Has anybody tried to run a saw with a 12 hp ride on mower engine and trans.?Thanks
Mine has an 18hp Briggs and Stratton, and it struggles with some of the harder wood types. I imagine you _could_ run one, but it might take some time depending on the wood.
I think some of the entry level hobbiest saws have as small as 5. What that harbor fright saw have?
The first saw I had used a 6.5 HP engine. It cut up to 18" wide. It worked fine but slow.
I think you could make 12 HP work. Assuming your using the transmission because it's a vertical shaft engine? If you use the transmission the output rpm will be really slow so you will need a huge pulley on it. You will also lose some efficiency through the transmission so I would avoid using it. Get a 90 degree gearbox instead.
At the end of the day you will be much better off using a horizontal shaft engine
The engine size will get you in the game, but that transaxle will give you nothing but grief between efficiency losses and speed. If you don't have a horizontal shaft do what FPP suggests above. The transaxle will be nothing but a time suck and disappointment.
There are considerations regarding blade speed and cutting speed relative to hp.
Tim Cook, Cook's Sawmill, has a good article on hp and blade speed. A internet search will find it, I can't post the link for some reason.
The blade speeds needed don't lend themselves to the use of the transaxle. A gear box ($$$) can be used but there's a reason manufacturers don't.
In the long run a horizontal engine will be the best approach. More hp means more blade speed and more hp means more torque. More torque means less blade speed drop which means consistency higher cutting speeds.
Having worked on a lawnmower transmission or two I have to agree with the advice already given. Ditch the transmission. It's designed for low speed use. The axle is probably 3/4" - 1" which is pretty small for sawmill use. Then there's the differential to deal with and the axle bearings on some are just bored through the cast aluminum casing. It's not a question of if it will fail, but when.
As for the motor it should work. If it's vertical shaft, I saw one DIY mill article that used a drive belt with a twist to a horizontal shaft. It seemed to work for him. I don't remember if it was in the forum or on YT. Blade speed can be adjusted by pulley size.
You should be able to find around a 20 hp horizontal shaft motor cheap. Steve
Ditching the ride on motor and transmission idea.Thanks for the info. I'll find a horizontal shaft motor and go from there.Thanks Ken
I'm planning to use 2 pieces of acme rod to raise and lower my cutting head.will be a Manuel crank setup to start maybe power later on.Any suggestions on setup? sprocket sizes? Shaft orientation? Should I have 4 posts or 2. I thought 4 but I'm having trouble with it jamming.is balance an issue with 2 posts?
Have you considered a chain and sprocket or a cable lift setup? The acme rods will be slow/take many turns.
I thought the acme rods would be more acurate.
Read that somewhere.speed is not really an issue for me.later I may add a 12v motor.
It's a sawmill and the accuracy of a chain is more than enough. Should be no variation along the cut, if the slack is taken out of the chain (or whatever system is used) when moved to the next position. Dropping the head down to the next set is something that has to be taken into account. Coming up not so much.
The nice thing about ACME threaded rods is it is self locking. With a chain lift you will have to deal with locking. If it is a cog like latch that it is fine enough that you can hit your desired height mark.
I picked up a new 2,000lbs electric winch for $49 during covid and used it to drive a chain connected to a sprocket on the manual crank that raises and lowers my cutting head. The winch uses planetary gears and doesn't drift. Being a cheap winch it goes slow and ended up being about the same speed as hand cranking it. I use the winch remote to power up and down.
Goes all day on an old car battery that lost it's oomf to crank a car.
