Myford ML7 backgear jammed

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ungifted amateur - 24 Jan 2006 02:43 GMT

This is my first post - please be gentle.

I have purchased a Myford ML7 (s/n 20206) and a small number of
accessories. The lathe has seen a lot of work but is in reasonable
condition with the former owner having replaced the leadscrew and
generally having looked after it.

I have access to a manual for the ML7 but I find that I am unable to
use the backgear. I have used the references in section B of the manual
to identify various parts.

The problem is that when I loosen the cap head screw (B19) and move the
backgear key (B16) to allow the Vee cone pulley assembly (B14) to
freely rotate on the spindle (B24) - it doesn't freely rotate. In fact
it doesn't rotate at all. Consequently when I operate the tumbler
release lever (B43) to engage the backgears it locks the spindle. It is
as if the Vee cone pulley assembly has seized on the spindle. No amount
of firmly applied force (by hand) will get the Vee cone pulley assembly
to spin on the spindle.

Has anyone else encounted this problem?

Have I overlooked something?

How do I fix this?

I have removed the oil nipple (B15) on the vee cone pulley assembly and
have introduced into the hole as much wd40 as it would hold but after
two days this has had no effect. I have checked that the backgear
cluster (B50) turns freely on its shaft when not engaged.

Looking forward to your imput.

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Duncan Munro - 24 Jan 2006 09:33 GMT

> The problem is that when I loosen the cap head screw (B19) and move the
> backgear key (B16) to allow the Vee cone pulley assembly (B14) to
[quoted text clipped - 6 lines]
>
> Has anyone else encounted this problem?

Yes. This sounds like the bronze sleeve carrying the pulley and smaller
gear has fused onto the main shaft.

It's caused by doing a lot of backgear work and not lubricating
regularly through the oil feed nipple on the side of the pulley.

> How do I fix this?

The whole shaft will have to come out, but it's not that difficult a
job. It's also a good idea to change the drive belt while you have it
all in bits unless it's fairly new.

Loosen the securing ring which tightens up the shaft and compensates for
endfloat. Remove the four cap screws holding the two bearings down.
These will have shims underneath them, so please take great care not to
lose them and to note where they came from (they will stick to the caps
or the headstock).

The whole lot will then lift out and you can dismantle the shaft. A
puller will be required to get it all apart. The shaft will need
cleaning up to remove the bronze and generally this is all that will be
required.

Stick it all back together with plenty of lubrication, set the endfloat,
and you should be back in business.

Signature

Duncan Munro
http://www.duncanamps.co.uk/metal/

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ungifted amateur - 24 Jan 2006 15:32 GMT

Hello Duncan,

Thank you for your reply.

I was hoping that I wouldn't have to pull the spindle but if forcing
WD40 into the oil nipple screw hole (after removing the nipple) does
no good I pull the spindle on the weekend.

As there is some play in the headstock bearings ( at least in the
larger of the two) I will also tighten these. I will seek profession
help for that job as I understand the bearings are irreplaceable and as
this would be my first bearing scraping I could easily destroy them.

Just to establish my amateur status - How does one remove bronze from
the spindle after the gears and bearings etc have been removed?

regards
ungifted amateur

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Duncan Munro - 24 Jan 2006 20:08 GMT

> Hello Duncan,
>
[quoted text clipped - 3 lines]
> WD40 into the oil nipple screw hole (after removing the nipple) does
> no good I pull the spindle on the weekend.

Even if you do free it off by this method, it will sieze up again fairly
quickly. The only proper cure is to take it apart, clean the bronze off
the steel shaft and if necessary clean up the inside of the sleeve with
hand tools if there is evidence of galling. To be honest, it's not a
particularly time consuming job.

> As there is some play in the headstock bearings ( at least in the
> larger of the two) I will also tighten these. I will seek profession
> help for that job as I understand the bearings are irreplaceable and as
> this would be my first bearing scraping I could easily destroy them.

There shouldn't be any need to scrape the bearings, they have removable
shims to take up wear radially, and an adjustable ring to set the endfloat.

> Just to establish my amateur status - How does one remove bronze from
> the spindle after the gears and bearings etc have been removed?

This is where the WD40 might be more useful, in conjunction with some
wire wool to give the spindle a good clean. IIRC the spindle on the ML7
is not hardened so you have to take care with this (i.e. don't go mad
with sandpaper etc.)

Signature

Duncan Munro
http://www.duncanamps.co.uk/metal/

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John Montrose - 24 Jan 2006 18:55 GMT

>The whole lot will then lift out and you can dismantle the shaft.

>Stick it all back together with plenty of lubrication, set the endfloat,
>and you should be back in business.

Just one thing to add: on no account forget to put the new the new
belt over the spindle before you reinstall it, torque up the bearings,
set the endfloat, reinstall the gear on the end, screw on the chuck,
refix the gear cover, refix the oilers. Don't ask, etc....

Reply to this Message

Adrian Godwin - 24 Jan 2006 21:16 GMT

> Just one thing to add: on no account forget to put the new the new
> belt over the spindle before you reinstall it, torque up the bearings,
> set the endfloat, reinstall the gear on the end, screw on the chuck,
> refix the gear cover, refix the oilers. Don't ask, etc....

I've got Myford's manual which has some general guidance on assembly
of the lathe, but I can't find any details of torque or endfloat
settings. Are there some specs for these somewhere ?

-adrian

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christopher@wurzel.demon.co.uk - 25 Jan 2006 17:04 GMT

>> Just one thing to add: on no account forget to put the new the new
>> belt over the spindle before you reinstall it, torque up the bearings,
[quoted text clipped - 6 lines]
>
>-adrian

I seem to recall that Myford produces an A4 sized laminated
instruction sheet specifically for doing this job. Why not give them a
call on 0117 925 4222 - who better to ask? ( there's a feed line for
somebody!)

