BAZMAK-Diary of a Myford ML7 lathe restoration

[bazmak]

Made and fitted a splashback and shelf to the rear of the lathe.Fitted an additional timber roof purlin and a centre support leg for the bench
Made a new switch mounting brkt and fitted a double power point
Bolted down the lathe.Machined a test piece using the QCTP,it works well
Lathe was about 4 thou out over 6" so i got it within a 1/4 thou.Like those capstan leveling nuts. Also set the Pratt Burnard chuck but could only get it to 2 thou. I think there needs to be more play between the mounting spigot and recess for it to move more.Any comments welcome as its a first for me
I was going to make a draw bar for my homemade MT3 test bar but realised the Myford has only a MT2 in the headstock so i held between collet and tailstock centre.TS is about 2/3 thou low but easily got it to 1 thou front to back
Now waiting for the thrust bearings to arrive from China so i can finish off the
leadscrew.Then i may try some screwcutting .W











ith low speed and high torque
thru the backgears should be much easier than the C4

 

[pp2076]

I served my apprenticeship at Forgrove at the top of Dewsbury rd near the Tommy Wass pub.,and at the bottom of Middleton Hill.
Middleton famous for the den of iniquity at the top called the Middleton Arms
And the steam railway preserved line and workings.Many a ride taken on it
but not many pints at the pub.Too rough for me

Never been in either.
Too rough for the authorities apparently as it has been demolished.
Ileft Leeds as a 18 year old in 1973

 

[goldstar31]

Sorry Baz but I didn't want to upset you about the MT3 test thing

I really think that the possible alternative is a MT3 to MT2 jumper.

I found one in my 'museum for white elephants'

My proper one i.e. MT 2, was ground from a scrap reamer with a MT2 shank.

I suppose that you have the obligatory bar with two rings to machine?

So now to the two spirit levels?

I'm in a worse state= lost one hearing aid, and with macular debenture firmly confirmed, - Woe is Me.


And it is snowing again

Norm

 

[Charles Lamont]

With a Griptru chuck you should be able to get a ground surface like that cutter running to a couple of tenths. The point of a Griptru is that you can adjust it for
any job, as it will not be equally precise at all diameters. If you don't have the instructions I will see if I can find mine.

 

[rad45]

Great forethought. You are certainly making every cm count,
I also like the coloured sheeting. Is that an off the shelf product in your country?

 

[bazmak]

Yes Norm i did the machine test piece or 2 rings as you call it.Was 4 thou out
over about 6" but my leveling nuts made it easy to get to 1/4 thou with 2 checks and a quarter turn on the leveling screws.So much for the bed twist not enough to worry about .The Mt 3 test bar worked well on the 2 chinese lathes and to align the capstan but i had forgotten the Myford has MT2.Not to worry gripping on the collet and tailstock centre did the same job
Thanks Charles any input on the griptrue would be appreciated
I assume that more float is needed between the spigot and recess in the adaptor plt and the chuck.Thats probably the reason some one has overtightened the screws and cracked the body that i repaired
The wall/shed cladding is called colourbond.Very big and economical building item over here.Painted galv rolled sheet in many profiles.The very basis one we call galvanised corrogated iron

 

[bazmak]

Thank you Charles any input would be most welcome.As i said previously
i have never owned one of these.When i first stripped it down i understood the
basic principles of how it worked and the innards looked in good order, apart
from hirlin cracks on the corners where the screws had been overtightened
Later i reasoned why. When i got the lathe running i had about 10 thou runout
and for the life of me could not get any adjustment,so i decided to put some time and effort into improving it.After almost a full day i have it down to 2 thou
how well i can keep it will be determined when i start using it.My thoughts only
are as follows but anyone more familiar please comment
The adjustment depends on the chuck body and the backplt moving a small
amount in relation to each other.I quickly realzed that i needed to loosen the
3 cap screws hidden under the myford adaptor plt so drilled 3 clearance hole
to enable access with an allen key.Also the spigot on the adaptor plt was 10 thou down so i remachined. I skimmed a couple of areas to ensure the plt and
chuck could move at least 10 thou.The because someone had ground grooves in the bp casting the adjusting screws were bottoming.The reason why someone had overtightened and cracked the body. I built up the ground ares with some m4 screws and then spent a few hours playing about.Still not straight forward but i managed to get within 2 thou.Which will do for now
Learned a lot about this chuck.Shame its been abused

 

[rad45]

Hi Bazmak and group. Looks like you have had to learn very quickly with your chuck locating. And that someone could do that grinding to a chuck, especially a high quality product like a P-B.
If someone did that to one of my Röhm chucks I would track him down to drop into the Donau (Danube to non Europeans)

 

[goldstar31]

There is a TWO page set of comments by Geo Thomas in his epic Model Engineer's Workshop book. He obviously saw just how much difficulty other less experienced workers were experiencing and decided to give his well considered experiences.