I have tractor trailer landing gear on my homemade mill that my friend built. A 12 volt electric motor moves it up and down okay. A logger whiplashed the mill head unloading logs a couple of years ago and snapped the right side rod. It's welded up and working but not good as new . These type gear boxes are two speed. Granny and fast granny.
https://www.truckspring.com/heavy-duty-truck-parts/trailer-landing-gear.aspx
(https://forestryforum.com/gallery/albums/userpics/13635/1000008567.jpg) (https://forestryforum.com/gallery/displayimage.php?pid=356765)
(https://forestryforum.com/gallery/albums/userpics/13635/1000008569.jpg) (https://forestryforum.com/gallery/displayimage.php?pid=356763)
(https://forestryforum.com/gallery/albums/userpics/13635/1000008570.jpg) (https://forestryforum.com/gallery/displayimage.php?pid=356761)
I like that set up.Thanks for the pictures.you got me thinking.
url=https://forestryforum.com/gallery/displayimage.php?pid=356810](https://forestryforum.com/gallery/albums/userpics/55256/IMG_8682.jpeg)[/url]
Chain lift set up on my old Timberking B16
Actually it's pre Timber King was a Belsaw product. But it is pretty accurate and the gearbox does hold its place fine.
:thumbsup: another good idea!
Another option is a dump truck tarp gearmotor - works well for me, powered through a cheap PWM controller for variable speed.
Ya! And I know where I can get one.Thanks
You're welcome. Be sure to use a PWM controller so you can creep up on your cut height.
Ken,
I see that you have posted two different threads re your sawmill build. I would like to suggest that you just have one thread. Ask all of your questions on it and have all of your responses in one place.
We like following along with new builds.
Good luck!
mh
While trying to find the sawmill build I remember seeing with a verticle shaft motor I ran across this one, and right in this forum too. It's not the one I was looking for, but it's a unique build to say the least.
Lawnmower Engine Powered Bandmill (sawmill) (https://forestryforum.com/board/index.php?topic=85912.0)
It just shows what you can do with what's on hand if you put your mind to it.
Here's one picture from his gallery.
(https://forestryforum.com/gallery/albums/userpics/40675/20150831_075127_28Small29.jpg) (https://forestryforum.com/gallery/displayimage.php?pid=190680)
Now the question,should bed travel on 4 posts or 2. I have started with 4 but seems to be binding a fair bit. I thought that 4 posts would be more balanced once motor and other gear is mounted.Should I rethink this? Thanks Ken
My experience has been that 4 posts is much better than 2. When I say 4 posts, its 4 posts to support the whole carriage plus 2 posts that the saw head rides up an down on. This is like whats done on the Hud-son Oscar series of saws.
I have 4 posts and 4 ACME screws. I made some brackets that wrap 3/4 of the way around the uprights. I tucked in some 1/2" thick blocks of UHMW plastic for a low friction fit. It's definitely not a precision fit. IMO, it is fine to wobble about. It's the height that is critical that it be robust.
You can see one behind my scale.
(https://forestryforum.com/gallery/albums/userpics/30640/20210616_b.jpg) (https://forestryforum.com/gallery/displayimage.php?pid=307118)
The scale is magnetically stuck to the post with a toggle clamp at the bottom.
How do I add a photo?
Look at the last item on the Index Page: How to Post Photos. (https://forestryforum.com/board/index.php?board=93.0)
l22
I like the 1 HP per tooth in the wood analogy but I think you really need to define cutting speed along with it.
I have cut a 36" red oak log with my 16 HP mill at an "ok" speed but would love more HP to go faster.
What I think is "ok" I'm sure would be unacceptable to others.
It would be interesting to know what manufacturers use to estimate cutting speed per HP, cutting width, species and blade characteristics.
I know there are more variables but those are probably the biggies.
My personal experience: I upgraded from a Kohler 15 HP to a Kohler 25 HP. I forget the exact numbers but it was about a 40% increase in torque. It cut like a different mill right away, especially in wide cuts. I can now feed quick enough that I'm not making fine powder sawdust on wider hardwood cuts.
I got some 1" 6 tpi acme rod but having a hard time finding nuts for it. any suggestions? I'm in Nova Scotia and there are very few options locally.moose herder id like to see more picks of your complete acme set up if I could.Thanks.oh I scrolled back and see all your pictures.
Here is how mine is attached on both sides with steel plate.
