I just did the swap over from a cable drive to a chain drive system on the saw head.... Since doing it the motor takes off so fast that the head almost pops a wheely and when I stop it back towards me it almost does the same thing . I know it is because the motor starts instantly.... is there a way to adjust so it will soft start and stop..???
haven't changed mine over yet, have all the parts just not enough hours in the day. Does your saw have the flow control on the end of the hyd valve bank in the feed motor control circuit. I run the saw from there with one hand on the flow control knob when advancing the head to fine tune the feed speed. With only a 24 hp onan for power I have to be careful not to feed the saw too quick. I would think that choking down on the feed control when starting the head would stop the "wheelies".
Could you post some pics of your installation so I have a reference guide when I do mine?
Joe
Did you install the springs meant to dampen the effect?
What about installing a rheostat (speed controller) in the circuit!
Chuck,
Timber Harvesters are hydraulic, no electric to regulate. That's why Joe was suggesting chocking down the flow control which does help during advance. The springs are pretty heavy duty and should absorb the shock during gig back.
I don't know how to tell you to do it but with a couple of capacitors tied
in the motor line will give your motor a soft stop. When you shut off the
power the motor will feed off the capacitors until they are drained.
This will bring the motor to a slow stop. Size of the capacitors regulates the speed.
if its hydraulic then use a needle valve. A flow control only controls the flow one way. So on the return it would still be too fast. A Needle valve controls the flow both ways Other wise you will need 2 flow controls. I put mine where I can adjust them as I saw and return. I used 2 flow controls(its what I had). I can control the speed both ways. One needle valve would be simpler.
I should elaborate: TH is electric over hydraulic. Capacitors can't be used on a TH, it is nothing like a Woodmizer...thank god.
The soliniods for advancing and reversing the head are located high up on the head frame. Only a single direction flow valve is within reach of the sawyer. Opening and closing hydraulic lines moves the head. There is nowhere a needle valve can be installed.
I maintain that the OP didn't use the proper size springs that are designed to dampen the shock. We will have to await his return to find out.
That said, IIRC, there is a bit of coast on gig back, it's not an instant stop. I am not near my saw to double check that for a while.
Sorry... I did not know that it was hydraulic...
So what not install a amall hydraulic accumulator to smooth things out.
Another thought: be sure to use (or see if you can change out to) a "motor spool" instead of a typical spool solenoid valve. The motor spool type will connect the work ports to the tank port when the valve is in neutral, thus allowing the motor to coast. You can likely change over the solenoid valves already installed on the mill (either DO3 or DO5) to a motor spool solenoid without changing the subplate (the valves have the same external dimensions, just internal plumbing is different).
"Soft starting" a hydraulic motor actuated with a solenoid valve is not possible (within the scope of my limited knowledge). I believe this is why TK uses a hand-operated directional control valve where circuit starts can be feathered. On the other hand, Cooks uses a solenoid valve for travel... so it must be made to function somehow (and I don't see the Cooks AC36 head doing anything too violent on gig-back).
After playing with hydraulics, it will take some convincing me to ever return to electric...
you could put the needle valve on the motor but you would pretty much be stuck with one speed. New spool valve seems to be the best. Course you would have to run a lot of hyd lines. A conundrum for sure.
Well allot of info... but first let me clarify..
I am using the heavy duty springs on both ends... I've tried to loosen the tension on the adjuster bolts and tighten them as well..
I am sawing at the same speed that I was when I had cable drive and sawing Cedar I am going through a log faster than most other species , Yes I could slow down the feed rate, by adjusting the flow control valve but that will defeat the idea of production...
I try to saw 5-6 days a week so production is a good thing ;D
It seems that when I change directions the motor either takes off so fast or stops so fast the saw head really does jump.. . I guess with the cable the pulley would spin a little and it worked smoother...
I will go back through the Posts to see what I can figure out I'm not a hydraulic mechanic so I guess I am going to have a challenge..
Oh.... Also the Flow control is mounted on the saw head so it couldn't be adjusted on the fly
Quote from: ozarkgem on June 11, 2016, 08:52:27 PM
if its hydraulic then use a needle valve. A flow control only controls the flow one way. So on the return it would still be too fast. A Needle valve controls the flow both ways Other wise you will need 2 flow controls. I put mine where I can adjust them as I saw and return. I used 2 flow controls(its what I had). I can control the speed both ways. One needle valve would be simpler.
