Advice needed to dismantle ML7 Headstock spindle

[dieselman]

Hi everyone


I need to replace the x2 main backgears on my ML7 as both the bull-wheel (one with the small tooth selector) and the gear wheel below that on the eccentric have lost teeth. I have got the replacement gears from Myford and have installed/replaced the lower gear with no problem.
It is with the dismantling of the spindle where I am stuck - I have taken the small gear off the rear end of the spindle followed by the travel adjuster and ball race no problem.
It is the friction/interferance fit spacer/collar behind the pulleys that I can see no way of removing. Can anyone help me or advise? Many thanks in advance.
Roger

 

[goldstar31]

Initially, you should have the ML7 book which is on the net.

The whole spindle will lift off if you carefully remove the two bearing caps and ensure that you have the appropriate shims to go back again at end of things.

If you recall the shell bearings are lead indium and are easily damaged Again , the bull wheel has 65 teeth not 60

Hope this helps

Norman

 

[dieselman]

Many thanks for your reply goldstar31

I have printed out a copy of the ML7 manual which has an exploded view of the headstock - but unfortunately no info on how to explode it!

I have managed to take the spindle out of the headstock but need to dismantle the spindle to replace the bullwheel with the broken teeth with the new one. This is where I need some advice.

 

[goldstar31]

When I did up my ML7- now gone, I used the section B 'Schedule of Parts' and you should find that the Woodruff keys are the key( sorry!) to dismantling. They will be tight and probably a soft hammer will avoid further damage.

I'm doing this- in fact a lot more on the ML10.

Probably a look at the Super7 has similarities which suggests progressive removal from the tail end.

The ML7 was a doddle compared to sorting out a military aircraft which had been converted from a civilian one.
It took two of us taking turns a whole 22 days- and that was just the airframe.

She's now in the Museum at RAF Cosford

 

[Hopper]

Bit of heat from a propane torch or even a good hair dryer (No love, haven't seen it) might help.

 

[Mike1]

Is this any help'

Mike

View attachment Myford.pdf

 

[goldstar31]

There is a considerable difference between the ML7 and the ML7-R. The latter is more akin to the Super7.

The ML7 has, as I mentioned, white metal bearings whereas the ML7-R and the Super 7 have a bronze cone bearing as the front bearing and a pair of ball races to the rear.

Again, I said that the bull wheels are different and the ML7 one controls the ability to go into back gear whilst the ML7-R and Super7 don't.

Again, the beds and saddles change- and so on almost ad nauseum.

So maybe someone who has a ML7 which hasn't been altered to accept the replacement bearings to the lead indium Glacier ones can help.

And having written all this, the ML7 is closer to the ML10 - or mine, because mine has cast iron bearings which some don't.

Perhaps our poster will have to quote his bed number- if it hasn't been machined off. My ML10 has two bed numbers!
It's not easy

Norman

 

[Charles Lamont]

Heat should not be necessary. It should come off with a few taps of a mallet.

 

[dieselman]

Hi all

First of all thanks heaps for all your replies and suggestions - I really appreciate the help as I am most definitely a beginner (with attitude - so the wife says!).

Norman I think you are right that the pulley and gears come off progressively from the tailend(away from the chuck) and I have managed this up to a collar/spacer pushed on behind the pulley assembly it is this that I can not see how to get off (thus allowing the removal of the pulley and bullwheel assembly).

Hopper I'm sure you are right that heat may well help - but again - I'm still stuck witha collar I can't grab hold of as it is hidden by the pulley cone!

Mike great article and very useful but my ML7 appears slightly different to the S7 and the ML7R layout where everything slides off the rear end of the spindle (there is a flange on the front of the bull wheel preventing everything moving forward).

The only thing I can think of is using some kind of pulling tool like for bearings and pull the pulley off against the rear end if that makes any kind of sense!
Roger

 

[goldstar31]

My thoughts are that you either have an inclusion like swarf or perhaps a woodruff key is fretted. If so, heat is a waste of effort. You'll need a puller and a bit of brute force.

Incidentally where are you, please?
N

 

[Charles Lamont]

You should be able to rest the front of the pulley against the bench vice jaws with a couple of bits of wood for protection and tap the spindle out using the pulley to push the distance sleeve off. In fact, if you take the locking grubscrew out of the bull-wheel, it may be better to use the bull-wheel to push the whole lot off in one go. Take it gently, though. The parts diagram shows a little radial pin at the inboard end of the thread, but you will have had to remove that to get the thrust bearing off. No other obstruction is evident from the diagram.

