DIY Scrap Iron Bandsaw Mill

[RetiredTech]

  I bought a 100amp PWM to slow the winch down while lifting the head so I can more accurately stop on the correct mark. It's a little easier since I changed the winch to a double line setup, but it still moves too fast. Unfortunately, it will not fit in my control box so I'll have to find another box to mount it in.  I'm a little concerned about heat build up around the controller. I see it has a fan cooled heat sink in it. I don't know how well it will hold up in a sealed enclosure or a dusty ventilated one. I'm going to give it some more thought before I jump into it. I may need a ventilated enclosure with a fan mounted near the top and filters to keep the inside clean. Am I over thinking this? I assume the fan would only run when the winch is moving. How much heat does it really generate? Summers get pretty hot down here. I don't want to fry the thing. One other problem I see is the rocker switch that comes with it to reverse directions is very small and flimsy. I'll probably get a SPDT toggle switch to replace it.

[fluidpowerpro]

I've used a similar 40/60 amp unit for a number of years now. It's not fan cooled. I have as far as I know never had any heat related issues. I would place a higher priority on keeping dirt out compared to ventilation. When choosing an enclosure. I would use steel over plastic because steel will dissipate heat better.

[RetiredTech]

  When I ordered this PWM the photo had individual heat sinks and no fan. I guess I was shipped an updated model. This one has a single square heatsink with a fan about the size of the ones we used on the original pentium  cpu's. I ordered two of these so I would have a backup just in case.
  Just thinking out loud. I'd like to use the old winch relays and only use the PWM for raising the head. I'll have to tear into the winch solenoid and see how it's built. It may not be possible without new solenoids. That would eliminate the rocker switch altogether and allow me to still use the wireless remote from the winch as well as the wired.

[fluidpowerpro]

You'll need to wire the winch motor direct to the pwm unit. You can do what you want on the control side such as replace the cheap fwd / rev switch that comes with the unit. At first I used an ATV winch rocker, but that proved to be not up to the duty cycle of a mill. I ended up using a heavy duty toggle switch  with a rubber boot. You can also wire in the remote control unit in that circuit, but I question the need for remote control on the up and down, unless you also add power feed.

[jpassardi]

I have done the same as FPP: 2 - 60 amp PWMs in a closed box. 1 for up down, 1 for power feed. Replaced switches with rubber booted toggles, the supplied rockers are unreliable. No issues with heat.

[RetiredTech]

  Well, I ruined another band yesterday trying to saw my backstops down. That's at least three so far. I decided it was time to try to get a heads up before I mow another one down. A couple teeth are completely gone on this one and it was on the mill less than 15 minutes. I don't think the sharpener is going to do it any good even if I had it working.
  I decided to try to add something to the bark guard of the stationary blade guide. That way if I had to remove it I can just remove the two bolts holding the guard on. Easy enough, but not so easy that I would remove it instead of trimming a bump off the log with saw. Because I know I would forget to put it back on until I mow another back stop down. If this doesn't work I'm going to have to go to wooden back stops. ;-) This can get expensive quick!
  It's really just a scrap cut off of a square tube. It looked like a piece of 2" angle iron when I first picked it up. I trimmed it up a little and added a gusset at the top for a little extra strength. Presto chango we have a Blade saver. I even gave it a little paint.

















It's a maybe a 1/4" behind the face of the backstop. I may have to trim it back a little more. I haven't had a chance to test it out yet. Maybe tomorrow. Wish me luck.

[thecfarm]

I might of said this before.
Looks like your stops go straight up and down?
I put inch marks on mine. 4 inches is really 3 inches and 6 inches is really 5 and so on.
If I set my head at 8 inches and my stops at 8 inches, I know I have an inch to spare.
But does not help if I set them at 10 inches and then change my mind and drop the head down to 8 inches and start to saw!!!  :

[RetiredTech]

  Yes they are fixed vertical. I have a pair of swing up stops I want to mount on the other end of the mill. That's where most of the sawing will be done once the mill is moved. I have thought about marking the height on the stops. It looks like a good idea. I knew where they were. I lowered the one at the beginning of the  log and got distracted and had to leave for a minute. I came back and started sawing without even thinking about the other end. I think I need the extra level of safety. It gets really aggravating after the first time or two.
  How often do you have to repaint the lines on your stops? Or do you make a shallow cut in the stop and paint that?

[Ljohnsaw]

Mine are marked with shallow cuts... Lots of them right at the top and down to about 1"  :

I used metal stamps and put the 1" less stamp just above the level. That way, when visible, I'm good. I have them marked to about 14" or so.

After stamping, the adjoining metal is raised. I hit it with a flap wheel. That makes the outline of the number shine . I then paste wax my sliding gear once or twice a year.

[Magicman]

You will find that you do not need the high side supports as much as you may think after you get one and especially two sides of the log flat.  In the picture below they are seen well below the final cut.

With sharp blades there is not much side load as you are sawing.



 
My sawmill has ¾" blocks welded to the bed rails which is all that the cant gets for the saw through.  They are seen here before I made the final turn.

[Ljohnsaw]

I use the high sides to keep my 40" logs from rolling Over the tops!

