[Thomas]

Today my workshop did the job.

[Greybeard]

Just a comment about the thread, folks. If new nuts are made to the same thread then it's not an issue  . I cut the threads on the lathe and cleaned then with a cycle thread die - the old nuts fitted without any difficulty.

Steve

[Thomas]

But Rick, I appreciate ANY comment and advice!

You might be right. But I can't say. My engineer at least told me that he will make one single part to see if it works fine. Yes, he asked me for the thread and he will check it in detail. He then told me that he can easily program his machine for one single part and that he then already has all data in his machine (a huge device). We also discussed the material and he said that they certainly have very strong material in their stock. I simply believe him and we'll see (now he has holidays but I'll show him your list when he's back in two weeks).

Meanwhile I am pretty sure about what happened to the sleeves. They carry tapered bearings. If I assume that the angle of the tilted rollers is about 15 degrees then the load from the machine (and the punches) go three quarters downwards onto the inner bearing ring and one quarter outwards along the spindle. Considering the many thousands of hits and heavy loads there is no wonder that the material becomes worn and breaks at its weakest point.

Cheers, Thomas

[Rick Parkington]

Hope you'll forgive me taking the chance to make what I hope is a worthwhile point about CNC machining. The only advantage of CNC (computer numerical control) machining is for the manufacture of batches of identical parts because most of the time/cost is in creating the computer programme, once that is done the machine will make 100 as easily as one - but to make one only would be an expensive way to do it. It is far better to get a one off job done by someone with a manual machine - but what makes a difference here (and is sometimes confused with CNC) is a DRO (Digital Read Out) - instead of relying on the dials on the hand wheels, where you have to account for backlash (wear) in the leadscrews, a DRO tells you exactly where you are, making an accurate job much less dependent on the operator's skill. It's the same sort of technology as the digital vernier calipers everyone uses nowadays.

Finally a word about the thread, it may be Whitworth form (55 degree included angle) or Cycle thread (60degree) and the engineer will probably want to know. You may get away with the wrong one but sometimes on larger diameter threads it makes them too tight. May be best to get him to machine a test piece in both 55 and 60 and see which one the nut fits best.

I agree with Steve that EN16T or 24T would probably be a good material to use although it will be called something else in Europe, you can find steel equivalent comparison charts online such as this one: https://www.actonbrightsteel.co.uk/datasheets/useful_information/international_specification_comparison_chart.pdf
Cheers Rick

[Thomas]

Hi all!

I was at my local workshop and one of the engineers at the lathe will make a copy of the tube (he does it in his free time). Then I will check it installed in the wheel. If that's fine I will order a second one for my rear wheel. If he has enough time he is willing to make more for the club shop. Compared to the effort he makes parts for low prices (to be discussed) and if the club and/or members are interested I would organize without financial benefit for myself. So, give me a message if you are interested in this tube and/or other parts. Three notes: First, we would need a draft or drawing. Second, he can only start with this job end of June. Hence, it requires time. And third, I am sitting in Germany and shipping/custom might be expensive (I would send it as a private parcel but one never knows).

I promise nothing but it's worth a try.

Cheers, Thomas

[Thomas]

Yes, Steve, we're all collectors after all.  I've a lot of old stuff in my shed just as a nostalgic reminder (Pistons, coils, broken bolts...). Thanks for the confirmation and your idea about the material. That will help!
Cheers, Thomas

[Greybeard]

Ive just been down to the workshop to check - I kept the broken tubes as souvenirs The thread is as you say 3/4 inch x 24tpi.
I'm afraid my choice of steel was restricted to whatever pieces of 1 inch bar I had available at the time so goodness knows what it is. If I was buying some bar I would be tempted to get EN16T or EN24T such as is used for fork spindles unless any engineers out there would recommend differently.
Both front and rear axles are identical.

