parts of helmet.

To start thistutorial, open new part.

I imported headmodel, but I made mistake and used large head instead normal so this wholehelmet is oversized. To make it good it is best to measure your head and tomake model according to those measures, that way helmet will fit you good.

So here is a head,and we can start.

Now add first sketchin vertical plane, as you can see measures are oversized. Ral head is about10-15% smaller (if you are not 2m high and have 150 kg), anyway this is how sketch should look like, just edit numbers so your head fitinside this sketch.

Now second sketch:

Same as first sketchthis one is little oversized, so be careful with dimensions.

Now we have two basic sketches, and now we will start making shape ofthis helmet. First make two extrusions based on these two sketches. Fromvertical sketch make normal extrusion, and from horizontal make it drafted for5-15°.

Now use Insert>Mesh Surface>Through Curves command. This is funpart, as you can play with this command and get various shapes just by usingdifferent options in drop down menu. You can play a little with editing theseextrusions to get different shapes of through curves surface.

Note that I didn'tuse tangent to second extrusion surface, after fey tryouts I found that this isbest shape for this helmet.

Now we will trim thisshape before adding thickness on it. I draw a line parael to X axes, from cornerof shape, so I can use that line as axe for my datum plane. Through that linemake a datum plane at angle of 13-15 ° from XY plane.

Make new datumpane parallel to one we just made, and on 15mm distance from it, and use it totrim shape we got with through curvescommand.

We can offset this shape to get first part of ourmodel. This will be part of helmet that come right next to our head, so youneed to offset it from your head to make place for comfort liners, and to makeit in thickness of plastic you will use for this part. Use Insert>Offset/Scale>Thickencommand.

Now we have to make openings for your nose and eyes. Make new sketch that looklike this:

Part of sketch thatcome near face is optional, and it size and shape depend on type of stripes youwill use for this helmet. Be careful to make enough room that you can put yourhead in this helmet!

After making thissketch, make extrusion of it and use intersection Boolean option with headshape made with thicken command.

We will startmaking outer shape of helmet. Use Thicken command again.

NOTE: for all thickencommands in this tutorial we will use Through Curves surface shape as baseshape.

If you know how muchspace electronics equipment for this helmet will take then make outer offset toyour calculations, and inner offset is smaller for thickness of plastic youwill use to make this helmet.

We will trim this part3 millimeters less then inner part but you can make it as you like.

New sketch, thisdefine all outer shapes. We will call it MainSketch in this tutorial

Now extrude part ofouter lines of sketch that define shape of helmet

I use offset tosurfaces that are almost tangent to gray colored shape so we do not haveproblems with Boolean functions on it.

And we use intersectcommand on it to make shape of helmet.

So far this is whatwe have:

New Thicken,this one is for back side of helmet.

New sketch with shapeof back side of helmet:

Again intersection ofthese two parts to get what we need:

For now we have partthat come near head, outer shape of helmet and back side of helmet. Before wemake glass or transparent plastic part, we need to make outlets that willsupport transparent part of helmet.

New Thicken,this time first offset have to be for thickness of plastic smaller of outershape, and second offset for same amount smaller then first offset.

This is what we get:

Now use lines of Main Sketch to make sheet extrusion

Add Thicknessto this sheet. First offset is with how much material it will be joint to outershape of helmet and second offset is how large outlet will be. I think thatdepend on type of connection you will use to join helmet and “glass”.

Now intersection oflast two features:

Here you can see howthis outlet look when finished:

Now “glass” (thiswill be some kind of transparent plastic, but I will call it “glass”) Thickness.It have to be same as outer shape of helmet.

Trimmed with samesheet we used to make outlet feature.

Now we need to make “ears”and colored lights to finish this tutorial.

One more time make Thickness,offset for this one depend on how you will make colored lights, so I made itonly 1mm. you will have to make it in size of boxes you will put lights in. Dimensionsof this Thickness is all up to your design!

I made it to touchoutlet for “glass”, you can make it to touch “glass” or you can left space between…it'sall up to your design.

We have to cutout center section of this part, make a sketch with rectangle, width ofrectangle should be big enough so you can have good sight from this helmet, so Ithink minimal should be as width of outer corners of your eyes, or width ofyour temples.

Extrude this sketchand subtract feature you get from thickness feature you made earlier.

As this part of design is depending on your solution of light boxes, I willuse sheet I used for outlets to trim it. You will use some other constructionfeature depending on your light box design!

