Belt replacement and condition of arbor/motor

[jlmeredith]

I recently acquired a used BT3000. Upon receipt I tested it by briefly turning it on. What resulted was a mess. Stuff was blowing everywhere. At first I thought it was just excess sawdust inside, but then realized that the blade has stopped turning and the motor was still running.

After shutting if off, I looked underneath to discover the picture below:



After some cleaning of the motor shaft, this is what it looks like:



It appears that the belt fussed to the motor shaft and the arbor and then proceeded to disintegrate. The material on the shaft is similar to rubber cement. Sticky and very difficult to get off.

My question - What is the best way to clean these parts? Is there any concern of this affecting the usage of the saw?

The gentleman who I purchased the saw from said that he used it once in 1991 for a flooring project and it then went into storage.

Due to the long period of storage, should I be concerned about bearings or any other mechanical parts that need to be replaced?

Functionally the saw is in near perfect condition other wise aside from some lubrication that is needed. The arbor and the drive shaft appear to be in good shape, turning freely and without any wobble. Whew!

Thanks for you help!

[LCHIEN]

20 years in storage - I can see why the belts rotted and I have heard of them doing that. Too bad you didn't have the owner turn it on before you bought it.

The BT3 uses 2 identical belts. belts can be had from most ryobi parts dealers, Same belt is used in all BT3 family members, ytou can also get them from Sears, go to the www.sears.com web site and click on parts, then put in model 315.228110 and you can identify the belts and they will cost about $9-10 each before shipping.

There's several tutorials for replacing the belts here on-line in the tutorials section. Read them.


I would think the bearings might be OK? You can see by just letting the motor run w/o belts for a while. If the arbor spins fine then its probably OK.

I don't know how to clean the rotted stuff off but I would try various solvents in increasing strength. Like WD40, rubber cement solvent, then mineral spirits then acetone etc. Try to keep the solvents out of the bearings.

[jlmeredith]

Belts ordered.

First pass at cleaning the motor shaft has resulted in success. Goo Be Gone and a toothbrush seem to have done the trick - with the shaft facing down to avoid allowing solvents to get in the bearings and motor. The motor and arbor both seem to spin freely with no play, so I think I am ok there.

Next up will be the arbor, which looks like it will be more of a challenge, but I think based on the helpful links Loring provided, I should be able to get it knocked out.

Thanks for the help Loring!

[mpc]

Those belt remnants almost look like twine wrapped around the shafts. Is it really as "corded" as it appears? If so, slicing with a X-Acto or sharp utility knife perpendicular to the shaft threads ought to get the big chunks out. I'd try cleaning the remaining small debris with a brass bristle brush - basically a toothbrush with soft brass bristles. They're available from most hardware stores and Harbor Freight Tools. HF Tools sells a 3-pack of brushes (3 different materials) that work well for clean-up jobs like this.

As for solvent chemicals... my long time interest in tinkering with cars makes me instinctively reach for spray cans of brake or carburetor cleaner. If this were my saw, after using the knife to cut away the big chunks, I'd spray carb cleaner into the corner of a rag getting it fairly saturated but nowhere near "dripping" wet. Then I'd use the rag to clean the metal parts. Or I'd spray the brass brush with the cleaner and then try scrubbing. As LCHIEN said, keep the cleaners away from the bearing guts - don't wash out their lubrication. Brake cleaner self-evaporates but it'll attack some materials, especially some plastics. Carb cleaner doesn't evaporate fully but it won't attack most plastics and it certainly won't attack rubber parts. It might slightly discolor some aluminum but it won't actually hurt the metal. Simple Green can be used to rinse away either brake or carb cleaner residue/remnants.

Once cleaned up and ready for re-assembly, take the time to clean the area where the motor & arbor support metal pieces slide against the fixed aluminum pieces. On the BT3000 saws there are thin metal "shims" to adjust the clearance; these can get jammed and then bent/busted if lubrication and basic maintenance isn't done on this area. On the later saws the shim setup is a little more durable. Basically though adjusting the shims (via the tiny Allen-headed setscrews in the beefy aluminum parts) and lubricating the shim faces and flat parts of the beefy aluminum parts is what is needed. It's not hard to do. Just don't use auto body wax - find a silicone-free wax. Folks on this website generally recommend Johnson's paste wax which can usually be found in the furniture polishing isle of Lowes, Home Depot, etc. Last time I bought some it was a bright yellow can. This wax is great for lubricating woodworking tool tabletops, shims, etc. A little wax in some of the gears is a good idea too. Just don't glob so much in there that it attracts sawdust.

