Tensioning method for homemade bandsaw mill

Ljohnsaw · May 12, 2016, 07:08:53 PM

Quote from: matt_K98 on May 12, 2016, 05:06:50 PM
That sounds like a good idea!

Now do you think it would make a difference if I mounted the rod in the center of the plate or near the front that way I can use a bolt on the back end to adjust the toeing.

Here is an example of what I mean,

Sure would. I just figured you could use the same holes with longer bolts. If you wanted to get real clever, figure out some sort of cam system. You flip it "off" to change your blade and back "on" to go back to your preset toe setting and tension.

matt_K98 · May 12, 2016, 09:15:24 PM

In regards to the tires I am using, what PSI would be ideal? I measured the PSI and they were both around 20-25 PSI, I decided to put 50 PSI in both tires and the blade seems to stay on the tires a bit better. The blade still wants to wander off the front but I have yet to fine tune the toeing so that may be the issue.

Ljohnsaw · May 12, 2016, 11:56:44 PM

What kind of tires? What is the recommended tire pressure on the side wall? I'm running mini doughnut spares that are supposed to be at 60psi. If I don't run them at a high pressure, they don't track well.

matt_K98 · May 13, 2016, 06:49:12 AM

I'm just using some small trailer tires, 4.80-8 I believe, with a max load rating of around 600lbs.
On the wall of the tire it's saying 60 PSI, I'm not sure if that's the recommended or max PSI though.

I will check the tire size to be sure. I have the intentions on eventually switching to cast or metal wheels. I was on a tight budget with everything else that I had to do so these tires were the only thing I could find in my price range.

Went outside and looked at the tires, they are actually 4.80-8

Ljohnsaw · May 13, 2016, 11:00:38 AM

On trailer tires, the max psi IS the recommended psi. They need the pressure to maintain the rigid sidewall for trailering - can't have sidewall flex or they overheat and you have a blowout. So, I would recommend you run no lower than 50 or 55 psi and 60 if you can (the blade tracks ok). Then they will also have a good crown for the blade to rid on.

matt_K98 · May 13, 2016, 11:35:36 AM

I messed around with the toeing a bit more and the blade seems to track near the center of the tire. Not perfect but looks "OK" for this moment.
I'm not sure if there is to much of a crown and the blade wants to just slide onto the ends?

matt_K98 · May 13, 2016, 12:55:49 PM

Thought I would just share some pictures of the blade tracking on the tires.

Here is the crown on the tire, the blade has a hard time running ontop of it.

Here is the blade on the drive wheel, the blade is running almost at full speed.

Here is the idle wheel, also running around full speed.

This is where the blade sits after I stop it.

I need to build some guards for the blade but just for now I will be extra careful.

PC-Urban-Sawyer · May 13, 2016, 01:20:36 PM

Quote from: matt_K98 on May 13, 2016, 12:55:49 PM

I need to build some guards for the blade but just for now I will ~~be extra careful~~ hope that I can outrun the blade if it jumps off and tries to cut my arms off.

There, fixed it for you.

All kidding aside, you should really get some guards made and in place before something bloody happens.

Be Careful!

Herb

Ljohnsaw · May 13, 2016, 03:36:08 PM

Quote from: PC-Urban-Sawyer on May 13, 2016, 01:20:36 PM
Quote from: matt_K98 on May 13, 2016, 12:55:49 PM

I need to build some guards for the blade but just for now I will ~~be extra careful~~ hope that I can outrun the blade if it jumps off and tries to cut my arms off.

There, fixed it for you.

All kidding aside, you should really get some guards made and in place before something bloody happens.

Be Careful!

Herb

Don't worry, he still has the blade on backwards so it won't cut him :D

As far as the tracking goes, looks pretty good. Would be interesting to see if putting the blade on in the correct direction would change anything.

Ox · May 13, 2016, 08:48:20 PM

The blade is turning the right direction for the engine rotation...it's just like my mill.

Looking at the PTO it turns counter clockwise.

If nobody is ever going to be around the mill, it's safe. But running a mill you have to be around it. No joking - blades can almost explode sometimes. For a test run I'd run without guards, but milling I'd want them. Just sayin'. :laugh:

Magicman · May 14, 2016, 09:05:30 AM

Quote from: Ox on May 13, 2016, 08:48:20 PMNo joking - blades can almost explode sometimes.

Yup, nice description. I once had a blade to break into two different pieces. We found ~18" piece lying on the ground beyond the log loader. Depending upon where it breaks, it can do some awful stuff. Two weeks ago I had another end that came put of the sawdust chute.

matt_K98 · May 14, 2016, 11:27:58 AM

Went to a local tractor supply store and priced out some steel for the blade guards, I will go back during the week to buy the steel I need, then I will start making the guards.

With the blade facing the right direction (I believe?) and tracking properly on the tires, I decided to start making the blade guides. I didn't have the money to spend on proper blade guides so for now I just used a good quality bearing with a bolt running through.

Ljohnsaw · May 14, 2016, 12:45:44 PM

Quote from: matt_K98 on May 13, 2016, 12:55:49 PM

This is where the blade sits after I stop it.

Quote from: matt_K98 on May 14, 2016, 11:27:58 AM
With the blade facing the right direction (I believe?) ...

Matt,
Just trying to help but I'm making some assumptions based on this picture. In the pictures with the blade running, I can not tell what direction things are going. So in the picture above, the idle wheel is on the right, the powered wheel is on the left. The blade teeth (in order to cut) need to move from right to left on the top side, left to right on the bottom side.

