Myford ML10 cross slide screw

[Mike131]

I need to make a long cross slide screw for my ML10 but I do not know what thread it uses, if anybody knows I would be extremely grateful for any advice as I have only just taken up model making.

 

[metalmuncher]

Hi Think its 3/8th acme same as the super 7. regards Metalmuncher.

 

[tel]

Most likely 3/8 x 10 tpi Acme.

Mike, an introductory post in the Welcome section would be nice - tell us a little about yourself!

 

[krv3000]

HI rdg have them dise in stock

 

[Mike131]

Hi Thanks for the swift replies guy's, as a compleat beginner to model making I am just refurbishing two Myford lathes a ML4 and a Ml10 which should hopfully see me through a few projects,
I have not really done any machine work since I was at school back in he early seventy's,
Mike131

 

[Runner]

Hi Mike,

I am impressed by your beginning project as making a new cross slide screw for your lathe. Do you intend making the nut as well? I have an old 9" Southbend lathe that has a badly worn cross slide screw and I was contemplating making a new one. The difficulties I see is that it is LH square thread thread and that the cross slide screw is fairly long and requires other maching operations. Is there any prefered order of machining eg screw cutting first, then the other machining ops?

It will be my first attempt at screw cutting on the lathe.

I read an ME article on making a new cross slide screw and it recommended making it longer and if space allows a bigger diameter. Making it longer gives greater travel but of course you have to extend the apron.

I would be interested to hear any tips on how I go about making a new one

Regards,

Brian

 

[steamer]

Brian,

We can help with that. What lathe are you going to cut this with?

Additionally, instead of cutting a new one from scratch, can you get the screw stock?

It may be easier to replace it with that.

Let me know


Hi Mike,

Where ya from, what do you do? Like Tel said, We ( the forum...not the managers) like to know who we welcome into our home....If you could please, post a note in the welcome section and tell us about yourself..that would go a long way towards getting you some help.

Thanks,

Dave

 

[Runner]

Hi Dave,

thanks for the suggestion about using off the shelf screw stock, however the cross slide screw has a larger diameter boss on it than that of the screw diameter. This would require a separate boss be made and fixed somehow to the non screw part of the cross slide screw. The greatest problem I see is finding a source for the screw stock. I live in Adelaide Australia, so my possible options are mail order or ebay. Any mail order sources?

I can only use the Southbend to cut a new cross slide screw so the suggestion of using existing screw stock is a very good one.

Mike,

apologies for seemingly highjacking your thread.


Brian

 

[steamer]

Hi,

Here you go. Available to ship in a couple of weeks

No affiliation.....but good company

http://www.mcmaster.com/#acme-threaded-rods/=f111po

Adding a boss to the end via loctite should be possible. It's odd that the screw wore out as the SB screws are hardened. The Bronze nuts usually wear out , but not usually the screw.

New nuts are easy....on the "Bay"

http://www.ebay.com/itm/South-Bend-...836?pt=LH_DefaultDomain_0&hash=item5637f78154

I believe there are several places that will make new cross slide screws and nuts...but like I said it's odd that the screw is worn. My SB9 nut was worn out but the screw seems like new.

http://www.homemodelenginemachinist.com/index.php?topic=14436.0

Regards,


Dave

 

[steamer]

NEVER MIND!....you should never post before coffee.....

If I see parts for a ML10, I'll let you know :-[

Sorry about that

Dave

 

[Mainer]

@Runner --
Note that a "square thread" is not what you have. It's an Acme thread. Square threads do exist, but not on South Bend lathes as far as I know. A true square thread is difficult to cut. (I made the same mistake years ago, and a crusty old toolmaker named Lars Larsen straightened me out.)
I'd give serious consideration to using screw stock. The enlarged boss should not be a problem. Make a collar of appropriate dimensions to slide on the screw, degrease and secure it in place with Loctite 609, and when that sets up cross-drill for a pin, also held with Loctite. Be careful drilling, as you will in all probability be going down the flanks of the screw with the drill cutting only on one side. You might have better success getting through the screw with a, say, 3/32" diameter center-cutting end mill followed by a 1/8" dia. end mill or whatever o.d. your pin is going to be. It will take some patience and care, but should be quite do-able.
Perhaps a better way would be to silver solder the collar in place, if you can arrange to do that.

