Myford super7 clutch

I have a myford super7 don't know how old it is ( can't find the serial number ) but it has a oil spy glass . The clutch is slipping and every time I ajust the clutch it starts slipping again after about ten minutes.

Has any one had the same problem or know how to fix it.

Many thanks. Tim

Tim,

There is a locking screw after the adjusting screw and you did it up tight, so the adjustment is not vibrating loose?

Tim,

Type "Old super seven" (note not S7 or Super7) into the keyword Search box and you will get an "old clutch" post from way back. It's as Robbo says, a second screw on top of the adjusting screw. The original had a screw slot top which is easy to fashion - no allen keys back then

Dennis

Edited By DMR on 14/04/2014 01:25:32

Tim, this is a Mark 1 Super Seven.

I had a similar problem with clutch adjustment and if the 'lock' grub screw doesn't help fix it then there is a "push-rod" below that might be broken or chipped at the bottom (which means that you cannot get the full range of clutch adjustment). From memory, this is a fairly simple cylinder that was not difficult to replace with a newly made one (you cannot buy Mk1 clutch spares). My Mk1 clutch had a bit of a rattle, which was a clue to the presence of the broken bit inside.

The actual clutch adjustment can be quite fiddly to get just right and it's worth taking your time to get it spot on. I struggled at first with either a very tight clutch (almost impossible to move) and one that slipped badly. I dismantled my clutch and could not see any real (major) wear and eventually managed to get it set "just right" but it did take more than one or two attempts. Very much worth the effort though!

Regards,

IanT

I set the adjuster screw and tightened the grub screw it was ok for 10 minutes then slipping again , when I checked the grub screw it was still tight so it looks like I will have to take it apart to see if any thing is broken

thanks all for the advice

Tim

I have an ml7 and i just use the belt tensioner lever as a clutch, its dirty but works for me

Tim,

I had the same problem (and provided a response to a similar question from someone else on this forum - but can't find it).

I adjusted the screw until the clutch worked reliably (if only for a few seconds) then counted how many turns it needed to remove the screw, introduced a tiny amount of Loctite (nutlock, NOT studlock) into the thread, using a piece of wire, then put the screw back in and screwed it in the appropriate number of turns. Problem solved!

I have read of a second screw being tightened up behind the first one to act as a lock - but would imagine that if the first one rattled loose, the second one is likely to do so as well.

Regards Tom

Tom,

The second screw to act as locknut for the adjusting screw was standard practice and as it came from the factory, as shown in the operating handbook.

The adjusting screw had a slotted end, while the locking screw was a socket hexagon. On top of these was a threaded plug to cover the hole.

Phil

I have a 1953 Super Seven Mark 1 like yours, the serial number is on the back of the back shear, probably facing a wall - rather inconvenient to get you head round the back to read!

This is the supplement for our old girls - details the factory procedure for adjusting the old clutches as well as the old parts diagrams etc - this is just the removed pages from the commonly available latter manual www.usinages.com/ressources/file/15705

but here's how I do it.........

There is a large flat head dust cap that sits flush with the bottom of the pulley groove (large flat screwdriver required), under that, there is a hex head lock screw (not sure what size), and under that is the flat head adjusting screw (medium flat head screwdriver required)

I take out the dust cap, remove the hex head locking grub screw, then get my medium driver down the hole, disengage the clutch and then wind the screw in, engage, dis engage, and repeat until until the clutch lever stops a quarter inch from its full travel when engaged, I then disengage for a final time, back off the adjuster just a natts and remove the screwdriver, engage the clutch (to stop the adjusting screw moving) while ensuring the pulley hole is well aligned with the adjusting hole and insert the hex head lock screw, and then the dust cap.

Keep the clutch clean - don't over oil, if you over oil you'll essensially create grinding paste in the clutch which would result in rapid wear.

You should feel as the push rod rides up the notch in the actuating shaft with a little lump at the end, assuring you it's in the right place - if it doesn't feel smooth or catches, time to inspect it.

Edited By Russ B on 19/09/2014 11:16:25

Edited By Russ B on 19/09/2014 11:17:44

Just to clarify - I don't oil my clutch =)

I mean don't over oil the bearing through the nipple in the pulley or the shaft boss through its nipple. When I got the lathe originally it was wet with clean oil, everything was covered and the clutch slipped all the time and had glazed over. I freshened up the clutch and the inside of the pulley with some emery cloth and after an initial bedding in, it has been fine since although does now need more attention, it starts to slip under moderate-heavy load - probably part and parcel of the old clutch mechanism, hence why it was one of the first things to change after just 6/7 years.

If I can't adjust it out, before I give up or try to replace the whole lot I seem to think the pulley might be softer than the clutch ring so I would look to machining it out and press fitting an insert in to it and machining it back to fit the worn clutch insert - how I would do that accurately with just the vertical mill would be the challenge. I do feel like I'm already expanding the clutch ring a long way before it starts to grab anything - I certainly don't want to over stress it and snap it.

Edited By Russ B on 19/09/2014 12:46:26

hello , my problem on a super 7 with a cone type clutch is that it sticks on and doesn't free , stop motor and you can free it by hand but next time you use it it sticks again , The adjustment seems ok with about 10 thou clearance on lever . Any one help with ideas ?

regards Phil

The normal recommendation is to get a hand book. Put Clutch in the search window [Keyword] and you'll get about 2 pages of different threads on mainly Myford clutches.

Ian S C

Although it seems counter-intuitive, to quote from the Handbook: "Cone Clutch. With the clutch disengaged apply two or three drops of oil" with an arrow pointing at the clutch disc. It may help.

HTH,

Rod

Sorry I haven't read all previous posts. I have the same S7 and my clutch has the same issue neededing adjusting every 10 minutes when I first got it. I stripped and cleaned the whole thing out and its been fine since. Old oil, mixed with whatever the clutch is made from had turned in to grinding paste - you'll want to get this out if you haven't already. And don't over oil the end bush or bearings on that end of the shaft/clutch assembly as it will fling out in to the clutch friction area.

The actuating shaft that goes down the spindle with the ramp that lifts wedge up into the clutch ring will need replacing on my machine as the ramp has rutted and makes it stiff with a lump in it right where it engages - it's not nice.

For now, when I adjust it, I take out the cover screw, lock screw and adjusting screw and clean out oil from the threads as well as possible if any exists and apply thread lock, I adjust the clutch so it's slightly loose and then tightening the locking screw down against the adjusting screw (with the clutch lever engaged in drive mode) tightening the adjustment up that extra bit.

I've done hours and hours of work and it doesn't need adjustment yet.

I hope this helps.