Pin drive bolts splitting Help Please

[CNGreen]

David,

Did you get the pin?

Got any pics of the new pin nuts?

BTW, just for clarity, are the nuts called pins? I thought the "Pin" in Pin drive meant the single large "bolt" that goes through the rim and the spinner spins on to?

[David Kirkham]

Originally Posted by CNGreen

David,

Did you get the pin?

Got any pics of the new pin nuts?

BTW, just for clarity, are the nuts called pins? I thought the "Pin" in Pin drive meant the single large "bolt" that goes through the rim and the spinner spins on to?

I haven't seen it yet. It should show up any minute. I will post when it does.

The pins are in the oven right now. When they get out I will take a pic and post it.

In the racing world, "pin" refers to the "drive pin" on the hub of a "pin drive" wheel. The "single large bolt" that the spinner threads on to...??? We just call it the snout.

David

[CNGreen]

Now, see that? I been edumacated today!

[David Kirkham]

Gents:

I am sorry to say, the education is about to continue.

When I measured the Trigo pins the first time, I just grabbed a simple protractor tool. They obviously did not have a 90 degree taper and 82 looked pretty close so I figured that is what it was.

Well, today I bused out the Mitutoyo angle gauge to check our pins as we made them...it wasn't pretty. Our pins are right on the money at 82 degrees, but I held the taper up to a Trigo taper and noticed it was slightly off...hmmm???

What gives?

Remeasured our pin...82 degrees. Remeasured the Trigo pin (this time with a proper angle gauge...76 degrees!!!!!!!



Let's see. Standard tapers in machining. 60, 82, 90, 100 and 120 degrees. NO 76 ANYWHERE I have ever seen.

Oh well. I'll wait to see what the adapter is actually machined to and then we will fix the pins. No big deal, but irritating, none the less.

Perhaps, (and only perhaps) this is why some people have had problems with the pins. Perhaps the taper of the pin doesn't match the taper of the hub adapter. If the tapers don't match, you will have very high point loading on the parts, exceed the yield of the material, and have a galling fest. Galling could very well cause the pins to tip and cause all sorts of grief.

David


ps. CNGreen
Better send me along the tracking number. Fed Ex didn't deliver today.

[Dominik]

Hi David!

The taper on the exisiting pins are not machined, rather hammered on in a die. Probably the same time the internal hex is done.
That's why the taper is off, wrong angle, and not concentric. The thread is probably also chased in that die.

Please measure if the thread is concentric, or just let the Trigo pin run on a 1/2" stud in a drill press.

Let's measure adapters, and if they are NOT 90 deg, offer pin in 90 deg nevertheless.
People could taper them on a drill press using a standard 90 deg taper.

Of course, if we can confirm that they (and Superformance) share all the same angle, you could offer the pins drive nuts in that angle.

Dom

[Paul F]

Originally Posted by Dominik

Sadly, that problem has been around for years with "wheels sticking" (due to non-concentric nuts)
I had new nuts done for my clients in Germany and South-Africa since years.
Gladly, we found someone to take on the problem in the US and solve it with the help of all here :-)
Ironically, Kirkham does not even use that setup!

Now we can start a new thread about the spinners...

Dom

But...but we haven't finished this one. David suggest we make the tapers match and make them out of good material.

David, you made a bunch of pins. Can we use them?

[David Kirkham]

Originally Posted by Paul F

But...but we haven't finished this one. David suggest we make the tapers match and make them out of good material.

David, you made a bunch of pins. Can we use them?

Hard to answer. Depends on your adapter.

Our pins are 90 degrees so they will fit a 90 degree taper. The Vintage hub adapters are a 60 degree adapter. We can make those too, without much grief.

The only adapter I have measured is a Trigo. It is 90 degrees. I assume the Vintage hub adapter is 60 degrees, but I don't know. I'd need one to measure.

Also, I don't know about the Compomotive; I'd need to measure one.

David

[Larry N Johnson]

Originally Posted by David Kirkham

The Vintage hub adapters are a 60 degree adapter. We can make those too, without much grief.

The only adapter I have measured is a Trigo. It is 90 degrees. I assume the Vintage hub adapter is 60 degrees, but I don't know. I'd need one to measure.

David

David,

I will attenpt to steal a Vintage Adapter from Terry Stapley and deliver it Monday. That way, you will have the Vintage Wheel, Vintage Pin, and Vintage Spinner. Now if we only had a 94-95 Mustang hub...

Originally Posted by Dominik

Except with Vintage it mattered less because they have 7/10mm play between pin and hole... (hole diameter in wheel: 19.7mm)
And apparently they also have a slightly better pin to start with! Or even a smaller diameter pin.

Dom

Dom,

David Kirkham and David Cindrich both measured the Trigo holes and the Vintage Holes. Exactly the same diameter!

The Vintage pin is slightly larger diameter than the Trigo pin. So, with the Vintage pin, it fits tighter than a Trigo. The Vintage pin is shorter as well.

Still, Kirkham's external-hex pin will be a far better answer because then the stud won't have to be trimmed to get a wrench on the pin! Very big deal. Eliminates the top of the pin from splitting. Of course the Trigo taper error is the biggest discovery so far.
Regards,

LNJ