Hydraulic Sawmill

Hilltop366 · September 07, 2018, 08:18:08 AM

I thought you might find that video interesting.

mike_belben · September 07, 2018, 08:46:43 AM

I got to thinking last night.. York 210 AC compressors use an electric clutch and they did make a double B belt setup that is fairly serviceable. I run one to power my road ranger and exh brake and its been flawless since i mounted it years ago. It mounts to a simple tapered shaft with keyway and wouldnt be hard to put on the backside of your drive band to power the drive wheel with an on/off DC switch. I dont know the rating but it may be too small for your motor. It is however the biggest DC clutch pulley i ever saw.

I contemplated suggesting an automotive flywheel, clutch, pressure plate and fork with hydraulic slave mounted right to the driver bandwheels shaft.. And it would certainly work, transmit big power and be locally serviceable if you used a common car part... But that imparts a major thrust load on the band wheel shaft and bearings that they arent designed for and could throw bands. So that idea snowballs into necessitating a fairly precise thrust surface and radial bearing plus lubrication that isnt full of sawdust to handle the pressure plate force when blade is stopped.

Early cub cadet mowers are also a source of smaller conventional clutch parts but it doesnt change the shaft thrust loading issue. Too much power really is a challenge to do on the cheap.

Im back to thinking big motor means run the bandwheel by hydraulic motor spool.

Crusarius · September 07, 2018, 08:55:20 AM

Mike I was thinking using an actual automotive clutch as well. wouldn't be hard to put clutch right on engine then a jackshaft with drive belt to the drivewheel. that will take care of the issues you mentioned.

I don't know much about auto tranny torque converters but that could be used as well?

mike_belben · September 07, 2018, 08:56:07 AM

Lightbulb.

Ford festiva or geo metro 3 cylinder automatic. Weld diff carrier, use CV axle to power the bandwheel. Id buy a whole rotten car and use the alternator, radiator, fan, power steering cooler, trans cooler etc etc. Even the headlights. Let off throttle and the torque convertor will stop the blade. Gives you lots of blade speed options. Power steering pump could be plumbed to a spool valve and then feed to your carriage lift and carriage feed mechanisms. Id use a motor with sprocket and idlers mounted to carriage that walks a taught chain on the bed. Sorta poor mans gear rack.

Hilltop366 · September 07, 2018, 09:21:55 AM

Looks like the guy in the video is using the auto clutch and transmission to power and disengage the band wheels which seems like the way to go for this much horsepower and torque. It sounds like he says that the mill was powered by a tractor pto before he switched over to the Mercedes diesel. The hydraulic pump is powered by a short shaft from the front crank pulley.

Things that might improve this design for safety, blade guards and pto shaft guarding.

To run a setup like this by yourself I'm wondering if it would make more sense to have the controls on the other side of the saw. This would put your log deck to your left and the lumber comes off on your right saving lots of footsteps during the sawing process and get you away from a lot of the sawdust and engine noise and exhaust fumes. The down side would be it would make it harder to see the back stops.

Hilltop366 · September 07, 2018, 09:23:24 AM

For saw milling you want a constant blade speed, can that work with a torque converter?

Crusarius · September 07, 2018, 09:27:58 AM

with a lockup torque converter, yes. once up to speed it can lock and create a 1:1 drive.

mike_belben · September 07, 2018, 09:48:14 AM

What he said. Not all lockups convertors are the same though. Some are hydraulic and some are solenoid but only in certain gears.

I wasnt suggesting change speed in the cut, but i assume a varispeed would be handy for tuning in different species and different tooth counts/profiles. We have it on all high end metal cutting bandsaws, and lord knows you need it for twist drilling and milling.

Do industrial band mills have variable band speed?

mike_belben · September 07, 2018, 10:12:59 AM

That mercedes powered home made mill was pretty slick. Mobile home axles for carriage, mower deck angle drive, clever little blade guide adjuster on the fly around the clamp. I still havent figured out exactly how you make a carriage reverse off a capstan drum. Wish they showed that in more detail.

Hilltop366 · September 07, 2018, 10:13:35 AM

Well that should work then as long as you can keep the torque converter in the locked position when sawing and not let it unlock during a cut like it does under a heavy load when driving. Probably a standard transmission with a remote clutch leaver would be a bit easier to rig up.

So then the next issue is a good steady engine speed governor.

Hilltop366 · September 07, 2018, 10:14:34 AM

Looks like the carnage drive is hydraulic.

Hilltop366 · September 07, 2018, 10:16:46 AM

There is another video of the mill with more detail a description that I watched a few months ago but I was not able to find it yet.

Hilltop366 · September 07, 2018, 10:20:13 AM

Quote from: Hilltop366 on September 07, 2018, 10:13:35 AM
Well that should work then as long as you can keep the torque converter in the locked position will sawing and not let it unlock during a cut like it does under a heavy load will driving. Probably a standard transmission with a remote clutch leaver would be a bit easier to rig up.

So then the next issue is a good steady engine speed governor.