 

[Runner]

Thanks Dave,

that saved me a lot of effort. I googled "screw stock" and got a lot of responses that related to "screwing the stock exchange" There's a lot of unhappy people affected by the GFC. I hope you can help Mike out with his Myford ML10, so he can regain ownership of his thread.

Thanks Mainer,

your right its an ACME thread. That's my problem post first and then think about it later. I shall use your suggestion and fix it with silver solder, however will the heat applied in silver soldering affect the material properties of the screw stock?

Brian

 

[steamer]

Thanks for the heads up Kevin! RDG got a lot of nice stuff.

So Mike....where would you like to begin? We seemingly have plenty on the table to talk about.

Dave

 

[Dr Jo]

Making a cross slide screw as a first off challenge strikes me as jumping in at the deep end as they are still available new.

Do you really need to replace the screw or is it just a worn nut?

Jo

 

[steamer]

I agree Jo....most of the time on the lathes I've worked on, the nut was worn.....but I don't know diddly about Myfords.

Dave

 

[Runner]

Dave,

measured the cross slide screw, it appears to be 7/16ths" X 10 TPI which is not a size supplied by McMaster Carr. They supply 3/8ths" X 10 TPI or 1/2" X 10 TPI. Yes the cross slide screw is badly worn. Any suggestions?

Brian

 

[steamer]

Well I've checked MSC, McMaster Carr, Travers, Reid, Ebay, Various Acme threaded rod sites...and RDG.

None had 7/16-10 rod

RDG didn't have any ML10 parts, but did have a LH 7/16-10 tap

http://www.rdgtools.co.uk/cgi-bin/s...CME_TAPS__LEFT_HAND_.html#a1115668U#a1115668U

I would get that as making Acme nuts this small is a challenge. I've done .354-10 LH by single pointing and it really wasn't fun!

The tool was held in with a #4-40 screw...the bar diameter is .1875.

At about $20 American...it's worth it!

That brings us to the screw.
What does the screw look like? Does it have a part number?
Have you done a search for that part on the net by part number.

Somebody has got to make parts for Myfords.....If you low on threading experience...that would be my first piece of advice...buy one.

If it has a gear or something on it, that will complicate things.

Take a look around and let me know what you find.

Dave

 

[lordedmond]

Myford ( RDG ) do have ML 10 spares in feed screws and nut imp and metric

http://myford.co.uk/acatalog/MYFORD_ML10_SPARES.html


About half way down page


I have no affiliation with this company only as a customer

 

[steamer]

Thanks Lordedmond! You know I looked at that site 3 times and I even have purchased from them in the past...still didn't see it.

Sooooo much stuff there.

Pete at the price RDG is quoting there, it would be your best bet I think.

Dave

 

[Runner]

I finally bit the bullet and decided to make a new cross slide screw for my ancient Southbend lathe, since purchasing screw stock was becoming a protracted exercise. I have found out that the lathe is a type 405 which was the forerunner to the type C. Because it does not have power cross feed, the cross slide screw is as simple as it can be and can be turned in the lathe without the need for a mill, which I don't have. It was my first attempt at screw cutting and my first attempt a turning between centres. I found a file that describes the profile of the 7/16ths X 10 TPI ACME LH thread and used these data to determine the angle 29 deg, the depth of cut 0.06", the flat size at the crest 0.03707", the flat size at the root 0.03187. Since the cross slide screw is badly worn and as expected the nut would also be worn I made the OD and root dia larger by 0.005".

The exercise was straightforward, and the result is that I have improved the backlash from tens of thou to a few thou.

The pics show the old and new and the extent of wear on the thread of the old one. This is my first attempt at posting pictures so I don't know if I am going to be successful.

Regards,

Brian