Another FreeCAD Assembly--Kerzel IC Engine

[ppemawm]

This is a complete parametric solid model (less fasteners, circlips, etc.) of the single-cylinder Kerzel internal combustion engine. It was created from detail drawings readily found on the internet. I took on this project simply because of its unique design which has several interesting and challenging part geometries. The model was built all in one file using the Part Design workbench essentially in the order of how you would assemble it on the bench.

If anyone is interested in the individual components, model history, or dependency graph I will post the 14.5 Mb FreeCAD file on Dropbox for download.

Note the small size, e.g. the flywheel outer diameter is 89 mm.
Now, if I only had a miniature lathe and mill in my 800 sq.ft. New York apartment!

The blue housing is a water reservoir for passive cooling.

Picture1.jpg (312.66 KiB) Viewed 10528 times

The intake valve (green) is actuated only by atmospheric pressure.

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If you look closely, you might see some part interference on the exhaust valve (red) pushrod sub-assembly because I did not make the effort to correctly time the angular position of the gears and cam.

Picture3.png (551.2 KiB) Viewed 10528 times

The tension springs on the speed regulator sub-assembly was a bit tricky to model with its circular ends

Picture5.jpg (176.3 KiB) Viewed 10528 times

Yes, the knurling on the carburetor needle valve is included on the model.

Picture6.jpg (149.69 KiB) Viewed 10528 times

OS: Windows 8
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.16.6700 (Git)
Build type: Release
Branch: releases/FreeCAD-0-16
Hash: 7b925d11aa69ac405b423635adb1e2833f18a817
Python version: 2.7.8
Qt version: 4.8.6
Coin version: 4.0.0a
OCC version: 6.8.0.oce-0.17

[DeepSOIC]

Interesting model... for testing migration to PartDesign Next
Awesome work!

[NormandC]

As usual, awesome work ppemawm.

Now, if I only had a miniature lathe and mill in my 800 sq.ft. New York apartment!

Here you go!
http://www.thingiverse.com/thing:1003137
http://www.instructables.com/id/3D-printed-CNC-mill/

[paul18]

+1

[yves78]

Hello,

I am a Freecad user and supporter. I have a lathe, and just got a milling machine, and my first main target is to build a kerzel engine.

It's very kind of you to propose to provide the freecad files, I am therefore very interested to get them.

I would be interested to get them using dropbox, or by any way you which would be convenient for you.

Regards.

[ppemawm]

I would be interested to get them using dropbox

The complete assembly model and components may be found at https://www.dropbox.com/s/4c804p1wuinlc ... FCStd?dl=0. This is a single 15 Mb file that takes less than a minute to open on an I7 quad-core laptop, requiring a bit of patience if you have a less capable machine.

Notes:
1. The model is based on detail drawings at http://www.floridaame.org/Plans/HHM1/HH ... 0Model.pdf
2. Build notes and photos can be found at http://www.floridaame.org/GalleryPages/g1h0106.htm
3. All components were created using the Part Design workbench in as much as possible. So, if you want to move any part then either make a Draft/Clone of the last visible feature of the part history and move that or move the first sketch of the part.
4. The model is in metric dimensions converted from the English dimensions on the drawings. There are a few drawing errors or missing dimensions which hopefully I interpreted correctly. There are 254 sketches so I would not be surprised at an error or two. I tend to use many simple sketches for pads/pockets rather than fewer more complex sketches required for revolutions,etc. to avoid constraint errors.
5. The most difficult aspect of the assembly is the timing of the cam, regulator arm, points, and gears. I was not too sure of how to do this correctly so you will see some part interference in the model. A simpler assembly file can be created by exporting a .STEP file of each component which can then be imported to a single file if you want to try to align these parts properly. This is probably a good candidate for the Assembly workbench, but I have not tried that yet.
6. Note that the valve and cam follower springs do not have the 1.5 closely spaced turns at each end. I gave up after several attempts to get a valid solid using only Part Design. If anyone knows how to do this without getting a "kink" at the helix junction I would be interested.
7. All parts have been validated with Part/Analyzes Geometry for Errors with RunBOPCheck enabled.

May this model be of some good use to you in your project. Please do not hesitate to contact me via a Forum private message if you have any corrections or questions about the model details.

[yves78]

Thanks a lot ! I downloaded the data, and it takes 1 1/2' to open it on a i3 2.1Ghz laptop.

I am not familiar with part design new functionalities, and it will be a good opportunity to get practiss . I am sure you spent a lot of time building that model !

I am intending to build the engine using the same floridaame set of Kerzel plans. The first use I'll do of the model is to explore it, in order to understand it. That a lot more easy that with 2D drawings !

I am working in metric, and before building, I will have to think about how to manage units conversions : for example, if there is a 3/8" hole, the direct metric conversion is 9,53mm.
But if I need to buy a (cheap, not specific one ) reamer, I'll only find a 10mm reamer. Therefore, the "tooling compliant" conversion will have to be 10mm, and not 9,53mm.
Sorry to pollute the forum with that type of discussions, but because I did not use the forum frequently, it seems I'm not allowed to post private messages (that the error message I get when I try). May be if you send me a first private message, will I it be able to get in touch.

Thanks a lot again for that job, and to share it.

[mario52]

hi

Therefore, the "tooling compliant" conversion will have to be 10mm, and not 9,53mm.

tray this macro Macro_CloneConvert for make conversion easily (clone or copy)

mario

[murdic]

less than a minute to open on an I7 quad-core laptop, requiring a bit of patience if you have a less capable machine.

Very nice model! It takes 2:40 to open on a 1.4 GHz Celeron....

[ralfsteck]

Hi,

could you contact me please? I have a question regarding your model and using it in a book. TIA.