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Wavy cuts need help please.

Started by MSTireman, July 05, 2021, 11:06:43 AM

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MSTireman

Appreciate all the responses. So far we have put a 5 foot level across the band and used it instead of a 12" straight edge to get level with the bed. The cuts are much better with a 1/16 or less of wave. I can control carriage speed with no difference in cut quality. My next step is to figure out how to slow the hydraulic motor that runs the blades. I got mfg info off the valve that controls the motor and am gonna call Monday to see if they have any info on adjusting it. It looks to have an adjustment on it, I just don't know if it's for pressure or flow.  From what I've read and been told, I need to reduce flow to slow my blade speed. 

barbender

To adjust your blade to the bed precisely, you need to make sure the level isn't resting on one of the set teeth- it needs to be flat on the body of the blade.
  
Too many irons in the fire

ladylake

Quote from: MSTireman on July 11, 2021, 01:31:00 AM
Appreciate all the responses. So far we have put a 5 foot level across the band and used it instead of a 12" straight edge to get level with the bed. The cuts are much better with a 1/16 or less of wave. I can control carriage speed with no difference in cut quality. My next step is to figure out how to slow the hydraulic motor that runs the blades. I got mfg info off the valve that controls the motor and am gonna call Monday to see if they have any info on adjusting it. It looks to have an adjustment on it, I just don't know if it's for pressure or flow.  From what I've read and been told, I need to reduce flow to slow my blade speed.
 

Maybe thats a flow divider valve that just need adjusting, if not they make flow divider valves.  Steve
Timberking B20  18000  hours +  Case75xt grapple + forks+8" snow bucket + dirt bucket   770 Oliver   Lots(too many) of chainsaws, Like the Echo saws and the Stihl and Husky     W5  Case loader   1  trailers  Wright sharpener     Suffolk  setter Volvo MCT125c skid loader

Peter Drouin

Wood Mizer has a tool to level the blade to the bed.
A&P saw Mill LLC.
45' of Wood Mizer, cutting since 1987.
License NH softwood grader.

Magicman

 

 
Correct barbender and Peter Drouin. 

Use the proper tool that will not contact and teeth
Knothole Sawmill, LLC     '98 Wood-Mizer LT40SuperHydraulic   WM Million BF Club Member   WM Pro Sawyer Network

It's Weird being the Same Age as Old People

Never allow your "need" to make money to exceed your "desire" to provide quality service.....The Magicman

tacks Y

MSTireman, The Logmaster manual I had was pretty weak. Like the others say, good advice. My Baker says with a 12" scale on blade level or 1/32" up lead. So the teeth side can be slightly up. Is your hyd drive direct? No belts to slip and slow blade?  

MSTireman

Quote from: tacks Y on July 11, 2021, 04:13:51 PM
MSTireman, The Logmaster manual I had was pretty weak. Like the others say, good advice. My Baker says with a 12" scale on blade level or 1/32" up lead. So the teeth side can be slightly up. Is your hyd drive direct? No belts to slip and slow blade?  
Yes sir my blade drive is direct hydraulic. 

JoshNZ

As a bit of an off topic hi-jack, why do some mills specify a slightly off blade alignment like that?

You want less flow going through the drive motor to slow it down. Divider would work but to slow it down that much you may consider swapping out the motor. Seems bizarre a factory made unit would be so far out, makes me wonder if we're missing something

MSTireman

Quote from: JoshNZ on July 12, 2021, 03:46:38 AM
As a bit of an off topic hi-jack, why do some mills specify a slightly off blade alignment like that?

You want less flow going through the drive motor to slow it down. Divider would work but to slow it down that much you may consider swapping out the motor. Seems bizarre a factory made unit would be so far out, makes me wonder if we're missing something
Thanks josh, I've thought about missing something on this mill also.  I've searched the internet and even though the company is not making mills like this anymore, I can't find any info on a LM5. You can find old brochures on almost any other mill they made.  I still haven't been able to get an owners manual from them either. Hope to get to fool with it again this weekend after work. 

