Installing a rheostat

[True North]

We have a Timber Harvester that does not have a variable speed feed on it. Does anyone know if it would be possible to install a rheostat so we can adjust our feed speed from the control box?

[york]

TN,
ya can`t do that-that is a 12V solenoid valve and it is either on,or it is off-you need to use the needle valve in the HDY. line,that feeds the feed motor...On the later TH mills they ran a loop in the head drive feed line back to the operators station and put the needle valve there.....Bert

[bandmiller2]

Bert is right it needs to be a hydraulic control.I thought timber harvestor had an adjustable needle valve for the feed to the right of the control levers.If not an easy installation valve is around $50.00 adjusts the feed foward but allows unrestricted gig back.Frank C.

[york]

Frank,
yes,on the later mills TH ran an loop that fed the head motor...the motor that move the head forward and back-ran a loop back to the saw station and put a needle valve in it,simple setup,but added a lot more hyd lines...

His mill has a needle valve on the head,he needs to find it...

[True North]

Thanks guys,

I found the needle valve. It is up by the engine. How involved would it be to move it back to the controls so you could control it from there?

[york]

TN,
Not cheap to do...you would remove the needle valve-then run a new HYD. line from where the needle valve got fed,thur the coils of HYD. lines back to your saw station-then into the needle valve-then another new line running back to the head drive motor...

takes a lot of new HYD. hose.....This is how TH did it on there later mills...

There is another way-which is more work,kinda of a winter project,what i did with my TH mill-will post few pic. later..

Bert

[Hilltop366]

If the valve is a rotary one could one control it with a reversible DC motor I,m thinking a car window motor with a built in gear reduction where you to reverse it by switching the + and -. if you get one from a junk yard you can get the switch too (the passenger side window get used a lot less and has a single switch)

[True North]

That's an interesting idea, Hilltop. How exactly would you hook up the motor to turn the knob on the valve?

[Hilltop366]

I,m not sure what the valve looks like or what the thread pitch is on it.( if it would need more reduction ) It might take a little machining to get set up. I was wondering if some small pulleys and a belt would work and give more reduction. I would think the belt should not be too tight as the valve is probably not designed for a lateral load.

If no farther reduction is required I have seen a simple low load coupling made from a sturdy hose (heater or hyd hose).  Being careful to not let the hose travel on the shaft an damage a seal or something else.

Also I was wondering if turning the valve by a motor it may require some stops to keep the valve from being over tightened or opened too far?

Or if a 12 volt  DC flow control valve can be bought?

Just ideas

[york]

HI all,

this is what the needle valve looks like-only TN has his needle valve up on the head...It turns really easy and not much to make a change in the oil flow.....

[Hilltop366]

Thanks York.
Sounds like a much smaller reduction motor would do the job. or maybe a dc servo motor ?

[Hilltop366]

True North
I was adjusting my electric sideview mirrors on my truck the other day and it got me to wondering just how easy does that valve turn?
Do you suppose a motor from a eleceric mirror would work?

[Jeff]

A mirror motor should work. Here is what I did with one. It opens and closes a gate.

http://www.forestryforum.com/board/index.php/topic,26330.20.html

[Hilltop366]

Nice job on the gate Jeff , I was really thinking of the smaller motors found in 1/2t trucks and cars.
If it turns real easy an only requires a little adjustment to make a difference?

[Jeff]

The motor and its gear reduction is only about 3" by 3" by 3/4"  Not very big.