(https://forestryforum.com/gallery/albums/userpics/13635/1000008559.jpg) (https://forestryforum.com/gallery/displayimage.php?pid=356881)
I was going to suggest Surplus Center but they only show 7/8 -6 . Are you sure it's 1"?
A reasonably good, competent machinist can make the "nut" for your threaded rod.
Have you looked at McMaster-Carr for what they might have?
https://www.mcmaster.com/products/nuts/lead-screws-and-nuts~/acme-lead-screws-and-nuts/?s=acme+nuts
Quote from: Ken Malone on November 22, 2024, 05:26:41 PMI got some 1" 6 tpi acme rod but having a hard time finding nuts for it. any suggestions?
Try Roton, they have all sizes at good prices. You want to use a bronze acme nut, last way longer. Steve
Ordered bronze nuts from Roton. Thanks everybody for sugestions. This is the best source for info .I have found. Great to get advice from people who know what there talking about.
Do I need a centrifugal clutch on the motor to drive wheel or just an adjustable idler pulley to engage blade
A lever engaged idler pulley is less expensive and less prone to wear out but either will work.
Going with idler pully. Thanks
Any suggestions to pull y ratio and motor size to run acme rods up and down. Using 6 tpi 1" acme.
A lot of trial and error for the sprocket sizes. Mine is dual speed via a 12/24 VDC switching. Since you are using 6tpi, I would make a guess that you will probably want to raise at 1"/second at the fastest. So the ACME rod will need to spin about 360 rpm for quick moves and be able to slow down to half that to hit your mark via voltage or a PWM controller.
I have tiny (12 tooth?) sprockets on the rods all connected in a loop. Then a larger sprocket on two on the left side. A smaller loop of chain hooks those to the wheelchair motor. I changed the sprocket on the motor a couple times until I liked the speed and power.
Here is an early picture of the setup with just one rod connected to the motor.
(https://forestryforum.com/gallery/albums/userpics/30640/20210622_a.jpg) (https://forestryforum.com/gallery/displayimage.php?pid=307286)
The big sprocket got moved to the motor and replaced with a slightly smaller one.,
My mill uses a 1/2 hp 56c motor mounted to a 5 to 1 right angle gearbox with about a 6" no 40 sprocket driving 1 1'4 5 tooth per inch acme screws. The sprockets on the screws are the same size as the gearbox sprocket. That works out to about 350 RPM on the acme screw. Mine is 5 tpi with 6 tp I'd shoot for 400 RPM Steve
Now on to idler to engage the drive wheel. Any suggestions and picks would be much appreciated.
Mine is direct drive unfortunately. I've got my mill tarped up for winter now. We got about 8 inches of snow for Thanksgiving.
No snow yet here in Nova Scotia but she's a comin
I can wait a little longer (a lot longer really) for snow here on the Southwest end of NS, what area are you in Ken?
I wonder how well a riding mower transaxle would hold up as they are not made to use most of the power the engine produces as most of the power is required for the blades, the drive belt is often the weak link but some models are more prone shaping axles or breaking teeth off a trans gear then the gear tooth lays over and jambs in the next go round and forces the case apart. Generally a yard and garden tractor have much tougher transaxles than a riding mower.
Hey hilltop Ken here in upper nine mile river.
I picked up a 14 1/2 briggs horizontal shaft and going to run mill with belt and manual idler pulley.
Just about ready to give her a try.
Is a compression spring needed on the blade tensioner? I was told it is a must but I'm not sure.
You really should have a spring: air bag, coil or rubber. The problem with not running one is that as the band expands with temperature it grows in length and tension is lost. The spring maintains band tension. The wheel belts provide a minimal amount of "cushion".
Yes put a spring tensioner on your mill. Steve
I picked up a 1/4 hp gear motor that is rated at 18 rpm ratio 95:1 does this mean the shaft turns 1710 rpm? It is rated at 750 in lbs torque I'm hoping to raise and lower mill with it.Any thoughts?
