Datsun-240z Vs Fairlady-z432

[Captain Obvious]

Hi Kats, I got some time to work on a proof of concept for the retaining collar. Since this is just proof of concept, I took several shortcuts. For example, I did not drill and thread the center and I made the taper collar out of aluminum instead of steel because it is easier to work with. I also made the angle 45 degrees instead of 60 degrees because that is how my lathe was set-up and I didn't want to change it. None of those affect the viability of a test of the retaining feature.

So here is my test rig:

I included a slight undercut on the shoulder and a small counterbore on the taper to provide material to forge into place to retain the collar. I'm not sure it was really necessary, but I'm just making this up as I go:

I tested the viability first with the portion through the ring longer than necessary so I could see the change in material from the forging operation. Here is the first forging on the press, using a hardened bearing race as the forging tool:

It worked quite well to retain the tapered ring. Here's the displaced material. Under magnification, you can see a small amount of flared out material at the corner of the shoulder:

And here's the part after the second forge test. I cut off the original forged area and did it again with the shoulder cut off closer to the ring. It's not perfect as the surfaces don't line up exactly, but I believe someone who really knows what they are doing could adjust a couple dimensions and hit it spot on. Maybe even I could hit it after one or two more test parts:

[Captain Obvious]

And since motion is such an important part of the concept, here's a video of the prototype rig:

 

[kats]

What a wonderful work , Captain!!

Thank you so much for your building and testing , and the video. 

You can be a manufacturer of the special nut !

Kats

 

[Jason240z]

On 21/07/2017 at 0:49 AM, kats said:

Hi Jason240z, did you have a coffee with Alan in London? I wish I could be there !!

And also thank you for the information of a engineering shop in your city, it is nice to know.

Kats

Hi Kats,  Yes I did.  Its always good to talk about cars and have a coffee/beer.

I've got some spindle pins being made, when I go to collect I'll show the shop the video's and can ask if they'd be interested in making a small batch if you'd like?

Lovely to hear the twin idler gear.  its a great noise.

Edited July 23, 2017 by Jason240z

[Captain Obvious]

Thanks Kats. I don't think I'm qualified to make real ones though. Material selection (for real), heat treating, plating... Those are the difficult parts for me.  

If I get a few more moments, I'll test the other (less likely) retention theories I mentioned before. I'm sure I can come up with an internal hidden retention pin, but the one I'm really curious about is the differential temperature assembly. That would be really neat if I could get that to work!

[Captain Obvious]

Hi Kats, Here's another concept for the lug nuts. I don't think this is what they did (I think they forged it into place), but if you really want to completely hide the retaining feature to confuse your competition, here's one way I came up with to do that. Again, since this is proof of concept only, I took shortcuts. Most noticeably, I did not make a tapered ring this time, but instead just used a simple cylindrical collar as it was much easier and does not affect the viability of the test.

I cut a groove on the inside of the collar and drilled two holes through the "nut" body:

I then pressed two small pins into the body:

I pressed the pins flush with the outside diameter of the body:

The lengths of the pins are such that when pressed flush with the outside, they protrude into the inner portion of the body:

I made a mandrel a few thousandths smaller than the ID of the nut body and tapered it on the end. I used a portion of an old bolt because it has a quality heat treat of at least grade 8.8:

While the pins are flush with the outside, slip the collar over the body, put the mandrel in place, and press the mandrel into the part on the arbor press. When you do this, it forces the two small pins outward and they catch the groove in the collar:

Thread the ID and you've got a retained collar with no externally visible retaining feature:

I still think they forged it, but it was nice to see this more elegant method work. 

[Captain Obvious]

And here's a quick video of this pin retained prototype rig. I think I need a better video camera:

 

[Jason240z]

thats lovely work you've done on those bits Mr Obvious.

[siteunseen]

If you start videoing your bits soak those crocodile fingertips in some Palmolive, Madge and use youtube, Richard, not photo****it. 

We would all benefit from your meticulous work. Sharing is proof you missed your calling, TEACHING!  You would and are the best ever, you and Blue.

I'm playing around now.  Been working in the heat and a few beers is like intravenously shooting it straight in.

Nothing intentional, you're my Andy and I'm Barney. 

https://m.youtube.com/watch?v=GmFp0I8AZqw

[Captain Obvious]

Haha! Thanks guys.

Site, you should see my fingers in the winter! In the winter, they spontaneously crack!  And I don't think I could ever be a teacher. I doubt I would have the patience for the people who really didn't want to be there.

[240260280]

Nice work CO!

 

A friend showed me that Volvo do something similar:

 

:

 

and Porsche:

 

[kats]

Hi Jason240z , I miss London, I have not visited almost a year. And here is another engine. Which one do you like ? I saw this OS Giken TC two days ago at Glion museum where my Zs are displayed.

Kats