Long shot here. But here goes. I'm looking for the DIN specs on the 911 steering wheel hub splines. Not the basic dimensions (e.g.: 20mm x 40 splines) but rather an actual DIN spec that I can supply my broach manufacturer. Before I venture down the road of having an original hub measured (with the chance for error that it involves) I thought someone here might have that info. I searched through the PET, but found nothing. Thanks.
Early S Registry Member #3291
Still hunting for my dad's (Roger Abraham) '70T Coupe in Light Ivory
Purchased new from Gruber Porsche Cedar Rapids, IA
I think this type of shaft is better described as 'serrated' rather than a spline which would tend to have more of an involute profile.
DIN 5481 defines Straight Sided Serrations and has tables showing the Class of fit for either a 55 degree or 60 degree included angle.
https://www.techstreet.com/standards...uct_id=1215856
http://ashgear.com/pdfs/hm81.pdf
Thanks Chris. This gets me a little closer. Still, there must be a tech spec on this somewhere. I think I'll call Momo.
Early S Registry Member #3291
Still hunting for my dad's (Roger Abraham) '70T Coupe in Light Ivory
Purchased new from Gruber Porsche Cedar Rapids, IA
The spec is simply the class of fit as highlighted in the DIN Standard as this will define all you really need to know.
Even if the serration angles differ the fit will need to be to the correct level.
If you can find a 'shadowgraph' you may be able to measure the spline angle and the diameters of the shaft and the base diameter of the internal serration.
At the highest level of fit these two diameters are likely to be identical as this Class is used for semi-permanent assembly and heat is likely to be needed to fit parts together.
The intermediate Class which is sometimes described as a transition fit is used for precise location of the parts but still allows for disassembly and the loosest fit allows a simple sliding fit but can introduce backlash.
The DIN Standard should provide all the information you need but a broach manufacturer should readily understand what is required.
Thanks for the further info. Looks like the best path would be to send off a hub and shaft to the broach people and let them figure it out.
Early S Registry Member #3291
Still hunting for my dad's (Roger Abraham) '70T Coupe in Light Ivory
Purchased new from Gruber Porsche Cedar Rapids, IA
That's what I would do, they will almost certainly have the expertise and understand the fits needed.
We make a number of components with involute splines and we always let our gear cutting guys detail the profiles as they do the job every day.
I understand the principles but don't have enough day to day experience to be confident in this area.
I am sure if you spend time with the DIN Standard you would be able to work it out but generally life is just too short
Jameel - I have no info, I just wanted to say as a former "shop boy" in a machine shop, I appreciated your pun in the title of your thread. Cheers!
Keith Adams
Calgary, Alberta, Canada
Early 911S Registry #906 | PCA member IG: @912R
1969 Blutorange 912R - 912 to 911 conversion
1969 Mercedes 280 SE (W111) Coupe
I'm known for corny puns. It's a habit I'm trying to break.Originally Posted by lkadams
I've got a shaft that I'm borrowing from a friend, so once that's in hand, I should be moving forward on this.
Early S Registry Member #3291
Still hunting for my dad's (Roger Abraham) '70T Coupe in Light Ivory
Purchased new from Gruber Porsche Cedar Rapids, IA
Hi
If you find the answer, and do not mind sharing, I'de be interested to know as well.
Thx
Olivier.
http://www.schray-antriebstechnik.de/raeumnadeln.htm are loacted right around the corner from me - they have 4 machines for broaching. If I may help let me know
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