I don't have a Griptru but all of this prompts my thoughts away from 'non backplate' Myford three jaw chucks and realise that I CAN do something better on my Sieg C4 in setting up.
"Martin Cleeve' had a very modified Myford ML7 which in later life earned him his living. He actually bought 'a half one' and did his work on a 4 jaw independent chuck and a faceplate until he was rich enough to add a three jaw chuck to his library. Like many of us, he couldn't get the accuracy to 'tenths' and - like Baz- opened up the register on the backplate and slotted the three holes for minute adjustments by knocking the chuck into alignment.

He clocked his adjustment with a tenths of a thou dial mike and years ago, I bought a tool room Boxford one. I still have it and it gets used extensively.
Digressing a bit further, I do set over my top slide to get 'tenths'. Older readers might recall that I raised the query some months ago - not to learn- but to discover whether readers- did read.

Regards

N

 

[bazmak]

As my previous posts i cleaned up the 7/16" dia leadscrew and reduded a couple of thou to 11mm.I ordered a couple of 11mm thrust bearing.An odd size
i thought at the time.They arrived yesterday so did a quick check of one
11mm i/d x 24mm o/d so i finished the first housing,fitted the bearing and trie
to fit to the leadscrew.No go,so after scratching my head i double checked the bearing.1 side was 11mm od but the other side was 10mm with the race cage
being 10.5mm bore.So much for Chinese quality control.I unboxed the second brg and you have guessed it.1 side 11mm bore the other side 10mm bore.
I used the 2 no 11mm halves and opened up the cage to 11mm with a drift
Assembled and fitted to the lathe.Bingo.I had in mind to use my homemade toolpost grinder to open up the bore on the other 2 brgs but thought it was
a little too much meat to take off.I checked and realised i could use one of my
12mm bearings at the other side which would locate on the od with the bore just having clearance on the leadscrew.Made and fitted the second housing
to replace the slotted spacer/collar and fitted to the lathe.Result with the new bronze bushes is a super smooth leadscrew.Without affecting the original parts of the lathe.Simple and cheap and well worth the effort.Anyone else doing it,remember to order 4 no 11mm bearings,use 2 and save the the other 2 10mm ones

 

[Cogsy]

Baz, those bearings you ordered are 10mm bearings, not 11, which is why they turned up as they did. Being a separable bearing, one race is sized to be a press fit onto the shaft and the other to be pressed into the housing but having a lot of clearance on the shaft. You can imagine if both races were pressed onto a shaft it would be incredibly difficult to set the exact distance between each race. You'd likely end up with either a severe preload condition or mobs of clearance. Bearings of this type have zero shaft retaining ability and there must be other mechanical means of keeping the shaft in place.

Btw, with metric bearings the part number tells you the shaft size - starting at 10mm it ends in 00 (like 6200 or 51100 as you have here), 12mm is 01 (6201), 15mm is 02 (6202) and 17mm is 03 (6203). From 04 onwards, just multiply the final two digits by 5mm to get shaft size (6204 - 04 x 5mm = 20mm, 6305 - 05 x 5mm = 25mm, and so on).

 

[bazmak]

Thanks for the input Cogsy. The bearings were still sold as 11mm. With me machining the housings i planned to push the first half in tight and the bore opened out a few thou for the second half.Preload holds the second half to the brkt and the first half goes round with the leadscrew. Works well and the 12mm brg does the trick. I will know next time. I have plenty of 10 and 12mm brgs
so i thought 11mm was an odd size.Buying 7/16" to suit the leadscrew would cost an arm and a leg. With the bronze bushes i did not need the thrust brgs
to press fit to the shaft only for thrust.Preload does the rest

 

[goldstar31]

I'm sort idling a moment or two between a rather awkward sit on lawn mower and doing aa adapter plate to take a Myford vertical slide, a Myford small dividing head( Thomas) and a Rotary Table ex Model Engineering Services- the Ivan Law guy
---------------to fit on my SiegS4
OK, so back to your ML7 and the lead screw.
The wear at the tailstock end is potentially only one bit of three points of wear. There is or are the Half Nuts and obviously the headstock end. Mine has a or had a shattered gear box.