I have a 18 rpm dc gear motor.when I power it up with a car battery I get about 3 rpm.Any thoughts? It also says 90 v on the tag . What does this mean?
I would think v=volts which would explain the low rpm at 12v.
Do you mean it would take 90 v to get the 18 rpm?
I think so.
It was likely made to run with a controller that converted 120 AC to 90 DC.
Yup your right.came off a treadmill.
I'm now on to building blade guides. I've seen many different configurations just wondering what is the best.Any ideas or pictures would be great. Thanks Ken
Ken, Do yourself a HUGE favor and just buy the Cook's roller guides. That's what I finally did after having regular bearings lockup at least once a year.
I made my own drilled mounting bolts with a zerk fittings to grease them. That was mounted on a rod that fits in a square 2"X1/4" wall tube. Two bolts per side allow for full adjustability.
In retrospect, I should have just used a piece of solid square stock instead of the round, it would have been easier to fab.
This was after rusting all winter.
(https://forestryforum.com/gallery/albums/userpics/30640/IMG_2023-02-10_17-25-13.jpeg) (https://forestryforum.com/gallery/displayimage.php?pid=337544)
This also shows the supports for the adjustable arm.
(https://forestryforum.com/gallery/albums/userpics/30640/IMG_2023-03-01_09-35-41.jpeg) (https://forestryforum.com/gallery/displayimage.php?pid=338366)
The whole boring build thread (https://forestryforum.com/board/index.php?msg=1290881)
I agree with John, you can get the assemblies from them with adjusters and save some fab time.
I also suggest their felt/diesel dripper if you plan to mill pine. I retrofitted one to my Woodmizer. Buying the parts separately is nearly the same cost.
Quote from: Ken Malone on December 16, 2024, 09:04:55 AMI have a 18 rpm dc gear motor.when I power it up with a car battery I get about 3 rpm.Any thoughts? It also says 90 v on the tag . What does this mean?
This is the Dayton Gear motor on my mill for forward and back.
(https://forestryforum.com/gallery/albums/userpics/13635/Mill_Gear_Motor.jpg) (https://forestryforum.com/gallery/displayimage.php?pid=357170)
(https://forestryforum.com/gallery/albums/userpics/13635/Mill_Gear_Motor2.jpg) (https://forestryforum.com/gallery/displayimage.php?pid=357171)
I would say the 90v is the intended operating voltage.
Just installed a new centrifugal clutch but it doesn't disengage . It turns at idle speed. Any thoughts? Thanks Ken
When I first got my saw the idle speed was set too high so the clutch didnt disengage. Whats your idle speed set at? Try bumping it down a bit?
My idle speed is 1700 rpm. The clutch is not supposed to engage until 2000 rpm.
That's a pretty high idle. I like it down below 1,000. I think mine is around 7 or 800.
What do you have for an engine? I don't think mine will run that slow without quitting. Thanks Ken
1700 sounds high to me also. Mine is at about 1000. It's a Briggs 16 HP Vanguard.
Was just thinking...
If it engages at 2000 it might need to drop below 1700 to disengage. Everything has a dead band and for a mechanical device like a clutch 300 might be too close. On mine I noticed that when getting close to engaging or disengaging, it makes sort of a clanking noise.
Ran it full throttle for about 2 min. Now it's working fine😁
Just wondering what the blade tension should be and how to gauge it .Thanks
There was a thread on here about a poor man's strain guage a long time ago. Two clamps and a dial caliper. Open the caliper up an inch or two, clamp the jaws to your blade. Zero the caliper out. Now tension your blade, and watch the reading on your caliper as you tighten. The problem is first- I never did this, just read about it; and second, I don't remember how to convert the measurements into psi of strain. Obviously this would be onerous to do every time you put a blade on, so you would figure out a method to correlate the adjustment on your tensioning device with the corresponding correct strain. Clear as mud?😊
The dial caliper method of strain measurement works quite well. I've used it on many (same size blades) and compared the measurement with a dedicated strain gauge. They are close and often identical. Conversion charts are available online. It's not necessary to measure every blade, IMO. Note the position of the tension mechanism for the representative blades and adjust to that set point when replacing same-blades.
