SX2P Mill Power feed

I've just ordered some parts to enable me to fit an X axis power feed to my newly acquired SX2P mill. What I'm struggling with is finding a simple method of declutching the power feed from the leadscrew when manual operation is required. I've found a few threads here and there, but they all seem to use a very basic sliding dog type clutch, which gives me the impression that it's not likely to be very reliable, so I'm wondering if anyone can suggest a better system? Given the choice, an electromagnetically operated clutch would be perfect, but I haven't found anything suitable or affordable yet!

I can't see why a dog clutch is likely to be unreliable? The slotted end of the X2 leadscrew is designed to work with a dog clutch.

Neil

Gordon,

I agree with Neil's assessment ...

As for motorising it: Solenoid actuation of a typical dog-clutch would be simple enough, as would using a stepper motor and toothed belt.

MichaelG.

The dog clutch is the simplest most reliable system, which is why it's so popular

An electromagnetic system would attract metal dust and swarf

Here [borrowed from **LINK** ]

http://www.lathes.co.uk/jason/

is a simple dog-clutch configuation that could be easily motorised:

MichaelG.

OK, thanks chaps, you've convinced me that a simple dog clutch is probably the best way to go. The diagram just posted by Michael (thanks!) shows quite clearly how one can be made to work and I'm sure it could easily be operated by some sort of solenoid. Will wait until the parts arrive that I've ordered and then get my thinking cap on.

Although a dogclutch should work in the slotted leadscxrew end of the X2 and X3 neither my feed or Neil's similar one use the slot as part of the clutch. We have a separate box containing a dog clutch, the output of which engages with the leadscrew and is operated by the simple turn of a knob. Usually needs a slight jiggle of the handwheel to ease the clutch into position as there is no syncromesh.

I have a standard Seig power feed on the table of my SX3 mill which does not have a clutch.

When the direction lever is in either the forward or reverse position there is a lot of resistance when turning the handwheel but if it is in the neutral position the resistance is minimised. No problem moving the table 100mm or so by hand. But much quicker to use the power feed fast speed button for bigger distances than by hand. The latest power feed unit from Seig has an in built clutch.

Paul.

I recently tried this route but abandoned it as you need a pretty powerful motor and this would have made the unit too bulky for my liking..

As Paul says the latest ones have a clutch unit pictured on the right, different clutch unit depending on machine but same drive unit.

This replaces the left hand leadscrew support and the output engages with the slot in the leadscrew

Edited By JasonB on 25/10/2016 13:21:58

.

I have some photos of my 'Jason' leadscrew dog-clutch, but may not be able to access them for a few days.

I will add them to the album when I can.

It's a simple and effective mechanism, and you will see that it survives in the Cowells lathes. **LINK**

http://www.cowells.com/90me.htm

MichaelG.

It might be worth having a look at a series of four video's by Stefan Gotteswinter, describing making a power feed for a milling machine.

https://youtu.be/r2YGstZ5lrg

HTH

I'm hoping that the motor I have ordered is going to have enough torque - if it hasn't, I'll look for another.

Michael - your assistance is appreciated - it's all good info!

Chris - those Stefan Gotteswinter videos are VERY helpful and I'll probably cobble mine together around that .design.

Thanks again chaps!

Gordon,

I've managed to load the photos today ...

Run through them in sequence, and it's almost animated.

... Should give you a good idea of how it works.

MichaelG.

WARNING

The end travel limit switchs on the Seig power feed units are a simple (won't say cheap) arrangement comprising 2 small swithces in a plastic box with 2 small push buttons. One on each side which are triggered wnen the table reaches full stroke. This has worked effectively for a number of years and have only had to change one of the switches costing a few dollars.

Recently I removed the power unit from the mill table and the X- and Y-slide to give them a good clean and inspection. At assembly I bolted the power unit to the end of the table and powerred it up to check if it would run before mounting the limit switches. Feed in both directions OK.

When I attached the limit switch unit to the front of the mill I got a small electric tingle from the outside of the plastic box. On inspection discoverred that the inside of the box was oily and was conducting a current to the outside. This short had not tripped my earth leakage breaker on the house power supply but measured 10 M ohm resistance to the active terminal on the power plug.

A reminder that oil, water and electricity can be trouble.

Paul.

Edited By Paul Lousick on 26/10/2016 03:41:49

Hi Gordon,

I have made a power feed for my sx1 mill. This has, I think, the same milling table as your mill.

Mine has simple sliding dog clutch which has proved reliable. Further details are here:

http://mikesworkshop.weebly.com/mill-power-feed

This might give you some ideas.

Mike

Morning all,

I may have missed something here, but who sells this conversion kit in the U.K.?

Matthew

Mine does! There's a bronze sleeve with a crosspin, and when you turn the clutch knob the shaft slides out and the pin engages with the slot in the leadscrew.

The mechanism is essentially the same as the Jason (lathe) except its the slot and pin are internal not external.

Neil

​Simple dog clutch with lever operation fitted to a Myford VMB mill (with side plates removed to see inside ). This arrangement has worked well for a few years. I used a decent sized stepper motor and controller which has more than enough power for the job.

Matthew,

Neil and Jason are working with power feeds which have been offered to us - ARC by SIEG. Based on past experience, ARC has so far kept out of placing power feeds on the market. There are pluses and minuses with the latest offering which Neil and Jason are using. So far they have been using these for between four to six months. As they stand, ARC is reluctant to introduce them. However, a competitor may introduce them, or you might be able to import it from LMS in USA in due course.... should you wish to take the risk!

Traditionally, these power feeds are too fast at the lowest speed. Several passes with lower depths of cuts would be required, depending on material being milled. This would still be okay, provided such a message could be communicated to the user.

More then 50% of users are new to the hobby, new to the idea of milling, with limited understanding. So, probability of 'breaking' a tool, damaging the material, or the power feed unit for such customers is high. This issue has never been addressed by any seller!.

A good percentage of the previous model failed within six months of use. Why? - was it a user related issue as mentioned above, or was it component failure?.... So, before ARC invests in this product for sale, we have asked Neil and Jason - who are experienced users to put the units on their machines, and see if they still work after a years use.

These units are expensive at over £350.00 (inc.vat) and ultimately ARC has to hold the can when it comes to 'issues'. We are unable to get away with availing our responsibilities as would be the case on direct component imports through fleabay for example. Nor could we say that this is a 'Maker Project' to excuse our responsibilities

Ketan at ARC