I am happy with the speed it travels it just stops and starts to quickly
Didn't realize there was no electric. ::)
Agreed, just install a manually adjusted metering valve.
So right now your head travels at one speed. A spool valve and flow control will probably up your production because you can tailor the speed for each log and up the return speed then slow it just before it gets all the way back. I really think you would be happy with that setup. I would guess there is an electric flow control somewhere but it would be big bucks and its electric. Why did you take the cable system off?
Or this but it still only gives you control in one direction.
www.surpluscenter.com/Hydraulics/Hydraulic-Valves/Flow-Control-Valves/15-GPM-12-VDC-BRAND-CEP1500-ELECTRIC-FLOW-CONTROL-9-5178-15.axd
Quote from: ozarkgem on June 12, 2016, 09:35:33 PM
So right now your head travels at one speed. A spool valve and flow control will probably up your production because you can tailor the speed for each log and up the return speed then slow it just before it gets all the way back. I really think you would be happy with that setup. I would guess there is an electric flow control somewhere but it would be big bucks and its electric. Why did you take the cable system off?
My head speed is adjustable with a control valve... It is allot faster coming back than going through a log... Pretty much we feed through the logs as fast as I can and still keep a good cut sometime going close to 1 foot per second and when it comes back it is faster than that. I guess with the cable there was some slippage so it worked smoother , With the chain when you let off on the return button or push the forward switch at stops and /or takes off like a rocket.
I took the Cable system off because I was going through 33' of cable every 2-3 days . I tried changing the pulley and had tried numerous type and size cable , So I though chain and sprocket might be the ticket LOL.. I guess it just another thing to learn.
I definitely have a bit of drift when I let off the button; not much, but some.
As mentioned above, Cooks mill operate the same way...they are near twins to a TH. perhaps they could help. There is also a former TH rep in PA who manufactures mills now and is willing to help TH owners.
Hi,
I have an older TH mill-on my mill there was a pressure relief valve in the lines for the head feed motor,it is about two inch square,you can set it down and take some of the sting out of that circuit,look for it,but on the newer mill you don`t have this PRV......
Quote from: york on June 15, 2016, 10:35:19 AM
Hi,
I have an older TH mill-on my mill there was a pressure relief valve in the lines for the head feed motor,it is about two inch square,you can set it down and take some of the sting out of that circuit,look for it,but on the newer mill you don`t have this PRV......
My Mill is a 94...Are you talking about the flow control that is about eye high right below the gears for the dial ??
No,not talking about the flow control-it is in addition to the flow control ,should be in that feed circuit,unless TH stopped using them-my mill had two of these PRV`s,the other being for head raise and lower-it is about 2in. square and has cone on side for adjustment.....
Quote from: york on June 15, 2016, 12:55:25 PM
No,not talking about the flow control-it is in addition to the flow control ,should be in that feed circuit,unless TH stopped using them-my mill had two of these PRV`s,the other being for head raise and lower-it is about 2in. square and has cone on side for adjustment.....
Don't have it on my mill..
Some where on your mill,there is a pressure relief valve,find it and back off the adjustment.....
Alot of the time, the PRV is built into the valve manifold, so try looking there. Although there may really be no relief valve in the motor circuit, and adjusting the relief at the manifold won't affect the instant stop of the carriage. For that, you need to install a cross-over relief valve in the motor circuit so that when the work ports to the motor are closed, and the motor briefly acts as a pump, the cross-over relief will allow the motor to free-wheel slightly (until the inertia of the drifting carriage is unable to overcome the relief valve). I was told to set cross-over reliefs about 200-300 psi above working pressure.
Quote from: Rougespear on June 16, 2016, 04:46:24 PM
Alot of the time, the PRV is built into the valve manifold, so try looking there. Although there may really be no relief valve in the motor circuit, and adjusting the relief at the manifold won't affect the instant stop of the carriage. For that, you need to install a cross-over relief valve in the motor circuit so that when the work ports to the motor are closed, and the motor briefly acts as a pump, the cross-over relief will allow the motor to free-wheel slightly (until the inertia of the drifting carriage is unable to overcome the relief valve). I was told to set cross-over reliefs about 200-300 psi above working pressure.
Thanks Time to call in a Pro I guess !!!