IF that is the direction you blade is going on your mill, then you are PUSHING the blade through the cut and you WILL have annoying little problems with cut quality because the blade tension will vary as you cut.

IF, however, the blade is running the opposite direction (i.e. backwards), then all you need to do is turn the blade inside out so the teeth can cut and all will be good. I have not needed to turn a blade inside out, but I'm guessing it might be a tad easier with an extra hand or two - they are pretty stiff. I think MM described how to do it once, IIRC.

Joe Hillmann · May 14, 2016, 12:53:12 PM

I would recommend building your guards out of wood. You are going to make mistakes when sawing and your blade will come off. If you have metal guards your blade will at least need to be sharpened, If you have wood guards you can probably put it right back on and continue sawing.

matt_K98 · May 14, 2016, 02:42:26 PM

Quote from: ljohnsaw on May 14, 2016, 12:45:44 PM
Quote from: matt_K98 on May 13, 2016, 12:55:49 PM

This is where the blade sits after I stop it.
Quote from: matt_K98 on May 14, 2016, 11:27:58 AM
With the blade facing the right direction (I believe?) ...
Matt,
Just trying to help but I'm making some assumptions based on this picture. In the pictures with the blade running, I can not tell what direction things are going. So in the picture above, the idle wheel is on the right, the powered wheel is on the left. The blade teeth (in order to cut) need to move from right to left on the top side, left to right on the bottom side.

IF that is the direction you blade is going on your mill, then you are PUSHING the blade through the cut and you WILL have annoying little problems with cut quality because the blade tension will vary as you cut.

IF, however, the blade is running the opposite direction (i.e. backwards), then all you need to do is turn the blade inside out so the teeth can cut and all will be good. I have not needed to turn a blade inside out, but I'm guessing it might be a tad easier with an extra hand or two - they are pretty stiff. I think MM described how to do it once, IIRC.

The blade is spinning to the left, so the teeth on the top are facing towards the powered wheel and the teeth on the bottom are facing towards the idle wheel.
If that makes any sense to you?

The way I have it now looks to be right, but you obviously are more knowledgeable about this, so if you think the blade is backwards then I will flip the blade inside out.

Magicman · May 14, 2016, 02:56:03 PM

However it is, the teeth should be pointed toward the powered wheel and it should be pulling the blade through the log. The sawdust should be exiting the log/cant and passing the powered wheel.

The powered wheel can not push the blade through the log/cant.

matt_K98 · May 14, 2016, 03:37:52 PM

Quote from: Magicman on May 14, 2016, 02:56:03 PM
However it is, the teeth should be pointed toward the powered wheel and it should be pulling the blade through the log. The sawdust should be exiting the log/cant and passing the powered wheel.

The powered wheel can not push the blade through the log/cant.

The way I have it the saw dust will exit the log from the idle wheel side. So if the blade can't push through the log then I would have to reverse the engine somehow.

Ljohnsaw · May 14, 2016, 03:48:05 PM

Quote from: matt_K98 on May 14, 2016, 03:37:52 PM
Quote from: Magicman on May 14, 2016, 02:56:03 PM
However it is, the teeth should be pointed toward the powered wheel and it should be pulling the blade through the log. The sawdust should be exiting the log/cant and passing the powered wheel.

The powered wheel can not push the blade through the log/cant.

The way I have it the saw dust will exit the log from the idle wheel side. So if the blade can't push through the log then I would have to reverse the engine somehow.

Yes - if space permits, turn the engine 180° and mount the drive v-belt between your pillow blocks or right behind your drive wheel. If that doesn't work, then you will have to move the engine to the other side (idle wheel will become drive wheel) and you will have to re-work your belt tension setup so as not to compete with your drive belt tension setup. Better now than later!

matt_K98 · May 14, 2016, 04:16:10 PM

I wish I knew this before I mounted the engine haha, However... I think I will be able to cut a slot for the pulley belt then I will remount the engine on the same side.

tnaz · May 14, 2016, 04:36:48 PM

I believe someone stated above you can turn your blade inside out so to speak and put back on and that will fix your problem; I don't know??? Worth a try.
#64
IF, however, the blade is running the opposite direction (i.e. backwards), then all you need to do is turn the blade inside out so the teeth can cut and all will be good. I have not needed to turn a blade inside out, but I'm guessing it might be a tad easier with an extra hand or two - they are pretty stiff. I think MM described how to do it once, IIRC.

Magicman · May 14, 2016, 04:57:10 PM

Turning a blade is no problem. Just wear leather gloves.

matt_K98 · May 14, 2016, 04:58:00 PM

Flipping the blade inside out won't work for my issue unfortunately. I also went outside to have a look and there is no possible way I can turn the engine 180°, the way my platform is there is nowhere to mount the belt.

Engine on drive wheel side.

Engine on idle wheel side.

The only option I found was if I put the engine in the center and run the drive pulley right behind the wheel, I would have to move the wheels out more but I think it could work.

Kbeitz · May 14, 2016, 05:26:59 PM

If you could put in a longer shaft then all you would need to do is to turn the engine around...
Or you could do like I did and run a jack shaft.

Ljohnsaw · May 14, 2016, 05:43:12 PM

Quote from: matt_K98 on May 14, 2016, 04:58:00 PM

The only option I found was if I put the engine in the center and run the drive pulley right behind the wheel, I would have to move the wheels out more but I think it could work.

That looks very doable. Also, with the engine mounted in the middle, it will be a little more balanced with respect to your winch lifting the head.

matt_K98 · May 14, 2016, 05:56:03 PM

The only downside I can find with doing that is the shaft won't be as supported as it should be. The pillow block bearing would be 4-6 inches away from the wheel.