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headrig/carriage friction?

Started by Revival Sawmill, November 27, 2016, 02:59:46 PM

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Revival Sawmill

I am hammering out the design of the mill, and wondering how people deal with the friction of the headrig going up and down the vertical parts of the carriage?  I've seen on the cook's videos that many of their mills use a bushing traveling up and down a chrome shaft, and one guy on youtube had a really slick system of bearings that rode on the flat surfaces of his carriage posts.  Any thoughts on what's best?
Thanks,

ozarkgem

Mine rides on cam followers on the flat surfaces of the post. When I build mine I will use the polished rods. The thing there is there will be almost no tolerance to play with. The guides will have to be dead on for spacing. I don't like the play my mill has. I think is slows it down with the head not being rigid.
Mighty Mite Band Mill, Case Backhoe, 763 Bobcat, Ford 3400 w/FEL , 1962 Ford 4000, Int dump truck, Clark forklift, lots of trailers. Stihl 046 Magnum, 029 Stihl. complete machine shop to keep everything going.

Kbeitz

My vertical post was 1/4" thick x 2-1/2" tube square steel.
I sprayed dry graphite on the tubes thinking that I needed it.
Everything was a tight fit. The weight of the carriage was enough
to keep it from hanging up. After a while things loosen up to a
point that I added adjustment bearings to take out the play.
Everything works great now.




 






Collector and builder of many things.
Love machine shop work
and Wood work shop work
And now a saw mill work

york

My mill is an old TH and it has 1'' rods...If you use the head frame,it needs to be dead nuts,but then again it should be,anyhow...
Albert

Revival Sawmill

What about friction in the headrig/mainbeam thing for the tensioner?  The cook's guy talks about not liking the threaded rod with a torque wrench system because they sometimes 'bind out' with too much friction on the slide?
Thanks,

Den-Den

Quote from: wooddust on December 04, 2016, 02:40:35 PM
What about friction in the headrig/mainbeam thing for the tensioner?  The cook's guy talks about not liking the threaded rod with a torque wrench system because they sometimes 'bind out' with too much friction on the slide?
Thanks,

I have a minor issue with that; no problem when tightening but when I remove the tension, I sometimes have to give it a "tap" before removing the blade.  Perhaps I am just used to it but don't consider it a problem.
You may think that you can or may think you can't; either way, you are right.

Revival Sawmill

Quote from: Den-Den on December 04, 2016, 06:15:41 PM
Quote from: wooddust on December 04, 2016, 02:40:35 PM
What about friction in the headrig/mainbeam thing for the tensioner?  The cook's guy talks about not liking the threaded rod with a torque wrench system because they sometimes 'bind out' with too much friction on the slide?
Thanks,

I have a minor issue with that; no problem when tightening but when I remove the tension, I sometimes have to give it a "tap" before removing the blade.  Perhaps I am just used to it but don't consider it a problem.

Does your tension system ride steel-on-steel or are there bearings or bronze friction plates or something in there? Grease?
Thanks,

bandmiller2

My band mill uses 1" rod and bushings pressed into a section of Shelby tube. There are grease zerks on the Shelby once or twice a year they get a few shots. No problems, but if I built another mill I would try angle iron uprights with "V" castor wheels. The angle would be attached to upright 2" square tube and adjustable. Frank C.
A man armed with common sense is packing a big piece

Den-Den



Does your tension system ride steel-on-steel or are there bearings or bronze friction plates or something in there? Grease?
Thanks,
[/quote]

It is steel on steel.
You may think that you can or may think you can't; either way, you are right.

bandmiller2

Den, my mill uses bronze bushings on a steel shaft. Usually steel on steel is not as good. If a band head was perfectly balanced any play would be detrimental. Most have a preload and are adjusted to cut level in that position weight forward or to the rear. Frank C.
A man armed with common sense is packing a big piece

ozarkgem

Quote from: bandmiller2 on December 04, 2016, 08:25:15 PM
Den, my mill uses bronze bushings on a steel shaft. Usually steel on steel is not as good. If a band head was perfectly balanced any play would be detrimental. Most have a preload and are adjusted to cut level in that position weight forward or to the rear. Frank C.
Do you have an pics of this set up? is it polished rod? Also what is Shelby tube? I have had a machine shop for over 20 yrs and never heard of it.
Mighty Mite Band Mill, Case Backhoe, 763 Bobcat, Ford 3400 w/FEL , 1962 Ford 4000, Int dump truck, Clark forklift, lots of trailers. Stihl 046 Magnum, 029 Stihl. complete machine shop to keep everything going.

bandmiller2

OJ, sorry on the picture thing. Shelby tube is pipe with very thick walls its seamless drawn over a mandrel and very expensive, I used it because I had it. The rod is cold rolled steel. Frank C.
A man armed with common sense is packing a big piece

peterpaul

Perhaps eccentric cam followers riding against the post would work well.   The ability to adjust not only the clearance but also the "tilt" of the head would be simple and advantagous. Low friction and zero clearance. 
Woodmizer LT15, Kubota 4330 GST, Wallenstein FX 85, Timberwolf TW6, homemade firewood conveyor

Ljohnsaw

I used some UHMW pads in home-made brackets (2" x 4" x ¼" wall tube cut into C shapes).  My head rig ride on the inside of a pre-welded (scrap) shelving unit frame.  The gray things at the top of the picture:

 

"front" side of the bracket.

 
John Sawicky

Just North-East of Sacramento...

SkyTrak 9038, Ford 545D FEL, Davis Little Monster backhoe, Case 16+4 Trencher, Home Built 42" capacity/36" cut Bandmill up to 54' long - using it all to build a timber frame cabin.

