Faster UP for older woodmizers

[pineywoods]

I have an older model manual woodmizer LT40. I saw mostly 4/4 barn boards. I don't off-bear, just saw the whole cant by dropping lower on each pass, leaving the previously sawn boards on top. this requires a lot of up-down travel of the saw head. Doesn't take much off that to start wishing for UP that goes as fast as down. Here's a cheap simple fix that requires no modification to the mill.

Here's the parts---

       
A stretch type garage door spring, 4 ft of 3/16 steel cable, and a bracket made of 1ft piece of 2 inch pipe and 2X2 angle. 2 pulleysare bolted to the angle iron. I used what I had in the shop, clothes line pulleys would work fine.

The whole works fits in the top of therear tower like this..
       

One end of the cable attaches to the head by threading through a hole here..

   

The cable goes over the pulleys and attaches to the upper end of the garage door spring. Bottom of the spring attaches to the head hold-down loop like this

     


Works like a champ...cost zilch if you have a decent junk pile...
   

[musikwerke]

Ingenious design and out of the way too.
I couldn't live without my junk pile.

[Bibbyman]

Looks great!  Besides going up faster,  I bet it takes a lot of strain off of the up/down chain and drive system.

Just wished you'd thought to add your post to the "Usefull Sawmill Mods".  :'(

[pineywoods]

There's an added benefit that I didn't mention. It cuts the current drain of the lift motor about in half, saving some precious amps for another project I have in the works.

[Bibbyman]

One thing I'd probably do is slip a piece of PVC or the like over the spring.  I'd hate to get some pink body part stuck in it as it retracted. 

Say,  maybe the spring could be dropped down inside one of the frame tubes?  Ya'think?

[pineywoods]

. from Bibby Say,  maybe the spring could be dropped down inside one of the frame tubes?  Ya'think?
.
Be easy enough to do that, I'd have to clean the old dirt dauber nests out of the tube

Already found one unusal side effect... at certain hights, the spring resonates with the vibrations  of the motor and it twangs like a plucked getar string ;D Bet I have the only musical mizer  ;D

[Bibbyman]

Maybe that's why WM uses air springs to counter the weight of the head on the LT15?

[beenthere]

Drop a safety cable down the center of the garage door spring, just so it contains the pieces can fly everywhere when (if) the spring reaches the fatigue level and fails.
A neighbor narrowly missed a face make-over when one of his springs failed, and it only took a chunk out of his ear.
Hiding it in the tube is good too.

[brdmkr]

I don't even have a band mill, but I still enjoy reading about how folks fix problems or make things better.  That was a great idea there pineywoods 8)  Thanks for sharing.

[MartyParsons]

Like Bibby said, Wood-Mizer uses a Gas charged shock as an assist for the LT10, LT15 and the LT70D. The electric LT70 does not need the assist. The LT70 assist is in the Mast or tube like you guys are talking about.
I like the spring idea.
Marty

[Dave Shepard]

I get frustrated with the slow up/down on our manual LT40 as well. I discovered that you can just reverse and slide the blade under the board and then drop down for the next cut. Sometimes you do have to hold the board so it doesn't slide off, but it works really well. If I am sawing a lot of 4/4, especially short and narrow stuff, I like to saw several boards and then tail them, as I have to carry them outside, it really saves a lot of time. When I have someone tailing for me, they better hurry up get back inside and get the next board, because I don't stop sawing except to turn the log. Unless they need help with a heavy slab.

I know I have some drag issues to work out with the gasser, as it is way slower than the electric, but when I get them addressed I am going to look into this setup. Thanks pineywoods.


Dave

[Dan_Shade]

I've found that sawmilling is like wanting a faster car.  If I win the lottery, I'll have a nitro powered sawmill!

[brdmkr]

I've found that sawmilling is like wanting a faster car.  If I win the lottery, I'll have a nitro powered sawmill!

I know what you mean, but lately I have been paying close attention to where my time bottlenecks are.  I saw by myself, and material handling (logs, slabs, lumber, sawdust) is by far my big time sink.  Sometimes I think I could triple my output if I could cut my handling time in half.

[DWM II]

Thanks Pineywoods, thats a mod I can definatley (sp) use.

