PDA

View Full Version : Band saw question on wheel diameter?



Bill Pace
03-05-2008, 05:14 PM
My buddy and were prowling the scrap yard and came on a pretty decent (appearing!) 9x16 Peerless band saw..... It followed us home.

On examination after getting it home, found why is was scrapped --- both wheels were in pretty bad shape from bad tracking/overtightening the 1" blade --(we guess/think?) 1" seems overkill on that saw anyway. But, hey, we couldnt stand to see that saw go in the jaws of that crusher!!

After some consultation between he, I, and Lane we have decided that since the 13" wheels will clean up as is to accept a 1/2" blade and being in the home shop, that 1/2" should be fine,--- with the least aggravation also. Debated a good bit on a 3/4" blade, but it would have required a ton of additional work on the drive wheel -- build-up with weld, or make awhole new one, -- and all its taking on the existing one is a clean-up on the lathe.

So, in order to attain this goal, it is necessary to remove a pretty good chunk of the damaged area to get a nice flat spot for the blade to ride on, -- especially the drive wheel. The idler wheel will take less clean-up, bringing into question-- do we need the two wheels to be exact diameters?

We have decided to err on the safe side, and make them the same, but we are wondering, what is the thinking on this ... is it all that critical? We really cant come up with any plausible reason to have critical dims on them.....

portlandRon
03-05-2008, 05:21 PM
If the wheels are not the same diameter the blade will cut the material at an angle. You could possible adjust/shim the fence/vise so it is 90 degrees to the blade.

A.K. Boomer
03-05-2008, 05:30 PM
So, in order to attain this goal, it is necessary to remove a pretty good chunk of the damaged area to get a nice flat spot for the blade to ride on, -- especially the drive wheel. ..



What portlandRon said with this added,,, I dont believe you want flat surface area where the blade runs --- I think you want a slight convex.

ptjw7uk
03-05-2008, 05:48 PM
the wheels do not have to be exactly the same just as long as the point the blade touches the rim is vertically in line so if the diameters are not the same then one of the wheel centres will have to be offset a bit.
Its just easier if both wheels and axis are the same
Peter

Lew Hartswick
03-05-2008, 05:59 PM
As "watsisname" said the blade doesn't have to be anyparticular
angle as long as the table is at right angles to the blade as it passes]
through. However it's a lot easier to hold the material on a level
table. :-)
...lew...

darryl
03-05-2008, 07:04 PM
The blade guides will keep the blade going exactly where it went before- somewhat at right angles to the table. There will be a tendency for the blade to ride the inner bearings more than the outer ones if the wheels are turned down, but it won't affect the angle it cuts through the work. If truly a lot is coming off the wheels, would it be possible to weld or silver solder a hoop together to press over the wheels to bring the diameter back up-

Bill Pace
03-05-2008, 07:41 PM
The blade guides will keep the blade going exactly where it went before- somewhat at right angles to the table. There will be a tendency for the blade to ride the inner bearings more than the outer ones if the wheels are turned down, but it won't affect the angle it cuts through the work. If truly a lot is coming off the wheels, would it be possible to weld or silver solder a hoop together to press over the wheels to bring the diameter back up-

Youve summed up a lot of the thinking we put into the problem.... Yes we pretty strongly considered doing a 'hoop' along with the aforementioned welding--spray welding, brazing, nickel, etc -- and even getting a piece of plate and cutting out a new one, but the bottom line was to do the KISS approach, -- the wheels had enough left to clean up for a 1/2" blade with some pretty quick basic lathe work, so it was really a no-brainer there. As you say, none of this will affect the cutting angles or tracking, that will be unchanged ... just a 1/2" blade going round instead of the prior 1". As for the bearings, this is a bear of a saw and has some hefty bearings, so with the smaller blade it shouldnt be a problem with the slight shift of blade position.

One possible problem, is the narrower blade not reaching completely thru the cut, but we're hoping there is enough adjustment on the down stop to bring that around --

All these repairs are well under way, we were just curious about the wheel diameters ----

By the way, I keep saying "we", but my buddy has the saw, Lane & I are just helping out -- he was in dire need of one, and was quite tickled when he found this one in the 'junk yard'

tiptop
03-07-2008, 08:25 PM
Sounds like a fun repair Bill, keep us posted and as usual some pictures are good to. Take care, Jay:)

mark61
03-07-2008, 09:19 PM
Why not sleeve the wheels back to the original size? Piece of pipe or even boiler plate cut out then machined or even flat stock rolled and welded for shrink fit to the wheels just like they do with buggy wheels.

