Myford ML7 Gearbox on an Early Super 7

[Russ BParticipant @russb]

ML7 with gearbox, or early Super 7 without?

[Russ BParticipant @russb]

Can a Myford ML7 Gearbox be fitted to a early glass sight Super 7 with ease and preferably no expense?

My brother has bought an ML7 with a gearbox to follow me in to this little modelling adventure, and has offered me the gearbox for a fair price, or the whole lathe as a swap for my early super 7 (to save removing and installing the gearbox)

I've been doing a bit of research so I've got a few direct questions but I'd welcome any suggestions or comments/opinions.

Does the leadscrew need modifying or replacing – will I have to replace his or modify mine?

As I see from researching, this is not a very early box, I think the leadscrew passes through. I also gather it will possibly need a replacement access cover as the ML7 and Super 7 differ slightly.

– I don't think I'd like to swap him, everything seems smaller on the ML7, ie. smaller leadscrew, smaller bull wheel, smaller top slide, less refined dials and hand wheels – and it only has three selectable speeds on the belts, and no clutch. Admittedly, none of this makes its any less suitable for my needs – they're just "nice to have" I guess.

I don't need a gearbox to be honest, again, it's another "nice to have" item but Its Christmas

[Chris TriceParticipant @christrice43267]

Some people question if a gearbox is that much of an advantage. Although they take a few minutes to set up each time, the regular change wheels offer maximum options.

[Russ BParticipant @russb]

Posted by Chris Trice on 11/12/2014 11:59:42:

Some people question if a gearbox is that much of an advantage. Although they take a few minutes to set up each time, the regular change wheels offer maximum options.

Chris thanks,

This has gone quietly through the back of my mind (at least twice) but I quickly dismissed it as I'm a bit of a Magpie when it comes to all things mechanical =)

I'm relatively sure it will take more time and effort to install and align than all the change wheel swapping I'll probably do over the next decade, by which point I may have lost interest anyway or up/down sized.

Edited By Russ B on 11/12/2014 12:33:46

[NJHParticipant @njh]

Russ

I can't really answer your question as to the suitability of this gearbox for your machine. I do have a S7 with a gearbox and I find that useful. I don't often need to screw cut threads ( how often do you need this?) but the advantage of the gearbox to me is the range of fine feeds available and these I use all the time.

Norman

[Enough!Participant @enough]

Posted by Russ B on 11/12/2014 11:47:08:

I don't need a gearbox to be honest, again, it's another "nice to have" item but Its Christmas

I don't know much about the gearbox but I assume that it's also used for automatic feed. In which case it lets you change feed rate on the fly (say for a finishing cut) without reconfiguring a bunch of change wheels. That's pretty handy over and above it's screwcutting uses. (In my case, it would be its primary advantage were it not for my ELS below).

Of course, better still is an electronic leadscrew such as John Dammeyer's which gives you pretty much infinite control (within range) over feeds and threads, imperial or metric at the touch of some buttons without needing change wheels or gearbox.

Edit: sorry, Norman, should read all the posts before posting mine.

 

Edited By Bandersnatch on 11/12/2014 15:34:21

[Swarf, Mostly!Participant @swarfmostly]

Hi there, Russ,

One thing to check is that the bed of your Super 7 has the two 1/4" BSF (or M6 on later models) tapped holes in the front of the bed, between the two head-stock 'push-screw' holes. The gearbox mounts to those and one of the holes for the left-hand lead-screw bearing.

Some Super 7s require a spacer between the gearbox and the lathe bed, though I believe this might not be necessary with later Super 7s.

Does your lead-screw have a coupling to a thinner left-hand end or is it all-in-one?

I suggest that you visit the Mytholmroyd Myford web-site and browse for Gearbox, then scroll right toi the bottom of the page and click on 'larger diagram' (or words to that effect). You should find a down-loadable copy of the illustrated parts list (aka 'exploded diagram&#39.

Best regards,

Swarf, Mostly!

[Swarf, Mostly!Participant @swarfmostly]

Hi there, again, Russ and all,

Dang oi!!!!!!!!! I know always to insert a space between a quote and a closing bracket so as to avoid that unwanted smiley but today I forgot!!!!!

And my apologies for the typo earlier!!

Best regards,

Swarf, Mostly!

[Russ BParticipant @russb]

Thanks all for the input, I had overlooked the fine feeds. I'm more than a bit of a novice and at the moment I don't like to use the feed – just in case I can't stop it should things go wrong.

I really should take the time to properly understand speeds and feeds now I've got HSS tool grinding terminology understood and practised. I've just been using a simple chart, rpm against diameter for a few materials with suggested depths of cut. They don't mention feeds, just a particular setting ( ARX1 for a Harrison whatever that works out at) on the lathe they were designed to be hung next to in a training room somewhere.

[Nigel McBurney 1Participant @nigelmcburney1]

Stick with the Super 7 ,a gearbox is not essential and in the case of the Myford where the lead screw is also used the drive the saddle when power feeding,it puts a lot of wear on the leadscrew. I have a gearbox on my super 7 but I rarely use it.The advantage ,on a non gearbox lathe, is the ability to cut a vast range of pitches.

[RobboParticipant @robbo]

Russ,

If you "don't need a gearbox" then don't bother. The change-over sounds easy, but is a lot of work. Not least your brother will either need a new, longer, leadscrew, or to lengthen the one he has on the gearbox. You will have to modify (shorten) your leadscrew. The Super 7 has a 3/4" leadscrew, the earlier ML7 had a 5/8" one.

You can change over the guards and their backplates, but that's a complete dismantle of that end.

[Chris TriceParticipant @christrice43267]

Which also means changing the lead screw half nuts on the carriage too. It's honestly not worth it. Just set up your change gears for fine power feed and swap them for screw cutting ratios on the few occasions you need to. If it still bugs you, consider selling your lathe to your brother and use the money towards another one already with the gearbox.

[Chris TriceParticipant @christrice43267]

Which also means changing the lead screw half nuts on the carriage too. It's honestly not worth it. Just set up your change gears for fine power feed and swap them for screw cutting ratios on the few occasions you need to. If it still bugs you, consider selling your lathe to your brother and use the money towards another one already with the gearbox.

[Russ BParticipant @russb]

Fair comments, thanks again to all, there are obviously some very clear benefits to having one, however the removal and installation doesn't sound straight forward at all – my machine doesn't even have the tapped mounting holes.

It would probably be wise to spend what limited time I have learning to use what I've already got. I know in the future I would like a newer model with power cross feed – or perhaps something a bit bigger if I have the space. A Colchester Student would be nice.

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