questions about setting up my Myford ML4

[Brian WoodParticipant @brianwood45127]

Thank you Andrew for clearing that up at last, I am glad to hear your new chuck performs well without the need for a collar, another plus it seems for David Bennett's observations

Thank you Jon for the education, I had not until now appreciated Myford had included a 7/8 inch x 12tpi variant

Kind regards Brian

[Jon CameronParticipant @joncameron26580]

Posted by Andrew Byron on 01/06/2020 13:44:32:

changing the subject, Jon, did you ever get round to working out which BSW bolts you needed?

Hi Andrew,

No unfortunately, This weekend included trying to tackle a 14' hedge, certainly would rather have been in my garage, but I will get to looking soon and let you know.

A new cross slide arrived last week for my lathe, after making a new gib strip and adjusting the gib screws, (had to rob one from my old saddle), I managed to get the saddle sliding nicely and I should now have irradicated a 10thou error that existed when you traversed the cross slide. As someone has previously machined the saddle and unfortunately mustn't have set it up correct……

Again thanks for the offer and I will come back to you on the bolts.

Jon

[Andrew ByronParticipant @andrewbyron13518]

No worries Jon, i can't promise i'll have everything you want but they did come from a company that re conditioned machine tools so there ought to be some suitable sizes in there, there are some specialist fasteners as well that presumably crop up on certain types of machine tools too, i really ought to go through and catalogue what there is as they may well be of use to other people and it's always nice for this sort of stuff to find a useful home as it were, i don't like to see things wasted.

[Andrew ByronParticipant @andrewbyron13518]

some developments since i last posted,i actually made something. firstly with a view to doing some threading i made a mandrel handle

 

 

I've turned down a piece of 20mm bar to fit in the end of the headstock, and drilled it out to take an m8 thread then tapped it m8. i cut the end off at 45 degrees and then drilled the rest of the shaft out with a long 8.5 mm drill.

that took a while, i'm not sure if there's a better way of doing that but i got through it. that's created an expanding end to lock into the mandrel once i've put a length of m8 threaded bar through it, i've also drilled a piece of flat bar to 20mm at one end and welded the shaft into it, and tapped it to m12 at the other end to take the crank handle, which is another opiece oif 20mm turned down to 12mm at the end and threaded with a die, with a suitably sized piece of tube slotted over it which is secured by a turned down washer bolted onto the other end

 

not exactly precison engineering but it's a start.

i've also been rebuilding a 1980's Mengele forage wagon for a friend, it had picked up a foreign object and the mechanism tha feeds the grass into the knives had tried to eat itself, unsurprisingly you can't get parts for it any more so i've had to make the bits that were bent beyond repair including some new nylon bearings for the feed in fingers:

I've had it running and surprisingly, it works and picks up grass. the nylon or rather oilon comes in a 90mm log, and is really odd stuff to turn down, the workshop looked like someone had been having a silly string fight after i'd finished.

I've acquired some 8mm tooling both inset tooling and HSS, and i bought some new grinding wheels for my old bench grinder so i could sharpen some of the old tooling and blanks that i have around the workshop, or at least try to sharpen them. Which brings me to the next thing i need advice on which os the gear train of the lathe,.

Currently it seems to be geared too quickly for the leadscrew when engaged and the tool is moving too fast along the work and just binds, this is the current gear train but it's not a very clear photo

can anyone advise on what set up i need to get a decent fine feed?

Edited By Andrew Byron on 22/06/2020 23:33:24

Edited By Andrew Byron on 22/06/2020 23:35:58

[Jon CameronParticipant @joncameron26580]

Hi Andrew,

Nice work on the little handle, you have no idea how handy, and how many times that will come in useful.

With regards to the lawnmower and bearings, that stuff is terrible to cut, and i did have a chuckle to myself about the silly string comment. Very true. Its great been able to make a part that the dealer tells you doesn't exist anymore.

Now moving onto your feed, it looks as though you haven't got them set up for compound gear train, possibly as they don't fit as they are. The banjo bolt closest to the lead screw gear, is driving onto its inside gear, from the next banjo which in turn is striaght from the reverser. Your only gear reduction is the gear on the reverser, and the gear on the leadscrew, the rest are idler gears and are not effecting the gear reduction as they are not driving onto another gear as a coupled set.