So, what is the position of the remaining two parts?


There are quite a few guys with worn leadscrews==========not just weary old moi

Regards

N

 

[bazmak]

Hi Norm,the lathe is as good as i can get it without fitting new parts
The half nuts and Leadscrew are good.The new bronze bushes as
previously posted overcome the the lightly worn leadscrew and along with the thrust bearings give the leadscrew an almost new feel,dont know how long it will last.I have just started to make an adjustable graduated dial for the cross slide but have had to order a set of BSF taps and dies from UK.I did not want to alter the leadscrew to metric so bit the bullet.With the myford in the new shed
i am building up all my imperial tools there with the metric ones in the main shed.Good job the sheds are only metres apart as i am wearing out a lot of shoe leather back and forth

 

[goldstar31]

The adjustable dials to replace the zinc alloy fixed ones is a splendid idea. Even my very inferior Myford ML10 is thus equipped.

I'm sitting with one of my vertical slides( now on the SiegC4) and it is a pain in the lower part of my anatomy .

Spring is almost here- with I hope, the last snows to come this week. So I'm in the shed, into the garage and into the Inner Sanctum- my Holy of Holies.

It does wear out shoes but my middle has been increasing towards a 36" from my continuing boyhood 32". Too many Masonic Chinese 20 course banquets and very large English formal dinners with lots of port. I'm becoming quite portly

Keep exercising

N

 

[bazmak]

Yes i love chinese and indian food and my waist has increased from 34 to 36
Still struggle to keep weight off as i have most of my life. I am drilling the 5" chuck backplt on the C4 for 100 divs. Then i can cut the graduations on the dia
in the lathe.Did most of the first one in the mill but not happy with it so will give a light skim and try again.I made the main body in mild steel waiting to be tapped 1/4bsf and the revolving section in alumunuum,with my std method of a grub screw and nylon insert to adjust the tension.Will post photos when its finished

 

[goldstar31]

Yes, I have ONE of my SC chucks drilled for a detent. Really, I should have one with 360 and another with 100 detents. I seems to have a lots of chucks but none Rhode Island Reds with feathers on.

I'm a wee bit 'Hon y soit qui mal de mer'

Norm

 

[bazmak]

Well new dial made and much improved.I used the 60hole deviding plt on the mill
and then by eye to finish the first one.I wasnt happy with it.So i drilled the chuck backplate
100 holes at 3mm dia using my homemade worm and wheel index head as previosly threaded.The head had been machined to suit the C4 so the backplt bolted directly on.The wheel is 120t and the worm dial is 60 divisions .That gave me 720divs divided by 10 = 72 or one full rev and 12/60 divs. Spot on.I then made and fitted a detent pin and brkt and off we go.Much better grooves on the lathe then trying to mill with a small pointy D bit. I mounted the collar on a mandrel and skimmed out the old grads but more important getting the collar dead true before cutting the grads.I also set the carriage stop for 3 different lengths apart from i minor niggle with
one bad line it looks good.I thought the grooves were overly deep but when the burrs are polished off its about right.May make another at a later stage when i do one for the compound. Practice makes perfect.Now waiting for my BSF taps to arrive to fit it to the lathe

 

[goldstar31]

Baz,

Most informative for most of us.

I'm cheating a bit really because I have a GH Thomas small Dividing Head which is destined to go from the Myford to the Sieg.


That's the one that all that funny stuff to do odd divisions (and the tide tables for HongKong Harbour)

So I expect that you will be adding a small additional motor to exploit the divisions on your chuck?
Cleeve and a lot of others including Tom Walshaw and Prof Chaddock did something similar

Kindest Regards

N

 

[bazmak]

My 20 piece BSF tap and die set arrived from the UK in 7 days
Quality is good for the limited use it will get and at 23 pounds
and free postage i am very satisfied.
Finished and fitted the micrometer dial.It works well but can improve
and will make a couple more later for the compound as well
I also spent a couple of hours stripping down and rectifying the 2 Myford oilers
One did not feed at all and one fed continually.Once i sussed out how they were supposed work i nudged a few things etc and got them going.I plan to make
a few open brass oil cups for the countershaft etc and see how well an oil can works on the Myford oil nipples.Need to be confident that oil is getting thru