Not a Myford owner but probably an “A” section belt.  Wrap a piece of string around 2 opposing pulleys cut at the overlap and measure the result. That should give you the belt length

If you are not used ot working on this type of machine I strongly suggest you do not disturb the spindle but use a link belt instead of a conventional type. Example from “new” Myford:

https://www.myford.co.uk/product/megadyne-a-section-link-vee-belt-for-myford-lathe-headstock-ml7-ml7-r-super-7/

Other suppliers out there.
You can fit this with just hand tools and no disassembly.

You got a bargin for £200 enjoy!

Robert.

It’s an ML7, not an S7.

Take the bearing caps off.
Lift the mandrel out.
Move the counte rshaft over to one side after loosening the thrust collar and pulley.
Then fit an new A23 belt.

Far better than the link belts (which don’t fit between the pulley and the counter shaft bracket on early ML7’s).

On a ML7 the belt is an A23 and a link belt has NO benefit. I would not use link belt, it is for lazy ——-s may well slip and cause vibration. Just do the job properly ! Noel.

Link belts are fine if you use the right one and fit it the right way round.  They do need quite a lot of tension.  At one point RDG sold a belt with moulded rubbery plastic links, but they were useless and did nothing but slip.  I bought a proper one that looks like the current “New Myford” item from RS who stock a range of them:

https://uk.rs-online.com/web/c/mechanical-power-transmission/belts-pulleys/link-belts/

I’ve used one on my S7 for years and also on my VMB to connect the 3ph motor to the spindle (having eliminated the central pulley which was just a PITA).

On 1 September 2024 at 09:04 gareth689 Said:

Thanks everyone.  I’m leaning more towards the standard belt rather than the link one.

Im based in Somerset.

Beginners are advised to prefer low risk options at first!

• Link belts are easy to fit and nothing is disturbed.   Very little lost if a link belt doesn’t perform.   Actually, they do work, but it has to be the right size and type.
• Standard belts are hard to fit because the spindle is significantly disturbed.  Messing up is painful.   Though it’s a council of perfection, I wouldn’t do it unless a link belt proved hopeless.

Beware well-meant advice from time-served Model Engineers!  They sometimes forget it took them years to acquire skills.  The danger is they might assume beginners are just as smart as they are, which is unlikely!

Take it step by step.   In particular, don’t start by dismantling the lathe and giving it a deep clean.  Risks introducing new problems due to mis-assembly: is the lathe faulty, or has the owner grokked it!  Although lathes aren’t rocket-science, there are a number of gotchas.   Doesn’t take long to build experience, but don’t rush it!

Dave