Now we will make “ears”for this helmet.

To do it we need tomake some planes and to make planes we need new sketch in XZ plane (inthis case I know it is plane of maximum curve of this model so I will use thisplane, in case you do not know where is maximum you will have to find it firstand then to make sketch trough that plane). This time you have to use Intersection Curve commandto add intersection line of sketch plane and outer helmet shape (gley dot-dashline). Now draw two lines one horizontal and one vertical, this lines will helpyou to find where the point of maximum distance of model from YZ plane is. Makevertical line tangent to intersection curve, and make horizontal line touchvertical line in intersection point of vertical and intersection curve. Now exitsketch.

To make this plane inone click you just select ending point of horizontal line, that way datum panecommand will have both axes and point for new plane.

Make new plane onsome distance (and parallel to) from previous one.

We will now use Main Sketch. We will use it to make “ears”.

Now use outer earline to make extrusion.

Trim extrusion with outersurface of helmet.

And with last planewe created.

Draft new feature fromplane that is tangent to helmet outer surface (plane we got from sketch line)

Unite this feature tohelmet.

Now make newextrusion of second “ear” curve from sketch we used in previous step. Thisextrusion will be From Extended, select plane that we useto trim previous feature, for end put any distance that get new extrusion outof helmet parts we have so far.

Now make offset ofside of feature closer to helmet, this feature we will subtract from helmet sowe get pocket, enter offset value you like.

Now subtract newfeature from helmet.

So we now havepocket:

Draft that pocket alittle,

To get this:

Now extrude circleform sketch, make it start on face of pocket and end it where you like.

Now draft thatextrusion;

Unite it with helmet andwe are almost finished with outer helmet shape;

Blend some of sharpedges a little;

I forgot to unite helmetwith outlet, so I will do it now.

Makeshell of helmet. I used 3mm, it is the plastic thickness I used for all partsof outer helmet shape.

Now we will cut partthat represents lights. Make planes from axes that come trough center ofcircular shape of “ear”, how many and at what angle depend on your design oflight boxes.

Use SplitBody command to make different colored boxes.

I colored spittedparts.

Use Insert>AssociativeCopy>Instance Geometry to make mirror of all solid bodies we made sofar.

And we are done withthis tutorial!

I hope you had fun!

As fun is mostimportant part of everything we do!

If you produce this helmetusing this tutorial please send me images so I can add them to this post!

Thank YOU for stayingwith me till the end! !

Blade bite Binsky, fishing lure 3D model (free CAD download file)

2011-08-25T23:31:00.001+02:00

Designed in Siemens NX6

I saw this beautiful lure and I couldn't resist to make a model. This is NOT the original design! This is just my 3D interpretation of images of original design, I do not guarantee that you will catch anything with lure made from my file!
"The Binsky is a vibrating blade bait that can be cast and retrieved or vertically jigged. It is designed with a shape and action to maximize all the fish catching qualities available in a metal lure."
from http://fishsenselures.com/

THIS IS NOT ORIGINAL MODEL if you want real thing you have to buy it!
download STEP model of this lure.

Fishing hooks (free CAD download file)

2011-08-25T23:18:00.001+02:00

Designed in Siemens NX6

These are models of most popular fishing hooks, two simple hooks, two double hooks and triple hook.
Hooks are designed as either single hooks—a single eye, shank and point; double hooks—a single eye merged with two shanks and points; or treble--a single eye merged with three shanks and three evenly spaced points.
Double hooks are formed from a single piece of wire and may or may not have their shanks brazed together for strength. Treble hooks are formed by adding a single eyeless hook to a double hook and brazing all three shanks together. Double hooks are used on some artificial lures and are a traditional fly hook for Atlantic Salmon flies, but are otherwise fairly uncommon. Treble hooks are used on all sorts of artificial lures as well as for a wide variety of bait applications.

download STEP model of eyed fishing hook

download STEP model of simple fishing hook

download STEP model of double fishing hook

download STEP model of triple fishing hook

Motor helmet 3D models (free CAD download file)

2011-08-20T00:47:00.001+02:00

Designed in Siemens NX6

This is design of two simple motor helmets. Links for model download are below images.

Firs version is just basic shape with few details on it. Second version is little more complicated and have place for some ears gadgets. These are not real motor helm models, these are just for fun models and need more editing to be functional.