I forgot to mention cheap and simple, so a good steady cheap and simple engine speed governor.

mike_belben · September 07, 2018, 10:26:10 AM

A manual trans with a remote hydraulic clutch master cylinder mounted near operator would work fine too. On the automatics with solenoids you can force lockup by applying voltage to the TCC coil. Theyll stall you out at a stoplight if you forget to unlock, just like a manual trans.

For governing a carbureted engine, a belt drive flyweight governor would be pretty straight forward. Hoof makes them. Or one could always rig up their own. Its just springs, flyweights and levers/cams.

Just grenaded the one on my bobcat and deleted it. Lawnmower pulley to idle the waterpump belt, and a bike lever on the handle with cable routed through brakeline. Works perfect.

On efi engine it'd be tougher. one could put an electronic based ignition box but they kill spark not fuel.. It could load up and wet stack the exhaust. Older diesels all pretty much have flyweight governors already inside the pump backhalf. Just need to dial it in.

mike_belben · September 07, 2018, 10:27:34 AM

Whoa whoa.. Good steady cheap and simple is 4 menu items. You can only have 2!

Hilltop366 · September 07, 2018, 10:32:55 AM

:D :D

I forgot to mention it would be a continuous speed governor not a over speed.

Hilltop366 · September 07, 2018, 10:55:37 AM

So could one simplify this a bit and eliminate the bush hog gearbox by placing the power unit to the left or right (depending on the drive shaft rotation) of the saw head. If using a front wheel drive it would kinda be like removing the front wheel bearing assembly and wheel and putting it on the mill carriage.

Hilltop366 · September 07, 2018, 11:01:12 AM

Sorry my brain won't stop, it went from eliminating the bush hog gearbox to.... the mill head could be stationary and raise and lower the log by putting a scissor lift on the log carriage to.....cut a slot down the side of the car for the top of the blade plus suspension modifications and put the band blade on the car using the front and rear wheel (the car would be across the and over top of the log.

I could be related to Red Green.

:D

Crusarius · September 07, 2018, 11:06:02 AM

if you decide you want to move the log vs moving the sawframe its changes all sorts of things.

kinda be kool to have a full hydraulic bed with quick detach couplings that only connect when the table is all the way one way. they you can do all your flopping and clamping then make your cut and dock it again to adjust.

May not be the best way but I can see that setup becoming quite a bit easier and cheaper to make. definitely be stationary at that point.

charles mann · September 07, 2018, 01:47:30 PM

Quote from: Southside logger on September 06, 2018, 10:17:07 PM
Rather than a clutch, why not use a tension / release, hinged plate system similar to the "auto clutch" on Woodmizer mills?

So, I found some actuators on surplus center. they range from 110# of pull/push force, up to 2000# of force. it wouldn't be hard to build a bracket that will accept 3 pulleys and be able to take the tension required.
it seems most are ext/retr at .500 in/sec. not to slow, but to fast. any ideas of pull force required to tension the belts? I could even hook up a limit switch to open the circuit and only if the belts get to loose, the actuator is energized, or i can manually override the switch.

Hilltop366 · September 07, 2018, 03:05:28 PM

I would be tempted to put a spring in the system so there is some give to the tensioner (think lawn tractor deck belt) then as long as there enough strength to put a bit of stretch in the spring your good and won't have to worry about over tensioning the belt.

I guess the first question would then be what size spring and if there is a mechanical advantage or disadvantage on your actuating lever to know the minimum amount of force and length of travel required.

mike_belben · September 07, 2018, 04:02:37 PM

In america we find uses for linear actuators, solenoids, hall effect sensors, PLC's, limit switches, linear bearings, ball screws...

Meanwhile some guy in poland or georgia hangs a 10lb weight bench plate onto a stub of cantilevered rebar and off she goes, sawin 4/4 lumber just the same.

We can spend a lot of money benchracing a junk build but only the guy with the junkpile can really sift through his own pile and pocketbook to figure out what he can do. My best advice on junkyard building is that the longer you have the project in mind but delay starting it, the more time you have for better components to land in your lap. Patience and luck produce the best junk. Thats what i tell myself anyway. I hate my junk collection but cannot part ways with it.

We need each other.

charles mann · September 07, 2018, 04:17:21 PM

So realistically, how much wt. tension do you think it would take to keep the belts tight? Its a lot of hp and 3 belts, not 1.

mike_belben · September 07, 2018, 04:40:59 PM

I dunno.. A vertical hanging belt that only has 3/4 to 1" of deflection like an auto tensioner does.. Probably 50 to 80lbs of steel hanging? Just a guess. May be way off.

charles mann · September 07, 2018, 04:46:23 PM

Quote from: mike_belben on September 07, 2018, 04:40:59 PM
I dunno.. A vertical hanging belt that only has 3/4 to 1" of deflection like an auto tensioner does.. Probably 50 to 80lbs of steel hanging? Just a guess. May be way off.

A good firgure to start with. Ill get a 0-50 and a 50-100 lb spring scale, need them anyhow for business. Fire the engine up and start yarding on the tension pulleys till the blade engages. Then add another 10# to that and get a spring of that wt. and an actuator.