Non-Planar Change Gears

Hello South Bend Universe!

I'm getting my new (made in 1935) South Bend dialed in and found this odd feature. Everything seems to be working alright but this just doesn't seem right. The stud gear isn't coplanar with the compound gear and I don't see a way to prevent it. Is this normal? Am I missing something?

Well, it's not normal and the misalignment shown in the picture is pretty bad. You also have a minor misalignment between the two reversing idlers and the gear at the end of the spindle. The first think that comes to my mind is that all those parts may not be from the original machine. You can probably temporarily fix the stud gear issue by spacing that gear outward but that's really not the permanent fix.

It will take a lot of fussing and fiddling around to figure why the parts to mate up properly.

See.....isn't having an old machine a lot of fun?

are you sure it is a 1935 model and not a 1934 model. That looks like in 1934 spindles/Banjo/lead screw journal, With a 1935+ headstock. Maybe someone wanted a reversing gear assembly on it and change the headstock, Without changing the spindle and lead screw journal.

stay safe and have fun.

Joe.

this is what I was talking about in the other thread...unless someone corrects me you have a later model headstock on a model 405 bed, they may have bought a headstock casting so they could have a reversing assembly and stuck the original 405 spindle in it... Take another pic from above and include the thrust bearing in it...a 405 thrust bearing is 3/8" thick IIRC while the later thrust bearing is 1/2" thick...mixing those parts together would make the spindle too short at the end.

edit- LOL I type SLOW...what Joe said.

The headstock slides along the bed. If you loosen the bolts, can you get it to line up?

allan

kitno455 said:

The headstock slides along the bed. If you loosen the bolts, can you get it to line up?

allan

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yes the headstock will slide back and forth, but if you look closely the reversing gear assembly is almost hitting the banjo. And no matter how much you move the headstock, you're not going to change the relationship between the spindle gear and the reversing gears. So moving the headstock is not going to solve the problem.

Stay safe and have fun.

Joe.

Why can you not just machine a spacer and and just shim it out. Looks to be only about only couple tens out.
Chet

coyotechet said:

Why can you not just machine a spacer and and just shim it out. Looks to be only about only couple tens out.
Chet

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what part would you shim. If you place a shim behind the reversing gear assembly, you would make things worse relative to the spindle. You would be better off replacing the top idler gear, with a larger one, and pushing the headstock to the left to realign them. But this would leave the headstock hanging off the back of the bed, more than it looks like it already is at this point. So you can fix one problem, but you create another one. Granted this does not seem like a big problem but it is not correct. and you still have the problem with the spindle. to fix the problem, we need to know exactly what he has. For instance what type of banjo does he have. Is it a single arm or a double arm. He needs to determine what he needs to do/purchase to get his machine running properly. that is if he wants to do that.

stay safe and have fun.

Joe.

Why not just get a wrench to remove the Stud gear nut and then remove the Stud gear then put a shim spacer of the correct size and replace the gear and nut. I just went back and removed the Stud gear nut and gear to see if it would work and looks like it should be very simple to do.
Chet

I think he can likely scoot the headstock without issue, but would still look into the reverser/spindle gear thing.

If someone put a 405 spindle in a later headstock, it is a cheap upgrade to use a later hardened spindle with the 1.5" nose and would let him use cheap and plentiful off the shelf plates/chucks,

another possible issue the 405 would have had 20DP end gearing all the way through the train but his reverser almost surely has 18DP stud gear, which would create a mismatch with the 20DP gears used on the 405

coyotechet said:

Why not just get a wrench to remove the Stud gear nut and then remove the Stud gear then put a shim spacer of the correct size and replace the gear and nut. I just went back and removed the Stud gear nut and gear to see if it would work and looks like it should be very simple to do.
Chet

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Looking at his picture, It looks like that gear needs to be moved approximately 1/2 Of the width of the gear. That is approximately .2". I measured my nut, It is approximately .284" thick. The end of the shaft is even with the outside of the nut. This leaves approximately .084" threads. I don't think that's going to be enough.. my recommendation is, fix it right the first time, Take care of the machine, and use it for another 80 years.

stay safe and have fun.

Joe.