Basic motor helmet model IGES file
Motor helmet model V2 IGES file

Sun Clock or Sundial (free CAD download file)

2011-08-14T16:39:00.003+02:00

Designed in Siemens NX6

A sundial is a device that measures time by the position of the Sun. All sundials must be aligned with the axis of the Earth's rotation to tell the correct time. In most designs, the style must point towards true celestial north (not the north magnetic pole or south magnetic pole). That is, the style's horizontal angle must equal the sundial's geographical latitude. When the sundial reads by shadows, the shadow-casting object - the sundial's gnomon - may be a thin rod, or any object with a sharp tip or a straight edge.
Sundials employ many types of gnomon. The gnomon may be fixed or moved according to the season. It may be oriented vertically, horizontally, aligned with the Earth's axis, or oriented in an altogether different direction determined by mathematics.

My model of sundial is around 1,8 meters high, suitable for gardens and parks (scroll down for download link).

Sun clock.igs [IGES file]

Flintlock long rifle 3D model (free CAD download file)

2011-08-10T10:46:00.014+02:00

designed in Siemens NX6

Flintlock longrifle model (1600x901 px)

Flintlock long rifle model.

History: Introduced at the beginning of the 17th century, the flintlock rapidly replaced earlier firearm-ignition technologies, such as the doglock, matchlock and wheellock mechanisms. It continued to be in common use for over two centuries, replaced by percussion cap and, later, cartridge-based systems in the early-to-mid 19th century.
My model is mix of styles and periods as I used more then 30 images of different rifles to design it. Idea for making this model come to me after PARTNER 2011 exhibition, after i become member of My City Military forum, and find out that there is huge amount of informations about modern arms but that there is no good 3D model of old rifles. After this models I will make model of percussion rifle, and models of pistols with both mechanisms, and after that I will try to find enough material to make some old Serbian weapons.


image from www.trackofthewolf.com

My model:
This rifle have .5 caliber 42" octagon barrel. It is 1" octagon with 1 turn in 59 inches polygonal rifling (this is ). The rifle is little less then 59 inches long. This model have single trigger, but I am working on double trigger in this moment. This model have smooth cheekpeice and no engravings.

Model after few changes:

Flintlock longrifle model (1600x901 px)

And finally finished model:

download this model

And always remember:

Flintlock mechanism 3D model (free CAD download file)

2011-08-06T19:32:00.006+02:00

designed in Siemens NX6

3D model of flintlock mechanism

"The basic goal of the flintlock is simple: to create a spark that can light the gunpowder stored in the barrel of the gun. To create this spark, the flintlock uses the "flint and steel" approach. The idea behind flint and steel is straightforward. Flint is an amazingly hard form of rock. If you strike iron or steel with flint, the flint flakes off tiny particles of iron. The force of the blow and the friction it creates actually ignites the iron, and it burns rapidly to form Fe3O4. The sparks that you see are the hot specks of iron burning! If these sparks come near gunpowder, they will ignite it." (quote from HowStuffWorks site)

image from science.howstuffworks.com

The flintlock mechanism (wikipedia article) was a firing mechanism used on muskets and rifles in the 17th, 18th, and 19th centuries. It is commonly referred to as a "flintlock" (without the word mechanism), though that term is also commonly used for the weapons themselves as a whole, and not just the lock mechanism.

The flintlock was developed in France in the early 17th century. Though its exact origins are not known, credit for the development of the flintlock is usually given to Marin le Bourgeoys, an artist, gunsmith, luthier (maker of stringed musical instruments) and inventor from Normandy, France. Marin le Bourgeoys's basic design became the standard for flintlocks and quickly replaced older firing mechanisms throughout Europe. Flintlock weapons based on this design were used for over two centuries, until they were finally replaced by percussion locks in the 1840s and 1850s.

My model of flintlock mechanism is just a part of flintlock long rifle model:

Model rendered in three positions: uncocked, half-cocked and fully cocked.

download this model

Zippo lighter, 3D model

2011-07-28T17:47:00.008+02:00

designed in Siemens NX6

Just a Zippo lighter CAD model I made today in some free time. I am not sure that inside parts are in real dimensions as I measured images of zippo lighters in photoshop to get most of dimensions, but it can be edited. I am trying to make render of flames so I can make more images, but it is hard to do in NX. If there is anybody who know how to set up material in NX to look like flames, please help me!

