Setting up a Tri-Leva Myford ML7

Hi everyone,

Totally new to Myfords and am having a problem setting up the belt drives to achieve a drive free rotation with levers disengaged and a firm drive when the speed is selected. At the moment when I turn the power on the motor starts turning as well as the chuck, though with suitable welding gloves on I can hold the chuck with some slight force.

Speeds two and three automatically disengage when changing selection but speed one, the slow speed, does not disengage any active speed lever, though all speeds disengage when the lever is returned to the rest position.

Reading through the Myford ML7, with Tri-Leva addendum, book helps a little, but the Myford Series 7 book hardly mentions the Tri-Leva and is of little or no help in this regard.

I also note that the upper belt trap is completely missing and need clarification as to whether this is a pre-requisite or not to a correct set-up.

Also, the tray top cabinet has two factory fitted flush switches with engraved plates on the left of the opening, with the upper one labelled "reversing switch" showing forward, off, reverse and off, all in a clockwise direction, and the lower switch labelled "speed selector" and agin clockwise from the left showing low at 9pm and high at 3pm with small white buttons at 12noon and 6pm.

The motor is a Brooks Gryphon apparently running at 2850rpm from a 230v 50hz single phase supply and the original wiring from the two front panel switches shows four worse for the direction control and 6 wires for the speed control, but the motor is bypassing those and running in a forward direction only via a push button starter on the oblique panel to the left of the front. The motor drive pulley is 1 7/8" diameter and the countershaft pulley is 6 7/8" diameter. I have a laser rev counter coming sometime today or Monday so will be able to monitor the actual spinning speed but at the moment it looks like the full 2850rpm.

I realise that there are a lot of questions in my opening message but any assistance would be most gratefully accepted and I am located in Hampshire, if that helps at all.

Does anyone in this forum have a Tr-Leva and help in anyway so that I have something safe to use.

With thanks in advance, Mike

Hi Mike

I have a Tri-Leva - super machine!

I have a copy of the Tri-Leva handbook (somewhere!) so wil try to find it if need arises. The problem you have sounds to me like mis-matched belts. They HAVE to be installed as a MATCHED set of three as (from memory) they are difficult to adjust individually. When I did a belt renewal (20+ years ago, I resisted the temptation to replace the damaged belt only, and got a set of three - not regretted it.

My location is N Norfolk, so not geographically helpful. If you need copies of H/B extracts, pleae PM me.

Rgds

Bill

Not sure of the wisdom of using a glove when trying to stop the chuck. I know an ambulanceman and attended someone who lost most of a finger due to a glove meeting a drill chuck last sunday.

Neil

I have a Tri lever machine, lovely bit of kit!

2850 rpm sounds bit quick on an ML7, fairly sure my two speed is much slower than that.

If the levers do not disengage properly it might be worth checking that the return springs are ok, I have experienced problems caused by those, they seem to very critical (on my machine anyway).

I do agree with Jack's comments about belts.

No power to the workshop for a couple of months now (house modifications), so not able to be more much help really.

Edited By V8Eng on 16/11/2013 19:19:09

The Trileva attachment can be very fiddly but once set up correctly they work very well. If the top belt trap is missing, it will not work properly, the purpose of these is to lift the belts away from the pulleys. It should be possible to fabricate a replacement but you will probably need to borrow one to copy. The lever linkages wear if not lubricated, the detent notches can wear away completely, this can cause failure of the lever to latch and also failure to release. Ensure lever return springs are not trapped or damaged. Examine each lever assembly for wear, compare each set against the other two. There is a rocker arrangement at the bottom which automatically releases the currently selected lever when either of the other levers is depressed. Worn or mismatched belts cause problems. Excessive belt tension should be avoided, finger tip pressure should be enough to engage each speed. The pulley sizes sound about right. It sounds as if the original 2 speed motor has been replaced but check motor information plate, it's possible someone disconnected it and didn't know how to reconnect it. 2800RPM motor may be fine for collet work but a bit fast if you want to turn big lumps.

Gentlemen, I thank you for your input and so far have managed to resolve the drag on the drive belts to the individual speed selectors though the belts are quite slack and do agree with the comments of "daveb" in that I feel that the trap is to guide the belts onto the top pulley. Whether I shall be able to find this trap assembly is something else.

I feel that the motor is far away from being the original and will replace it with a 1425rpm version though would appreciate input on the benefits of 3phase over single phase.

Finally, managed to get a perfect cut across and 8" length of mild round bar and it seems that I was running far too slow a turning speed combined with a too slow cutter feed speed, so round 1 to me, though it took a friend of mine with more than 35 years experience of lathe work about 3 seconds to sort me out, you just can't beat experience.

If there is anybody within a relatively short distance of Hampshire who has a Tri-Leva I could look at for comparative reasons then I would love to hear from them.

With thanks, Mike

Mike

I have sent you the scans of the Tri-Leva relevant extracts from the ML7 manual. Have you received them?

I ask because I did a 'copy and paste' of your email address and have a nasty feeling that I may have included the final full stop - in which case the message will be wandering around in e-space!!

Rgds

Bill

Morning Mike

Sorry that I have only just seen your query

If it is of any use you would be more than welcome to come and see my ML7-R Tri lever.

I have installed an inverter and it has made life so much more pleasant.

I live in Henfield in West Sussex - hopefully not too far away.

Richard.

I think the motor on these was a 2/4 pole type 2800/1450 rpm. You would need a wiring diagram to set it up.

Ian S C

Hi Richard and Ian,

Thanks for the replies and I managed to find, and purchase the bits required to complete the Tri-leva assembly, which now works a real treat but also have a proper Myford 2 speed motor. Just sorting out the wiring so that it will fit onto the original separate switches on the stand and will then post some pics.

Best regards,

Mike

Hi Mike

I have just purchased an ML7 with tri leva and, like you the belt trap is missing.

Can I ask where you managed to get one from?

Kind regards

John

If you need a copy of the wiring I have one and can send you to you but I would need an address. I'm not very good on the computer but might be able to get my neighbour to send you an attachment but would need your email details. There was quite a discussion on here some time ago about the Tri-lever so you might be able to locate it.Ted

Hi could I trouble you for a scan please of the tri lever handbook

Edited By JasonB on 25/07/2020 19:17:20

I really need a copy of the tri lever handbook of anybody cab help

What's being discussed seems to be the Tri-Leva section of the regular ML7 user manual rather than any "Tri-Leva Handbook" (if such exists). You can get the ML7 User manual here.