Just about finished my build,down to finding an appropriate spring for my blade tensioner.wondering if a hockey puck might work? Would it provide enough cushion?
I believe a hockey puck will be too hard. I would look for a spring or dense rubber.
I have thought of a puck for that, I would be interested to see if it worked.
I'm thinking it would have to be held in a way that allowed it to expand as it is compressed.
I was thinking of mounting it by drilling a hole through it and putting it on a pin or bolt. If one would not compress enough maybe two stacked?
I used a 50x64mm yellow die spring. I haven't confirmed blade tension yet, but all seems to run fine.
So curiosity got the best of me and I googled "compressive strength of a hockey puck" and came up with about 80000 psi to failure or breaking apart.
Quote from: Hilltop366 on January 31, 2025, 10:07:19 AMSo curiosity got the best of me and I googled "compressive strength of a hockey puck" and came up with about 80000 psi to failure or breaking apart.
It needs some cushion, I dont think a hockey puck has mush. A spring is best by far. Steve
Timber king has such a spring that goes on the outside of my threaded rod, I think 3/4 inch. call and ask for Matt and they might sell you the spring, threaded block and even the screw and handle if you like. they are a sponsor, although they may consider it proprietary.
@Will_Johnson
17384502322635371998853636799469.jpg17384502322635371998853636799469.jpg17384502322635371998853636799469.jpg
I'm going to try this. The die springs I have don't seem to be strong enough so I'm going to try using 2
What about valve springs?
You should use 3/4" acme rod, last a long time and tensions up easy. Yellow die springs are plenty strong, nothing wrong with using 2. Steve
I agree, use a square machine thread, not a bolt thread to minimize friction each time you tension the band.
Rather than guess at spring rate, I would either run the numbers to determine spring rate needed or give Cook's a call and buy a spring sized for a 1 1/4" blade. It will be worth the $25. In the end you'll spend more time and $ guessing.
I wouldn't use anything less than 3/4" threaded rod. People don't seem to realize just how much tension is actually needed to properly tension a bandsaw mill blade.
I'm starting the rails today.Any thoughts on bunk spacing. The rails will be 16' long and the mill is about40" to front edge of blade.Thanks
I'd make it to cut at least 16' , my bunks are 3' on center. Steve
I agree, note that if you plan to cut a 16.5' log you'll need at least 17' plus the carriage length. 3' bunk spacing at most and make one bay half that so you can mill a short log or cant if needed.
You can't have too much extra space on each end. Unless your placing the log on the mill with a machine you will find that it's a real pain trying to get a log positioned exactly as you want it. They often don't roll straight off of the loader arms.
I've often wished I had roller toe boards because then it would be much easier to position the log.
The last few feet on one end or both ends could be made of a lighter material as it would only be required to hold the mill head and not a log.
If you are planing to make it portable it is not as good but the lighter made end(s) could also be made so they fold out of the way or easy to remove and stow.
Look into making you bunks moveable. Could just make the end fixed and 2 or 3 moveable in the middle.
(https://forestryforum.com/gallery/albums/userpics/30640/150107_005.jpg) (https://forestryforum.com/gallery/displayimage.php?pid=173363)
Having trouble with tensioner. The shaft runs through 2 pillow blocks,when I apply tension to the blade I can't seem to get the blocks to travel the same so the idler wheel tows in.Any thoughts?
Ken, I reviewed your diagram, can you post some pics of the actual parts? I do not see the pillow blocks in the diagram/blueprint.
how does it pull the wheel?
My idler shaft is built with adjustments to the wheel and on a slide that moves. the thread is on the bracket to the wheel, and it slips against the frame on the other end. no bearings. it is hard to explain.
Preferably the pillow blocks are mounted to a common structure and bolted down tight. The tensioning device then acts on that common structure to move both pillow blocks equally.
