I've gotten the wheels for my mill from Cook's, and they mentioned the need to be able to tilt them forward and backward as well as left/right. I've designed a mechanism that will allow me to do the left/right adjustment for blade tracking easily. I've figured a way to tilt the wheels forward/backward to change the down-angle of the blade as they suggested, but it makes the whole thing vastly more complicated. I'm wondering how often this down-angle adjustment is required? Is it infrequently enough that I could get away with shimming a bolt system, or should I go forward with the hinged adjustment similar to a tracking mechanism?
Thanks,
If your talking about the guide wheels I did not make adjustments for anything
but up and down and in and out. I have not seen where I need any other adjustment
so far.
(https://forestryforum.com/gallery/albums/userpics/39553/Dog_stopper~3.JPG?easyrotate_cache=1479675522)
I believe he is referring to the band wheels. Once set you should rarely if ever have any need to adjust the forward/back tilt.
On my large wheels I only have adjustment for tracking...
Why would you want to tilt them forward and backward ?
Simple is good. Shims should be adequate for the tilt.
Instead of bolts and shims I would go with two bolts side by side, one pulls the pieces together and the other pushes them apart. That way you can make very fine adjustments and do adjustments while there is a load on the joint.
I've never had to adjust again after the initial setup. I would use shims for simplicity.
My drive wheel is not adjustable. I guess the put in on right the first time. The idle wheel can be tilted right or left.
Yep- I was referring to the band wheels. I just assumed that the guide wheels should be in a plane at right angles to the vertical plane of the band wheels? Right? The guys at cooks hinted that being able to adjust the down-angle of the blade would allow some 'tuning' that would be necessary to cut quickly. If that's just a once-in-a-while thing, I'll definitely use shims instead of hinges/pivots and control bolts!
Thanks!
The vertical tilt of your blade guides should be adjusted so that the blade is parallel to the bunks on your mill frame, regardless of the tilt of the band wheels.
The ability to tilt the bandwheels is for tracking purposes. As GMM stated above, blade guide adjustments have nothing to do with the bandwheel adjustments.
Quote from: wooddust on November 20, 2016, 03:34:26 PM
I've gotten the wheels for my mill from Cook's, and they mentioned the need to be able to tilt them forward and backward as well as left/right. I've designed a mechanism that will allow me to do the left/right adjustment for blade tracking easily. I've figured a way to tilt the wheels forward/backward to change the down-angle of the blade as they suggested, but it makes the whole thing vastly more complicated. I'm wondering how often this down-angle adjustment is required? Is it infrequently enough that I could get away with shimming a bolt system, or should I go forward with the hinged adjustment similar to a tracking mechanism?
Thanks,
The adjustment you speak of is important as I learned about a year ago. I would adjust my lt70 blade guides to correct a misalignment of the bandwheels concerning the top /bottom adjustment. When cutting a difficult species such as Sitka spruce, my blade would deviate/wave/annoy etc until this adjustment was corrected. I'm no engineer so I don't understand the forces at work here but once this adjustment was done proper, my mill cut the Sitka spruce very well. I only made this adjustment once in 10,000 hours on my mills hour meter. I think shimming would be sufficient.
Thanks for the replies! They've led me to a few MORE questions!
1) Is this down-angle adjustment necessary when switching species/characteristics of wood being sawn?
2) If the blade guides are adjusted to be in a parallel plane to the bunks/deck instead of a plane perpendicular to the plane of tilt of the bandwheels, then how does tilting the band wheels forward or backward affect the cut?
3) Is it necessary to be able to perform this tilt adjustment to the drive and tension bandwheels individually, or should I attempt to keep them at the same tilt, and adjust them simultaneously by shimming the entire beam assembly?
Also, sort of related,
4) do I need to be able to 'toe out' the drive band wheel just like the tension/idle bandwheel for tracking, or is it acceptable to 'fix' that one?
5&6) If so, is it fixed parallel to the beam running to the tensioner bandwheel, or is it fixed at a predetermined toe-out/tracking angle? What is that angle?
Thanks again!
1) As said before, this would be something you would adjust once and likely never touch again.
2) There will be slightly more pressure on the back of the blade (from the blade guides pushing down), making the blade less likely to climb (or dive?, check Cooks' to confirm this) in the cut. Cook's is the only manufacturer that I know of that recommends this. I believe others just plump the wheels. I'm not sure of this though.
3) It doesn't matter how you get there so long as both wheels are the same.
4) You can get by with being able to adjust only the idle side but you may have trouble getting the blade to track in the same position on both wheels.
5,6) I would start with both wheels parallel to the beam and coplaner and only adjust the drive side if necessary to get the blade tracking evenly on both wheels
Quote from: Kbeitz on November 20, 2016, 03:58:53 PM
If your talking about the guide wheels I did not make adjustments for anything
but up and down and in and out. I have not seen where I need any other adjustment
so far.
(https://forestryforum.com/gallery/albums/userpics/39553/Dog_stopper~3.JPG?easyrotate_cache=1479675522)
I find those guide wheels wear cone shaped and need to be tilted down when they do or buy new guide wheels. Steve
When it comes to the blade guide wheels you also want both blade guides angled slightly towards the idle band wheel. That way when the back of the blade makes contact with the flange on the guides it is contacting on the side that is going up which helps keep the blade from diving.
2) If the blade guides are adjusted to be in a parallel plane to the bunks/deck instead of a plane perpendicular to the plane of tilt of the bandwheels, then how does tilting the band wheels forward or backward affect the cut?
The closer the band wheels are perpendicular to the deck the less correction work the guides have to do. The up and down tilt of the band wheels may also be needed for getting the blade to track properly but in my opinion the side to side tilt of the band wheels is much more important for tracking (and on my mill, which runs on trailer tires, gets adjusted nearly every time I run the mill)
3) Is it necessary to be able to perform this tilt adjustment to the drive and tension bandwheels individually, or should I attempt to keep them at the same tilt, and adjust them simultaneously by shimming the entire beam assembly?
I think I would make them individually adjustable. But since the up and down tilt doesn't need to be adjusted often I would make those adjustments with shims if it is easier.
4) do I need to be able to 'toe out' the drive band wheel just like the tension/idle bandwheel for tracking, or is it acceptable to 'fix' that one?
My mill has 20 inch wheels and I would guess the drive wheel is toed out 1/8 inch or so and I haven't adjusted it since the first time I got a blade to track. Even though that one doesn't get adjusted any more I would have never been able to get a blade to stay on if it wasn't adjustable at first.
Both L/R and vertical tilt adjustments are part of the full alignment which I do once a year on my LT40. Very little adjustment but one needs the adjustment to be available. I would think shims would be fine.
I used shims under the pillow block bearings to adjust vertical tilt... simple is good!
Cooks has a very good vid. that will help you all,going to go find it for you...Ok listen to this guy...
https://www.youtube.com/watch?v=5u73MNTPnWg
Nice! I want one.
Now I really liked that video...