any engineers info needed on a myford super 7

C

cooper1203

Member
Hi all, winter is here and im looking for a hobby to keep me occupied in the coming months b4 I can start on the rover again. I thought I would get into model engineering as I remember seeing stationary steam engines as a kid and pestered my parents for kits every Christmas.

I have been advised to get a myford lathe as parts are widely available, good quality machine and would be able to upgrade as I progress in skill with out having to buy a whole new lathe as well as being versatile.

I have seen on that is very cheap for a myford super 7 (£925) second hand obviously but all there other machines from the same place are double that. and similar prices else where depending what comes with them. I haven't been to see the machine yet (prob tomorrow) and just wanted a few bits of basic info to know what I am looking for

The description of the machine says MYFORD SUPER 7 3 1/2" x 19", change wheels, clutch, 3 jaw chuck, face plate bench machine, single pulley on motor drive only. The guy in the shop told me that some of the gear ranges wouldn't be available but wouldn't be a prob. I did ring myford and spoke to one of their tech guys and was told that the speed range wouldn't go below 500 rpm but I could use "back gears???" to slow it down to about 95 rpm. what does all this mean??????

second question is what should I be looking at in terms of wear and what should I make sure I have to have a "plug and play" machine?

sorry for the long winded ramblings but I am a complete novice and know nothing.

many thanks
Coop
 
Hey Coop,

The back gear the guy was talking about is on the gearbox. The Myford has a stepped pulley for most speed changes and an optional backgear assembly that allows you to step speeds down to a lower range (think like a transfer box on a Land Rover). Check out this exploded diagram to help explain it http://www.myford.co.uk/acatalog/info_684.html

The one you're looking at may not have the optional back gear assembly. But you may be able to purchase it directly from Myford if you want to have it.

As for looking at the machine itself look at the following:
- Run the machine and listen for bearing noises, it should sound fairly quiet and smooth. Like with cars you may want to not buy the first one you look at, get an idea of how they should sound or at least search Youtube for videos of one running to get an idea.

- Check for excessive backlash in the lead screws. Move the carriage in the Z axis (left and right when facing the lathe) and in the X axis (Back and forwards) individually. There will be a little play before load in each direction, but not too much. If you feel it moves more than, say 5 degrees of rotation of the hand wheel it may need adjusting, or it may be excessively worn. Do the same for the Compound slide (thats the one you can change the angle of movement).

- Check that the saddle, cross slide, and compound slide feels snug on it's gibs. if loose you can most likely tighten them up, but take a look at the side of the slides to see if there's issues with wear.

- Assess the condition of the bed. Look at the bed, does the surface look clean and without major wear or dings?

- Look at the chuck. Any evidence of tool crashes. Has someone done silly things with it that can cause damage to the mechanism.

- Check operation for the screw cutting mechanism. Make sure it engages and disengages easily. Again listen to how it sounds.

As for accessories. At the very least you will want the following:
- Drill chuck for tailstock with correct arbor
- Live center for tail stock. That's the point thing on a bearing that is help by the tail stock. It supports the end of longer workpieces while machining.
- Cutters. An assortment of tool bits. Grade of steel and geometry depend on the projects and material you'll be machining.
- Quick change tool post is a very nice to have. But not essential
- Boring bar, to bore holes or machine internal details.

I'm sure I've forgotten loads, but it should get you started. I found having a lathe really helpful for the Rover. Not just for making replacement parts but also for making tools to help with jobs. Best so far was cones to squash seals when assembling hydraulic cylinders.

Good luck finding a Myford!

Steven

Quick Edit, Here's a video for you: https://www.youtube.com/watch?v=7_Euuetoe40
 
wow thanks for the reply. the place has a few myfords at differing prices so I can have a good nose tomorrow and compare them most are out of my price range though. I shall write down the list of essentials you gave me and ways to test the different parts of the machine.

will report back tomorrow

once again many thanks
Coop
 
hi, just a quick update... I went and saw the machine today and only thing I noticed was it didn't have a scale on the sadle feed so there is no way of telling how far u have come down the piece of work (was told myfords don't have those). Other than that I couldn't tell the difference between a 4k machine and this one in terms of appearance and feel of movement.

The business with the single pulley on the motor is who ever had it before fitted a faster motor (over 2000 rpm rather than the 1450 or what ever it is) they did tell me I wouldn't need the low speeds if I was cutting steel and aluminium???

as far as equipment goes I would get everything I needed to use the machine ie cutters tool post as well as a tail stock chuck. I did ask about a live centre and he said well if it doesn't come with one we sell them for 10 quid so im sure he would probably throw one in with the machine. It also comes with change wheels.

What does one use screw cutting for????? will I need to do it for model engineering if all I am making is stationary model steam engines or hot air engines. The guy was trying to get me to buy a myford 7 b with a gearbox on it for 1800+vat or a myford speed 10 with a gearbox on it for 845 + vat as apposed to the one I was looking at for 750 +vat.

many thanks
coop
 
Hey Coop,

Sounds like you have some good options there. The ML10 you mentioned is worth a punt if you can run the extra hundred quid. Having the option to change speeds is a excellent thing to have. Speed is dictated by a few things. Material, diameter of the workpiece and the sort of operation you're performing (cutting, boring, drilling etc).

Easiest way to explain thread cutting (aka screw cutting) is to watch this video. http://youtu.be/x2P42fCIYSg
When thread cutting you want a very slow speed as the carriage moves in the Z axis pretty quickly. To be honest I've rarely used it, but it's nice to have the option.

YouTube is a great resource for learning this sort of thing.
 
You've probably figured this out by now but lathes have two sets of gears, one to drive the spindle and a second set to drive the lead screw which moves the carrage. If the main drive fromn the motor is by belt youcan always turn up or buy a set of pulleys and change the belt like a bench drill to get differing speeds. using change gears is a rather slow process but generally gives you a bigger range of options. Gearboxes on the lead screw are much faster to use, the common Norton box has two levers you just pull out and click into different holes to change the speed while others have a selection of levers. this allows you to move from very slow traverse to very fast and vice versa without he need to unbolt the gears and work out which ones to replace them with. Worth the money if you can get it. Check also the hole through the spindle, these allow you to stick long stuff out the back of the head.

You will probably need someone with a machine level to set the unit up (level) on the bench. make sure the machine's weight is taken under the headstock bearing behind the chuck, that is where the main leg should be.
 
Hi all that's for the replies. I have decided to hang fire for a little while as 1000 pounds is a lot of money if I decide I cant get on with it. Im going to go to a model engineering show in jan and have a good look round and see what sort of things are about then make my mind up. I have also been looking on ebay and while I haven't been to see the machines to see what state they are in they seem to sell around the 7-800 mark. If there are some that come up localish to me I can go look at them and get a general idea of the state of play in the machines.
many thanks
coop
 
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