Small CNC or bigger manual mill?

Hi Folks,

I am thinking about upgrading my basic milling machine for something a bit more fun and am in a bit of a quandry.

My current miller is an Amolco bench top with x/y table like this one:

I have the budget for a reasonably robust CNC machine (possibly Wabeco) and I have the space for something as large as a Bridgeport.

As a new(ish) Model Engineer, I am currently making clocks, but am enjoying the toolmaking aspect of the hobby and feel that something that will limit me to the smaller end of the scale may prove frustrating in the longer term.

The hedonistic solution would be a new CNC and a second hand manual mill, but I don't really have the space for both.

John S's previous comments on CNC/Mach3-wizards have made me think that I could get away with having one to play with generally, rather than staying manual.

Any interesting musings on what I should be considering?

Cheers,

Rob

Rob, having recently acquired a small CNC mill I can endorse JS's comments absolutely! Even for simple jobs, it is so quick to use a Mach 3 wizard, for example to drill a couple of holes in each of two plates that had to line up exactly as I had to do last night. Just clamp down the part on a bit of MDF against a fence on the table, reference the mill to the corner and surface, then fire off the wizard. Result - holes in exactly the right place on both parts. By manual methods I'd have had to fiddle around clamping them together (they were different sizes), how to hold the combination, locating the drill, and all the rest of the palaver. No Gcode writing involved at all.

The CNC mill I bought is a Denford Novamill which is an older design but built like a proper industrial machine with ballscrews etc, and I've quickly found that it does exactly what you tell it to, you don't need to worry about backlash etc. I would recommend either buying something with ballscrews of good quality, or retrofitting them to a machine. If you buy a machine I would recommend a Denford Novamill or a Triac (?) if you want something a bit bigger. However they are a bit old so the controllers run under old versions of Windows - but anyway I had to build a new controller for mine to work with Mach3 as it had got separated from its electronics. I also have a VMB big mill but I didn't want to start rebuilding that.

Here's an idea - you could get a bigger manual mill (X3?) and convert your Amolco to CNC? I used to have an Amolco and was quite impressed with it and it did strike me that it could easily be converted as there's quite a lot of room for ballscrews. And there's lots of space in the base for the electronics. One worthwhile mod that I did was an column extension which gave at least 2 additional inches of working height.

If you have any questions about CNC I'm happy to answer from my so far limited experience - as well as building the controller for the Novamill I've converted a Super 7.

Cheers, John.

Sometimes it is nice to be able to manually control a CNC mill; sometimes it's just faster than pushing buttons.

So, I have tried to control my CNC mill using a gamepad controller (mine was from a Playstation 3) but have just recently purchased and installed an MP3 Pendant from CNC4PC.

Now I have a rotary control, just like the large mill I have; I have 3 "speed" settings for fine work, general "get the metal off" and "rapid traverse".

Of course, you don't get the touch feedback you'd get with a directly connected feedscrew, but you can move around the machine with the controller in your hand, so you can see what is going on. You also get a DRO on all 3 (or on mine 4) axes.

Mine fit into my LinuxCNC (emc2) machine in about 2 minutes; I'm sure Mach3 would be fine, too.

Another JohnS

As someone new to engineering, I would recommend going for a manual machine and gaining a good understanding of how materials react to being machined. The bridgeport in the form of a turret mill would be an ideal choice as it is a very robust machine and in the fullness of time you can add things like dividing heads and rotary table to it to make it even more versatile. This is not to say that I am anti CNC but I think (sure) a learner should cut thier teeth on manual equipment first. Good luck with your choice. Jim.

Thanks for the thoughts chaps.

I am leaning towards getting something like a Bridgeport, which no doubt I can sell on if the CNC bug doesn't go away. I think it's my closet techie that wants to play with the computer side.

This way, I can learn about it all sensibly and decide what (and how) to do properly.

Now I just need tips on what to look out for in the second hand turret mill world... But that's another challenge on the road!

Rob

You could always do what I did and CNC your bridgeport when you're ready