Slitting a lorry tyre

[jonbarrett]

Following its first real outing at the Robot Crusade, Thundering€™s 1m diameter steel wheels proved a little vulnerable and might as well have been made out of chocolate.

New €˜resilient€™ wheels are being build which should absorb and dissipate impact energy a little better

I€™ve scrounged a 1m diameter steel reinforced lorry tyre that I plan to slit along the tread grooves to produce two strong rubber rings. Trouble is I€™m having difficulty cutting it.

I€™ve tried a: jig saw with metal blade; grinder with metal cutting disc; reciprocating saw; hack saw; die grinder; router; circular saw and even a chain saw. The only tool to actually cut through the rubber and steel was the circular saw but the heat generated virtually set the tyre alight in seconds.

Any ideas?

I contemplated a water cooled tile cutter but I need a minimum 35mm cut depth. I€™m guessing an oxyacetylene flame would simply set the tyre alight while the fumes poisoned me.

Professional tyre recyclers seem to use €˜shear€™ tools but I can€™t imagine how I could fit a set of bolt croppers/metal shear between the deep treads while I cut.

I wondered about easing the job by chain-drilling along the tread groove but even drilling through the material is proving very difficult.

I never knew tyre where this tough.

[fluppet]

Not that this is entirely practical, but have you thought about pouring some liquid nitrogen on it? Id be inclined to cut from the inside out; pour a little N2 into the inside (preferably so it concentrates in the middle), then have a hack with the circular saw. Carefully. Id have thought it would make it brittle enough to cut, although you might want to be careful you dont just shred the whole thing. Itd be extraordinarily tedious, dangerous, and a bit expensive, though.

You might be able to etch your way through it, given long enough and something suitably nasty. They *are* designed to be resilient, though.

Just a thought. Ill be interested to hear how you get on. Are you *sure* you cant just use two tyres? (Even if you were going to cut them down, its probably easier to mangle the half youre removing than keep both sides intact - cut lateral grooves, pour on the nitrogen, then whack it with a hammer...)

--
Fluppet

[maddox]

Freeze it with nitrogen is a good idea.And then a hacksaw.Maybe some cooling liquid.Or the ali cutting trick I use at the moment- WD40.

And, if the tyre doesnt work, maybe TAN like wheels?They are damageable, but sturdy enough to keep you up and running for a while

[jim]

I was going to suggest a big sharp non-serrated knife. Depends whether there are any steel wires going across the plane youre trying to cut.

[teamchip]

Hi Jon

I know the feeling! Chip uses car tyre rubber and that was a nightmare to cut let alone a lorry tyre.

I too tried a jigsaw with various blades, angle grinder, hacksaw etc.

I know you have tried this but I found the reciprocating saw the best with good quality fine tooth blades.

The stainlees steel strands though are pigs to get through and really blunt the blades rapid.

It took me hours to cut 4 tyres for our wheels and they are only about 8 inch diameter, yours I know, are a bit bigger!

Good luck and if you come up with a good method let me know.

Tom

[maddox]

Motorbike racetyres are plyed with Kevlar, way more easy to cut.Thats something we learned making TANs wheels.Also karttyres are easier to cut than cartyres, just because the steel plies.

[jonbarrett]

Thanks for all then help so far.

My comments are:

Andrew: hadn€™t though of freezing it. Never used nitrogen and not sure where to get it but it would be interesting none the less.

Lee: Tried a hacksaw. The steel reinforcement is so hard its like the blade has hit glass.

Mario: My first idea was some MDPE (PE80) hoops 1m diameter, 15mm wall, 100mm wide. I know it exists but cant find a single supplier in the UK.

Jim: The professionals use machines with huge hardened steel discs working like rotary shears. Not sure even these would handle a lorry tyre.

Tom: I€™ll try the reciprocating saw with different blades. One uses a carbide grit instead of teeth.

As an aside, I€™m considering a different construction using a 25mm diameter MDPE (high pressure water pipe) slipped inside two-ply steel reinforced high pressure hydraulic hose to provide a semi rigid plastic/steel/rubber rim. First quote for the toughest hose with 25mm bore was £170.00. Anyone in the hydraulic business that would like to beat that quote please say!