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Hello everyone! first-time poster, but a long-time lurker here.

I'm in the process of restoring a Delta/Rockwell 20in Bandsaw, model 28-363 to be exact, and i'm having some interesting problems with the bearings on the lower shaft. Seeing as how i've seen a couple awesome restorations of essentially an identical saw to this one on this website, I thought there might be someone on here who could help.

I'm doing the project for a friend, and when he traveled to purchase the saw he noticed there was a pretty significant wobble in the lower wheel. The man he bought the saw from hadn't used it much/didn't know a whole lot about it, so my friend was able to haggle on the price more because of this issue.

When I was given the project, I was simply told there was a wobble, and that the bearings would need to be replaced. I had planned on doing this anyways, and didn't think much about it.

However, when I pulled the lower drive-shaft housing apart, to my surprise I was met with a nearly brand-new set of bearings. They weren't even dirty. However, the bearing on the wheel-side of the shaft seemed to be horribly over-sized internally, causing the wobble.

Upon closer inspection of the shaft, I noticed that the part of the shaft where the bearing sets is actually a smaller diameter than the threaded part in front of it which is designed to hold the lock-nut in place.

When the new bearings were pressed on, whoever did it used a bearing that would fit over the threaded part, but gave no effort to eliminate play on the part where it seats up with the shoulder on the shaft.

The part of the shaft in question almost looks like it was original to the design, and wasn't turned down or worn-in.

Has anyone ever seen a shaft like this, or knows of a good way to fill in the gap to make the "new" bearing fit with no play?

Any forum research i've done has turned up nothing, and the exploded parts view in the owner's manual i was able to find isn't very forthcoming.

Attached are some pictures of the shaft to help with the issue.

Office supplies Titanium Metal Cylinder Writing implement


Office supplies Writing implement Cylinder Auto part Metal


Automotive tire Office supplies Skyscraper Audio equipment Cable


Thanks for looking!
 

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Pretty sure your shaft is toast… most likely a bad bearing sometime in it's lifetime and it ate the shaft. If you post your question over at the owwm site, you will probably get a lot more suggestions on how to fix it… from replacing the shaft, to welding it up and then turning it back to proper diameter. You can also post a want ad in the BOYD section over there and see if someone has an extra laying around.

Cheers,
Brad

PS: While not from that exact model, here is what the shaft should look like:

Wood Office supplies Metal Close-up Steel
 

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Agree with both mr unix and daddy,I have actually done this on a few occasions,the person who doe the welding must be made aware that the excess heat from welding can warp the shaft ,it has to be done gradually with two overlapping beads,stop & let it cool down,weld 2 more .
Machining it is easy if the right bearing is available for accurate measurement.
 

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Discussion Starter · #5 ·
Pretty sure your shaft is toast… most likely a bad bearing sometime in it s lifetime and it ate the shaft. If you post your question over at the owwm site, you will probably get a lot more suggestions on how to fix it… from replacing the shaft, to welding it up and then turning it back to proper diameter. You can also post a want ad in the BOYD section over there and see if someone has an extra laying around.

Cheers,
Brad

PS: While not from that exact model, here is what the shaft should look like:

Wood Office supplies Metal Close-up Steel


- MrUnix
Brad,

I am posting the question there as well, thanks, gotta love OWWM!

Thank you for the BOYD suggestion, I guess i was too focused on just fixing the shaft as-is. I just didn't think the shaft could wear so evenly. That must have been a pretty catastrophic bearing failure.
 

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Discussion Starter · #6 ·
Agree with both mr unix and daddy,I have actually done this on a few occasions,the person who doe the welding must be made aware that the excess heat from welding can warp the shaft ,it has to be done gradually with two overlapping beads,stop & let it cool down,weld 2 more .
Machining it is easy if the right bearing is available for accurate measurement.

- distrbd
I figured such a process would probably be in order, just wanted to see if there were other options first. I still have the new bearing that was installed on the machine ready-to-go, so sizing isn't an issue. Seeing as I have access to such machinery, this'll be a fun project…
 

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I just didn t think the shaft could wear so evenly. That must have been a pretty catastrophic bearing failure.
Not really… happens a lot more than you would think. Once the bearing seizes, it's just metal on metal with the shaft spinning but not the bearings inner race - so it just wears it down slowly, similar to what would happen (faster) on a lathe. That is one reason I always recommend replacing bearings on any newly purchased used machines. You never know what kind of use/abuse a machine may have been subjected to over it's lifetime, or when (if ever) the bearings have been replaced. It's pretty cheap insurance, and not replacing them can result in some pretty catastrophic damage, as you have unfortunately witnessed first hand. Much cheaper and easier to replace bearings (that can easily be found at any number of different places), than trying to find a replacement shaft or fix the damage later on… which on some machines can be extremely difficult if not impossible.

Good luck with it and keep us posted on your results!

Cheers,
Brad

PS: It could have been worse… it could have spun the outer race instead of the inner one, in which case, it would have eaten the bearing housing in the cast iron, which is much more difficult to repair and could potentially have caused even more damage to other components.
 

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Discussion Starter · #8 ·
Good luck with it and keep us posted on your results!

Cheers,
Brad

PS: It could have been worse… it could have spun the outer race instead of the inner one, in which case, it would have eaten the bearing housing in the cast iron, which is much more difficult to repair and could potentially have caused even more damage to other components.

- MrUnix
I will keep you guys updated, thanks for the confirmation!

And yeah, that would certainly be more of a headache. Any attempts i've made at repairing cast iron, other than TIG brazing very large castings, have been moderately (and temporarily) successful at best.
 

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Sorry about your luck. I've worked on enough vintage (and modern) machinery to see that shaft was horribly worn immediately. The reasons are a plenty as to why this could have happened. On larger machinery like this that was likely not used in a home shop, usually it's because whom ever used it regularly didn't own it and/or didn't know or care enough to let the right people know that it was making noise and operating incorrectly. It's hard to know what you'll run into when looking at old machinery that's why I always use check lists for various machinery when inspecting before purchase.
 

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Sorry about your luck. I ve worked on enough vintage (and modern) machinery to see that shaft was horribly worn immediately. The reasons are a plenty as to why this could have happened. On larger machinery like this that was likely not used in a home shop, usually it s because whom ever used it regularly didn t own it and/or didn t know or care enough to let the right people know that it was making noise and operating incorrectly. It s hard to know what you ll run into when looking at old machinery that s why I always use check lists for various machinery when inspecting before purchase.

- bigblockyeti
No worries, i'm just the guy fixing the problem, its my friend who took the financial dive.

I actually just fix/repair machinery mostly, but haven't encountered a worn shaft this bad. Just thought there'd be someone more in the know here, as I've seen a couple sweet restoration jobs on this site of essentially the same saw, whereas any wood machinery i get my hands on is usually from a more contemporary era. And actually, judging from what I was able to ascertain from the faceplate, it looks like this particular saw was owned/bought initially by the US Army Corps of Engineers. Couldn't ask for a bigger org. with no personal agency. They probably sent it to surplus the minute it started getting really loud.

And yeah, my friend has now agreed to let me come along to ask all the right questions the next time he wants to buy something. Lesson learned.
 
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