Broke Trunnion Bolt on Delta

[Dansmith]

Today I was trying to align my blade to miter slot on my Delta Contractors Table Saw (34-444) purchased in 1993. I was pleased that I had it lined up within about .001 after tightening 3 of the 4 bolts (had to do this more than once because it would go slightly out of alignment again when tightening).

When I tightened the 4th bolt (most difficult one to reach), I sheared the bolt. According to the parts list, the bolt is 13/16" long (5/8 EDIT: 5/16"diameter). Based on what came out, about 3/8" there must be about 7/16" left in the threads.

Questions:

1). Anyone ever turn over one of these tables? I did take off the wings and fence guides. Is there a good and safe way to do this?

2). Any suggestions as to the best way to get the remaining screw out? I read somewhere about actually taking off the trunnions completely and then turning the exposed part of the screw. If I take this approach, how difficult is it to re-align the trunnions?

[JPG]

I know nothing about that saw.

I know that trunion alignment(after reassembly) can be difficult(at least when I did so).

You sheared a 5/8" bolt?? Doubt thee did that. It more likely was previously damaged.

Unless you have decent access to the end(S) of that bolt, a total breakdown is likely needed to gain that access.

[Hobbyman2]

All I can say is oops!!


Harbor freight has a couple different bolt extraction sets , I,,,sorry ,,,,,,,,the wife ,,,, seems to have a tool cabinet with a lot of them .



As to turning one of those over ,,sorry I am useless for advise .

Just go slow .

good luck

Hobbyman2

[Dansmith]

Thanks for the responses.

Hobbyman2, typo in my post that I will attempt to edit. It is a 5/16" bolt, not 5/8". I guess I would have to be pretty darn strong.

[Hobbyman2]

I ,,,I keep saying,,, I usually say I buy tools for the wife,,,,sort of a joke her and I have going,,,, but since she wouldn't know how to use em if she wanted to ,,,,I should stop saying that!!


i bought her a coon hound for her birth day once,, after the dog chewed up her slippers 3 or 4 times it was my dog!!




Any way,,,,you probably all ready know this , they sell a tool ,,,,called a easy out,,or screw extractor ,,that the twist is reversed , you drill a small hole in the bolt and then insert the easy out in it and twist it counter clock wise , it usually backs the broken stud out, ,ya just have to be care full drilling the hole in that small of a bolt.

To my knowledge those are not case hardened bolts , that one might be since it is on a saw .

Good luck

Hobbyman2

[robinson46176]

The good news is that it broke after you had loosened it several times and so it isn't rusted tightly in place like bolts I have fought all of my life on ancient farm machinery.
My solution of choice would be drilling the center of it (very carefully as mentioned above) with a left twist drill bit. On a bolt not tightly stuck the bit will usually spin the piece out. If it does not spin out then you are already drilled for using an extractor. The scary part about extractors is that the oldest brand was named "Easy Out". Those of us that have used them for a very long time might call them "Easy Breaks"... When one breaks the piece stuck in the hole is harder than most drill bits... You shouldn't have that problem since your bolt shouldn't be stuck tight but that is a fairly small bolt calling for an even smaller extractor.
A basic set of left twist drill bits should be in every shop that uses bolts. Avoid buying them or extractors at Harbor Freight.


.

[Dansmith]

Thanks for the replies. I am going to go look for the left hand drill bit today. I think that will do the trick as it seemed easy to break the bolts free from tight. Looking at the broken bolt, it is shiny and somewhat lightweight. It does have a built in washer.

Still haven't figured out how to safely turn the table. Need another person of some strenght. Wife tried and it was too heavy for her. May have to wait till Thursday when my brother is available.

[Ed in Tampa]

I would remove the motor before I turned the machine over. If you do not remove it make sure you secure it, you do not want a heavy motor flopping around.

I would then scribe a line on the bottom of the table showing where the trunnion was.

Then I would remove the trunions. If you lived a good life a portion large enough to grasp of the broken bolt will be sticking above the table. If the bolt broke even or below the surface of the table you know you haven't lived a good life and you need to improve.

To remove the bolt follow the comments above. But remember easyouts are better known as easy breaks and if you break one off in the bolt you will hate yourself.

Next time tighten the trunions bolts do not torque them down until they break.

[Dansmith]

I would remove the motor before I turned the machine over. If you do not remove it make sure you secure it, you do not want a heavy motor flopping around.

I would then scribe a line on the bottom of the table showing where the trunnion was.

Then I would remove the trunions. If you lived a good life a portion large enough to grasp of the broken bolt will be sticking above the table. If the bolt broke even or below the surface of the table you know you haven't lived a good life and you need to improve.

To remove the bolt follow the comments above. But remember easyouts are better known as easy breaks and if you break one off in the bolt you will hate yourself.

Next time tighten the trunions bolts do not torque them down until they break.

I did take motor, extension tables and rip fence guides off. Good idea on the scribe. I must be a heathen because I could feel nothing sticking out of the bolt area.

As to over-tightning (need to stop working out ), that one was the one that was hardest to reach. No tighter than the others. I wonder if using a stronger grade bolt would help? Or, could that lead to stripping the thread as opposed to shearing a bolt?

[Ed in Tampa]

I would remove the motor before I turned the machine over. If you do not remove it make sure you secure it, you do not want a heavy motor flopping around.

I would then scribe a line on the bottom of the table showing where the trunnion was.

Then I would remove the trunions. If you lived a good life a portion large enough to grasp of the broken bolt will be sticking above the table. If the bolt broke even or below the surface of the table you know you haven't lived a good life and you need to improve.

To remove the bolt follow the comments above. But remember easyouts are better known as easy breaks and if you break one off in the bolt you will hate yourself.

Next time tighten the trunions bolts do not torque them down until they break.

I did take motor, extension tables and rip fence guides off. Good idea on the scribe. I must be a heathen because I could feel nothing sticking out of the bolt area.

As to over-tightning (need to stop working out ), that one was the one that was hardest to reach. No tighter than the others. I wonder if using a stronger grade bolt would help? Or, could that lead to stripping the thread as opposed to shearing a bolt?

If you did not gorilla the bolt I suspect it broke do to a defect. When tightening these bolts remember you only need to tighten them enough so the two pices of metal pressed together will not slip under low lateral load.

Biggest problem is making sure the two are parallel to each other. If they are not perfectly parallel the blade will will heel when tilted to cut a bevel.

Most people make sure the blade is parallel to the fence and forget to insure the two trunions are perfectly parallel to each other. Parallel in the same planar front to back and left to right.

My opinion a perfectly aligned Saw that has trunions mounted directly to the table is far superior to other methods but they are harder to align.