[pineywoods]

An improvement update. After using the spring assist, I came up with an improvement. When the head was higher than about 18 inches, the extra lift wasn't much. Added a pulley and another spring. Both springs attach to the bottom of the pulley bracket. More lift and it's consistent over the full range of head travel.


 

[Ocklawahaboy]

On my particular mill, the down is faster than I would like. It seems the minimum drop I can do is about an inch.  Does this modification make the down action more controllable?

[pineywoods]

On my particular mill, the down is faster than I would like. It seems the minimum drop I can do is about an inch.  Does this modification make the down action more controllable?

Nope, won't help much, BUT, Like everything else involving a sawmill, there is a learning curve. Trying to stop the head where you want it when dropping down is an iffy situation at best. There's too many variables. IE water tank and fuel tank empty or full? When was the last time the rails were lubed? What most of us do is try to stop somewhere close but a bit lower than the desired point. Then jog back upward in short bursts..The accuset /simple setworks option adds electronic speed control to the head up/down motor so it can stop exactly where needed.
However there's a little more to it. Likely, here's what's going on. The up/down drum switch has an extra set of contacts that are closed when the control handle is in the neutral position. They short across the motor, causing it to act like an electrical brake. If that contact is not functioning, what you will see is the head may coast down 2 or 3 inches after you release the handle. Normally the head should stop downward travel within 1/4 to 1/2 inch after releasing the handle.  Fix is easy enough, pull the cover off the control box and adjust or clean the contacts so they close completely with the handle in the neutral position. Only one set of contacts involved. All the others should be open

[Chuck White]

Thanks for posting your 2-spring mod, Piney!

Can't really tell, but is the second spring inside the main "garage door spring"?

With the sawhead all the way down, how far up would you stretch the spring before connecting the cable clamp?

[pineywoods]

[quote author=Chuck White link=topic=27272.msg938995#msg938995 date=1358287996

Can't really tell, but is the second spring inside the main "garage door spring"?

With the sawhead all the way down, how far up would you stretch the spring before connecting the cable clamp?
[/quote]

Nah, nothing so sophisticated, the 2 springs are side by side, just alike, matter of fact, they both came off the same garage door ;) That's where the pulley came from also.

I cheated on the hookup. Raise the head all the way UP, the pull some pressure on the springs. They will stretch some more when you lower the head. Might be advisable to string a piece of small cable through the center of the springs, leave it loose and fasten each end securely. Serves no functional purpose, but will retain the pieces if one of the springs breaks.

[Chuck White]

Thanks Piney, I really appreciate your post!

[Chuck White]

Well, I finally got pics of the Pineywoods lift-assist mod!

Top of Lift-Assist


Bottom of Lift-Assist


Pineywoods Lift-Assist


Nothing at all difficult about this mill-mod!

Thank you Pineywoods

[WoodenHead]

How old does your mill have to be to use this mod?   ;D  My LT40 is a 2006 and at the moment I don't have either the simple setworks or Accuset.  I hope to upgrade to one of these in future.  Do you think there is still value in adding the spring(s)?  Will this mod interfer with simpleset or accuset?

[pineywoods]

Probably wouldn't do much for the newer woodmizers. The older mills had no external alternator, depended on the small alternator built into the motor flywheel. With limited electrical supply, the up/down and feed motors are small to keep the current drain to a minimum. Don't know what year the changeover to external alternators and bigger head motors was made, my guess would be `1997. This mod has the effect of reducing the head weight by 50-100 pounds, thus making life easier and faster for the head up/down mechanism.

[Chuck White]

My mill has a 105amp automotive alternator.

The reason I added the Pineywoods assist kit was I was going through a couple of sets of up/dn motor brushes per year!

The previous owner installed the debarker (which I just love) and it added quite a bit of weight to the sawhead, therefore causing more draw to the up/dn motor!

[WoodenHead]

If your up/down goes slower than mine, then I can certainly see why you did this mod! 

I do have the external alternator.  I was thinking of adding the mod to hopefully speed things along on the upwards movement.  The manual up/down crank of the LT28 was much, much faster!  Yes it took a little effort, but only a few seconds (even for large movements).  I also like the idea of relieving the load on the motor a bit. 

I'm not sure if the up/down motor of the super hydraulic will fit or not.  Maybe that is the way to go instead.