Each pillow block can have jacking bolts to adjust tow/tracking, but once that's adjusted, the pillow blocks are bolted down tight.
You don't want to be screwing around with adjusting tracking every time you tension your blade. That would get old real quick.
Does this make any sense?
This is my set up
Ken, here is my setup.
(https://forestryforum.com/gallery/albums/userpics/30640/20210519_c.jpg) (https://forestryforum.com/gallery/displayimage.php?pid=305357)
The big plate with the 4 holes is welded to the 2x2x¼" tubes that make up that sort of "n" shape. On the near end, pass through the 2½x2½x¼" collars. There is a third one further back on the right. The collars are attached to the head frame.
Near the rear of the "n" shape you can see the bolts holding the pillow blocks. Not visible is a tracking adjustment. To tighten the band, a little hydraulic puck fits behind the heavy plate and the head frame, peaking out from behind. The ½" screw at the top of frame is hand tightened to hold the tension and the puck is removed.
To release tension, pump up the puck again, loosen the ½" screw and release puck and remove. Usually it is slightly cocked and stuck. A tap on the plate usually pops it free.
Here is the tension locking bolt.
(https://forestryforum.com/gallery/albums/userpics/30640/20210519_b.jpg) (https://forestryforum.com/gallery/displayimage.php?pid=305355)
If you don't have a hydraulic puck, you could use some ACME rod here. On my first mill version, I used some rod from a scissor jack. Worked ok but finally blew out the thrust bearing.
This is the drive side but same setup for tracking on the idle side.
(https://forestryforum.com/gallery/albums/userpics/30640/20210519_g.jpg) (https://forestryforum.com/gallery/displayimage.php?pid=305361)
The four big bolts clamp the top and bottom blocks to the rails. The pillow blocks are attached to a frame welded to the bottom block. There are two pieces of all-thread going through the end plate and the bottom block. I lengthen or shorten one side to adjust tracking.
Lots of great ideas there, thanks for the pics.I think I might start again.
Ive got my mill in the shop for mods. Its a Hud-son HFE-36.
I took some pics of how its done on my mill for you to look at.
Thanks for all the pics, I appreciate the input.
Ljohn. Does this look right.if so I'm going to build it today.ThanksIMG_20250315_065123.jpg
Wow! Looks like my drawing in my head!
Yes, that will do it. Think long and hard about getting it in the right place before welding. Mine is attached to an adjustable plate that provides tracking adjustment as well as coarse tension adjustment. I have about 3/4" travel on the tension adjustment. An inch would be better to ease getting the blade on. Getting the blade off, not so hard 😉
The tracking adjustment doesn't need to be super easy to do. You'll do it once and probably good for years. But releasing and tightening the tension for blade changes will be a daily occurrence. Maybe 5 or 6 times a day 🙄🫤
Not noted on your plans but you probably want your pillow blocks on the bottom so the wheels hang as far below your frame as possible. Unfortunately, I have a small bracket that hangs below my engine. That limits me to just shy of 14" between the blade and the frame. I was cutting a lot of 4x7s for my rafters. At one point I was cutting them from a 4" x 30" flitch. I couldn't cut more than one at a time before having to move MHE in to extract it.
Thanks for the input,I built my bunks so the blade is 1" above at lowest and 32" at top. Thanks again,Ken.
Not what I meant. I'm talking about throat depth. How thick you can cut something. Typically, you whittle down a log to a beam you need. But if you are slicing up some flitches, you need enough space between your cutting part of your blade and the lowest part of your head, the throat. Mine is limited to just under 14". So even if I'm cutting up a big cant into 2x boards, I can cut 6 boards before I have to stop and remove them.
I typically work alone and don't want to stop and remove each board after each pass. I'd rather make a stack and then slide that onto some forks.
Oh,I got it. About 15" .
Finally cut my first log today. Worked great except idler pulley needs tweeking. Thanks for all the advise throughout this project.Ken.IMG_20250403_180146.jpgIMG_20250403_175933.jpg