bandsaw wheel balance?

[brick1]

most other bandsaw forums tell us to make sure our wheels are balanced...as much as possible. these shopsmith wheels are drilled on one side and are nowhere near balanced!! is there a specfic reason these are drilled out of balance????

should i put the drilled areas facing each other, or opposite???

thanks, bill

[JPG]

most other bandsaw forums tell us to make sure our wheels are balanced...as much as possible. these shopsmith wheels are drilled on one side and are nowhere near balanced!! is there a specfic reason these are drilled out of balance????

should i put the drilled areas facing each other, or opposite???

thanks, bill

The drilling is to balance the wheels relative to them rotating. There is no reason to balance them from side to side.

I would be curious how you are determining they are 'nowhere near balanced'.

As an aside, the ss bandsaw is 'different' from most typical bandsaws, so be careful what you apply when 'read' from non-ss sources.

[efmaron]

JPG,
In what way is the SS bandsaw different from other bandsaws.

[nuhobby]

All Shopsmith bandsaw-wheels (at least the upper ones -- if not both of them) have a Conical shape which tends to "lead" the blade toward the input-shaft side of the machine, against the blade-bearings/bushings. This action is most effective if the upper wheel is canted a little bit; the upper part of the rim should be closer to the input-shaft-side of the saw than the lower part of the upper rim is. All this differs from the "usual bandsaw" which has flat or crowned rims, and has the upper wheel exactly coplanar with the lower wheel.

I've seen older SS wheels which were almost fully machined after casting. Newer-style wheels have the rubber-tire-grooves running true, but the edges of the wheel-castings may not appear to run exactly true. Regardless, the drilled balancing holes (partial holes) are meant to rotationally balance the wheel.

[heathicus]

I thought this image might help.

This shows the Shopsmith bandsaw and how the wheels are coned and at an angle with each other. The three small circles are the bearings that keep the blade from climbing all the way off the back of the wheel.

[ATTACH]9930[/ATTACH]

The tilt of the wheels is exaggerated for illustrative purposes, of course.

This shows just about every other bandsaw and how the wheels are either flat, or crowned, and should be both parallel and coplanar.

[ATTACH]9931[/ATTACH]

So you can pretty much throw out any "tune-up" or alignment tips you find that aren't specific to the Shopsmith bandsaw. One of the first things they're going to do is tell you to put a straight edge against the wheels and make sure it touches the top and bottom of both wheels at the same time. I can say from personal experience that if you do that with a SS bandsaw, the blade will not stay on the wheels!

[JPG]

Chris
Heath

Well Said!

However: Only the bearings at the rear behind the upper wheel 'guide the blade and prevent it slipping off the wheel'. The lower are to limit blade movement due to cutting pressure. The blade should just clear them when not cutting. EDIT: As a clarification, the upper guide bearing is adjustable to just clear the blade, the lower guide bearing is NOT adjustable(front to rear) and the back of the blade does ride against it thus guiding the blade onto the lower wheel.

I do not think the wheels are 'cone' shaped, but the upper wheel is 'canted' with the top in further than the bottom. I think both wheels are flat across the outer circumference.

[charlese]

most other bandsaw forums tell us to make sure our wheels are balanced...as much as possible. these shopsmith wheels are drilled on one side and are nowhere near balanced!! is there a specific reason these are drilled out of balance????

should i put the drilled areas facing each other, or opposite???

thanks, bill

I would suspect a bent (crinkled blade) striking the guides, rather than an out of balance wheel. Have you changed blades? Have you removed the blade and run the lower wheel to see how smooth it runs? You can also spin the free upper wheel to feel - (check) balance.

I would also inspect the upper wheel bearing for missing or broken parts of the bearing. This gives a chance to pack grease into the bearing. The running of just the lower wheel will allow you to check that bearing. In order to replace that bearing, you have to order a new lower wheel shaft and maybe with a wheel. The bearing and shaft are one unit!

[heathicus]

Chris
Heath

Well Said!

However: Only the bearings at the rear behind the upper wheel 'guide the blade and prevent it slipping off the wheel'. The lower are to limit blade movement due to cutting pressure. The blade should just clear them when not cutting.

I do not think the wheels are 'cone' shaped, but the upper wheel is 'canted' with the top in further than the bottom. I think both wheels are flat across the outer circumference.

You may be right, JPG. I got my info, not from a long history and deep knowledge of Shopsmith tools (and I didn't even sleep at a Holiday Inn Express last night), but from an article I happened to have read just the other day!

http://www.tool-hunter.com/shopsmith-po ... aw-article

[brick1]

the wheels are aligned as Heath describes. the upper whell is canted, and the lower is straight, (using a straight edge). the wheels are "DRILLED" on the front side, power head side, and they seek the heavy side when spun free. the bearings are smooth, oiled and in perfect shape. the "DRILLING" is done on the side closer to the power head unit, or out of sight until you remove the wheel......

i'm going to set the wheels balance point opposite each other when i put the blade on.....? i'll see how it runs and adjust to suit.......having built numerous automobile race engines and a great many woodworking tools, not to mention house fans.........hee, hee.......we will see how these go??

i cleaned the 3/8" offsets this evening, oiled lightly and reinstalled with "anti-sieze", because the steel threads are in contact with aluminium parts.

take care, bill

[reible]

Hi,

How about I make a prediction?

I think that there will be a slight difference in the wheels and that amount of difference will be enough that the two will end up not staying in the relationship that you expect them to. I'd say give it a try but mark the wheels so it will be easy to see if they stay in sync or not.

The idea has me interested enough that I'll test it on my bandsaw...

Ed