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914World.com _ 914World Garage _ CAD Guys (or Gals)

Posted by: Eric_Shea Apr 9 2005, 02:55 PM

914 rear brake caliper inner adjuster gears are NLA. Anyone care to CAD one up? It would help me get machining quotes.

There's 13 teeth, they're about 9mm to the tops of the teeth and about 11mm long with a 4mm hex adjustment in the end. Other than that, I really don't know any of those fancy engineer measurements.

Any takers to help preserve the 914?

Posted by: BatFromHell Apr 9 2005, 03:15 PM

Can you post a pic of it?
Then I can tell you what measurements I need
in order to complete CAD dwg.
AutoCAD OK?

Posted by: i love porsche Apr 9 2005, 08:52 PM

i could attempt it 3-d in pro Engineer, if you can give me a crude 3 view drawing with some dimensions, i could probably swing it

Posted by: type11969 Apr 10 2005, 08:00 AM

If you get all the dimensions for me, I'm almost 100% sure that solidworks can generate a file for you that can be fed directly into a CNC machine. I'll have to do some research on how to accomplish that though. I can also generate drawings like the others that have posted.

Posted by: Eric_Shea Apr 10 2005, 09:21 AM

Here's a shot...

Attached image(s)

Posted by: Eric_Shea Apr 10 2005, 09:23 AM

I could send one of these to whoever thinks they can nail it.

Posted by: Mueller Apr 10 2005, 01:03 PM

I think you are better off sending out the gear(s) out to get some quotes....

the measurements seem to be in between a 48pitch and 32pitch for the diameter.....I've looked thru a few catalogs I have and nothing seems to match...not a lot of 13 teeth gears...there are some and the metric gears have too large of a pitch diameter from what I can find....

Attached image(s)

Posted by: BatFromHell Apr 10 2005, 11:21 PM

Eric:
This piece has been made by a process called "broaching".
Basically, a piece of roundbar is taken a hex head is machined
at one end and then a broach which has the same pitch as the
adjuster but just a negative of it in a complete circle. (Similar to a thread die. This broach is pressed down onto the round bar until the
spline is formed and then it is pulled back off.

Therefore, there may exist a standard broach to create this adjuster.
Try to check with a machine shop that specializes in metric threads and splines. My suspicions tell me that this may be a standard Porsche spline. I have been doing some research on Porsche production splines particularly the half shafts on the 911 and 914. Most of these splines are NOT standard metric splines used today but "special" Porsche splines which are very close to metric splines fabricated today.

The only other suggestion I have is to give this adjuster to a machine shop that specializes in metric fabrication and have them CMM (Co-ordinate Measuring Machine) the part and they can reproduce an exact part on a CNC machine. Since it is a very small part the CMM process shouldn't cost that much.

Good Luck