Myford ML7 Geartrain

[Bbob49]

Hi folks
Recently inherited a Myford ML7 with the quick change gearbox fitted. Having little experience of lathe working, i am having difficulty setting up the change wheels to cut english threads using the gearbox. the feed speeds are not working out as per the gearbox settings. Can anyone point me in the direction of an idiots guide to help with this.

 

[goldstar31]

The PDF's for both the ML7 itself and the gearbox which fits both the ML7 and the Super7 are available on the 'net.

Try small- lathes quick change gear box.

One odd fault may be the lever on top of the box which gives the THREE different settings. I had to make a new spindle part.

To see what is happening or not, use a torch to light up inside the gear box slit to see whether the box gets all three settings.

No, it isn't in the book!



Norm

Metric gear cutting usually require a different banjo but others seemingly have bought non standard gears to those suggested in the manuals. Meantime, sove the English problem first

 

[Bbob49]

Thanks for the response Norm and I will have a look for the .pdf's.

I think I have proved the gearbox is ok as I cranked the input by hand and the feed rate checked out in a number of positions. So i'm fairly sure that it's the gear train ratio is wrong.

Bob

 

[goldstar31]

Bob

Thanks for your note.

Of course, you can get funny answers if you are setting the 'fine feed' configuration.

My Super7B is sort of being inoperative( owing to being left in my new shed ) but it will be no problem to do a look at the how the cogs on mine were left- but wait till tomorrow please!

Be patient, please ( until an old fart starts his new day as I still have not lights in the new thing)

Cheers

Norm

 

[goldstar31]

Bob

'Meantime back on the ranch' but don't be offended but you are looking on how to set your lathe to screw cut 8Threads per inch as the gear box does the rest.. This should be- said he waving his wooden leg aloft- be inside the change gear covers.

I think:hDe:

 

[Bbob49]

Hi Norm
Many thanks again for your input. There's no hurry since i'm another "old fart" without any deadlines. With respect to the gearbox cover, it's missing so no help there.

If you can get back to me in your own time that would be great.

Cheers

Bob

 

[bmac2]

Ok ok. I'm only 60 and I just have to go down stairs not outside to have a look.
If it's the one inside the cover this is what I have.



Hope this helps.

 

[goldstar31]

Bob


As far as I can see, there are only two ordinary gears ( which can be changed)apart from the two twinned gears that drive the big gear into the box.

I think( still) that you are engaged for fine feed and not screwcutting.

Engage the gear box setting for 8TPI and manually turn the spindle and see what is cut. If it goes wrong, swop the 19/57 gears over and check again.

If that doesn't solve the problem, let me know which two loose separate gears are below the fibre gears.

Sadly, my two loose gears have their identifying teeth numbers on the wrong way which means to the get your answer, I have to strip the whole quadrant assembly out! And put it back again( merde!)

Norm

A note suggests that if you have a 44 20DP in the set up, your lathe has been set up for metric working!!!!!!

Norm

 

[Bbob49]

Hi Bob and thanks for the photos. This tells me a lot and pretty much confirms that my set-up is wrong.

Bob

 

[Bbob49]

Good morning Norm
I am now beginning to understand the problem. It would appear that the quadrant currently fitted is for metric set up and does not allow the 2 wheel configuration for imperial cutting. I will i think concentrate on setting up for metric for which I may need a couple of change wheels. I was only going to use the imperial set-up for practice since I thought that the machine was geared up for that.

Will get back later and let you know how I am progressing.

Thanks again for all the help.


Cheers

Bob

 

[goldstar31]

I have a Metric quadrant which is lying under my bench-- unused. With the cost of Imperial stuff escalating in the UK as it is being replaced by Metric stuff, I bought a second hand SiegC4 for metric working. 'Baz' has been assisting here!

Having read- and re-read Martin Cleeve on Screwcutting on the the Lathe, Cleeve had two leadscrews- one imperial and the other metric . Of course this was his for his ML7. Might I commend it?

Unfortunately, having a gearbox is not all that is desirable as it actually reduces the number of possible threads which can be cut.

With that all in mind, I also bought a little Myford ML10 which has obviously no gear box but can utilise my extra cogs such as a pair of 21 20DP and a 63 transposing gear as the 127 correct gear is too big in diameter in 20DP and Module1.

By the time that I totted up the accessories which came with the ML10, they worked out at far more than the total purchase price.

I suppose that being a retired accountant sort of bloke that I think --- differently to most:fan:

Keep in touch- there's method in my madness


Norm

 

[Bbob49]

Thanks again Norm
Is the Martin Cleeve info in book form or online?.

The metric quadrant on the ML7 has been 'Hand knitted' by someone. It's not too pretty but is I think serviceable. I have sent for a 63 gear which should suffice for my needs.

Thanks again for your input which has been excellent.

Bob

 

[goldstar31]

Hi Bob

Thanks ! Unfortunately, the book called Screwcutting in the Lathe is not on line. So it is the same for George Thomas's Model Engineers Workshop Manual. The latter has much and already dimensioned( Imperial) for the Super7 and the ML7.

If I recall Cleeve also hand knitted a quadrant for his ML7. He must have been quite a character because he bought half a new ML7, fitted it out with TWO motors and wrote a whole series of articles on how to make nits for his ML7 out of blocks of steel which he joined -- with home made socket screws.

The sad thing about all this is that I tried to publish these after his death but an American bloke and myself actually started to put them on the 'net but ran into litigation- copyright problems- with the new owners of Model Engineer( then)



Nil Illigitimi Carborundum! Per Ardua Asbestos.

Battle of Britain Day

A RAF 31-er

Norm