 

[dieselman]

Thanks once again for your suggestions.

Norman - my location is Hamilton, New Zealand.
Charles - thanks for the reply - I too thought about that - was just a little worried about using too much force on the pulley. I have in mind that there is a woodruff key behind the bull-wheel so it would be the pulley cone I would have to use. I will have another look and let you guys know how I get on. Wish me luck!
Roger

 

[goldstar31]

My own progress of getting to grips with the ML10 has come to an abrupt end with the wrecking of my boundary fences in last nights storm. So as far as trying to get some sort of answer to help you has to wait.

Cars, shops and houses have been wrecked and my problems are there fore ' no great thing' With a bit of luck, I might get a few minutes to look at my lathe headstock as the lathe is in bits to carry.

I have the request to be in Rotarua in November. 25 hours flying as an 87 year old and getting insurance is an even bigger problem.

Good luck

Norman

 

[dieselman]

A very big thank you to all of you guys you made me think about the problem and earlier today I managed to dismantle and change the bullwheel! I'm so relieved! Yes you were absolutely right Charles and I followed your suggestion and although it was quite tight it finally came off the spindle - I used a rubber mallet. The putting together again was a lesson in patience everything was 'tight as' (kiwi expression) - the collar did not want to go back on again and although I gave it a good thump there appears to be a little play in the pulley cone - like it has not gone back on far enough. The ball race and adjuster went back ok and the end cog. I remounted the whole assembly onto the shell bearings after coating everything in oil and married up the upper bearing halves and shims. After everything was tightened down I ran the lathe with a mike placed on the front of the mandrel - it moves/flickers a fraction of a thou but looks good - no noise or vibration - no movement apparent from the pulley cone even with that slight play I mentioned earlier. So I'm hoping that might be problem solved - thanks once more.woohoo1woohoo1
Norman I hope your home damage is not too great - where abouts are you?
Hope the weather improves for you although in UK you are in winter now eh?
Mind you the summer here in NZ has been very disappointing so far. What takes you to Rotorua?

 

[goldstar31]

I've unearthed my headstock unit for the Myford ML10 and my guess is that your ML7 one is fairly similar.

My Bullwheel seems to be secured with one grub screw- which should be removed completely. Again, at the other end are the external gear. Mine is finally locked with a grub screw- and I would assume that this is already removed along with the collar with another grub screw.

So I am left with a worrying situation of a ****** zinc alloy metal pulley and an equally fragile (broken) bull wheel in cast iron.
The risk of breaking part of the pulley is high. Confession---- my Super 7 two speed one has a broken bit.
As far as I can see, I would buy or fab a puller which will embrace the widest part of the pulley. I have one which is in two halves - and called a bearing separator rather than the three legged puller. I have both and extractors for ball joints and whatever. So the two sided extractor will exert a wide area!

Experience over far more years than I want to admit suggests a slow and even tightening up but stopping to hit the other end to attempt to knock it off a probable taper or obstruction. I guess that there is a Woodruff key causing the problem.

Whether the bull wheel will 'come' with the pulley is unknown. If it doesn't, then the bearing puller must be employed again.

I costed out the bearing puller( mine was part of a set) and it was only £19.

So back to------------------------mending fences!

Cheers

N

 

[Mugs]

Very helpful advice, but I’m stuck further back in my disassembly of the headstock shaft. My Myford ML7 headstock shaft has a pin (70-1231) located just past the 25 tooth gear and locking collar, which prevents the thrust bearing and everything beyond from coming off. Can anyone suggest how to remove this pin?
thanks

 

[Charles Lamont]

I think the pin is a driving dog to make sure the thrust collar goes round with the spindle. Pliers should do it.

 

[Mugs]

Thanks Charles. It does fit the keyway on the locking collar, but like a lot of parts on this 50 yea old machine it seems to be stuck. I’m new to this type of disassembly and am trying to be careful not to break/make things worse.

 

[Charles Lamont]

Have you taken the spindle out of the machine?
Rather than pliers, gripping the pin with a toolmaker's clamp sometimes works.
If not, you should be able to grip the top of the pin in the bench vice, using soft aluminium sheet vice protectors, and use the spindle as a lever to pull it off the pin.

 

[Mugs]

Thanks for your advice Charles. I never thought of a toolmakers clamp, and that did the trick. Thank you