Leadscrew thread form

[John RuddParticipant @johnrudd16576]

I'm looking at making an extented version of the X axis leadscrew for my Chester 626 mill.

Does anyone know what the thread form is? It looks like M24 x 3 but has a more flattened crest….My thread gauge seems to fit ok…..

[John RuddParticipant @johnrudd16576]

[JasonBModerator @jasonb]

30degree Trapizoidal is the most likely if it measures in metric, this is the metric version of ACME that is 29degrees.

Though being of far Eastern origin it could be Acme Form to metric sizes

E

Edited By JasonB on 30/10/2016 07:55:31

[Chris Evans 6Participant @chrisevans6]

Check out places like Automotion Components, suppliers of leadscrews and nuts. Cheap as chips in upwards of 1 metre lengths with choice of nuts to suit.

[John RuddParticipant @johnrudd16576]

Thanks for the info guys…

What about just extending the original shaft? What would be the best way

On the leadscrew, On the right hand end, there is a section that is 16 mm dia with a 5mm keyway for the handwheel, this approx 50mm long, then a bearing shoulder, 20mm dia and approx 20 in length….then the threaded section….

I need to extend it to accomodate an Align 500 power feed….

[John HinkleyParticipant @johnhinkley26699]

I have a Warco VMC mill – a Chester 626 by another name – and the Align 500 X-axis power feed fitted "out of the box" without the need for any modifications. Can I ask why you think it needs extending? Unless it isn't the 500P version.

John

Edited By John Hinkley on 30/10/2016 10:24:24

[John RuddParticipant @johnrudd16576]

John,

It is the same model as yours…

I've created an album, Align AL500.

There are several issues….How does the main unit attach to the table? I guess it is by using the holes in the unit and bolting to the bearing support on the end of the table?

Secondly, the bevel gear bore is smaller in diameter to that of the leadscrew( its metric not imp….) looks like the shaft is 16mm and the gear bore is 5/8… Not an insurmountable problem, just needs boring out, but the key and keyway are different too….

The bore diameter of the dial is bigger than the o/d of the bevel, needing a bush or sleeve.

I'd certainly appreciate any help you can offer in installing this

[John HinkleyParticipant @johnhinkley26699]

John (Rudd),

Just been out to the mill and stripped off the handle/dial/bevel gear. The machine is a metric one, but the shaft of the leadscrew measures 0.625 in Ø (5/8&quot or 15.8mm. So you takes you choice. The bore of the bevel gear fits perfectly on this. Be sure you aren't trying to fit it with the supplied casting – that's for a Bridgeport machine only.

Maybe if your bevel gear isn't the right bore, you've been sold the wrong power feed unit? If you will forgive me, you may have not measured the bore/shaft dimensions accurately enough. Have you tried fitting the bevel gear on to the shaft?

This what my installation looks like when complete:

I found that the limit switch also needed slight modification. As supplied, the cable exits at the bottom; I needed to make a new exit on the side to clear the Y-axis feed mechanism:

All these pictures and more are in my album "Warco VMC Mill". Here's the relevant page from the installation manual, though I assume that you've got this anyway.

Hope this helps,. Good luck,

John

[John RuddParticipant @johnrudd16576]

John,

Thats an enormous help!!

I see your dial is a lot shorter than mine….I may have to mod mine to fit….

My gear is definitely 5/8 and the shaft is definitely 16mm….

My handwheel is diferent to yours too….not really an issue for me.

The biggest problem I will have will be broaching the keyway out to 5mm…..fortunately its brass so not too hard. Or the alternative would be to have a partially stepped key?…( the keyway in the handwheel is 5mm)

I'll also need to make a bush for my dial and gear….the dial bore is bigger than the o/d of the gear on which it sits….

Many thanks for your help, I'm indebted to you….

[John HinkleyParticipant @johnhinkley26699]

John,

There are obviously more differences between the Warco and Chester offerings than I thought. The key in the lead screw on my machine is approximately 2mm wide, certainly not as large as 5mm. ( It's all screwed back together again so I can't measure it accurately. ) Don't lose heart; nothing is insurmountable.

John

[John RuddParticipant @johnrudd16576]

Posted by John Hinkley on 30/10/2016 17:15:43:

John,

There are obviously more differences between the Warco and Chester offerings than I thought. The key in the lead screw on my machine is approximately 2mm wide, certainly not as large as 5mm.

John

Apparently so, even cosmetic items like handwheels and dials make a difference to installation…..

I'll report back on my progress….

[John Stevenson 1Participant @johnstevenson1]

John,

Just replied to your post on the other forum.

 

[ EDIT ] to whom it may concern, because, believe me some people don't have anything less to do that John Rudd Is NOT one of my sock puppets

Edited By John Stevenson on 30/10/2016 18:16:16

[John RuddParticipant @johnrudd16576]

John,

Thanks, I replied…much appreciated.

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