Hello Everyone,
I have an older LST-12 and it bound up on me in the middle of a cut last night. I read the article posted here by Richard J. Gindhart, "Care and Feeding of Rocksaws". Per the article I checked the blade and it runs true, but the carriage is way out of alignment with the blade. He says in the article that the system should be realigned but doesn't go into how to do that.
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Any thoughts on "aligning the system"?
Is it the carriage that is aligned or the arbor or both?
Thanks for any input, my next call is to Lortone.
Have you completed this alignment yet?
If not here are a couple thoughts.
Harbor freight Item# 93051 is an indicator and a vise grip type attaching tool. You might also check out just the indicator and a magnetic base.
Items 623 and 5645.
Mount the indicator base on your vice so it is solid. Put a mark on your blade near the outer edge. At the front of the blade and above the level of the blade collar, bring the indicator tip up to the blade and in until the indicator reads about .100". Set the indicator to zero. Gently rotate your blade so the mark is in the back and move the vise with the indicator still in position to the back and measure the same mark at the back of the saw. This will tell you how much your blade/carriage is out of alignment.
The next part is probably more art than science, but here is the science part.
I am going to assume you will adjust the blade arbor and not the carriage.
Divide the amount of misalignment by the distance between your mark in the front position and the mark in the back position and you will have the amount of misalignment per inch of blade. Example; the distance between the mark in the front(where the indicator was) and the back position (where the indicator was) reads 11.25". The misalignment was .025" .025/11.25= .002" per inch of blade.
I have numbered your arbor bolts 1-4 in the attached picture. Here is the art part of this. You need to decide how to loosen the arbor bearing bolts. You are only going to loosen 3 of the 4 but you may need to SLIGHTLY loosen the 4th. You are going to pivot the arbor on one of the two bearing bolts closet to the blade. It doesn't really matter which one remains tight. For the purpose of this post loosen all but #1. 2,3 and 4 should not be sloppy loose just loose enough that with a few light hammer taps, the bearing can move under the bolt.
Lets assume the front of the blade needs to move closer to the vise. you are going to tap the outboard bearing (at bolt 3) to the right. How much should you move it? Remember the misalignment per inch number? .002" x the distance between the centers of bolts 1 and 3.
Measure the distance between the centers of bolt 1 and bolt 3 and multiply it by .002 (misalignment per inch). Lets assume the measurement between bearing bolts is 5". The amount you need to move the bearing is .010". Measuring the movement may be difficult. Expect the bearing to move as you re-tighten the bolts. Re-measure the blade misalignment and repeat process while holding your tongue in a different position each time. After a few tries you should find the correct tongue position and the alignment will be very close. Swearing seldom helps (much) but sometimes putting a penny in your left shoe can be beneficial.
How close is close enough? I can't say. I will tell you, the closer the alignment is, the nicer your finished cut will be.
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Topic: Carriage alignment on a LST-12? (Read 4156 times)