Then double-check the fence, SMT, miter slots, etc for proper alignment to the blade. Note that the basic Ryobi stands are not super-rigid so you may find your saw alignment gets bad if your floor is uneven as you move the saw. Find a good spot and paint/mark the floor where the table legs so you can always put the saw in the same spot and have things aligned properly as a result.

mpc

[herb fellows]

Yes, get most of what you can out with chipping away at it, then I think acetone is going to be your final solution. Gloves, mask, safety glasses etc. and maybe the green scotchbrite pads, lots of ventilation.

I read somewhere that wd-40 will soften rubber, so you might want to try that on the full mess to make it easier to remove the bulk of it.
No first hand experience though.

[Black wallnut]

Jamie, you need to resize the last image.

[jlmeredith]

Apologies for the super sized photo! It should be fixed now!

[jlmeredith]

Update on belt replacement

So here is what is left of the belt after cleaning:



It appears the belt must have been made of rubber and twine!

I managed to get the covers off and access the guts of the drive mechanism. I was able to get all of the gunk off of the drive shaft with some goof off and a brass brush. It cleaned up great and appears there is not real damage.

The arbor was even more coated than the drive shaft mainly because the belt had more contact with it.





Now I am wondering if the arbor bearings are going to need to be replaced or if what I am seeing and hearing is just a result of bearings that have sat for too long and need some movement to get any lubrication left moving around in the bearings.

The arbor turns fine, but there is some resistance and a small noise (sounds louder in video than it really is). See the video below for a live view.

http://www.youtube.com/watch?v=JGOHnxhWiCU

Next up will be to clean the arbor and prepare it for belts.

The good news here I guess is that all of the shims were still in place and appear to all be in good shape.

Thoughts anyone?

[jlmeredith]

mpc - thank you for taking the time to give me some great advice! Aside from the arbor question previously posted, so far things look good. The saw really does not seem to have been used much. Little or no wear and tear and very little in the way of usage indicators I would have expected from such an old piece of equipment.

[toolguy1000]

So here is what is left of the belt after cleaning:



It appears the belt must have been made of rubber and twine!

I managed to get the covers off and access the guts of the drive mechanism. I was able to get all of the gunk off of the drive shaft with some goof off and a brass brush. It cleaned up great and appears there is not real damage.

The arbor was even more coated than the drive shaft mainly because the belt had more contact with it.





Now I am wondering if the arbor bearings are going to need to be replaced or if what I am seeing and hearing is just a result of bearings that have sat for too long and need some movement to get any lubrication left moving around in the bearings.

The arbor turns fine, but there is some resistance and a small noise (sounds louder in video than it really is). See the video below for a live view.

http://www.youtube.com/watch?v=JGOHnxhWiCU

Next up will be to clean the arbor and prepare it for belts.

The good news here I guess is that all of the shims were still in place and appear to all be in good shape.

Thoughts anyone?

i don't own a bt3xxxx, but is the arbor noise in the video normal?

[Daryl]

That is a bearing right there on top of the shaft, under the black piece that is loose. Since the shaft is only supported by one bearing now, it would be normal for it to be a bit rough. If you can grab the bearing with a thumb and finger and give it an easy turn, you will be able to feel any problems with it.

[JimD]

It would seem to be pretty hard to determine what caused the belts to fail. If the shafts will turn at all it seems unlikely that a bearing issue led to the belts failure. Maybe they were just really old, as has been suggested, but lots of really old belts do not fail. It also could be that there was debris in the belts - like small pieces of wood - that caused them to fail.

I lost most of both belts when a small offcut fell into them when I was making a raised panel cut with the blade tilted. I replaced both belts and my saw has worked without issue for 5 years or so. I bought another couple belts thinking this must happend from time to time but they sit unused in a drawer. The belts are tough to replace because they must be tight to work and there is no mechanism to release the tension, allow for belts replacement, and then reapply tension. So you are trying to slide belts into position that are already tensioned. You can but not easily. Once started, you can tap them across using a block of softwood to contact the belts.

I doubt there is an issue with the bearings. I don't think you can do anything about it if there is other than replace the bearing. I've made a lot of sawdust with my bt3100 and there is no noticable play in the arbor bearing. When there is play, the saw kerf will be wider than the blade (because the blade will wobble when loaded).

I'd put the belts on it and try it. If the kerf is noticably wider than the blade, I'd order the bearing.

Jim