Joe Hillmann

Mine is just a square tube inside a square tube that is a very sloppy fit.  On the outer tube I drilled holes and welded nuts over the holes.  Then I used bolts in the welded nuts to take up the slack between the two tubes. 

When the engine isn't running it tends to bind but the vibrations of the engine allow it to move smoothly.

ozarkgem

Quote from: ljohnsaw on December 05, 2016, 03:08:25 PM
I used some UHMW pads in home-made brackets (2" x 4" x ¼" wall tube cut into C shapes).  My head rig ride on the inside of a pre-welded (scrap) shelving unit frame.  The gray things at the top of the picture:

 

"front" side of the bracket.

 
What size motor do you run? Does it have enough power to pull the mill?
Mighty Mite Band Mill, Case Backhoe, 763 Bobcat, Ford 3400 w/FEL , 1962 Ford 4000, Int dump truck, Clark forklift, lots of trailers. Stihl 046 Magnum, 029 Stihl. complete machine shop to keep everything going.

ozarkgem

Quote from: bandmiller2 on December 05, 2016, 06:46:21 AM
OJ, sorry on the picture thing. Shelby tube is pipe with very thick walls its seamless drawn over a mandrel and very expensive, I used it because I had it. The rod is cold rolled steel. Frank C.
Ok DOM tube. I have quite a bit of that around. Has the Cold Rolled rod held up ok? I was thinking of polished rod but you talk about expensive!
Mighty Mite Band Mill, Case Backhoe, 763 Bobcat, Ford 3400 w/FEL , 1962 Ford 4000, Int dump truck, Clark forklift, lots of trailers. Stihl 046 Magnum, 029 Stihl. complete machine shop to keep everything going.

bandmiller2

OJ, its been 16 years and I can see no perceivable wear on the cold rolled rods. Theirs always a good coat of grease on them. Frank C.
A man armed with common sense is packing a big piece

Ljohnsaw

Quote from: ozarkgem on December 05, 2016, 06:26:41 PM
Quote from: ljohnsaw on December 05, 2016, 03:08:25 PM
I used some UHMW pads in home-made brackets (2" x 4" x ¼" wall tube cut into C shapes).  My head rig ride on the inside of a pre-welded (scrap) shelving unit frame.  The gray things at the top of the picture:

 

"front" side of the bracket.

 
What size motor do you run? Does it have enough power to pull the mill?
These were the only pictures I had showing the guides.  I don't have power feed, if that is what you are asking.  That is Version 1.0 of my mill :D

That was a 2.25 hp DC tread mill motor.  Worked ok for testing.

Version 2.0 I replaced that with a 7hp gas.  Worked better and I did some "serious" cutting with that.

 

Current version (3.0) has a 18hp twin cylinder B&S gas engine with electric clutch.  Works pretty good.

 
John Sawicky

Just North-East of Sacramento...

SkyTrak 9038, Ford 545D FEL, Davis Little Monster backhoe, Case 16+4 Trencher, Home Built 42" capacity/36" cut Bandmill up to 54' long - using it all to build a timber frame cabin.

ozarkgem

What brand of clutch did you use? Is it 2 groove?  Nice looking build.
Mighty Mite Band Mill, Case Backhoe, 763 Bobcat, Ford 3400 w/FEL , 1962 Ford 4000, Int dump truck, Clark forklift, lots of trailers. Stihl 046 Magnum, 029 Stihl. complete machine shop to keep everything going.

ozarkgem

Quote from: bandmiller2 on December 05, 2016, 08:04:31 PM
OJ, its been 16 years and I can see no perceivable wear on the cold rolled rods. Theirs always a good coat of grease on them. Frank C.
IF its been 16 yrs you did it right. Do you have any pics or videos of your mill?
Mighty Mite Band Mill, Case Backhoe, 763 Bobcat, Ford 3400 w/FEL , 1962 Ford 4000, Int dump truck, Clark forklift, lots of trailers. Stihl 046 Magnum, 029 Stihl. complete machine shop to keep everything going.

Kbeitz

I see you got away from using the red twist belts (junk) not
good for anything over 2 hp.
Collector and builder of many things.
Love machine shop work
and Wood work shop work
And now a saw mill work

Ljohnsaw

Quote from: Kbeitz on December 06, 2016, 08:55:24 AM
I see you got away from using the red twist belts (junk) not
good for anything over 2 hp.
Yep, learned my lesson!
Quote from: ozarkgem on December 06, 2016, 07:03:59 AM
What brand of clutch did you use? Is it 2 groove?  Nice looking build.
I made a dual pulley for the electric.  The big pulley mounted behind the tire was a twin groove - all I could find in 14" at the time.  I put the twin belts on the 7hp and they fell apart.  For the 18hp, I turned the twin groove 14" pulley on my mill to make it a single groove.
John Sawicky

Just North-East of Sacramento...

SkyTrak 9038, Ford 545D FEL, Davis Little Monster backhoe, Case 16+4 Trencher, Home Built 42" capacity/36" cut Bandmill up to 54' long - using it all to build a timber frame cabin.

scrout



I just used some skate board bearing to center the upper part of the slide.  You really do not need much precision with the system, I just didn't want the paint to get scraped off all the time.  If the blade itself moves side to side or back to front as the carriage height is adjusted it will not affect the cut as both those movements are in the direction of the cut.  The only way the blade can go is up, acting against the weight of the saw frame and the blade tension.  Most saw frames are way to heavy to move up due to pressure on the blade, it just bends or breaks.  I saw Matt Cremona's linear bearings on his design, kinda looked like a waste of very expensive parts, and I would worry about just how much weight they can hold in a vertical application.

Kbeitz

That little bit of side to side play will grow into big oscillations
that will give you sawing problems.
Collector and builder of many things.
Love machine shop work
and Wood work shop work
And now a saw mill work

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