All the best. Steve

[Thomas]

This is really helpful to know, Steve! I already ordered two new tapered SKF bearings and will ask my CNC workshop tomorrow if they can make a tube or two (if the rear axis has the same design). I will also ask them how much they charge for more so that club members can benefit. Which steel did you use for a replacement? And what thread is it? I measure 3/4" and 24 tpi. Is that correct?
Cheers, Thomas

[Greybeard]

Hello, Thomas. Both the front and rear axle tubes of my 37 Lion had broken off in the same way as yours have. Replacement tubes were not available so I had to make my own. It seems that there is a weakness in the design which was never addressed. I fully anticipate that the replacements I made will eventually suffer the same fate. Fortunately, due to the support of the spindle any break should not lead to a catastrophic failure in use but will make further adjustment of the bearing impossible.

https://www.marston-sunbeam.org/sunbeamForum/index.php?topic=1012.msg3970#msg3970

Perhaps it's a a part that the club could have remanufactured.

Steve

[Thomas]

You are right, of course, Claudius! Always be careful. And yes, it seems that the machine development made significant progress within a relatively short time. In any case, I highly appreciate your input. Thanks again for it. I now found out that there are two identical tapered bearings in it (SKF 95079 in my case). I guess I will buy two new bearings for replacement.
Cheers, Thomas

[klaudius]

The fact that it looks different has to do with the fact that my Sunbeam is 1932 and yours is 1937. Even the conservative Sunbeam moved with the times.
I just wanted to discuss the possibilities on my Baispiel. On such supporting parts, complete replacement is better than flying over the handlebars.

Regards
claudius

[Thomas]

A CNC-Workshop is a good idea, Claudius, I have one close by and will ask them. But again, your spindle looks different to mine. You have adjustable ball races on the threads while I have complete bearings on the tube surfaces. My thread is only for bearing adjustments with two nuts.

[klaudius]

Hi
Any CNC company can do this. At that time I also had it rebuilt and hardened. If the camp is to be used again, you have few alternatives.

Personally, I wouldn't have improvised anything for safety reasons. Damage like that can break a lot of bones.

greetings
claudius

[Thomas]

I found out what is wrong. The wheel spindle is housed in a tube which carries the bearings again. The thread at the tube end is broken off. It should carry the two nuts to adjust the bearing clearance.
It seems problematic to leave such a part manufactured and wonder if one can weld it. It is perhaps not necessary to have the adjustment nuts attached directly to the thread end but one can perhaps  position a washer or a ring between the bearing and the nut. Or is this tube available somewhere?

[Thomas]

Thanks a lot, Claudius, but it seems that my setup is different.

[klaudius]

Unfortunately I don't know the 37 structure. I recently replaced both bearing shells on my 32 9A - they were damaged. I definitely wanted to keep the old technology and not use modern bearings. The original clamping tool of my 32 looks like this. This allows the cone to be adjusted very sensitively. Unfortunately, I don't know if your camps were like that in 1937. But from my point of view it is not quite logical.
greeting
claudius

[Thomas]

1937

[klaudius]

Hi
What year is your machine?
Regards
claudius

[Thomas]

Here are a few pictures of the situation in the brake drum. There is a loose double nut stuck on the axle. I am not sure if the the assembly should be put together along with the wheel spindle to set the free play in the bearing. 

[Thomas]

Hi all!

I have discovered an axial play in the bearings of my front axle. What is wrong and how can I fix it?

https://www.stsci.de/wp-content/uploads/2022/05/wheel1.mp4
https://www.stsci.de/wp-content/uploads/2022/05/wheel2.mp4

The book of the Sunbeam says: ,,Loosen nut on left-hand of spindle and turn cone as necessary by means of the double-ended spanner. "

Is that double-ended spanner for the two grooves as indicated in the picture? If yes, how can I adjust it without the bearing rotating with it? On the other hand it seems that the outer bearing ring moves inside the hub. I am confused.

Cheers, Thomas