--

Chris Edwards (in deepest Dorset) ..."There must be an easier way...!"

Reply to this Message

Adrian Godwin - 25 Jan 2006 20:36 GMT

>>I've got Myford's manual which has some general guidance on assembly
>>of the lathe, but I can't find any details of torque or endfloat
>>settings. Are there some specs for these somewhere ?

> I seem to recall that Myford produces an A4 sized laminated
> instruction sheet specifically for doing this job. Why not give them a
> call on 0117 925 4222 - who better to ask? ( there's a feed line for
> somebody!)

Thanks, I'll try them. I wonder why they don't put it in the manual ?

-adrian

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ungifted amateur - 25 Jan 2006 22:15 GMT

Thank you to all who replied.

I now am much better informed as to the problem and it's probable
solution.

regards
ungifted amateur

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christopher@wurzel.demon.co.uk - 26 Jan 2006 10:22 GMT

>>>I've got Myford's manual which has some general guidance on assembly
>>>of the lathe, but I can't find any details of torque or endfloat
[quoted text clipped - 8 lines]
>
>-adrian

    Manual? - that's a laugh, I'm still waiting for the manual for the
Super 7 Connoisseur I bought three years ago!

    Sadly, I know from significant personal experience that Myford
ain't the company it once was. If it weren't for their outstanding
reputation and the reservoir of 'goodwill' they built up over 60 years, I
suspect they would have long followed most of their contemporaries into
oblivion. Watch this space!

    I'll stop there before I say something libellous!
--

Chris Edwards (in deepest Dorset) ..."There must be an easier way...!"

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MagicPaddler - 17 Dec 2008 18:30 GMT

>This is my first post - please be gentle.
>
[quoted text clipped - 28 lines]
>
>Looking forward to your imput.

I also qualify to be called a ungifted amateur. My handle has to do with
another hobby of mine. I have found this forum to be very useful in learning
about how to improve my lathe. I am hoping that I can return the favor by
documenting how I solved the problem. I also have a Myford ML7 with a
frozen gear that prevents the back gear from working. I recently acquired my
lathe from a junk man. Nothing would move on the lathe. Every moving part
stuck in place. There was very little rust just dried oil holding things
together. I used penetrating oil and some times a propane torch to loosen
things up. This worked on every thing but the Vee Cone Pulley Assembly B 17.
To free this up I needed to remove it from the shaft. First I removed the
Headstock Assembly as pictured hear.

http://i221.photobucket.com/albums/dd254/Magicpaddler/Lathe/PICT0113.jpg

The nest task was to remove the 25T. Gear B7. After removing the Grubscrew
B6 I tried a puller but it required so much force I was afraid the gear would
break. I tightened the Locking Collar B8 with pliers against the 25T. Gear B7.
Then I put a puller on that pulled on both the collar and the gear and
tightened up the puller. This allowed the gear to be moved about .0015
inches. Then I removed the puller and retightened the collar and re
installed the puller.

http://i221.photobucket.com/albums/dd254/Magicpaddler/Lathe/PICT0114.jpg

I did this about 10 times and this broke the gear loose so the gear could be
pulled in a more conventional way. This small puller grips the gear tight and
has a jaw that contacts a large spot on the gear and was able to safely
remove the gear after it was broke loose.

http://i221.photobucket.com/albums/dd254/Magicpaddler/Lathe/PICT0115.jpg

The Thrust bearing B 12 and thrust washer B 11 were removed easily by hand.
The Distance sleeve B13 was removed with the Vee Cone Pulley Assembly B14.
This required a puller and some heat from a torch. The puller has more than
enough pull to bend the pulley so go easy.

http://i221.photobucket.com/albums/dd254/Magicpaddler/Lathe/PICT0116.jpg

I cleaned up the shaft and the inside of the pulley with a nonmetallic
scouring pad. Then the pulley would drop on and spin freely.

http://i221.photobucket.com/albums/dd254/Magicpaddler/Lathe/PICT0119.jpg

The problem seams to be that the pulley material (aluminum I think) galled to
the shaft. The above picture shows the damage to the pulley. I think this
will happen even if the back gear is not used unless this is oiled well.

I also found that almost all of my oil zerk (oil nipples) are plugged. I
have used a ice pick to free up the ball but they are still blocked. They
all needed to be removed and blown out with 100 PSI air to clear them.

To see the pictures you may need to cut and past the addresses.
I hope this is useful to others.

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motorbikeman - 14 Oct 2009 12:31 GMT

>This is my first post - please be gentle.
>
[quoted text clipped - 28 lines]
>
>Looking forward to your imput.

Hi, I don'y have any answers to these queries but I do have a further
question... I have just got a Myforld ML7 and the back gear is operating
nicely. In order to avoid the problems described above I would like to ensure
that I keep the back gear well lubricated however I can't find an oil nipple
on the large end of the vee cone pulley. There is a grub screw in the vee of
the centre pulley but it seems to be there just to secure the pulley. Does
anyone have any advice please.

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MagicPaddler - 04 Feb 2010 00:31 GMT

I think if you oil it frequently on the one oil nipple and use it once and a
while it will be fine. The oil will migrate to the other end of the pulley.
I know my lathe did not suffer from being used with out lubricant because my
lathe was almost never used. It suffered form never being lubricated. It
set covered for the last 40 years.

>>This is my first post - please be gentle.
>>
[quoted text clipped - 9 lines]
>the centre pulley but it seems to be there just to secure the pulley. Does
>anyone have any advice please.

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Model Forum / General / Models / February 2010

Myford ML7 backgear jammed