Which belt for Myford lathe?

[gareth689Participant @gareth689]

Hi all, just picked up what I think is a Myford ML7.  Never used a lathe before but it was £200 so just had to.

it does however need a belt to go on this part?  I don’t even know what to search to find it, as I’m clueless.

Could anyone tell me what belt I need for this?

Thank you ☺️

[OldironParticipant @oldiron]

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

[DiogenesParticipant @diogenes]

It’s an A23, as discussed towards the bottom of this recent thread

https://www.model-engineer.co.uk/forums/topic/myford-countershaft-and-belt-help/#post-749144

– do read Hopper’s comments about shims etc. which will be encountered when removing and replacing the spindle!

[Robert Atkinson 2Participant @robertatkinson2]

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.

[Roderick JenkinsParticipant @roderickjenkins93242]

+1 for the linkbelt, I’ve been using a similar one on my Myford S 7 for about 10 years now.

Rod

[Mark RandParticipant @markrand96270]

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).

[Robert Atkinson 2]

On Robert Atkinson 2 Said:

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.

I put a link belt on my S7 but cannot stop it slipping need to bite the bullet and fit the recmemded one

H

[noel shelleyParticipant @noelshelley55608]

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.

[DiogenesParticipant @diogenes]

👍 I’m not a huge fan of link belt either..

Gareth, what region of the country do you reside in?

[John HaineParticipant @johnhaine32865]

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).

[gareth689Participant @gareth689]

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

Im based in Somerset.

[gareth689]

On 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

[Robert Atkinson 2Participant @robertatkinson2]

I did start my post suggesting a link belt with “If you are not used ot working on this type of machine…”. As the OP stated that he didn’t even know what to search for I assumed they had probably not replaced many V belts never mind disassembled a lathe headstock.

My very early ML7 has a link belt identical to the New Myford one and it runs perfectly. It was fitted by the previous owner who was highly skilled and had built at least two locos using the ML7.

Robert.

[bernard towersParticipant @bernardtowers37738]

Definitely a link belt in your situation and this enables you to run the machine and if faults occur they can be diagnosed and repaired, not the same with a non runner.

[gareth689Participant @gareth689]

<p style=”text-align: left;”>That makes sense.  In that case I will try the link belt.  Nothing to lose really.  I have some mechanical experience and have stripped and rebuilt many engines but completely new to lathes and not sure I can be bothered taking it all apart, especially as I’ve checked it with a dial indicator and there doesn’t appear to be much wear in it.</p>
Would this be the correct one?

 

or are there any others that you would recommend?  I read about Fenner but can’t find in stock and is significantly more costly in most places.

[Neil LickfoldParticipant @neillickfold44316]

I installed the above Myford link belt recently to the headstock. Very happy with it. It does need to be the correct way around. It does work in reverse, but have not done any slip test on it. I am not into seeing how big a cut I can take on my S7. I am more interested in having the highest precision in roundness of the parts I make on it. I have another lathe for roughing out stock with. In the process of making a Myford Nose adapter for my other lathe. So I have the stock in the chuck, and just swap out the chucks with the stock still in the chuck.

I put the linkbelt from the motor to the clutch many years ago. It made a big difference to the surface finish, as there was less total vibration. The headstock link belt makes the lathe rpm alot more consistent than the normal full section belt. I did not notice any change in vibration, ie not seem more vibration with the link belt on the headstock. I set the tension a bit like the old belt. When it takes a cut, you can see the free side with a little slack happening. If there is too much slack happening, there seems to be an effect on the surface finish.

I had another belt that has the metal rivets that twist and lock the links. I have not used that one yet. I just had an unfounded fear of the rivets running somewhere in the bottom of the Vee.

What I did notice, is that for the same 50hz in top speed, instead of being 610 rpm as it was with the old Vee belt(Installed 1996) the new Myford sectional belt now has a top speed of 645rpm. This is the top speed on the spindle and the lower speed from the motor to the clutch. I guess as it stretches and wears in, the rpm will lower to the correct value that is on the plate. In time it may need a  link removed. Also not a big deal. In 96, I replaced the belt with a Gates belt that has the sections removed to improve the small radius deformation of the belt to the pulleys. Same for the motor to clutch belt.

I think that if the belt is too tight and something goes wrong, I would rather stall the spindle than stall the motor anyways.

I do like that the link belt is done without disturbing the spindle assembly. Both the S7 and the ML7 have their quirks when it comes to removing and then reinstalling the spindles. Read the lathe Manual and it will explain what is required.

[john fletcher 1Participant @johnfletcher1]

If you do decide to fit a new belt as opposed to a link type, be careful not to mix up those shims under the bearing caps or lose one. Having fitted a Fenner link belt to my Super 7 several years ago I’d stick with that personally. So convinced,  I went the hole hog and fitted Fenner belt on the mill and drilling machines, no problems at all. John

[gareth689Participant @gareth689]

I’ve ordered the link belt from myford.  Than you for the advice.  Maybe one day I’ll be confident enough to put the correct belt on it.

I will no doubt be back for more advice when it gets delivered.

[John Haine]

On John Haine Said:

Link belts are fine if you use the right one and fit it the right way round.

What way is the right way round? My S7 could do with a new belt and I cannot be bothered to pull the spindle out so fancy using a link belt. Could someone post a pic of which way round the belt goes please.

[John HaineParticipant @johnhaine32865]

[John HaineParticipant @johnhaine32865]

this on a Super 7

[BazParticipant @baz89810]

Many thanks John, a picture is worth a thousand words!

[peak4Participant @peak4]

The instructions for two of the most common link belts are available here.
Personally I find the installation instructions on the Acculink less than clear, but made more obvious when viewed in conjunction with the Fenner ones.
I would concur that the original black or white ones from RDG were hopeless.

Green Megadyne Acculink (the ones I use)
https://megadynegroup.com/files/resources/attachments/md_broc_acculink_web_am_en.pdf

Red Fenner Powertwist (top link seems to be in colour, second one B&W)
https://www.fennerdrives.com/install/

Bill

[noel shelleyParticipant @noelshelley55608]

is the belt in John Haines picture fitted the right way round ? Noel

[noel shelley]

On noel shelley Said:

is the belt in John Haines picture fitted the right way round ? Noel

I didn’t want to be the first one to mention that 🙂
If one is familiar with NuTlink belts, it might be easy way mislead yourself, as I did originally when I bought one of the original RDG plastic ones.

The NeoLink ones, apparently run either way.

Bill

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