[JoshNZ]

Great idea but I'm betting they get removed before long! I run that guide close down the side of a log so often it would drive me nuts.

I've been sawing nearly 4 years on my machine and I found I only ever really have the backstops in 3 places, down, 6" up, or "way up". For 6" up I'd grab the stop with the point of it butted into my palm/thumb muscle (at a crease of my hand or whatever - somewhere it felt familiar) and index finger pointed down touching the bed, this was safely short of 6" by a half inch or so I did that for years until I finally did paint some lines on it. Mainly because I employed some help and I wasn't so sure about his certainty of where his thumb muscle was hah xD.

Way up for giant logs you don't want to roll over (and it gets turned long before way up becomes a problem), all the way down once you have a flat face, and 6" up for standing cants up, and all other logs that aren't giant. For standing cants up 6" is all you'll ever need, if you position the wider face of it against the stops.

If the safety brackets you've designed don't cause you any grief that will be great but if not I would try to develop more of a routine or process that you go through, to prevent this happening.

[Magicman]

I use the high sides to keep my 40" logs from rolling Over the tops!

 
A 40" log will not roll over 4" of side supports.


 
And this was a 40" log.  Raise them to turn the log and then immediately lower them to below wherever the blade might be.

[thecfarm]

I only use the log stops when the log is round and to support the flitches.
I just use a black maker that wears off and then redo it.
The flitches is when they get the work out.  ;)
I stand up 6-8 and start sawing.
The inch marks helps out because I can hold the flitches better. Before I did the marks I would kinda be on the low side of supporting them.

[RetiredTech]

 Made a little upgrade to the sawmill. I've been having a problem with the head raising too fast to hit the correct measurement ever since I added the electric winch. I had added a pulley to the head to cut the speed in half, but it was still too fast. I bought a PWM motor controller but never installed it. I kinda wanted to keep it simple. What I finally did was to add a second pulley to the lift side to slow the winch even further. I should be about 1/3 full speed now. It made a big enough difference that I stop on the mark about 50% of the time now. That may be good enough. Time will tell. I also discovered that Minwax paste wax on my vertical posts really smoothed out the raising and lowering of the head better than anything else I've tried. I got the idea from a woodworking video I watched about planer that didn't smoothly.
  It's hard to tell from the photo what's going on with the cables. The cable leaves the winch and goes down around the pulley on the top of the saw head. It leaves the saw head and goes back up to the new/old pulley on the post below the winch then back down and attaches to the saw head.  The pulley at the bottom of the post is just to raise the other side. 
 I spent the day yesterday sawing some beetle killed pine. Not very productive, but the mill worked great. about 75% of the pine was already gone too far. Some actually had termites in the standing tree.

[RetiredTech]

  I finally bought the 14" pulley. I wish I would have bought it when I was building the mill. I hate having to recreate the hub. This should put me back on the torque curve for those big oak logs. Here's a picture of the pulley and the 8" wheel that will become the hub. It may have to wait for next winter to be installed. There's just too much going on right now.

[Crusarius]

can't you just drill holes in the pulley to make your hub? May need to add some gusseting to prevent cracking but it should work.

[RetiredTech]

@Crusarius I'm afraid not. I built my mill from an old trailer axle. The pulley mounts to the back side of the hub and has to be spaced back far enough to clear the tire. I looked for a picture of the current 12" pulley mounted on the mill. The only one I had only showed half the pulley. But this is a picture of the 12" pulley I'll be replacing. There's a 3/4" spacer between the pulley and the axle hub.
  I knew the 12" pulley was too small, but at the time I could get it locally fairly cheap. I had originally wanted a 13" pulley and thought the 12" wasn't that much smaller and should work OK. It does work, but coupled with the 4 1/4" engine pulley and 21.5" tire diameter it runs a little fast. I guess it's not too bad, but it does bog the engine when cutting bigger hardwoods. I looked for a smaller engine pulley, but it's mounted to the flywheel of the engine and I never found a source. It's just a pain to cut the pulley out and get it welded up to the wheel where it runs true.

[Magicman]

but it does bog the engine when cutting bigger hardwoods

Sawing wider widths puts more load on all engines.  I have constant control of my feed rate so the instant that I hear any drop in the engine's RPM, my fingers automatically react and slows the feed rate.  

I always push my feed rate to the maximum that my engine will handle regardless of the sawing width.

[RAYAR]

How often do you have to repaint the lines on your stops?

My log stops are painted yellow and I use a black permanent marker to mark them. Afterwards, I respray them again and the marks bleed through, Now you have to use a solvent/oil based paint for the marks to bleed through, they will not bleed through with a water based paint.

[RetiredTech]

 @RAYAR That sounds like a good idea too. I never got around to marking the stops. I made the little bracket to contact the stop if it's to high. That along with the suggestion to lower the stops to just above the bed after the second side is cut has worked out great for me so far. I have had to trim an occasional knot or root flair but I have not sawed another stop! My record was 2 in one day.

[RetiredTech]

 I'm starting to feel like a sawyer! I finally sawed through some metal that was not a part of the mill!

[Magicman]

Congratulations !!     Your blade lost that battle.