About Zippo lighter: besides having gained popularity as “windproof” lighters, Zippo lighters are able to stay lit in harsh weather, due to the design of the windscreen and adequate rate of fuel delivery. As such, until recently they were highly popular with backpackers and within the military.

Constuction of zippo lighter: the cases of Zippo lighters are typically made of metal and are rectangular with a hinged top. On most models, the top of the case is slightly curved.
Inside the case are the works of the lighter: the spring-toggle lever that keeps the top closed, the wick, windscreen chimney, thumbwheel, and flint, all of which are mounted on an open-bottom metal box that is slightly smaller than the bottom of the outer case, and into which it slips snugly.
The hollow part of the interior box encloses a rayon batt which is in contact with the wick. The fuel, light petroleum distillate or synthetic isoparaffinic hydrocarbon (commonly referred to as lighter fluid or naphtha), is poured into the batt, which traps it. It also contains a tube that holds a short, cylindrical flint. The tube has an interior spring and exterior cap-screw that keeps the flint in constant contact with the exterior thumb-wheel. Spinning this rough-surfaced wheel against flint results in a spark that ignites the fluid in the wick.

old version with "cam" that is not shaped to fully close the lighter

new version with new "cam" that look and work (in CAD of course) like real lighter

After few hours of trying this is first "flame" result:

Tower crane 3D model (free CAD download file)

2011-07-25T14:29:00.008+02:00

designed in Siemens NX6

This is unfinished 3D model of Tower Crane, I designed as much as I could just by looking at images of tower cranes on internet. I over dimensioned most of model, as at first i had idea to try to make it in plastic. Most of cable work is unfinished as I do not have enough info about cable system. If anyone have informations I need to finish this design, please contact me.
NOTE: In this design I didn't use real profile dimensions for steel beams, but in .prt files profile dimensions are editable in sketches.

NOTE: Design is based ONLY on photos of tower cranes i found on internet so do not take it seriously.

EXPLANATION: fore jib connector part as it is now is designed only to hold constrains in assembly.

So far assembly of this model consist of 20 parts (more will come as model get more details):

apex
apex rear conector (connection between 'apex' and 'rear pendant counterjib conector')
cabin
cable conector (connection between two 'rear cables' holding counterjib)
counter weight segment
crane body segment ground base (ground segment)
crane body segment (repeating segment)
crane climbing segment
crane cabin segment
crane jib - base (jib segment connected to 'crane cabin segment')
crane jib last (end of jib segment)
crane jib main (repeating jib segment)
motor (motor behind cabin)
fore cable (repeating cable that hold jib)
fore cable conector (connection between `apex` and `fore cable`)
fore jib connector (unfinished part, connection between 'crane jib main' and 'fore cable')
rear cable (repeating cable that hold 'counter weight segment')
rear pendant counterjib conector (connection between 'rear cable' and 'counter weight segment', and 'rear cable' and 'apex rear conector')
trolley (trolley with cage and long cable)
trolley sc (trolley without cage and with short cable)
ASSEMBLY (part only, due to some error I was not able to make it in STEP format)

assembly

assembly front view

assembly

assembly left tri view

assembly right tri view

crane body segment ground base

crane body segment

crane climbing segment

crane cabin segment

cabin

apex

counter weight segment

apex rear conector

rear pendant counterjib conector

rear cable

cable conector

crane jib - base

crane jib main

crane jib last

fore cable conector

fore cable

fore jib connector (not finished part)

motor

trolley

trolley /hook

trolley - short cable - no cage

No	Part name	STEP link	NX6 part link
1	ASS crane	ASS Crane	Assembly NX6 file (7MB) and Zip of all parts in one file (35MB)
2	apex	Apex STEP file	Apex NX6 file
3	apex rear conector	Apex rear conector STEP file	Apex rear conector NX6 file
4	cabin	Cabin STEP file	Cabin NX6 file
5	cable conector	Cable conector STEP file	Cable conector NX6 file
6	counter weight segment	Counter weight segment STEP file	Counter weight segment NX6 file
7	crane body segment	Crane body segment STEP file	Crane body segment NX6 file
8	crane body segment ground base	Crane body segment ground base STEP file	Crane body segment ground base NX6 file
9	crane cabin segment	Crane cabin segment STEP file	Crane cabin segment NX6 file
10	crane climbing segment	Crane climbing segment STEP file	Crane climbing segment NX6 file
11	crane jib - base	Crane jib-base STEP file	Crane jib-base NX6 file
12	crane jib last	Crane jib last STEP file	Crane jib last NX6 file
13	crane jib main	Crane jib main STEP file	Crane jib main NX6 file
14	fore cable	Fore cable STEP file	Fore cable NX6 file
15	fore cable conector	Fore cable conector STEP file	Fore cable conector NX6 file
16	fore jib connector (not finished part)	Fore jib connector STEP file	Fore jib connector NX6 file
17	motor	Motor STEP file	Motor NX6 file
18	rear cable	Rear cable STEP file	Rear cable NX6 file
19	rear pendant counterjib conector	Rear pendant counterjib conector STEP file	Rear pendant counterjib conector NX6 file
20	trolley	Trolley STEP file	Trolley NX6 file
21	trolley sc	Trolley sc STEP file	Trolley sc NX6 file

