Broken trunion

[Rjgooden]

I have a 2007 grizzly 0478 tablesaw with a broken trunion. I called grizzly and the part is discontinued, anyone have any suggestions on what to do? I thought about welding but not sure how accurate and strong that would be. I have no how this got broken I just noticed I was getting burning on the wood when I cut thicker material so I checked my blade for straight. It was out and upon closer inspection found the break. Any idea would be greatly appreciated. I hate to scrap the saw it was a great machine that did everything I wanted.

 

[Mike Davis]

No joy...

 

[Hmerkle]

It can be welded or brazed, but may need some machining after that work to "put everything back where it should be..." that is the potential hazard.

 

[bob vaughan]

There may be design flaws that put unnecessary pressures on the the trunnion bracket and that's why this model was discontinued. Having the parts brazed may repair the break, but it may not eliminate the pressures that caused the break in the first place. I really can't be optimistic about what I see there. Good luck.

 

[Rjgooden]

Looks like I may be in the market for a good used table saw. I don’t think I can justify the cost of a new one.

 

[Charles Lent]

Welding cast iron is difficult and should only be done by an expert welder with cast iron welding experience. There are special high nickel content rods that cost about $3 each when I last bought them 10 years ago. The cast iron pieces need to be pre-heated evenly and slowly before welding and slowly cooled after welding, or it will break again, usually during the cooling cycle. You will be much better off having someone braze it back together. A table saw trunnion should last a very long time if brazed, as long as it was done correctly. The success of brazing it will be much higher than welding.

My son and I own a metal fabrication shop. Not looking for business, just saying this to show my experience with cast iron.

Charley

 

[Rjgooden]

Charley where are you located?

 

[tvrgeek]

Hybrids are much lighter weight. Often the trunnion is aluminum. Basically, a contractor saw on a box. I do not know that saw. Hybrid the trunnion is attached to the top. Cabinet saw the trunnion is attached to the base.

OBE, no parts. SOP for Griz.

 

[Jim Roche]

Ron, looks like you're in Washington? If you're not opposed to a road trip to Raleigh, I know of a place that welded a broken trunnion for vintage bandsaw and did an excellent job for very reasonable (At the time $20). I thought it was going to have to be brazed but he asked me if I had any opposition to him welding it if he could and I said no, I'd prefer the weld.

Hamilton Machine Shop
908 Withers Rd
Raleigh, 27603
919-779-6892

Good Luck,

Jim

 

[Rjgooden]

Thanks Jim. I’m going to a local metal shop tomorrow to see what they can do, if no go I might contact them

 

[Charles Lent]

Charley where are you located?

I am in Kannapolis. Son and shop are in Enochville, but we are not taking work right now. Son is in process of preparing his land for a modular home arriving soon. I'm about to have cataract surgery. He has no time for doing work for others at this time. I just wanted to give you good information about how to fix your saw correctly, as many people think welding cast iron is easy. Doing it properly is not at all easy, and if not done right will lead to destruction of your part. It will shatter if not properly heated and cooled slowly, even if the correct rods are used for the repair. It's a fine art that even most semi professional welders have failed to master.

Brazing, though it's gold color looks ugly for a repair, is actually the safer way to repair cast iron. It still isn't as easy as soldering copper, so find someone who knows how to do it right. A professional welding shop in your area would be a good place to start, but ask questions and look for examples before giving them the job.

Charley

 

[Oka]

This is correct, the nickel-alloy cast rod is the one he is talking about. I have cast-45's, but there aree different mixes, guys who specialize in fixing exhaust manifolds will know if using the nickel alloy rod or brazing will know which is better. Pre heat is required, usually 250-400f range

Welding cast iron is difficult and should only be done by an expert welder with cast iron welding experience. There are special high nickel content rods that cost about $3 each when I last bought them 10 years ago. The cast iron pieces need to be pre-heated evenly and slowly before welding and slowly cooled after welding, or it will break again, usually during the cooling cycle. You will be much better off having someone braze it back together. A table saw trunnion should last a very long time if brazed, as long as it was done correctly. The success of brazing it will be much higher than welding.

My son and I own a metal fabrication shop. Not looking for business, just saying this to show my experience with cast iron.

Charley

 

[tvrgeek]

Slightly tangent, but seems we have well informed folks here...

What are the differences in welding between grey iron ( I assume the Grizzly trunnion) and ductile iron? ( as in our better planes.)
Does not brazing a large part also require preheat?

 

[Rjgooden]

Okay, so I took the trunion to my local machine shop and had it brazed. After putting the saw back together I can’t seem to get the blade parallel to the table it is out by .02 and no matter what I do it will not get squared. I think it might be brazed a little out of square. I know it doesn’t sound like much but I think it is causing some problems with feeding the wood through. Any thoughts? I marked everything and put all the spacers back in place. After several hours of taking apart and putting back together I think I am at a loss. The saw still works but the fine cuts are a little off.

 

[Mike Davis]

It should be parallel to the slots and not more than .002 off. You can file the adjustment slot a little if necessary.

 

[FredP]

Did you set the stops? They may have been adjusted by the previous owner to compensate for the broken part. I am assuming this is a cabinet saw. If so the table is adjustable. Square the table slots Square to the blade. On a unisaw you simply loosen the table bolts, bump it into position and re tighten. I don't own a grizzley so I may be FOS. YMMV.

 

[tvrgeek]

Looking at the pars diagram, the trunnion hangs from the top by 4 bolts through the two trunnion brackets. There does not seem to be a cam or anything to help you adjust it like my Ridgid had or the mod kit for a Delta contractor saw. Unless it is hitting something, those holes could be tweaked to allow more adjustment. ( page 44 of manual)

https://cdn0.grizzly.com/partslists/g0478_pl.pdf

https://cdn0.grizzly.com/manuals/g0478_m.pdf

 

[Rjgooden]

Thanks guys I tried everything that the manual offers. One of the mounting holes was on the broken part and I think it is limiting the adjustments just enough to cause a small problem.

 

[tvrgeek]

File.

 

[tvrgeek]

Of course, it is an excuse to get a newer saw with a riving knife.