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General Forestry => Sawmills and Milling => Topic started by: donnieb5213 on August 09, 2018, 10:58:10 PM

Title: blade tracking adjustments on 1986 Woodmizer LT40
Post by: donnieb5213 on August 09, 2018, 10:58:10 PM
I have an old WoodMizer LT 40 that I have put a new blade on.  How do I adjust the idle wheel to track correctly.  Also how do I check my variable speed control which doesn't seem to working all the time.
Title: Re: blade tracking adjustments on 1986 Woodmizer LT40
Post by: Chuck White on August 10, 2018, 06:36:19 AM
The tracking adjustment is on the front side of the sawhead, in front of the idle-side blade wheel!

Loosen the locknut and adjust a little at a time until the blade is tracking in the correct position!

A small adjustment can shift the blade tracking a lot!

NOTE:  This procedure should be outlined in you owner/operators manual!

As far as the variable speed control switch goes, if it was me and it wasn't working correctly all the time, I would just call Wood-Mizer and order another one!

Hope this works out for you, and Welcome to the Forestry Forum, donnieb5213!
Title: Re: blade tracking adjustments on 1986 Woodmizer LT40
Post by: Crossroads on August 10, 2018, 08:32:53 AM
You may have a loose wire inside the control box. I had that happen on my first mill. 
Title: Re: blade tracking adjustments on 1986 Woodmizer LT40
Post by: Ben Cut-wright on August 10, 2018, 09:41:08 AM
Quote from: donnieb5213 on August 09, 2018, 10:58:10 PM
I have an old WoodMizer LT 40 that I have put a new blade on.  How do I adjust the idle wheel to track correctly.  Also how do I check my variable speed control which doesn't seem to working all the time.
There are good videos at the WoodMizer website showing most common adjustments.

Test for proper voltage available at the control box terminals while the motor is under load.  Test both positive and negative sides.  If you have difficulty doing this with the tools you have, get someone to monitor the circuits while you operate the device. 

The speed control potentiometer (pot) is one component to check when the variable speed stops or stutters.  Not a lot of trouble to replace and good maintenance if yours is very old.  Get a new knob when you replace the pot.

The terminal strip screws and wire connections should be inspected and tightened.  Be certain the tiny wires are actually UNDER the screws, not off to the sides. 

Moisture on those control boards can cause havoc.

There is updated solid state device available for the older units. This is not an entire control box, only the driver for the motor.  There are other modifications to be made in the control box when the new style driver is installed.  IF you are not comfortable with the instructions, WoodMizer or someone here can be of help.

Wiring, terminals, and connections powering the control must be sound.  Clean and check integrity of these wires.

The direction switch terminals and contacts can be another area of concern.  Clean, tight connections, bright and lubed contacts are needed.

Motor brushes or a bad commutator can cause poor speed control and not be noticed at full motor speed.

Anything which might interfere with forward head movement can cause a mechanical bind.  Dry kinked chain, bolts being hit by the head, chain idler sprocket not properly aligned, worn or binding on its shaft.  Check the rollers carrying the saw head for bad bearings or faulty outer shells.

Don't replace any parts until you check and diagnosis everything you can first.  Try to determine the exact component causing the problem right now.  IT won't always be the most expensive part, or the part you have no way of testing that is faulty.