Worker helmet (free CAD download file)

2011-07-23T17:36:00.012+02:00

designed in Siemens NX6

This design is for fun only. I made it as I needed model of worker helmet for rendering of one of my other projects. It is designed as free style interpretation of images of helmets I downloaded from internet. I do not have real helmet so I do not know how suspensions for helmet are designed, if there is anybody who can finish that part of design please share that with me.

I decided to share this model, so you can find links to NX6 part (.prt), STEP (.stp) and IGES (.igs) files at bottom of the page. If you improve this model please share improvements with me.

Worker helmet.stp [STEP file]
Worker helmet.igs [IGES file]
Worker helmet.x_t [parasolid file]

The Beginning (Mechanical) Engineer’s Checklist

2011-07-13T16:32:00.003+02:00

1. NEVER loan out your copies of:
-Machinery’s Handbook
-Shigley’s Mechanical Engineering Design
-Making Things Move: DIY Mechanisms for Inventors, Hobbyists, and Artists (okay this one is a shameless plug, but Dug North told me it’s “destined to be be a classic of sorts” so you can blame him)

2. Project planning follows the rule of pi. Take how much time you think you can complete something in, multiply it by pi, and that will be the actual length of time it takes.

3. Parkinson’s Law: Work expands so as to fill the time available for its completion. Don’t give yourself too much time for a project or it will never get done. Speaking of done, check out The Cult of Done Manifesto. If it weren’t for the last minute, nothing would ever get done.

4. Everything is a spring.

5. If it moves and it shouldn’t, use duct tape. If it doesn’t move and it should, use WD-40.

6. Document everything you do. Someone will ask you to justify your design at some point, and “it kind of sort of looked right” is never a good answer. This is especially true on collaborative projects. The group will forget who did what and it will make going back and changing things that much harder.

7. Design is an iterative process. The necessary number of iterations is one more than the number you have currently done. This is true at any point in time.

8. Ask questions. If you don’t know something, say so. Your credibility as an engineer lies not in being infinitely intelligent, but in knowing how to get at the right resources to figure it out. If you cheat, people will die.

9. Designing for disassemble is just as important as design for assembly. It will never work the first time you put it together. Oh, and make sure that everywhere there is a screw, there is a place for a screwdriver to install it. And for a hand to fit around said screwdriver.

10. Business will always be a part of engineering. Don’t work for free (unless you really want to) and don’t work without a contract. Don’t design a better mousetrap THEN expect someone to want it. The products that sell the best are not necessarily the ones that are technologically superior.

11. Design is based on requirements. There’s no justification for designing something one bit “better” than the requirements dictate. Better is the enemy of good enough. Get it done then go play outside.

12. Engineering is done with numbers. Analysis without numbers is only an opinion.

13. Be friendly and talk to your machinist and/or shop techs. You may have a fancier title or degree, but that does not make you better. A short conversation on how to make a part more easily machinable/moldable/etc. can save thousands of dollars and make you both look good. You may even learn something.
_________________________________________
Original text is on this address: http://blog.makezine.com/archive/2011/03/the-beginning-mechanical-engineers-checklist.html

Tower crane 3D model

2011-07-08T18:18:00.011+02:00

designed in Siemens NX6

/Finished project article is here/
Project of tower crane I started just for fun. Why tower crane... I live in Belgrade and we have huge bridge currently building, and from my window it look like this:

So I was interested in tower cranes design, and after looking on internet I decided to try to "build" one in NX6. It is not real project, I do not know anything about cranes so I can't do real design with all calculations. It is just design that can be used in games as rendered model or something like that.

Few renders of work in progress:

Need more info to finish this design...