Emco 50 CNC Mill …Increasing X and Y table travel ?

[The Novice EngineerParticipant @thenoviceengineer]

Has anyone experience of increasing the table travel?

[The Novice EngineerParticipant @thenoviceengineer]

Hi

I have had the Mill now for a year or so and love what it can do.

During my conversion of the mill from Emco control to Mach3 I did alter the limit switches to gain about 6-8mm on each axis, however I now find I am hitting the limit of what I can machine in a ~198x 95 work area.

I was recently looking at making some spoked wheels ~ 4" dia and before that cutting out a 4"x8" control panel. Both times disappointed . Trying to machine the part in 2 setups wasn't really good enough. [An optical finder is on my build list !]

I was thinking that I could maybe replace the ball screws and push the work area upto 275 x 125.

Has anyone got any experience of doing a modification like this?

Thanks Steve

[John HaineParticipant @johnhaine32865]

What limits the work area Steve? Certainly on my Novamill it isn't the length of the ballscrews, but possibly the position of the ballnut. But you'd need to make sure you had enough engagement of the dovetails.

[EmgeeParticipant @emgee]

Steve

If you remove the rear Y axis ball screw cover and shorten it you can get 100mm + movement, perhaps 120mm.
Doubt you will gain any extra in the X axis with the length of table fitted, you need a longer table to accommodate a longer ballscrew.

Emgee

[The Novice EngineerParticipant @thenoviceengineer]

Update
Thanks for the input.

I have had a bit of time to take a look under the covers. I reduced the stepper current so I can run to dead stops without causing damage. Then disabled the limit switches.

At first glance the Y axis can be extended by modifying the Front and Rear covers to give around ~120mm.

Gaining more movement on the X axis is a bit more limited , moving to the left running up to the ball nut is possible to gain ~8mm. Moving to the right the limitation is the stepper motor hitting the case side. There is a Cap Head screw under the Table that is the physical stop, [it appears to hit the Ball Nut housing] removing this an option.

A little more time later this weekend.

Steve

[John HaineParticipant @johnhaine32865]

Steve, would it help if you had more table area so that you can get workholding clamps out of the cutting envelope? I don't know what size the Emco table is, but over on the Denford forum someone described adding the Sieg long X1 table available from Arceurotrade on top of the Novamill table to give more length and I think a bit more width. Of course it eats up a bit opf daylight under the quill. You could do something similar by using a slab of aluminium or steel, with threaded holes outside the work area for clamps.

By the way, you don't really need to reduce the stepper current as you describe, steppers are very tolerant of hitting the buffers if you are moving slowly.

Edited By John Haine on 15/02/2019 08:21:02

[EmgeeParticipant @emgee]

I have the F1 mill which I believe has the same structure, the mill sits within a walled open top cabinet with a sliding front to gain access. When the table X axis is sent full travel in either direction there is very little space between the table and cabinet side, more on the RH side because of the stepper motor.
The walls and door do keep 95% of the chips contained within, some still get thrown out over the top if working hard.

Work envelope is stated as 200x100x200 (XYZ) and with BT30 quick change tooling suits many needs in the model engineers workshop, but bigger is often better, Arcs cnc mills have greater size envelope but my machine of choice would be a Denford Triac with ATC if I could find a little used machine.

Emgee

[The Novice EngineerParticipant @thenoviceengineer]

Update 2

After altering the covers on the Cross Slide I now have 124mm Y travel , and shortening the switch actuating rod on the RH side I have 205 X travel.

So a useful work area of 204×123 [allowing 0.5 mm at each limit switch before hitting the end stops!].

I have fitted a tapped plate to the table that allows greater flexibility for fixing items down.

[EmgeeParticipant @emgee]

24mm is a useful increase in the Y axis, what electronics did you use for the conversion ?

Emgee

[BazParticipant @baz89810]

Novice Engineer, you have a PM

[The Novice EngineerParticipant @thenoviceengineer]

Update 3

Here are some more details of what I modified on the Mill to gain the extra X Y workspace .

Y Axis

This is where the greatest improvement was made. By removing the front Guard and rebending the front of it I gained around 24 mm of movement on the table [when moving to wards the rear column], I also changed the lower cap head screw that secures the cover over the Z ballscrew on the rear column for a low profile dome head, another couple of mm for little effort.

The rear cover [accessed from behind the mill] includes the limit switch actuator for the forward movement [Home position] of the table, this was gently re-bent to allow more movement

X Axis

There was slight gain on this axis when moving to the left, by shortening the microswitch actuator rod ,~ 8mm removed. [this operates the limit switch under the right hand cover over the stepper motor]. This allowed the stepper motor assembly to come up to the ball nut housing, I set the switch for about 1mm gap here.

 

 

The other item to be modified was the cable gland fixing for the stepper motor cables. The gland plate was moved back ~ 18mm with a spacer plate. before I did this when the table moved to the maximum right and back the stepper motor cover would jam against the gland.

 

I hope this information will be useful to others.

I will post some information on the electronics I used as another thread.

Steve

Edited By The Novice Engineer on 28/02/2019 20:44:49

[The Novice EngineerParticipant @thenoviceengineer]

Here is a shot of the parts from the Emco manual, part 19 is the rear cover that operates the Y axis limit/home switch.

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