Bolt Strength - Cross Trainer repair.......

[BillyGoat]

Gents/Ladies/Boogymen!

I've got a cross trainer that needs some TLC and I'm wondering if the fix I had in mind is going to hold up or send the wife into hospital.....

Basically, the part that holds the arm at the back has snapped. It's big old bit of metal that goes round and I'm sure it's under stress, but it's just sheered in half.

Here you can see the part that has snapped......

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This is the rear view, where you can see how wide the shaft part is.....

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And this is the other side that's still OK.....

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The snapped part attached to the arm is well and truly stuck, as is the shaft in the middle. Even taking the bolt out the other side doesn't allow a mm of movement.

When you move the good arm, you can see the bit in the bearing on the snapped side move, so the shaft part goes right through the middle. I see no split pins, circlips or anything else! Weird.

The only idea I had was to drill out the middle of both sides and pass a nice strong new bolt all the way through, but I'm not sure it would be strong enough.

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Can't get anything there to weld it, just not enough room.

Is it destined for the bin or is there any point to my plan? Would a bolt take that punishment????

Thoughts?

BG

[Timllfixit]

Have a look on the head of the bolt. If it says 4.6 it's mild steel. If you have one of those I would replace it with an 8.8(high tensile). Try an engineering supplier or fixing specialist. High tensile studding is available if you can't get a long enough bolt. I would think that would be difficult to drill out accurately to a larger diameter.

[Hitch]

Cant see why the old pin wouldn't knock out tbh, Can you get it over a vice or a socket on a bench to give a good smack?
I doubt the sheared side would go through the bearing easily, knock it back the other way...?

What size is the pin then, 25mm? M10 bolt?

I think id try and replace the whole pin myself.

[BillyGoat]

I was hoping the sheared bit would come out, so I tried on the bit that had most grip. A paid of grips that had the most amazing hold and my get didn't shift it. It's like its tacked in place.

If I take the other side, I run the risk of totally destroying it. Might have to try though.

[wrinx]

Looks like you need to tap the bolt back through by hitting the head until it's flush with the bearing on the good side.

The sheared side appears to have been bent/distorted during the shearing process so it'll not come out without being filed flat/round first.

Once that's been done it will hopefully slide out or only require gentle persuasion.

wrinx

[kellys_eye]

If you can get the metal into a vice you can use a couple of sockets (one over-sized and one undersized) to press the bearing out of the bracket in its entirety. Easier to get another bearing in than mess with trying to get the bolt out and ruin the bearing anyway....

[BillyGoat]

It was an 8.8 bolt, but that wasn't the bit that snapped. That just goes into the metal tube bit that's sheared by about 40mm into some threads.

Can't really get sockets on to push it out - on the other side, the X arm bit is attached well and truly, so can't even get to push it out. I'm guessing it's assembled and then rammed together. It's shipped with those bits attached from pictures I can find online.

Final ditch attempt was to drill out the middle, like I'd initally though. Got through one side with a small bit, getting bigger.

Then started at the other side, 1st, 2nd - snap. No warning, no snagging. Just snapped. Looks like it's heading for the scrap head

[BillyGoat]

Managed to whack out the bit and made a hole all the way through.

Ordered some cobolt bits going up in size to the diameter I need.

As I thought it was a gonner, I took the snapped arm out to the garage, stuck a drift in it and whacked the crap out of it with a big lump hammer in the vice - it just made my ears ring and didn't move.

Managed to get the stuck bit out, due to sheer luck and back onto my old plan. If it works - great. If not, it's only 20 clams down the swanny. I'm sure if I leave it outside, it'll be gone in 28 seconds.

BG

[steviejoiner74]

I had one of them cross trainers and the heaviest thing it had to deal with was the clothes hanging from it in the spare room,I think I used it twice