Tensioning method for homemade bandsaw mill

Ljohnsaw · May 14, 2016, 06:19:06 PM

True, but what is the diameter of your axle? Worst case you would have to use a higher strength steel or a larger diameter. Can you get away with just moving out an inch or so? It looked like you almost had enough room there. It looked like the plate the pillow blocks are mounted on would need to be trimmed just a little bit to expose the axle a little more and that would do it. If the post is in the way, move the pillow block further toward the front edge?

Joe Hillmann · May 14, 2016, 06:48:03 PM

You could also just put a half twist in the belt. That would reverse the direction of the wheels. You will wear out your belts quicker and you may have issues with your clutch if you are using your belt as a clutch.

plowboyswr · May 14, 2016, 07:29:26 PM

I would do like Kbeitz and run a jack shaft. Means 2 more bearings and another shaft but less headaches.

matt_K98 · May 14, 2016, 07:32:17 PM

It worked out better than I thought it would. Just tapped the pulley off with a hammer then oiled it up and slid it down the shaft, a key way was already cut so I put a key in and taped it into place. I left about half an inch clearance between the pulley and the steel plate that the pillow block bearings are bolted onto. Measured the clearance and there's only around 3" of shaft sticking out. I am using 1 1/4" rod for the shaft so it should be fine.

I also Centered the engine and using a level I aligned the pulley with the clutch, instead of using a 50" belt I now have to use a 70" belt. Only thing left to do is to drill some holes into the frame to mount the engine.

Ljohnsaw · May 14, 2016, 10:15:33 PM

Congrats! You are back in business! 8)

Ox · May 14, 2016, 10:43:24 PM

Gotta love it when a plan comes together! A belt and some holes to drill ain't bad for fixing up a bad thing.

matt_K98 · May 26, 2016, 01:39:49 PM

Been really busy and haven't had much time to post an update on the mill. I have made a few major changes, the mill was a little front end heavy and would want to tip if it hit a bump, so I cut the legs off and just centered the tubing, this seemed to fix the issue and it is a lot more stable. To slide the engine up more I had to weld another 3.5" tube onto the front, I had to shim on top of the tube so the whole platform was level. I got a small piece of 3/16" steel sheet and welded it onto the tube to make it level, but the sheet was so thin and the heat was making it warp and it never worked out for me, so I decided to just cut the whole platform off and buy a 1/4" thick sheet and weld it back on.

Here is a picture of what I have done with the legs and platform.

I put the wheels on and alligned the pulley to the clutch on the engine then mounted the engine onto the platform.

I was messing around with the winch lift and the way I had it setup was not ideal, the handle on the winch would hit the engine and I could only raise the platform about half way. So I started to think of a new way I could get the winch to work. I ended up mounting the winch on the top and run the cable through the steel tube, this fixed my issue with the handle hitting the engine but now I had a problem with the cable rubbing on the winch.

Here is a picture of the winch on the top.

You can see The hole I drilled for the cable to run through is big enough that the cable doesn't rub, but the cable is rubbing on the bolt that's on the winch, I believe this is because all the weight is pushing on the bolt and when the winch turns the cable digs into the bolt, so I was thinking of putting a pulley so the cable runs on the pulley instead of the bolt. I can't use a wall mount pulley since the cable is feeding through the tube, so I need to find a way to install a sheaved pulley.

If anyone has an idea that would work better, or any tips would be appreciated.

Kbeitz · May 26, 2016, 06:46:35 PM

I would get one like this. The handle will then be in the front and you
wont need to worry about the handle flying around and removing skin.
When you let go of the handle it stays put. I also started out with one
like yours.

matt_K98 · May 26, 2016, 06:56:06 PM

Quote from: Kbeitz on May 26, 2016, 06:46:35 PM
I would get one like this. The handle will then be in the front and you
wont need to worry about the handle flying around and removing skin.
When you let go of the handle it stays put. I also started out with one
like yours.

That winch looks like it would work a lot better than the one I have now but the only one I can find around my area is $90, I really don't want to spend that much, if I can make the winch I have now work then I would prefer to do that.