JoshNZ

The hydraulic motor (or pump for that matter) could have been replaced with one of incorrect capacity. I was playing around with a casappa pump/drive on a press I built recently and ended up needing to pull it apart for whatever reason. The housing is the same for about 60 different pumps of the series, but by lengthening the gear sets inside (capacity) and giving up space on the end blocks that secure them they can quite drastically change the flow rates/torques etc. So if your drive is anything like that you might be able to consider that too but probably more trouble than it's worth.

Are you sure your engine isn't over revving? Is the hydraulic pump pulley driven? Pulley ratios haven't been tampered with?

Could there once have been a flow divider that fed another feature of the mill that has been deleted or something?

Are you sure it's 1200rpm on the band wheels? Borrow/buy a cheap laser tacho and confirm?

Does the mill have any other components sucking on the hydraulic circuit? How is the blade stopped? Just being nosey now XD any photos haha?

Ive forgotten what's been said in the these already sorry if I'm repeating questions

tacks Y

I find it hard to believe there is a major problem. I have see a couple of the LM5s in the last couple years, none in person. I would think leaving the plant it ran fine, so what is diffferent or wrong?  How many hours on the mill? I had the same results once on my mill, rpms to slow and clutch slipped. Look for the simple.

MSTireman

I don't think we have a major problem or at least I hope we don't.  The mill had 290 hours when we purchased and is showing 360 as of last weekend. The biggest problem with the mill is probably the dummies running it so far.  I think it was manufactured around 04-05 according to the date code on the engine. I've never sawn before so the learning curve is steep as everyone on here knows. It doesn't help matters that I'm a weekend warrior either.  Most of the info I'm gaining is from this forum and videos on the net.  One thing that has been consistent as far as info is blade speed. I have checked the band wheel speed with 2 different photo tacs and both agree to within 30 rpm.  I think that once we get it slowed down just a little everything will fall into place. 

And to answer a question for josh
The hydraulic pump is direct drive off of crankshaft so no pulley ratio to worry about there. The engine is rated for 85 hp at 2400 rpm. We usually run around 2200. I can't see where anything has been taken off the mill as far as valving. It looks to have the main pump dedicated to the blade drive/hydraulic functions of the mill then. Smaller pump run off the timing cover for the controls.  I'll do my best to get some pictures this weekend. 

Once again, I appreciate all the responses. 

fluidpowerpro

If you do determine that its a blade speed issue, instead of adding a flow control to slow the motor down, from an efficiency standpoint, you would be better off sizing your pump and motor to get the correct blade RPM (based on a given engine RPM). If you add a flow divider/flow control in that circuit, it will likely create a lot of heat, and your hydraulic oil temp will get too high. 
I can help you size these if you like. Just send me a PM.
Change is hard....
Especially when a jar full of it falls off the top shelf and hits your head!

JoshNZ

No chance the pumps been put on the band wheel and the drives been put on the engine hah..?

There probably is something else going on, with alignment/wear/tension etc but a modern mill coming off factory with a band running twice as fast as it should seems more odd than anything else to me. And should be on the list of things to fix, whatever else is going on aside

ladylake

Quote from: fluidpowerpro on July 14, 2021, 11:55:53 PM
If you do determine that its a blade speed issue, instead of adding a flow control to slow the motor down, from an efficiency standpoint, you would be better off sizing your pump and motor to get the correct blade RPM (based on a given engine RPM). If you add a flow divider/flow control in that circuit, it will likely create a lot of heat, and your hydraulic oil temp will get too high.
I can help you size these if you like. Just send me a PM.
I can see where a flow control  valve would create heat by blocking off part of the flow. Does a divider valve where part of the flow is sent to the motor and the rest sent to  other hydraulics create heat too.  Could be this mill has  one and the previous owner adjusted it thinking more band speed would be better.  Steve
Timberking B20  18000  hours +  Case75xt grapple + forks+8" snow bucket + dirt bucket   770 Oliver   Lots(too many) of chainsaws, Like the Echo saws and the Stihl and Husky     W5  Case loader   1  trailers  Wright sharpener     Suffolk  setter Volvo MCT125c skid loader

tacks Y

Ed or Herman give any idea of rpm to run? Try running at 1800 rpm maybe or 2k? Take a look at a hp and torque curve chart for your motor, I would think the engine would do good at a slower speed. Your hyd oil is good right? No foaming while running or milky? You checked your wheel speed on the drive wheel?

