PING Jim Wilkins

shaft OHC motor and a set of massive worm gears . What is the overall reduction in your drive train , and do you think 6 horses is enough ?
More to the point , what is considered a good feet-per-minute speed for the band ? This motor came from a pressure washer or maybe a log splitter that had a pump failure and is governed at one speed . I bought it for a tiller I have - and no longer need (got a rear tine now). So now I'm considering going ahead and building a band mill that will handle up to 12 foot logs up to a couple of feet in diameter. Build will be similar to yours , with the power head assembly on jack screws .
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I followed Suffolk's recommendation of a 1-1/4" wide, 3/4" pitch, 0.045" thick silicon steel Timberwolf blade running 5000 feet per minute, lubricated with bar oil + kerosine from a spray bottle. The blade stock was welded to fit my measurement. https://www.suffolkmachinery.com/
The Lovejoy L099 coupler on the 6.5HP engine shaft has held up so far although it gets quite warm. The rubber spider of an L095 didn't last long. My motorcycle wheels are quite heavy and the engine has trouble accelerating them at idle, so I slip the manual clutch. The drive train geometry isn't right for a go-kart centrifugal clutch with a chain sprocket, though that might have been better.
The Suffolk tech suggested that my blade guide arrangment might be contributing to the blade rising or falling in the cut when it starts to dull. The guides are supposed to lower the blade 1/8" to stiffen it from twisting while allowing 0.005"-010" clearance underneath for sawdust. Suffolk uses 6201 bearings in their guides.
6.5HP cuts 12" oak with a sharp blade at about 1" per second. It can manage up to 20" with some difficulty which increases as the blade dulls. Right now blade deflection limits how hard I can push and more HP wouldn't really help. Since I'm cutting beams or 10" planks there's only one full thickness cut per log. I'd say 5.5 - 6.5HP is adequate for hobby use but not to make any money.
I sized the capacity for the max diameter of my trees at 6-8' above the ground. If the saw frame won't clear the butt end of a log I slab it with a chainsaw. Another consideration is the width of your planer.
Handling the half ton logs was very slow and difficult until I built a gantry hoist crosswise above the center of the track. They are easy to rotate when hanging from a rope sling running through a pulley.
Waxing the ends of green logs slows drying enough to greatly reduce cracking. I brush on molten toilet ring wax, which is less brittle when cold than canning paraffin.
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On 8/11/2019 9:44 AM, Jim Wilkins wrote:

thing - one more question (for now) . What did you use for the frame that carries the wheels , 2" heavy wall square tube ? . I'll probably use beeswax on the ends of logs though most of my stuff may be cut green and seasoned as planks . My goal is to side my house with white oak board/batten from trees cut on our land . There are some very nice 16" plus diameter trees deep in the woods , and they grow close together so
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Yes, that part is a straight ladder frame of 2" square tubing. The wheel axles are hung below it to maximize the throat depth. The saw track and upright frame and overhad gantry hoist tracks are 3" channel that was cheap surplus pallet rack. The blade guards are wood to avoid damaging the teeth when installing a blade.
C3 x 4.1 channel is more than stiff enough but perhaps overpriced if bought new. Commercial band mill tracks are angle iron, which sheds sawdust better than my flat-topped track. OTOH mine spans 8' between leveling feet so it's simple to set and keep level. The log supports are separate, only the saw weighs down the track. I don't have any smooth level ground to support the one-piece track that commercial saws use and mine looks like an elevated railroad trestle, the ties being doubled 2x6's with 3/4"-10 adjusting screws at the ends.
My first bandsaw mill was built on a trailer that could be tilted with the tongue jack to self-feed by gravity. Since it used a 1/2 HP electric motor it didn't have the runaway problem of a vibrating gas powered saw, but it took half an hour to cut a 10" x 8' plank. I set this one as level as possible and then level the blade, the log supports and the cants when squaring them. It's like leveling a lathe or mill, you don't really have to but it gives you an easy measurement reference.
I originally thought the vertical throat depth should be at least half the 20" width capacity so I could cut a log on the diameter, but in practice I first slab large logs square to inspect them for defects and stabilize them on their supports, so for example I cut off 2" or less slabs and planks to give a 12" square cant and then slice it into two 6" x 12" beams or four 6" columns. 7"-8" would have been enough throat depth.
Maximum log length is 4' less than the track length, 2' at each end, because I may have to lift a log or sawn beam when the saw head is at either end.
Building the frame required a 4x6 metalcutting bandsaw and a stick welder. A lathe and mill were necessary for the moving parts, especially to adapt those not intended to work together. I think you could use cam followers to simplify the job. I machined the needle bearing track wheels and column rollers from scratch. The needles are welding rod. http://rbcbearings.com/camfollowers/index.htm
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Oops, it's 1.5" square. I used the 2" elsewhere.
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I've cut some oak green and some that air-dried for many years. The green planks gave less trouble from cracking but more from cupping despite being stickered fairly closely and stacked under heavier beams. I didn't quarter-saw any. 10" x 1-1/2" rough planks mostly had to be planed to 1-1/8" to remove all cupping.
The dried oak wasn't significantly more difficult to cut and blade life has been about the same.
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After considerable experimentation I found how to fairly efficiently cut rough slabbed planks to width and make stickers (or battens) as small as 3/4" square, using simple wooden fixtures. The details depend on what you build, I'm just telling you it can be done easily. I drilled the tracks for the swing-up metal F clamps commercial bandsaw mills use but I haven't needed to make and install the clamps yet.
https://northernwoodlands.org/articles/article/lumber-pile I sloped the corrugated roofing cover panels upward toward the center overlap with stickers of increasing width, turned on edge. They're (mostly) all the same 1" thickness but their width is whatever thickness the reject planks were when I cut to the beam outlines traced onto the ends of the log.
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On 8/12/2019 12:23 PM, Jim Wilkins wrote:

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I think I covered the major design considerations as well as I remember them from 12 years ago. The construction details depended on what I had on hand or could scrounge up, so it may not be a good model to copy.
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