mark61

torker
03-07-2008, 11:21 PM
Bill ol' buddy...you might want to reconsider this 1/2" blade idea.
A 9X16 saw wants a stiff backed blade. Why? Think about it...the saw puts a fair amount of pressure on the blade...forcing the blade to bow up a bit in the middle.
A 1" blade is a stiff bugger that can really take that upward force.
At even 10"(much less than the 16" it is capable of) a 1/2" blade is going to bend up so much that you'll be constantly plagued with cracked blades and broken welds.
I think I'm not talking out of my butt here :D
I've been using my 4X6 saw for cutting a lot of bigger stock since I started my business(it uses 1/2" blades. I go through blades like crazy (about 20 since Sept.)when cutting this bigger stuff.
Without exception they always break...either from a crack formed in the back or a broken weld.
When I cut smaller stock they usually last until they are dull... I often get a couple months out of them.
Just a thought anyway. Seems a lot of trouble just so you can wreck blades.
I'd go the extra mile and sleeve the wheels as was mentioned.
Hell...give me the measurements and I'd even make the rings for you...all you pay is shipping.
(Sorry..I like keeping machines close to original...lol!)
Russ

Carld
03-07-2008, 11:47 PM
Torker is right, the blades do bow front to rear under pressure. Is this a horizonal or verticle bandsaw?

Bill Pace
03-08-2008, 10:02 AM
Aw, come on guys, --- dont diss our project!! Dang it!, We've got enough doubts already-----

Seriously, I'm afraid those are some of the same worries going thru our heads.


But heres our thinking .... Trimming the wheels back was a necessity anyway, they would have to be cleaned/flattened to accept a rim. It just didnt make sense to NOT try it with using a 1/2" blade (a .035 bi-metal blade will be about $35), this approach requires nothing but a couple hours in the shop. And (we keep telling ourselves) this WILL be in a home shop situation--- I totally agree Russ, at your house this approach would not be a good idea ... or under any heavy use. If it starts eating blades, we'll just have to remove the wheels and make another run at them with another approach.

The 2 wheels are basically at this phase now, with the drive wheel needing a bush to take care of a, somewhat, 'hammered' shaft and bore. As you would expect the saw was REALLLY grungy, and we're trying to get it looking a bit more presentable, but it is a LOT of just scut work. Will be unable to get a length of the blade until its almost reassembled and we can take a measurement (the original was 10' 1 1/2")--- hopefully toward the end of next week.

And the bottom line is, as with a lot of you guys, (I'm talkin to you, Russ!!) this kinda thing is just a real 'kick' to bring something like this back to life ----
"don need no steenkin coke to get high, man!!"

Carld
03-08-2008, 12:00 PM
If it's a horizonal cutoff saw I think it will work fine. If you use the bimetal blade it will help as they are very rigid. I would probably be doing the same thing because I have saved stuff from the trash pile too.

I say go for it and have fun.

torker
03-08-2008, 02:27 PM
Bill..lol! I hear ya! I'm just glad you guys rescued the saw. And you now have all the time in the world to change your mind half a dozen times about where to go with this.
AND.. a good downfeed control will help make those little blades last :D
(Pssst...I know a few guys who can help you build such a system ) :D

wierdscience
03-09-2008, 12:09 PM
A shrunk on ring works well for things like automotive ring gears,locomotive drive wheels etc,no reason it won't work here.

I vote to put it back to original and carry the 1" blade,you won't regret it one bit.

Paul Alciatore
03-09-2008, 01:44 PM
......
I've been using my 4X6 saw for cutting a lot of bigger stock since I started my business(it uses 1/2" blades. I go through blades like crazy (about 20 since Sept.)when cutting this bigger stuff.
Without exception they always break...either from a crack formed in the back or a broken weld.
When I cut smaller stock they usually last until they are dull... I often get a couple months out of them.
......
Russ

Russ,

Are you using the bi-metal blades? If not, do so. They outlast the cheap ones by 8 or 10 to 1 and at twice or three times the price are a lot cheaper to use. Besides, you save time changing blades.

wierdscience
03-09-2008, 03:06 PM
Bill ol' buddy...you might want to reconsider this 1/2" blade idea.
A 9X16 saw wants a stiff backed blade. Why? Think about it...the saw puts a fair amount of pressure on the blade...forcing the blade to bow up a bit in the middle.
A 1" blade is a stiff bugger that can really take that upward force.
At even 10"(much less than the 16" it is capable of) a 1/2" blade is going to bend up so much that you'll be constantly plagued with cracked blades and broken welds.
I think I'm not talking out of my butt here :D
I've been using my 4X6 saw for cutting a lot of bigger stock since I started my business(it uses 1/2" blades. I go through blades like crazy (about 20 since Sept.)when cutting this bigger stuff.
Without exception they always break...either from a crack formed in the back or a broken weld.
When I cut smaller stock they usually last until they are dull... I often get a couple months out of them.
Just a thought anyway. Seems a lot of trouble just so you can wreck blades.
I'd go the extra mile and sleeve the wheels as was mentioned.
Hell...give me the measurements and I'd even make the rings for you...all you pay is shipping.
(Sorry..I like keeping machines close to original...lol!)
Russ

Russ,the blades form a burr on the back from rolling against the backup roller guide.That is where the cracks start,it's similar to what happens to a mushroomed head on a chisel.
What I do is feel the sides of the blade at the back edge every so often.If I feel a burr raising on the sides I just hold a whetstone against the blade while it's running to stone the burr off.