New guy and lt40 manual speed control help

[mmartone]

Hi guys,

I had all the pines in my yard cut (50) and was carrying them to wewahitchka to have a guy cut my wood for me. After $1000 worth I had a look at my pile and figured there was $6000 more to go! I started looking for a used mill and found this well modified (not in a good way) lt40. I made a deal that I thought was decent and brought it home along with its 12' extension. After some conversation with WM they helped me determine I needed an updated set of boards, pcb, diode assy and mosfet assy to the tune of $406.84, I installed them as the instructions stated. I now have high speed forward and reverse, not exactly what I was hoping for.
I'm a marine diesel guy and do main engines, gensets, ac/dc electrical, fiberglass (you get the point). I work on most anything but I'm thinking I still have a bad board. Checked the wiring of the drum switch and its right. I'm going to call them again tomorrow just hoping to get some help.

Thanks
Mark

[drobertson]

MMartone, welcome to the forum, I was trying to figure out you description of the problem, do you mean you have only one speed foward and it is fast?

[mmartone]

Yes sir, 1 speed, fast in forward and fast in reverse, as it should be.

[thecfarm]

mmartone,welcome to the forum. WM will be able to help you. They will see you through your problem. What are you building? Sounds like alot of lumber.

[Magicman]

Hi Mark, and Welcome to the Forestry forum. The call to WM will be your best choice for the proper fix.  Push the button to talk with the "electrical" person.

[pineywoods]

MMartone, what year is your mill? If it's older than 1997, the forward speed controller circuit board is no longer available. However, the post 97 controller will work in an older mill BUT it's not quite a direct replacement. Look over the installation instructions carefully.. Been there, done that with my 95 manual mill. If you go poking around with a meter, be aware that the controller board does not control the speed by reducing the voltage to the motor. It turns the full 12 volts on and off 2000 times a second. The ratio of on to off time controls the speed. It's called Pulse Width Modulation. You should be able to hear a 2000 cps squeal when moving the head forward.
A 12 foot extension on a manual mill is a bit unusual.

[mmartone]

Mill was built 0286, the serial has an E at the end and an EX stamped under it. I talked with WM about it and they said in the old days the mills were built the extensions were built with them, probably not be a perfect fit for any other mill except this one. I have the original manuals and a bonus, the 87 color brochure!
I know they use pwm for speed control, since the speed is nothing but fast I'm guessing there no pulsing.

[mmartone]

Yes theres going to be a ton of lumber! The guy that cut my trees has been having me do the repairs on some of his equipment, bobcat, stump grinder etc. He brought me some nice cypress logs he cut a few weeks ago, bonus.

[pineywoods]

Best I remember, one of the things that was slightly different is the connections between the speed control pot on the panel and the controller board. If the old one didn't work, possible someone has been poking around in there trying to fix it. Those controllers are usually pretty robust. What got to mine was water, corroded everything. The new design will handle a drive motor twice the size of yours.

BTW welcome to the forestry forum. You won't find a friendlier, more helpful bunch of folks anywhere.  We may have to nickname you MM#2 , as we already have an MM, short for MagicMan.  ;D

[Buck]

Welcome MM#2. Please share your findings.

[customsawyer]

Welcome to the forum. Don't worry about this as WM will get you through this.

[mmartone]

Just got off the phone with Mike at WM, quick check to his instructions and he says the MOSFET is bad. Had a look and could see I just bought it and he is sending me a new one over night, talk about awesome service! I believe that I may be able to saw some wood after this week!

[Chuck White]

Welcome to the Forestry Forum, mmartone!

It's a great place and lots of good people and info.

[mmartone]

Spent some time today on the phone with Mike from WM and did some more trouble shooting, seemed like and hour but may have been less. He is supposed to overnight me a new MOSFET board, should fix my rig. Think I have a nice piece of hickory with a nice crotch and maybe more in it, going to pick it up friday I hope. Thanks Mike! 8)