Thread: Exploding Trolley

I just got back from the local hospital after having my hand x-rayed, luckily no breaks but severe enough bruising.

I had some Aluminium plate delivered this morning 6061 T6 1/2" plate for the CNC project. Too heavy to carry easily.

So I get the trolley out and the tyres are flat!, crank up the compressor and pump up the tyres, did the first to about 40psi and was pumping up the second when the rim let go with an almighty bang that brought the wife running out of the house. My hand was right in the firing line.

The rim is in two halves bolted together with 4 bolts and the heads of two of the bolts pulled through the rim, I haven't found the other two bolts, but I suspect they might have let go first.

So, my safety tip for the day is... take care when pumping up the tyres on those cheap trolleys. Might be worth replacing the bolts holding the rim halves together with hi-tensile and putting decent washers under the heads.

Regards
Ray

I have another trolley, exactly the same, and it appears to have only two bolts holding the rim halves together there's two bolts missing?
maybe the one that exploded was the same? Faulty assembly in the factory perhaps?

Hope you recover quickly!

A warning for us all with cheap trolleys. Just checked my $25 Supercheap trolley, it has 4 bolts in each wheel.

Ray gee that not good hope the hand is ok

you been pinching the bolts for saw handles again haven't you

Have been around and seen tyres from pushies to semies fly off rims the old lock rims were the worst I thought till tubeless rim came in. Bridgstone tyre fitted stuck the rim and tyre in the cage to inflate it exploded rocking the truck shattering the office window bending the cage.

Thanks Kev, and Wheelingaround, the hand is just fine, they made me have a tetanus booster I think it's more than 40 years since the last one. The tetanus injection is more painful than the hand.

Just reviewing what I did, and a couple of things that I can think of to pass on to others that might avoid someone else having the same accident.

First and foremost, check that all the bolts holding the rim together are there. I am pretty convinced now that there were only two bolts of the four actually there.

Second, the tyres are pretty small in volume, relative to a car tyre and so the pressure rises very very quickly and it's easy to go too far, which I obviously did. The answer is short bursts and check often as the pressure rises.

Third, I think 20 or 30 psi will be sufficient in future.

Hope that someone files all this away in memory and avoids the same accident in the future.

Regards
Ray

Hi Ray,
Sorry to hear about accident, hope theres no permanent damage.
I was just talking about the same thing the other day over here
http://www.woodworkforums.com/f184/m...61/index3.html
We were trying to get some trike flat track tyres onto the trike rims when I was about 18- 19, we went up to the local hardware and bought all new bolts to be safe. We only had a foot pump at the time and were taking turns. I was pretty exhausted, and said to my mate half time you have a go, within 10-20 pumps it blew the rim apart, strait into his shin in 2 spots, 2 of the bolts sheared and the other 2 pulled through the rim leaving a hex hole from the heads. Still have the rim around here somewhere.
Dave

Hi Ray
Do you think you could be a victim a a covert clandestin mission by those orientals to mame and disfigure the Australian population?

Now that the horse has bolted and run over the hill....I have never been a great fan of pneumatic tyres on small wheels. In my world they are always flat when you want to use them and that is why I much prefer solids. My rough work lanmower has wheel barrow tyres on it and that is the limit to the pneumatics around here
My mate has a trolley similar to yours, by desccrition, and his wheels buckled under the weight of some thing a little weighty. I made up a trolley and used solid wheels from a wheely bin and it will carry big loads well and.....you don't have to pump them up!

I hope your convelecence is short so you can get back to the important part of life....Shed Time

Commiserations RayG, I hope you heal up nice and quick.

And thanks Dave J......because as I was reading RayG's story I was thinking "I'll be right, I don't have a compressor, I use a foot pump", not so. I'll be a bit careful with the little cheap Chinese split-rims in the future.

Isn't it amazing how dumb things sound when you type them out? I use the foot-pump to pump up trailer and car tyres so, of course, it'll blow apart a rim if you don't look out.
And "cheap Chinese split-rims"? Talk about dumb.......read it out aloud...it sounds even dumber.

As usual accidents dont happen they are caused,no offence to anyone at all but "common sence" should be to check max inflation pressure first on any small rim.

Hi Pipeclay,
I cannot speak for Ray's tyres, but the one we did was under the max pressure. We were trying to get the bead seated with plenty of soapy water,when the cheap hardware bolts gave way.
Dave

Thanks to seanz, DaveJ and chambezio for asking, the hand is just fine. I'm back on the project trail. I swapped wheels with the other trolley (4 bolts this time).

Originally Posted by pipeclay

As usual accidents dont happen they are caused,no offence to anyone at all but "common sence" should be to check max inflation pressure first on any small rim.

Ha! now he tells me....

Actually, the reason the rim blew apart was,it was only attached by two bolts rather than the four it was designed for. Nothing to do with maximum pressure.

I advise anyone with one of these cheap trolleys to check their rims are properly bolted together, preferably with high tensile bolts and decent sized washers. I'm still amazed by how much power can be released by such a small tyre.

Dave's trike tyre blowing out would have been very scary. I shudder to think.

Regards
Ray

Glad to hear everything is fine.
You must have good hospitals down there, if you were up here you would still be there.
With the trike accident we had neighbors from 4 doors down each side come running as they didn't know what happened, it went off like a bomb.
Did you end up getting that slab of aluminum moved?
Dave

Couple of weeks back I noted that the bolts were loose on mine

Originally Posted by pipeclay

As usual accidents dont happen they are caused,no offence to anyone at all but "common sence" should be to check max inflation pressure first on any small rim.

Sorry to disagree but accidents do happen. I have heard this argument so many times and commonsense is not always that common.
Anyway I hope your hand mends real quick Ray and it doesn't keep you out of the shed.

If reading what was written by the original poster and his conclusion to the cause what was the "accident" that happened without cause?

Originally Posted by pipeclay

If reading what was written by the original poster and his conclusion to the cause what was the "accident" that happened without cause?

Yep, no question, it was my own stupidity in not checking the bolts holding the split rims, and it's warning others to be careful with these seemingly harmless little wheels that prompted me to warn others of the danger.

Of course if I had a JSA prepared then the JSA would now need updating to reflect that the rim bolts need to be checked..

If I can help just one other person avoid the same problem, or at the very least be aware of the danger, then this thread will have acheived something.

Hi Dave, Yes, I did get the Al plate moved, all good. I won't actually be ready to start any layout of the motor mounts until the mill arrives, which has now been delayed for a few weeks.

Regards
Ray