Kbeitz · May 26, 2016, 06:59:45 PM

Got mine from E-bay....
You coulg hook on a large chunk of angle iron and mount your winch on sideways
with the handle sticking out front.

Ox · May 26, 2016, 07:45:25 PM

Maybe drill holes opposite each other just above the bolt you don't want the cable to be on, put a sacrificial bolt through the holes and have the cable chew up that bolt? You'd need to keep it oiled or greased to make it better on the cable. I know this may be crude, but my life has made me think this way first - simple and cheap.

matt_K98 · May 27, 2016, 12:56:46 PM

I've been working a little more on the winch and I think I found a solution.
I ran into another issue today, the centrifugal clutch is grabbing the V-belt when the engine is idling. I'm not sure if there's a problem with the clutch, or the belt is to tight. The clutch is new and has never been used so I don't see why it would be the clutch, and the belt doesn't feel like it's too tight, so I'm lost to what is causing it to grab.

Ga Mtn Man · May 27, 2016, 02:28:40 PM

Perhaps your idle is too high causing the clutch to partially engage?

matt_K98 · May 27, 2016, 03:07:24 PM

The clutch Engages at 1800 RPM, and my engine has a max of 3500 RPM, so at idle the engine should be around half of that, so the clutch should be borderline of engaging.

I find that when I loosen the drive belt the clutch won't spin, but if I tighten the belt the clutch engages.

Ljohnsaw · May 27, 2016, 03:56:37 PM

Quote from: matt_K98 on May 27, 2016, 03:07:24 PM
The clutch Engages at 1800 RPM, and my engine has a max of 3500 RPM, so at idle the engine should be around half of that, so the clutch should be borderline of engaging.

I find that when I loosen the drive belt the clutch won't spin, but if I tighten the belt the clutch engages.

You should be able to get your idle down to 600 rpm. If the clutch is "almost" engaging at your idle, then you are going to wear it out too soon.

matt_K98 · May 27, 2016, 04:01:36 PM

How do I lower the RPMs without the engine stalling ?

Ljohnsaw · May 27, 2016, 04:05:31 PM

Is it already just above stalling? If so, the you can't do much more. I was just saying if you haven't already tried, back out the idle screw until it's just popping over. The other thing you might need to check - if the carb has a low idle jet, you might mess with that a little to smooth out the idle as you get it lowered.

matt_K98 · May 27, 2016, 04:13:14 PM

The idle screw doesn't seem to be making much of a difference, I can take the whole screw out and it will still spin.

matt_K98 · May 27, 2016, 04:44:43 PM

The clutch felt really hot, so I took off the cover. Does anyone notice anything wrong?

Ox · May 27, 2016, 05:29:14 PM

You can get heavier springs for that clutch that will allow the clutch to not engage until at a higher RPM. They're cheap.

Kbeitz · May 30, 2016, 11:58:20 AM

When I have a clutch like that grab I just put a few drops of
Oil on it. Never had a problem doing that.

matt_K98 · May 30, 2016, 06:56:02 PM

I removed the clutch completely off the shaft and cleaned everything. I wanted to make sure that the issue was with the clutch springs, like Ox said. So I put the clutch back on so I could see the springs when the clutch is engaged. Started the engine and the clutch engaged On idle, so that explains why My clutch isn't working properly.

I will have to purchase different clutch springs.

grouch · May 30, 2016, 07:56:28 PM

Kinda late seeing this, but just in case anyone else needs the info...

Surplus Center has ACME threaded rods and nuts.

Ox · May 30, 2016, 09:29:34 PM

I wanted to see a centrifugal clutch work when I was a kid. Took the outer housing off and started her up. I had the throttle linkage hooked up temporary and forgot to take it off, causing the engine to speed right up when started. That clutch engaged, alright! The shoes and the big long spring in those days went flying all over the barn. Took me a while to find all the parts again. You guys are the first to hear this story, I think. I'd forgotten all about it until today.