Axminster CT918 Belt Issues

Hi Guys,

Im new to this forum & to using lathes solo i have my dads on Axminster CT918 lathe & have been re learning some of the skills he taught me when i was to young to take it all in properly, been using it for a few weeks now & i had a belt snap about 2 days in i put this down to the fact it had been sitting a good few years & was probably in bad condition, i fitted 1 of the spares he had hanging up & carried on 2 weeks later i used the 2 spares he had & have bought another & that is on the verge of going too!! it uses Gates polyflex 5M710 belts so very small & cost £16 a go! i also found a stash of 5 broken belts for it in 1 of his boxes so i im assuming this has to be a very common problem?

I have checked the condition of the pullys & they seem ok to me there was a lot of play in the 1 that is part of the clutch set up as it has some plastic bushes so i re made these from brass in case that movment was the issue but its still killed the new belt

Im thinking its not the best set up & could be worth changing to a variable speed motor setup but not sure what i would need to do this

any help would be much appreciated

Damon

Damon,

I have a Chester 9 x 20 lathe, very similar in design/looks to the 918. I've not had to replace the belt on mine in the years it has been in service....( 10 plus....)

I added a three phase motor /inverter to mine and binned the single phase one.( stayed with the 3/4hp size, but had to machine the motor's shaft to fit the pulley)

As to your belt issue, how is the belt breaking? Is it fraying or snapping?

Some checks to make:

1) Check the pulley alignment, unlikely to be the issue but rule it out.

2) Check the pulleys for any damage to the V grooves, scoring,pitting,burrs etc.

2) Belt tension....is it too tight? With the tensioning lever in the 'run' position, the tension on the belt should be about 1/2" deflection on the longest run....( this is an arbitrary figure....'wet finger in the air' kinda measurement for the purists!)

3) It might pay to go for a longer belt if the tension is too tight.

I got my spares from Beeline Engineering in Milton Keynes cost a lot less than £16!

Edited By John Rudd on 22/10/2020 12:43:55

hi mate

thanks for the reply points 1 & 2 seem ok to me, i think it could be tension issue, when in the high speed configuration you have to stretch the belt on to the pullys so already under some tension, i will try & get some pictures if the belt holds up, will check out thw place you mentioned for replacments too

Hi Damon,

I have the Warco 918, same lathe as yours but like Johns it is converted to a 3 phase motor/inverter.

The belt on mine is a 5M730 so a bit longer than your 710, it is easy to change on all 3 pully combinations and none of them are tight to start with, adjustment on the tensioner is as John says.

Ron

Edited By Ron Laden on 22/10/2020 14:52:33

Damon, looks like the belt is failing due to being too tight and being "encouraged to roll over the pulley's edges"

If I recall, the earlier 9xx series were fitted with a 710 belt, later models of the Chester flavour had a 730.

I think of all the belt issues reported on here, most are about the shorter 710 belt....

Probably the reason why my Chester has never had a belt fail...

Hope you get sorted..

Edited By John Rudd on 22/10/2020 15:18:17

hmmm seems like trying a longer belt could be worth while then i always though it was strange that it was tight on the high speed configuration

thanks mate going to give the longer 1 a go, fingers crossed it even says in the manual 5M710! lets see what google can find for the longer 1!

HI Damon,

There was a discussion on broken drive belts on this class of lathe nor that long ago, The problem with the belt being tight on one of the speed ranges is quite common, my Chester 920 is the same. Just get the next size belt and use on the affected speed ranges. The post is here

https://www.model-engineer.co.uk/forums/postings.asp?th=117687

Thanks Mike had a read through that just now so good info in there