Linked belt for Myford 7

Maybe ansking the question when the horse as bolted but Ive just ordered a link haedstock belt for my super 7 so who else is using one ?

H

I am. Where did you order it and for which version of the S7?

Yup, had one on mine for years with no probs whatsoever.

Opinions seem to vary between claiming that the drive is less smooth, whilst others clam a smoother drive. (maybe a uniform belt section compared to a belt with a thick section in one part? )

My experience is confined to fitting a plastic link belt to a Myford ML4. This did improve matters, but it must be said that the original belt was WAY past it's life span, and was disintegrating!

For my big lathe which replaced the V belt driven ML7, the importer's advice was:

When the V belts for the Headstock required replacement, rather than disturb the roller bearings and oil seals, cut off the old V belt and replace with a link belt.

Over sixteen years later, that is a bridge yet to be crossed!

I have used link belts in other applications, (other than machine tools ) without any apparent problems.

Howard

Edited By Howard Lewis on 06/02/2020 16:35:57

I have link belts on both primary and secondary drives on my S7. One advantage over the conventional vee belt is said to be that the link belt won't take up and "memorise" a set if left taut and unused for a period. Replacing the drive to the spindle with a link belt obviously avoids the need to dismantle.

On the other hand, the greater bulk of the link belt may make shifting to and from the top speed pulleys more difficult.

Initially I fitted a plastic belt sold by RDG as suitable for the S7 - however it was designed for the older smaller bore lathes that have wider vees and slipped horribly. I ended up buying a more expensive one from RS the right size for the pulleys and it has been fine.

There is nothing wrong with using a Temporary link belt if you are not wanting to strip the machine. If at all possible then use a proper belt. Just ask the question. Would you consider taking a drive belt off a car & fitting a temporary link belt. I think it was Fenner who 1st invented them for emergency use. Mainly in factories that ran line shafts, which powered multiple machines from the one shaft. I have recently finished my work on the Myford & while doing it fitted the original spec ones that I bought from Myford's in Halifax. The machine runs near on silently. The Heastock shaft is not hard to remove from the Super 7.

Steve.

    Must admit didnt fancey stripping down to fit a belt

   H

Edited By Harry Wilkes on 06/02/2020 18:00:17

https://www.ebay.co.uk/itm/Brammer-Type-Link-Belting-Z-Section-10mm-Machine-Drive-Belt-Nut-Link-Style-Belt/253792890910I use two machines with linked belts. The Smart & Brown model A has one as standard from the 1 1/2 hp three phase motor to the three speed intermediate gearbox. I have a spare 13mm? belt standing by, but the old one keeps going. The Tom Senior light vertical with the R8 spindle and 1 hp three phase/ VFD has a 10mm? linked belt. There is a preferred direction of running the belt to match the normal forward, but the belts will happily run in reverse. The preferred direction is with the outside of the belt like a ratchet, the gentle slope running forward. There was an initial bedding in of the TS belt with dust and small bits coming off, but that has stopped now.

I think linked belts are a very good idea, especially as you can fit them without removing things like lathe spindles, as long as you can get enough slack to get them joined up.

The link is Lister Spares

Edited By old mart on 06/02/2020 21:49:36

Edited By old mart on 06/02/2020 21:51:11

I have seen them as original supply on machines nowdays and the manufacturer promotes it here.

Fenner Link Belts

Steve

I'm very happy with the powertwist belt on my S7. As we often find, high power industrial practise does not always transfer well to our tiny, low powered machines.

Rod

S.D.L

I have seen them as original supply on machines nowdays and the manufacturer promotes it here.

Fenner Link Belts

Steve.

Hmmn.

Steve.

On my mill and on the old Myford I use Brammer fibre belts with the metal mushroom head .I tried the modern power twist belts and eventually they slipped .I think they might have stretched but I haven't had this problem with the Brammer belts.They are a pig to get joined.

Frank

Tell me about it. My lathe came with them on. Tried being gentle to take a link off to remove the thing. Ended up with the hacksaw. I have a lot of friends who have them. Mainly on there milling machines due to inaccessibility.

Steve.

I haven't had this problem with the Brammer belts.They are a pig to get joined.

Brammer used to supply a tool to help join them IIRC - nothing special, just a sheet metal pressing that had a cutout to fit the head of the pin to twist it. I may have one somewhere.

I've never had much luck with link belts & would not use them through choice. Persistant slip with a new belt was the main reason I chose to replace my original Boxford CUD with a Super 7 - no option but to use a link belt with an underdrive Boxford. I was never comfortable with the amount of tension link belts require to function, particularly with plain bearings.

I don't recall fitting a new vee belt to the Super 7 as being particularly arduous - certainly not bad enough to not want to do it or to look for shortcuts.

There is another form of joinable vee belt that I came across at my last employment. This was a conventional rubber vee belt that was perforated though the thickness of the belt on a constant pitch. It was joined with two metal plates & screws, the wider plate had two clearance holes on the same pitch as the holes in the belt & was as wide as the belt top width, the narrower plate had two tapped holes & was as wide as the narrower side of the belt - two shoulder screws were used to join the ends of the belt together. The only reference I could find to these was in the USA or Japan - no trace of a UK supplier. I seem to think that the belt was fitted to a pump on a machine that came in from the States.

Nigel B.

I've tried various linked belts and all of them require greater tension than a conventional belt to transmit the same power on my Super 7, fine for industrial machinery but possibly not optimal for the long term health of the plain bearings on a Myford.
I do regularly make use of the full 1hp available to me though so anyone performing only light work may never have any issues.

I have used a link belt on my Myford from the motor to the countershaft, I was not impressed with it, the belt had to be drum tight before it would transmit power without slipping. Maybe I was doing something wrong if I was can someone please enlighten me.

Last year I replaced the plain Vee belts on my ML7 with cogged Vee belts. These are more flexible than the plain type and made a big difference to the smoothness of the lathe. It's only a 10 minute job to take the spindle out to change the belt.

I discovered the cogged belts after having vibration problems with my mill after getting rid of the standard twin belt stepped pulley drive and fitting a single belt 3 phase inverter drive. With a conventional Vee belt I got horrendous vibration due to the long belt flapping about. I looked at linked belts and promptly decided against them due to the price! As a last resort I tried a cogged belt and that transformed things immediately. There is still a slight vibration at higher speeds but nothing like it was with the conventional belt.

John

Just thought I'd post an update I fitted the linked belt I recently purchased on my S7 today found it easier than I thought it would be to join it and so far I,m pleased with it.

H

There is a right way round you know with these belts. Maybe that's why some find they slip.

regards Martin