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Help with UNISAW 34-771

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Forum topic by DangerDoug posted 01-15-2019 10:25 AM 477 views 0 times favorited 14 replies Add to Favorites Watch
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DangerDoug

83 posts in 1915 days


01-15-2019 10:25 AM

Please excuse any redundancy on this question, but my UNISAW is ready for a tune up.
I cannot stop the back-of-the-blade from hitting the rip and leaving behind the dreaded saw marks. Tried moving the top several times, with and without a dial caliper, tried many blades; on and on. It also vibrates and squeals.
So in all three issues:
  • Cannot center the blade
  • Some vibration
  • Squeals and blade seems to slow down quickly, more than it used too.

Time for bearings? Where to order OEM, or good quality bearings?
Motor issues?
Both?

Any help would be greatly appreciated.

Model 34-771
Serial LG 78991
[bough this saw new back in the 70s]


14 replies so far

View hkmiller's profile

hkmiller

119 posts in 349 days


#1 posted 01-15-2019 01:22 PM

I’m thinking you need new bearings in that Arbor

-- always something

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DangerDoug

83 posts in 1915 days


#2 posted 01-15-2019 05:06 PM

Ok thank you. I see there’s lots of info on the web, you-tube etc.
Appears the load-spring is an issue, good that I looked before breaking it down.

Edit – found the load spring on Renovo,,but that site lead me to ebay…ugh

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DangerDoug

83 posts in 1915 days


#3 posted 01-16-2019 02:48 PM

Parts ordered! Could be weeks before they all are delivered, but can limp along with smaller 8” skill saw blades on the Unisaw.
[they seem to work ok, better anyway]

View firefighterontheside's profile

firefighterontheside

19808 posts in 2124 days


#4 posted 01-16-2019 02:57 PM

I replaced arbor bearings on a Unisaw a few months ago. Might be some good info for ya in my thread. What fence do you have.
http://lumberjocks.com/topics/291225

-- Bill M. "People change, walnut doesn't" by Gene.

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DangerDoug

83 posts in 1915 days


#5 posted 01-16-2019 11:20 PM

Bill thanks, good intel on the thread.
Biesemeyer 32” rail (bought that separate 20 years ago) lol.

There’s a lot I don’t know apparently, didn’t know the belts need tensioning.
Also is there a spanner wrench/socket that fits the lock ring?

View MrUnix's profile

MrUnix

7180 posts in 2467 days


#6 posted 01-17-2019 01:01 AM

Replace the bearings… both in the arbor and motor. Don’t order them until you verify what you have now – then give Lynne a call over at Accurate Bearing and she will hook you up (read here). And what makes you think that the pre-load washer (load spring) is an issue? As for the lock ring… I’m guessing you are talking about the spanner nut that holds in the outer bearing? If, so… you can usually tap it off with with a flat head screwdriver and small hammer. I wouldn’t worry about the belts until you have the arbor rebuilt, and then tension while running.

The table should be the easiest part – there is only 4 bolts.

Cheers,
Brad

-- Brad in FL - In Dog I trust... everything else is questionable

View runswithscissors's profile

runswithscissors

2961 posts in 2293 days


#7 posted 01-17-2019 03:18 AM

When you replace the belts, get 3 matching ones from the same production run. The serial numbers on the belts will give this information.

-- I admit to being an adrenaline junky; fortunately, I'm very easily frightened

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ruger

70 posts in 363 days


#8 posted 01-17-2019 03:44 AM

I can’t see the load spring really being the problem unless it wasn’t ever installed. or unless it cracked and fell out of the lip it rest on in the arbor. I changed out my arbor bearings last year on my 34-802 , without removing the top. just remove blade, remove back arbor nut,, tap out arbor shaft from the back,, remove the larger nut from the back,and knock out rear bearing , your done… it’s not rocket science. i’m a retired 65 year old mechanic did auto trans repairs in a ford dealership for 40 years,have all kinds of pullers and bearing spreaders, but didn’t need any kind of special tools. just don’t cock the rear bearing when installing you will be fine. the whole repair took me about 2 hours. and i have a cast bench dog router table and router hanging on the right side of my saw,hit my head a few times on the router working on installing the back bearing but thats my fault for being to lazy to remove router.lol.

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ruger

70 posts in 363 days


#9 posted 01-17-2019 03:48 AM

I can’t see the load spring really being the problem unless it wasn’t ever installed. or unless it cracked and fell out of the lip it rest on in the arbor. I changed out my arbor bearings last year on my 34-802 , without removing the top. just remove blade, remove back arbor nut,, tap out arbor shaft from the back,, remove the larger nut from the back,and knock out rear bearing , your done… it’s not rocket science. i’m a retired 65 year old mechanic did auto trans repairs in a ford dealership for 40 years,have all kinds of pullers and bearing spreaders, but didn’t need any kind of special tools. just don’t cock the rear bearing when installing you will be fine. the whole repair took me about 2 hours. and i have a cast bench dog router table and router hanging on the right side of my saw,hit my head a few times on the router working on installing the back bearing but thats my fault for being to lazy to remove router.lol don’t forget to loosen the 2 set screws in the pulley.

View DangerDoug's profile

DangerDoug

83 posts in 1915 days


#10 posted 01-17-2019 10:15 AM

Thanks for all the advice.
Good idea about the motor bearing, never would have though of that.
I’ll work on replacing the belts/bearing first, see if there is an improvement.
Rechecked the blade/fence alignment this morning,,,the only thing that looks out is the laminated piece bolted to the square tube (left side). It might have a slight bow, so the rip goes in slightly to the right—then back left, once past the blade.

Which explains why the ripping on the left side of the saw (aprox 12” max rip) works better.
Also, a 24” miter crosscut sled works fine.

So maybe a combination of small problems.

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DangerDoug

83 posts in 1915 days


#11 posted 01-17-2019 11:44 AM

update: positioned the Biesemeyer on the side to check straightness, as suspected is not as straight as thought:
Using a 48” straight edge was able to slip double thicknesses of newspaper in the middle of the fence, about the same location (parallel) to front of the blade. In other words; a slight bow.

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firefighterontheside

19808 posts in 2124 days


#12 posted 01-17-2019 10:05 PM

That could definitely be at least part of the problem. Can you shim it?

-- Bill M. "People change, walnut doesn't" by Gene.

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DangerDoug

83 posts in 1915 days


#13 posted 01-18-2019 09:03 AM

Bill,
Well can now…pealed of the laminate and replaced the side with BB ply. Pic of a steampunk dial indicator, added flush magnets to the underside; it works well.

Although still have the eerie feeling the arbor is pulling/moving the right, but only under a load. Occasionally I use 2 other unisaws at work, even my neighbor has one, all three work the way they should.

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firefighterontheside

19808 posts in 2124 days


#14 posted 01-18-2019 01:51 PM

You get those new bearings in and you should be set.

-- Bill M. "People change, walnut doesn't" by Gene.

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