tacks Y

Another thought, ck blade flat to mill at both rollers. Possible one roller is off?

fluidpowerpro

Quote from: ladylake on July 15, 2021, 03:01:49 AM
Quote from: fluidpowerpro on July 14, 2021, 11:55:53 PM
If you do determine that its a blade speed issue, instead of adding a flow control to slow the motor down, from an efficiency standpoint, you would be better off sizing your pump and motor to get the correct blade RPM (based on a given engine RPM). If you add a flow divider/flow control in that circuit, it will likely create a lot of heat, and your hydraulic oil temp will get too high.
I can help you size these if you like. Just send me a PM.
I can see where a flow control  valve would create heat by blocking off part of the flow. Does a divider valve where part of the flow is sent to the motor and the rest sent to  other hydraulics create heat too.  Could be this mill has  one and the previous owner adjusted it thinking more band speed would be better.  Steve
It all depends on the pressure in each side of the circuit. If the pressures were equal, then theoretically no heat will be created. If however one side is at high pressure and the other is low, then yes, a lot of heat is generated.
I would speculate that the side not feeding the saw motor is feeding a set of open center directional valves to run the cylinder functions. When your not using those functions, the oil on that side is at low pressure because it is going to tank. 
Change is hard....
Especially when a jar full of it falls off the top shelf and hits your head!

fluidpowerpro

Quote from: MSTireman on July 14, 2021, 11:07:48 PM
And to answer a question for josh
The hydraulic pump is direct drive off of crankshaft so no pulley ratio to worry about there. The engine is rated for 85 hp at 2400 rpm. We usually run around 2200. I can't see where anything has been taken off the mill as far as valving. It looks to have the main pump dedicated to the blade drive/hydraulic functions of the mill then. Smaller pump run off the timing cover for the controls.  I'll do my best to get some pictures this weekend.

Once again, I appreciate all the responses.
Based on the above, it makes total sense to have 2 pumps. One dedicated to the blade and the other for the cylinder functions. This minimizes heat. In an ideal world, the blade motor takes all of the flow that the pump is putting out and you have no need to regulate flow. (no heat/wasted energy)
Unless something has been changed from the factory, I think its haphazard to re-engineer anything at this point. I sure would think LM knows what is needed to make their saw work....
Tom
Change is hard....
Especially when a jar full of it falls off the top shelf and hits your head!

barbender

It being twice as fast as it should be, seems like a mistake somewhere along the line. I've never heard of a blade being driven that fast.
Too many irons in the fire

fluidpowerpro

I suppose we cant rule it out. Maybe LM uses different size pumps and motors on different mills and somehow the wrong one got installed at the factory.
I just dont want to get ahead of ourselves. 
Idea...
Get the P/N off of the pump and motor and then call the factory to confirm that they are correct...
Change is hard....
Especially when a jar full of it falls off the top shelf and hits your head!

barbender

The problem is that Logmaster has been out of business for some time, iirc.
Too many irons in the fire

fluidpowerpro

I guess that kind of rules out that plan....My bad...
It still may be of value to get the P/N of the pump and motor, I can do some detective work and likely figure out what their displacements are. With that we can calculate the theoretical output of the pump and resultant motor RPM.
Change is hard....
Especially when a jar full of it falls off the top shelf and hits your head!

tacks Y

Another thought.... just because most mills here run slower what about larger mills? Or is there an ideal blade speed?

MSTireman

Quote from: fluidpowerpro on July 15, 2021, 11:28:13 PM
I guess that kind of rules out that plan....My bad...
It still may be of value to get the P/N of the pump and motor, I can do some detective work and likely figure out what their displacements are. With that we can calculate the theoretical output of the pump and resultant motor RPM.






Top four pics are the valve assy on top of motor with electric solenoid to engage the blade drive. On the top pic of valve is part number of what I think to be pressure relief valve from my research but why does it have two? Next, from top to bottom are part number for the hydraulic valve assy, motor for saw, and finally hydraulic pump.  I appreciate you taking time to help me try and figure this out.

 

 

 

 
 

 
 

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