69gaugeman

It is really hard to tell from the pictures, but if I were to hazard a guess, it looks like Greg's splines are not involute. Not knowing for sure, but if they are straight cut there is another significant point of weakness.

Would it be possible for you to 'blue' up the splines and slide it in and out while twisting it so we can see the contact pattern? It might give me more to go on.

xschop

Greg, do you mind answering post # 79? Forgive me if It was answered somewhere along the multitude of replies. I'm OK with cut splines if the material is stronger than factory, which it is, and would take more abuse than factory before snapping.

69gaugeman

Interesting statement.

Of course, what the material is, is only part of the equation. There are a lot more factors involved.

I will agree however that if the shaft material is stronger AND is manufactured correctly, that would be a good thing. I would just like to see proof that it is before someone says it is. That is all.

GregBBRD

OK.

Edwards has posted pictures.

I'm going to close this thread and re-open another product introduction thread.

69gaugeman:

1. Thank you for your observations and very limited technical input.

2. I sincerely wish that I had known what your field of expertise was, before I started down this road of making replacement short shafts and other driveline pieces. It would seem that you possibly might be able to have answered many questions that took months to slowly answer. However, given everything you've said, I truly believe that this shaft would look exactly how it does today, given your input. 300M is a far better, stronger material. Rolled splines are slightly superior to cut splines....over a long period of time....but there is absolutely no proof that they are superior prior to cut splines until any stress risers are allowed to form (which could take years, if they ever form, at all.)

3. You have still not gone back and corrected any of the things that you mistakenly said. These are the things that irritated me off and lead me to this point.....which you are certainly completely aware of.....which is why you refuse to go back and acknowledge them. And of course, your choice of comparing me to the "hack of the 928 world" (my opinion) really pissed me off.....but you knew this, also. As a matter of fact, you just keep piling the lies on top of another.... I never said that my shaft was "infinity stronger" than the stock shaft.....I simply said it was stronger.....which any expert in materials would instantly agree with, given the material and the heat treating specifications.....but you know this, also.

4. On a personal note, I really wish you were not so mule headed *** and really interested in being constructive, instead of just being interested in being another "Internet Cleverhole". Certainly, this "wonderful" Internet allows little misstatements to be amplified. Without the interactions of people discussing things in person.....little statements or assumptions are more difficult to correct....like your multiple posts that state I said the shaft was harder than the stock shaft, which I never even remotely said. If this discussion had occurred, in person, this would have immediately been corrected. Instead, you've said this multiple times and even accused me of "backpedaling" regarding this statement....which, of course, I never made.

And, of course, you would have been picking your *** off the ground, the instant you even remotely compared me to the "hack of the 928 world" (my opinion) which is the absolute worst insult you could ever throw, at me.




To the rest of you:

Thanks for your interest and support, which has been overwhelming. I will contact all of you that have indicated you are interesting in buying this upgraded shaft, this next week. I will not be able to even remotely fill all of the orders, until the next "batch" of shafts is completed.

Sorry this got so ugly. And sorry that the moderators do not equally apply the rules equally to all.

GregBBRD

BTW.....

I have arranged to have the shafts tested to failure, even though the company that did the material testing (and will do the destructive testing) thinks I'm being really silly.

I will have this done, before the next group of shafts is offered for sale.

The cost of the next group of shafts, because of the costs involved with the price of buying the shafts and the testing charges will be about 20-25% higher than the cost of this batch of shafts. Note that this all of this is being done to satisfy the obvious. (Obviously, every time the cost of making something goes up, the price has to also go up....especially on tiny production runs of part for a tiny market.

300M, properly heat treated, is stronger than the stock shaft. There simply isn't a steel that is stronger (that is readily available to us mortals) than 300M, for this application. 69gaugeman knows the material. He knows the heat treating. He knows this shaft is stronger.....but apparently just feels the need to be a complete ***.

Stress risers from the cut splines? 10 years and 100,000 miles to form? 20 years and 200,000 miles to form? Never form? Who knows? They sure as hell are not going to be there, now!

So, if you are on the list to get a shaft from the next production run, please personally send 69gaugeman a "thank you" PM (who is too cheap to pay $18.00 a year to be a member of Rennlist, but has 5,125 posts, as a user!)

I was trying to make a higher quality, more economical clutch shaft, that would be available when Porsche runs out of the stock shafts....which will be very soon. It's no skin off of my nose, if everyone wants it to have aerospace documentation for the obvious......it just makes it cost more!

Sometimes.....like in this case.....jumping through silly hoops to satisfy the obvious is very counter-productive and just adds to the already high costs involved in creating custom replacement pieces, in tiny production runs.