Yes promacjoe your right looking at it more closely I see that there is no threads sticky out from the stud gears as it is now. And he has lots bigger problem with the reverse lever gears and bracket no lining up with the spindle gear.

Dobermann said:

You also have a minor misalignment between the two reversing idlers and the gear at the end of the spindle.

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Good catch! I hadn't noticed that yet. Thanks! (and also, ugh!)

promacjoe said:

are you sure it is a 1935 model and not a 1934 model. That looks like in 1934 spindles/Banjo/lead screw journal, With a 1935+ headstock.

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I'm definitely not sure. All I know is that it (or at least, the ways) were shipped in 1935 as a model 405-R. The closest I've come to finding a solid reference was this description and this catalog. It seems that the building consensus is that it's a newer headstock.

kitno455 said:

The headstock slides along the bed. If you loosen the bolts, can you get it to line up?
allan

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This seems like the best plan - I have a smidge of ways left behind the headstock and can move it over a bit. Do I need to worry about any special alignment issues once I loosen things or should the ways take care of that?

iwananew10K said:

Another possible issue the 405 would have had 20DP end gearing all the way through the train but his reverser almost surely has 18DP stud gear, which would create a mismatch with the 20DP gears used on the 405

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How would I check if this is the case?

Better photos below, including photos of the thrust bearing (methinks).

Do I need to worry about any special alignment issues once I loosen things or should the ways take care of that?

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not really, as long as the headstock is not hanging off the bed much, it should not be a problem. Get it lined up and that will be one problem solved.

Originally Posted by iwananew10K said:

Another possible issue the 405 would have had 20DP end gearing all the way through the train but his reverser almost surely has 18DP stud gear, which would create a mismatch with the 20DP gears used on the 405

Click to expand...

The spindle gear is 20DP. The reversing gears are also 20DP. The stud/idler/screw gears is 18DP. Since they are not directly connected with the 20DP gear, it really doesn't matter what DP they are. This is normal, every 9N and 10K lathe is set up like this. As long as your lead screw is 8TPI, you do not have a problem. the only possible problems you would have with it is to change gear threading plate. The information given on it would not be correct. But this is not a problem since that information is available on the Internet. Also the plates are available from members of this group.


at this point your real problem is the misalignment of the spindle gear to the reversing gears. I am pretty sure you have a 1934 spindle/: pulley/bearing. I'm also pretty sure that your bed/headstock is of a later model, Probably the same year as your bed. Which is strange. I'm not sure why anyone would change the spindle And use one with a smaller thread, unless all of his chuck's were using that thread. my best advice to you is to find a good spindle, cone pulley and thrust bearing. Once you have everything on hand and make sure everything is correct, replace your spindle and related parts. That way your Lathe will be standard and you will not have near the problems that you have now.

also, you might want to change the banjo to one with a double arm. They work better with the 18DP gears.

stay safe and have fun.

Joe.

I think I see one more "fly in the ointment" here. In the original photo posted, it appears to me that the reversing tumbler structure is clashing with banjo. I'm wondering if the stud gear misalignment is a result of the headstock being moved to the right to give some clearance between the two. If that's true, then it's not going to be possible to move the headstock to the left to improve the gear match. But as with most things I talk about, I could be wrong!

I kind of touched on that in my first post, but admittedly that could be an optical illusion due to the angle of the photo. If you look at the latest photos that he posted, You'll see That the banjo is not interfering with the reversing gear assembly. Although I do believe he needs to change the banjo. An interference problem is not why i think it should be changed. The problem with the banjo is trying to get all the normal thread pitch/feed rates that he may need on his machine. Although I believe it can be done, A single arm banjo is just not a good choice for that.

Stay safe and have fun.

Joe.

Dobermann said:

I think I see one more "fly in the ointment" here. In the original photo posted, it appears to me that the reversing tumbler structure is clashing with banjo. I'm wondering if the stud gear misalignment is a result of the headstock being moved to the right to give some clearance between the two. If that's true, then it's not going to be possible to move the headstock to the left to improve the gear match. But as with most things I talk about, I could be wrong!

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Luckily - that's just a weird perspective thing from the photo. Phew!