Choice of chain

Guys,
Given the sort of stesses & abuse we inflict on our drive set-ups, in terms of performance and reliability would a 3/8 pitch duplex chain be a better choice than a 1/2 pitch simplex chain, or visa-versa??

Thanks,
Geoff.

If you have the room and weight, the 3/8 duplex is better.

But I still aint convinced of the wisdom of using chains in robots.

geoff we always used kart gold chain and it never failed. i guessed if it drove them karts at the stresses they use then a robot should be fine. duples is heavy. you will be fine with (i think)3/8 kart. good quality gold stuff tho mate.

The main reason of chain failure in robots isnt the strenght of the chain itself, but the abuse it is given.
Not the forces nor impacts. But the bad alignment, the flexible supports and the tension.
The most succesfull chain users have gearboxes as stiff and solid as the ones using gears

I have always used simplex 3/8 chain in a monocoque thet flexes all over the place. No failures so far ;). To be honest looking at the power we are using 3/8 is probably too big, but its the cheapest readily available solution.

My first 2 robots had bog standard moped chains and starter motors, never had any problem with them.

Hydra uses a combo of 3/8 and 219 go kart chain. These as mario says are mounted in a relatively stiff prame with guides on the sprockets to stop the chain jumping and with chain tensioners.

Andy

Depends on the torque you are applying ,and therefore ratios, we have always used 3/8 industrial simplex with no failure only a little
loosening up,:talker:

I have found on St Hammer that the drive is the part that receives the most wear. Bosch 750 motors driving a complex drive train of 5:1 followed by a ratio of 4:1 giving a reduction of 20:1 the final drive sprockets have hooked and have been replaced once already.
When I get time I will fit final drive with ½€ sprockets to reduce the damage on final drive.
Mind you this drive system bent a 12mm silver steel lay shaft when I was testing the robot!
:uhoh:

1/2 is cheaper than 3/8€ duplex :proud:

specs of tensile strength for each chain.

3/8th duplex has a minimum tensile strength of 16946N

1/2 simplex has a minumum tensile strength of 13344N

depends on how much tourque your pulling.. i work with litrally miles of 1/2 duplex chain at work. Its not light stuff.

Toxic uses 1/2 chains, I have only ever had 1
problem...... when tiberius snapped one in two
when it got nipped quite a lot !!
At the same time tiberius put a 1 hole through
both sides of 20mm steel box 2mm thick then 5mm dent into my co2 main bottle , ouch !!