Drive Belts

[clubbyr8]

I bought a M900 lathe from Hare & Forbes at their annual November in Sydney, and the thing has absolutely destroyed the drive belt (I've had the lathe less than two months).
The variable speed mechanism was lubricated as per Hare & Forbes instructions and it seemed to work ok.
When I get a replacement belt, is there any sort of adjustment required to stop this happening again? The instructions that came with the lathe aren't exactly informative.
Any help would be appreciated.

Regards

Bob

[DarrylF]

I have the same lathe under a different brand, and the same thing happened to me.

The two halves of each of the variable pulleys have to move smoothly open & closed. You should be able to move the outer halves by hand - even if fairly stiff.

On mine I removed the circlip on the end of the motor shaft (careful! it's spring loaded - you have to hold the spring in place). Then removed the spring (actually the spring removed itself to the other side of the workshop :)). A pair of bent circlip pliers is really a must. The outer pulley would not move along the shaft. Eventually managed to pry it off the shaft.

The shaft has a hole right where the outer puley goes. The edge of the hole on mine was burred, and as the pulley moved in & out it was shaving off small pieces of metal from the pulley. The bits of metal of course eventually caused the pulley to bind. I cleaned, filed off the burr & polished the shaft, lubricated everything (being careful not to get any lubricant onto the pulley faces where the belt runs), and put it back together.

Then make sure everything that's supposed to move does so smoothly and put a new belt on. Mine works nicely now - better than new in fact.

It's worth having a spare belt, and re-lubricating regularly.

Good luck with it.

[jhunt_2000]

Thanx DarrylF, cause mine just did exactly the same thing...

[clubbyr8]

Thanks for the response Darrylf. I've checked the pulleys and they seem to move ok. I contacted H & F and they told me that the quality of the belt that is originally supplied from China leaves a little bit to be desired. So, they are going to courier me a replacement belt out today and if this one shreds, will send someone out to look at the lathe. Pretty good customer service.

Bob

[Sprog]

Originally posted by clubbyr8
I've checked the pulleys and they seem to move ok.
Bob

Check that the pulleys are in line, they are usually not inline and shred the belt.
There is probably enough movement in the motors bolts mounting holes to align the pulleys.

[clubbyr8]

The replacement belt from H & F turned up this morning. Put it on and the lathe seemed run ok. After about an hour I noticed the belt had a few marks on the right hand side. On playing with the speed change mechanism, I noticed a few burrs on the spindle pulley. Will have to wait now until I can get a pair of circlip pliers.

Thanks for the suggestion Sprog, I checked the pulley alignment and they seem pretty close (to my eyes anyway).

Bob

[TonyG]

I bought an MC 1100 last year and had exactly the same problem. As well as the fixes described by Daryl, I had to dismantle the drive and remove about 1 mm from the back of the fixed side of the motor pulley, to get it aligned properly. It now works well.

The replacement belts for the MC 1100 are available from any bearing sales shop. Ask for an M23 belt, it will cost $4 to $5.
(M is the section size and 23 is the length of belt in inches, if you cut it and stretched it out).
An M section belt is 10 mm across the top and is 6 mm deep. You can measure the approximate length by wrapping string or similar around the outside of the belt.

Another serious problem I encountered was that the tail stock centre height was 1 mm. higher than the head stock. This created problems if using the running centre to steady a job in the chuck.
I spent a whole saturday afternoon filing off the base of the tailstock casting to fix it. This is difficult to do and keep everything flat.

[col2]

Hi all, I too have a H&F WL18 - their version of the MC900. I've had it since late Dec 02, ie about 13 months, and used it most weekends.

A few months after I got it I had to dismantle the motor shaft pulley and clean up some burrs, and I've just finished cleaning the pulley assembly on the headstock spindle.

Ever since I've had it, the speed change mechanism has been really stiff to move _ I just assumed it was meant to be that way. But at the H&F open day in November I got talking to one of the turners who was demonstrating and had the same machine, and his speed change mechanism moved with about 1 finger of pressure. His answer was to regularly clean it.

I was finally prompted to service mine when it got so hard I could barely move it. Then when I had tapped the fixed pulley off, I had to call in a mate with a wheel puller to get the "moving" pulley off. As far as I can tell, it had glugged itself up with a mixture of oil and sawdust, probably blown into the pulley housing by the motor fan.

The fellow I spoke to at H&F assured me that he had never had one that siezed up on the shaft - I haven't bothered to ring him back and claim an Australian first.

It now moves more freely than it did when I first got it. The answer is I think to strip and clean it as soon as it starts to feel a bit stiff, and maybe to limit the ingress of sawdust into the headstock housing (or maybe to leave the pulley cover off).

Despite having to do this work, I still think the WL18 is reasonable value for the money. I too will have to get a pair of circlip pliers.

cheers

Colin

[gatiep]

Two points to note.

Check the edges of the 'fingers' of the pulleys where the belt runs. It is a good idea to run a bit of emery paper just to round these sharp corners.

Lubricate with Graphite powder. Puf some into the pulley boss where it slides on the shaft. It does not attract saw dust like most the other lubricants.

The points mentioned by the other posters to this thread are very valid.

Cya