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saw head raise and lower and carriage travel

Started by charles mann, October 16, 2018, 12:52:37 AM

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charles mann

looking for a method of lifting my heavy saw head and travel for the carriage. i have located, im guessing the current motors, since i can not locate, even on the lesson website, the motors that i have the data tag info on, for both raise/lower and carriage travel for the LT40, just not sure if they will have the tq, even with the 60:1 gearbox to lift and hold the head during operation. The lift motor is a 1hp and the gearbox has a 1410 in lb output tq. 

i was thinking of using either the lesson motor, or any other 12v dc motor manufacturer, with a GB, or a 2500-4000 lb atv/utv winch, and cutting the drum apart and welding a sprocket on, but both will be going to a chain drive, depending on the recommendations from you folk with more knowledge than me.

Im not against manual controls, but would like power options if possible.

I was thinking of a winch for the carriage drive to, but winches are not designed for continuous operations, that the travel will require. The lesson motors state continuous operation for their usage, just not sure if a winch motor is. I found a website called DB electrics, which sell winch motors, some in the 4hp range, but again, if not a continuous duty cycle and variable speed, I'm afraid using it for travel, and using a pot will burn it out. 

Any other continuous duty variable speed motors out there that would be recommended?

I did look into worm gear manual winches, which is fine to get me up and running, but they all are for nylon strap or cable. Cable would be fine for final attachment to the saw head beam, but not sure about cutting it apart and welding a sprocket on it.

I guess iv got to much tunnel vision, and not thinking outside the box clearly enough to decide which direction to go, mostly for the carriage travel, something i can operate slow during the cut, then speed up on the return. 

Since going with a heavier than normal power unit, blade engagement options are limited and either expensive or design challenging with my limited fabrication tools and skills for this application, and challenging for a raise/lower system. 

I need some outside guidance please.

Thanks in advance 


Temple, Tx
Fire Fighting and Heavy Lift Helicopter Mech
Helicopter and Fixed Wing Pilot

mike_belben

You want a varispeed 90vdc reversible motor and controller.  They look like this.  Dayton has been making them a long time.  Theyre pretty dependable in my experience.   

KBPC-225D Black (9391) DC Drives, Nema 4 - KB-Controls.com, Your online Shopping for AC & DC Controls & Drives

Dayton Model 3XA84 DC Gear Motor 180 RPM 1/4 hp TENV 90VDC

Auger feed motor from a pellet stove might work.  Or 24v wheelchair gear motors.  Or hydrostatic ZTR mower drives if youre going all hydraulic. 
Praise The Lord

mike_belben

Consider ball screws to raise and lower the head instead of chain or cable and winches.  The screw itself will lift huge amounts of weight with relatively small input torque, those reducing the size and expense of the motor(s) youll need to buy for the job.

Huge CNC machining centers pretty much always use ballscrews.
Praise The Lord

1938farmall

If you have any hydraulics, take a look at the timberking method.  It is elegantly simple & easily adaptable to additional weight.
aka oldnorskie

Hilltop366

For the lift I believe it is Bandmiller2 that has had good success with using a hydraulic cylinder with a double pulley over the rod end (think forklift mast) and cable. Running the cable over the rod end pulley gives you twice the saw head travel than the cylinder extension.

The advantage of using a cable instead of chain is that the cable travel can easily changed from vertical to horizontal with a small pulley and the hyd cylinder can be mounted either vertically or horizontally where ever there is room. 

Using eye bolts to fasten the cable to the saw head will give you easy adjustment for levelling.

charles mann

Quote from: 1938farmall on October 16, 2018, 09:51:23 AM


If you have any hydraulics, take a look at the timberking method.  It is elegantly simple & easily adaptable to additional weight.
No hydraulics yet, that will be phase 2, installing a 12v dc hydro motor/pump for bunk operations. 
Cant get a good look at the TK setup. I have contacts to a couple guys in the DFW area of tx, that have TKs and was going to contact them to get a looky look at the mill. 
Temple, Tx
Fire Fighting and Heavy Lift Helicopter Mech
Helicopter and Fixed Wing Pilot

charles mann

Quote from: mike_belben on October 16, 2018, 08:21:04 AM
Consider ball screws to raise and lower the head instead of chain or cable and winches.  The screw itself will lift huge amounts of weight with relatively small input torque, those reducing the size and expense of the motor(s) youll need to buy for the job.

Huge CNC machining centers pretty much always use ballscrews.
similar to a acme rod, only, from what I'm gathering, a smaller lead screw can be used due to the way the system works in holding power, compared to a acme rod & nut
Temple, Tx
Fire Fighting and Heavy Lift Helicopter Mech
Helicopter and Fixed Wing Pilot

mike_belben

Other than both being leadscrews, theres just no comparison. A recirculating ballscrew is a high precision, low resistance screw with almost zero backlash.  
Praise The Lord

Crusarius

the biggest bummer to a ball screw is the cost. especially for a 6' long one. I was picturing a linkage in my head that would allow an 18" screw to move the head 36" or more. but thats a very complex setup for the kind of weight you are talking about.

mike_belben

Oh absolutely.. Ball screws are out of most guys league unless youre a machanic at a mega manufacturer and its just more dumpster fodder to drag home.   

If i had to buy the parts, a small right angle worm gear is best bang for the buck.  Have it run a jackshaft thats end keyed for sprockets and roller chain.  The gearbox makes for small torque input and has self braking.   The chains terminate at small turnbuckles or eyebolts to square the carriage (note all forklifts always have slack adjuster on mast chains.)

For quick raise to return i would look at a cam lever or air/hydraulic cylinder or maybe even air bag to bump the head up quick and easy and not loose place of the gearbox height for next board cut.  Just all depends on what the user has for junk available and what inputs he/she will feed it. Air vs AC vs DC vs hyd etc.
Praise The Lord

mike_belben

Well, a worm winch works too but i never found one in a dumpster. Have gotten lots of gearboxes.
Praise The Lord

charles mann

Quote from: Crusarius on October 17, 2018, 12:17:49 PM
the biggest bummer to a ball screw is the cost. especially for a 6' long one. I was picturing a linkage in my head that would allow an 18" screw to move the head 36" or more. but thats a very complex setup for the kind of weight you are talking about.

Exactly. My intial route was 1" or 1.5" acme rods, but looking at a winch too with a sprocket in place of the drum. Iv also been kicking around the idea of using the same motors and gearbox as WM uses on their LT 40-70.
Im just trying to get this thing going, and upgrade later.

I do like mike's theory of using an airbag to bump the head up for a return pass.
I will be putting board return fingers on it, so the airbag sounds like a good idea, and 1 of those 12v dc compressors might just work for phase 2, using automobile bags and compressor.

I think i will save my $1400 in amazon gift cards till i find out if the atv winch idea will work just to get going.

I will though, be getting a travel motor and pot, chains and sprockets, a thick wall 3/4" section of tubing, to transmit the power to the other side on my carriage for an even pull on both sides.
Temple, Tx
Fire Fighting and Heavy Lift Helicopter Mech
Helicopter and Fixed Wing Pilot

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