What gears do you have? The lower banjo stud, next to the leadscrew. Try putting a smaller gear to the inside, and a larger gear to the outside, to enable the small gear to mesh with that on the leadscrew, and the larger gear to mesh with the smaller outward facing gear on the stud above. If this still doesnt work, possibly change from top to bottom the two gear pairs, as i think you have the larger gear to the top which isnt helping to bridge the gap further down. Ideally, 60T in mesh with the tumbler gear, 20T joined to it by a 3/32" pin, The 20T in Mesh with a 65T on the next stud down, connected to a 30T again by 3/32" pin, The 30T in mesh with the gear on the leadscrew (smaller if possible).

Hope this is of help. Knowing what gears you have a fine feed can be made easily, but in short your changegears in effect are idle and doing nothing to change the gear ratio.

Jon

[HopperParticipant @hopper]

For your finest feed, take the three largest gears in your set and the three smallest gears in your set. Mount them as described already, smallest on the headstock spindle and the largest on the lead screw. Then pair them up so small drives large, with small on the same stud driving the next large and so on. For example, a 20 on the spindle drives a 60 on the first stud paired to a 20, which drives a 65 on the second stud, paired with a 25 that drives a 70 on the lead screw.

[Howard LewisParticipant @howardlewis46836]

WRT to fine feeds, if you can get hold of extra 20T gears and a 60T, you can set up a fine feed of 0.00427"/rev.

Gears from a ML7 will fit, but need to be drilled part way through to take the 3/32" driving pins.

The set up is:

Mandrel :Driving Collar and 20T, First stud: 60T/20T, Second stud 65T/20T, Leadscrew 60T and Driving Collar

The 65T has to go in the middle of the train to avoid a clash between the two 20/60 meshes.

You may need to fettle the inside of the banjo at the Mandrel end, and maybe the location in it for the first stud.

The Cross and Top Slides have 12 tpi leadscrews, so the dials with 80 divisions are not exact thous. You need 83 divisions to get a closer, but still not exact calibration.

The Lathes UK website says that the earliest ML1, 2, 3, and 4 had 7/8 x 9 tpi Whit threads (Standard 7/8 BSW ) then changed to 7/8 x 12 tpi, before the very latest ones used 1.125 x 12 tpi, (But without the 1.250" register used on the 7 Series machines introduced in 1947 )

HTH

Howard

[Andrew ByronParticipant @andrewbyron13518]

thanks for the advice, i had a look at what gears were with the machine and including the ones on it there are 1 x 50T with a damaged tooth, but about half the tooth still there so it works and it on the current gear train. 1 x 60T, 1 x 45T 1 x 35T 2 x 20T 2 x 25T 1 x 40T 1 x 30T and 1 x 35T.

I have also bought two ML7 gears, a 70T and a 50T to replace the damaged one. when i bought the ml7 gears i also bought some suitably sized silver steel rod, what's the best technique for locating the drilled hole in the right place to convert them to fit the ml4?

Edited By Andrew Byron on 24/06/2020 09:26:50

[Jon CameronParticipant @joncameron26580]

Hi,

For drilling the hole in the ML7 gears, the easiest, though possibly not the best if you intend to use the gear a lot. Is to line up another gear on a piece of steel turned to the bore dia. (5/8" from memory). Since you have the 50T gear with a broken tooth, it makes sense to use this one as the pin will no longer be easily retained without making a plug to fill the drilled hole.

Line the 50T up on the shaft, along with the new gear you want to drill the pin hole in. Hold together vertically in a vise with the hole for the pin in the old gear facing you. So that they cannot move while drilling. (packing pieces may be a good idea, Brass or aluminium strips). Then Drill right through the hole in the 50T (with the broken tooth) to the new gears that you have bought. You don't need to drill completely through only about half way through. check the pin will go in the hole then seperate and do the other one.

With regards to fine feed, As above go for the smaller to larger gears towards the leadscrew. In your case, and for the best fine feed with what you have available. 20T on the tumbler, 1st stud, 50T:20T, 2nd Stud 60T:25T Leadscrew 70T. If you wanted to change for a faster feed all yould do is change the tumbler gear to a 30T or 40T and you will increase the speed of feed. With the 20T on the spindle it will be a slow feed.

Regards

Jon

Edited By Jon Cameron on 24/06/2020 10:09:35

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