Author Topic: Saw head dropping (Read 2370 times)

delvis · « **on:** March 30, 2014, 02:48:39 PM »

I fired the LT40 up yesterday for the first time since the late fall and started a sawing job. As the day went on I noticed I was having trouble with the Accuset or at least I thought I was. After finishing several cuts on each cant, I noticed the sawhead didn't want to raise unless I put it in manual first. I would then bring it back to the start of the cut, put it back in pattern mode, and get down to where the next cut needed to be. This worked okay but it seemed to happen more and more toward the end of the job.

I finally realized that the sawhead was trying to drop on its own slowly and because it was in pattern mode, the computer was constantly trying to make sure that it stayed where it was supposed to. That's about the time I realized it was slipping in manual mode at times as well.

From what I just read on the forum it sounds like I may need to grease the contacts on the up/down switch. I would like to know if anyone here has had this same thing happen to them and if the problem was limited to the switch or if there was a problem in the lifting motor itself. I haven't taken any covers off yet to see if there is anything obvious sticking out, but wanted to know what experiences other people have had.

Thanks as always.

drobertson · « **Reply #1 on:** March 30, 2014, 03:48:30 PM »

Are you getting any error codes?

backwoods sawyer · « **Reply #2 on:** March 30, 2014, 10:21:25 PM »

in my manual there is an upgrade for a brake on the up down system, never had any isssuse with it not holding.

delvis · « **Reply #3 on:** March 31, 2014, 07:56:19 PM »

Not getting any error codes but I did think it was an issue with the computer at first. That is, until it started giving me a problem in manual mode. It seems to be only when the head is moved down that it wants to keep going that way. The last cut I made the other night, the head dropped enough that I almost sawed into my first log post. I stopped the cut and because of the angle downward had to remove the blade in place and slide the head back. I won't be able to really get into it until after mud season now because everything is just getting too wet and muddy now.

backwoods sawyer · « **Reply #4 on:** March 31, 2014, 09:40:59 PM »

check the conections on the transducer cable,

delvis · « **Reply #5 on:** March 31, 2014, 09:49:45 PM »

Will do. The other day was the first time the mill had been fired up since the late fall so there may be a few gremlins but this hasn't been the case in the past.

jcbrotz · « **Reply #6 on:** April 01, 2014, 04:39:12 AM »

Is the motor actually driving it down? or is it drifting

petefrom bearswamp · « **Reply #7 on:** April 01, 2014, 09:42:26 AM »

Try cleaning the transducer connections.
WM tech suggested this.
This worked for me when I had the same problem

delvis · « **Reply #8 on:** April 01, 2014, 08:01:46 PM »

I didn't take the cover off to see if the motor was driving the gear box or not JC.

Pete, I will definitely do this. Thanks.

delvis · « **Reply #9 on:** May 30, 2014, 09:39:08 PM »

Update: We're still looking for a solution to the head dropping problem. I called WM today and spoke with Mike in the electrical department and he gave us some ideas to look at but we couldn't get back up there because of the weather.

I did notice the head only seems to drift when trying to set it at 12". It will dip down 1/32" and then come back up and then repeat over and over. It doesn't do it at any other height.

Any more suggestions from anyone who may have run into this same thing would be greatly appreciated. I will be glad when we get this figured out.

Thanks,

Mike

POSTON WIDEHEAD · « **Reply #10 on:** May 30, 2014, 09:44:22 PM »

Mike….call me . David

POSTON WIDEHEAD · « **Reply #11 on:** May 31, 2014, 08:25:34 PM »

It was good to meet you on the phone today and chat awhile delvis ( Mike ).

MartyParsons · « **Reply #12 on:** May 31, 2014, 09:26:20 PM »

Hello,
I would suggest you change the up down gear box oil. It is not a easy job to get the old oil out. We have a vacuum pump at the shop and that works best.
The gear oil that works the best is 80W 140. This is not what is recommended by WM but it will help to keep the gear box from drifting down.
The next option is to add the electric brake kit.
With out knowing more on hours and what engine year etc. I would bet the gear oil will fix the issue.
Hope this helps.
Marty

POSTON WIDEHEAD · « **Reply #13 on:** May 31, 2014, 09:34:07 PM »

Marty…..mine was dropping on and off over a period of 5 months….just every now and again.

They don't have an electric brake yet for my 2010 - 2011.
I changed my gear oil to a 75W-140 and it seems to help so far. WM sent me a new belt to install also, which I will put on tomorrow.
After 2 days of changing the oil….I ran the fool out of it sawing almost 14 hours with NO sign of it creeping down.
I hope this fixes it and hopefully the oil change is not a temporary fix.

By the way….why is the drain plug 3 inches above the bottom of the gear box?
No big problem as I have a "SUCTION TANK AND HOSE"

…….but was just wondering.

Thanks Marty….I appreciate your time and input.

MartyParsons · « **Reply #14 on:** June 02, 2014, 06:47:56 AM »

Hello
The gear box company made the gear box more efficient so they added Synthetic gear oil which helps where the application is a constant run. So adding gear oil that has a higher visc. reduces efficiency and helps hold the saw head from drifting.
The drain is on the back of the gear box but is almost impossible to remove.
Marty

delvis · « **Reply #15 on:** June 07, 2014, 08:58:10 PM »

We changed the gear oil the other day and the first sawing job after this was good with no head dropping. Thank you to POSTON for pointing me in this direction.

Woodmizer: Please have the gear box manufacturer put a drain plug on the side of the gear box that is exposed when the side cover is taken off. That gear oil was horrible to siphon and did not taste very good. Lol

If this acts up again, we'll be looking at fabricating a small brake to hold the head once it stops travelling up or down. It actually looks like it would be fairly straight forward to do.

Thanks again folks and happy sawing.

POSTON WIDEHEAD · « **Reply #16 on:** June 07, 2014, 09:16:16 PM »

Thanks for the update Mike……since I changed to a heavier gear oil……my height has been sawing true…..no creeping.
Good luck to ya !

MikeON · « **Reply #17 on:** June 08, 2014, 09:17:00 AM »

My LT40 Super used to drop down during a cut. It turned out to be the connection where the transducer cable hooks to the back of the setworks. I replaced the short cable that went from the connection to the circuit board in the setworks and that fixed it for a while but the problem came back. I finally drilled out the connector, and soldered the wires solid, and epoxied the hole where they passed through the connector. That was about 8 years ago and the problem never came back.

Ga Mtn Man · « **Reply #18 on:** September 21, 2016, 09:12:28 PM »

About a six weeks ago I noticed my sawhead was drifting down, sometimes as much as ¼". This was somewhat disconcerting for both me and my customers. $:-\$ I was sure it must have something to do with my recently installed remote control but after bypassing the unit the drift problem was still there. Hmmm... Now what? I typed in "head drift" in the search form at the top of this page (you do know there is a search form up there, don't you

), and this topic popped up near the top of the results. As Marty and PostonLT40HD suggested, I changed the gear oil to 80W-140, filled all the way up to the fill hole to keep the bearing lubed, as recommended in another thread. Honestly I was doubtful that this could possibly fix the problem but it's been six weeks and...

No head drift since!

The FF is an awesome resource.

MartyParsons · « **Reply #19 on:** September 21, 2016, 09:24:40 PM »

Hello,
glad this solved the issue.
Marty

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Author Topic: Saw head dropping (Read 2370 times)

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