Need advise on my sawmill project

jpassardi · January 31, 2025, 06:54:34 AM

I believe a hockey puck will be too hard. I would look for a spring or dense rubber.

Hilltop366 · January 31, 2025, 08:51:01 AM

I have thought of a puck for that, I would be interested to see if it worked.

I'm thinking it would have to be held in a way that allowed it to expand as it is compressed.

I was thinking of mounting it by drilling a hole through it and putting it on a pin or bolt. If one would not compress enough maybe two stacked?

ktm250rider · January 31, 2025, 08:56:32 AM

I used a 50x64mm yellow die spring. I haven't confirmed blade tension yet, but all seems to run fine.

Hilltop366 · January 31, 2025, 10:07:19 AM

So curiosity got the best of me and I googled "compressive strength of a hockey puck" and came up with about 80000 psi to failure or breaking apart.

ladylake · January 31, 2025, 03:12:49 PM

Quote from: Hilltop366 on January 31, 2025, 10:07:19 AMSo curiosity got the best of me and I googled "compressive strength of a hockey puck" and came up with about 80000 psi to failure or breaking apart.

It needs some cushion, I dont think a hockey puck has mush. A spring is best by far. Steve

doc henderson · January 31, 2025, 03:35:52 PM

Timber king has such a spring that goes on the outside of my threaded rod, I think 3/4 inch. call and ask for Matt and they might sell you the spring, threaded block and even the screw and handle if you like. they are a sponsor, although they may consider it proprietary. @Will_Johnson

Ken Malone · February 01, 2025, 05:52:08 PM

Ken Malone · February 01, 2025, 05:54:04 PM

I'm going to try this. The die springs I have don't seem to be strong enough so I'm going to try using 2

Magicman · February 01, 2025, 07:17:48 PM

What about valve springs?

ladylake · February 02, 2025, 04:01:50 AM

You should use 3/4" acme rod, last a long time and tensions up easy. Yellow die springs are plenty strong, nothing wrong with using 2. Steve

jpassardi · February 02, 2025, 09:24:15 AM

I agree, use a square machine thread, not a bolt thread to minimize friction each time you tension the band.
Rather than guess at spring rate, I would either run the numbers to determine spring rate needed or give Cook's a call and buy a spring sized for a 1 1/4" blade. It will be worth the $25. In the end you'll spend more time and $ guessing.

RAYAR · February 03, 2025, 03:58:42 AM

I wouldn't use anything less than 3/4" threaded rod. People don't seem to realize just how much tension is actually needed to properly tension a bandsaw mill blade.

Ken Malone · February 22, 2025, 02:31:57 AM

I'm starting the rails today.Any thoughts on bunk spacing. The rails will be 16' long and the mill is about40" to front edge of blade.Thanks

ladylake · February 22, 2025, 06:00:50 AM

I'd make it to cut at least 16' , my bunks are 3' on center. Steve

jpassardi · February 22, 2025, 08:25:46 AM

I agree, note that if you plan to cut a 16.5' log you'll need at least 17' plus the carriage length. 3' bunk spacing at most and make one bay half that so you can mill a short log or cant if needed.

fluidpowerpro · February 22, 2025, 02:16:25 PM

You can't have too much extra space on each end. Unless your placing the log on the mill with a machine you will find that it's a real pain trying to get a log positioned exactly as you want it. They often don't roll straight off of the loader arms.
I've often wished I had roller toe boards because then it would be much easier to position the log.

Hilltop366 · February 22, 2025, 05:02:34 PM

The last few feet on one end or both ends could be made of a lighter material as it would only be required to hold the mill head and not a log.

If you are planing to make it portable it is not as good but the lighter made end(s) could also be made so they fold out of the way or easy to remove and stow.

Ljohnsaw · February 22, 2025, 10:57:01 PM

Look into making you bunks moveable. Could just make the end fixed and 2 or 3 moveable in the middle.

Ken Malone · March 03, 2025, 06:01:39 PM

Having trouble with tensioner. The shaft runs through 2 pillow blocks,when I apply tension to the blade I can't seem to get the blocks to travel the same so the idler wheel tows in.Any thoughts?

doc henderson · March 03, 2025, 08:54:42 PM

Ken, I reviewed your diagram, can you post some pics of the actual parts? I do not see the pillow blocks in the diagram/blueprint.

how does it pull the wheel?

doc henderson · March 03, 2025, 09:01:02 PM

My idler shaft is built with adjustments to the wheel and on a slide that moves. the thread is on the bracket to the wheel, and it slips against the frame on the other end. no bearings. it is hard to explain.

fluidpowerpro · March 03, 2025, 11:06:47 PM

Preferably the pillow blocks are mounted to a common structure and bolted down tight. The tensioning device then acts on that common structure to move both pillow blocks equally.

Each pillow block can have jacking bolts to adjust tow/tracking, but once that's adjusted, the pillow blocks are bolted down tight.

You don't want to be screwing around with adjusting tracking every time you tension your blade. That would get old real quick.

Ken Malone · March 04, 2025, 04:10:18 AM

Does this make any sense?

Ken Malone · March 04, 2025, 07:00:11 AM

This is my set up

Ljohnsaw · March 04, 2025, 11:13:45 AM

Ken, here is my setup.

The big plate with the 4 holes is welded to the 2x2x¼" tubes that make up that sort of "n" shape. On the near end, pass through the 2½x2½x¼" collars. There is a third one further back on the right. The collars are attached to the head frame.

Near the rear of the "n" shape you can see the bolts holding the pillow blocks. Not visible is a tracking adjustment. To tighten the band, a little hydraulic puck fits behind the heavy plate and the head frame, peaking out from behind. The ½" screw at the top of frame is hand tightened to hold the tension and the puck is removed.

To release tension, pump up the puck again, loosen the ½" screw and release puck and remove. Usually it is slightly cocked and stuck. A tap on the plate usually pops it free.

Here is the tension locking bolt.

If you don't have a hydraulic puck, you could use some ACME rod here. On my first mill version, I used some rod from a scissor jack. Worked ok but finally blew out the thrust bearing.

This is the drive side but same setup for tracking on the idle side.

The four big bolts clamp the top and bottom blocks to the rails. The pillow blocks are attached to a frame welded to the bottom block. There are two pieces of all-thread going through the end plate and the bottom block. I lengthen or shorten one side to adjust tracking.