What 'decent' Milling machine?

[Chaz]

Silyavski bet me too it and i was going to say same.

You can find Old machines like that Bridgeport that just need new life breathing into them.
You don't waste your time trying to use there old standard controllers just rip them out and retrofit with modern one. Often there control on these things are limited with very little memory.
You'll find on older machines the drives will require 0-10v analog signals rather than step & dir like modern stuff uses.
Ounce upon a time this made life difficult for your average person to retrofit or Very very expensive after market controllers so often things like drives and motors where replaced making it expensive and uneconomical in some cases.!! . . But not anymore now Cslabs have a analog Controller at sensible enough money that was designed just this purpose of retro fittng old machines. Even ones that use 12 or 24 logic.!

This means often all you need to replace is the Controller and with a bit of re-wiring you can re-use all the existing components and get the machine working like it's never done before.!
Just be aware thou most industrial spec machines require 3 phase power.! Often this is just for the Spindle not the Motors or drives. On many old machines like that Bridge port you'll find either Steppers or Brushed DC servos. Depending on drives etc often it just means changing or rewiring a transfomer so use single phase.
The Spindle is the main thing that will require 3 phase but often you can just run these straight from a VFD. Or you can buy Converter that will transform single phase to three phase if large HP.

Personally I'd wait for some Old iron to come along and replace everything with moderern servos and controller etc before buy those mickey mouse toys.

Thanks to both. So basically look at something like the Bridgeport? I dont mind doing some retrofitting. I used the PlanetCNC USB controller before and loved it.

Thoughts on the Denfords, are they considered 'toys' or more like the real deal?

[JohnHaine]

I have a little Denford and it's excellent for what I want to do. A Triac would be nice as it's bigger, about the size of my VMB, but I don't have room for it. Unless you are very particular I'd have thought a Triac would be a good buy. When I got my Novamill I was thinking of converting an X1 or buying a KX1, but the Denford knocks those small machines into a cocked hat, it's just in a different league. A Bridgeport is great, but takes up lots of room, and is very very heavy! I would guess that with a Triac you would get the same accuracy as a Bridgy but won't be able to shave off metal as the same rate.

As for what it's worth, things are worth what people will pay. This particular one is not in an auction but you could try making an offer. I think eBay gives you a facility to see previous deals on similar items, so you could see what's been paid in the past? The price looks a bit high to me but I've seen some high prices for Denfords on eBay.

[Chaz]

I have a little Denford and it's excellent for what I want to do. A Triac would be nice as it's bigger, about the size of my VMB, but I don't have room for it. Unless you are very particular I'd have thought a Triac would be a good buy. When I got my Novamill I was thinking of converting an X1 or buying a KX1, but the Denford knocks those small machines into a cocked hat, it's just in a different league. A Bridgeport is great, but takes up lots of room, and is very very heavy! I would guess that with a Triac you would get the same accuracy as a Bridgy but won't be able to shave off metal as the same rate.

As for what it's worth, things are worth what people will pay. This particular one is not in an auction but you could try making an offer. I think eBay gives you a facility to see previous deals on similar items, so you could see what's been paid in the past? The price looks a bit high to me but I've seen some high prices for Denfords on eBay.

So I found a Denford Traic PC, dont know much about the control system. What will the cost be to convert to Mach3? How much of the electronics is reusable?

[Jess]

So I found a Denford Traic PC, dont know much about the control system. What will the cost be to convert to Mach3? How much of the electronics is reusable?

I think quite a bit technically is. Denford have been pretty good at providing documentation and so forth. So, in principle, you can probably wire a breakout board to those drives, if they're working.

However, the electronics are often pretty old and basic. Most of the conversions I've seen seem to replace everything, except perhaps the motors and maybe the transformer.

Personally, I'd budget for replacing all of the electronics.

[Chaz]

I think quite a bit technically is. Denford have been pretty good at providing documentation and so forth. So, in principle, you can probably wire a breakout board to those drives, if they're working.

However, the electronics are often pretty old and basic. Most of the conversions I've seen seem to replace everything, except perhaps the motors and maybe the transformer.

Personally, I'd budget for replacing all of the electronics.

Thanks, including motors?

[Jess]

I think if the motors are working (at a guess, they probably are), then I think they'll be just fine.

I'd emphasise the 'budget for' though; worst case, you might have to fork out, but obviously, every penny you don't fork out, is a penny you can spend on your vices (and clamps, endmills etc.,)

The problem with the stock electronics is that it's basic (eg., the drivers are probably only half-stepping etc.,) and conservative (voltages are lower than necessary etc.,). So, it's not going to run as smoothly or as quickly as it otherwise could.

Having said that, it's also quality stuff; so it's often worth flogging the bits you don't need on eBay, especially if they're working - last I looked the motion control and driver boards seemed to fetch a decent price.

On my very small Denford, I've only replaced the stepper drives and DC supply (the original was part of the original drive board). I've been able to keep the door latches, e-stop, various relays, spindle control board, transformer etc., The main reason I replaced the drive board was actually that it was a real pain to interface to. After a couple of months of 'is it the drive or is it the BOB or is it my wiring' hassle, I broke down, bought a Gecko and had the machine working (with LinuxCNC) in a couple of days.

[Chaz]

Wondering if this is the same mill?

http://www.mycncuk.com/threads/1605-Denford-Triac-Mill

Seems a lot might be reusable. So budget for a cheap retrofit? Budget for going servo versus stepper? Info welcome, many thanks.

[JAZZCNC]

So I found a Denford Traic PC, dont know much about the control system. What will the cost be to convert to Mach3? How much of the electronics is reusable?

Depends on how old and what's inside.? Often if converting your better just replacing control and the drives with modern stuff. You'll have a far better performing machine.

The AC Transformer can be re-used but often the Caps and Bridge rectifier are on one of the boards your removing so you'll need to make a little board with new caps etc or use another PSU.
For this reason I prefer to use a new often higher voltage toroidal supply has the steppers are often well under performing. Along with smaller Switch mode PSU for Relays etc to save messing around with differant size Caps etc for differant DC voltages required. The stock transformer gives several AC voltages.

The Spindle speed controller can be re-used but you'll need Controller or BOB that can provide 0-10V signal.

The Contactors and Relays can often be reused, as can most of the other bit's n bobs inside.!

Not difficult to do but Not something I'd encourage anyone who as NO experience to take on.!!

[Chaz]

Depends on how old and what's inside.? Often if converting your better just replacing control and the drives with modern stuff. You'll have a far better performing machine.

The AC Transformer can be re-used but often the Caps and Bridge rectifier are on one of the boards your removing so you'll need to make a little board with new caps etc or use another PSU.
For this reason I prefer to use a new often higher voltage toroidal supply has the steppers are often well under performing. Along with smaller Switch mode PSU for Relays etc to save messing around with differant size Caps etc for differant DC voltages required. The stock transformer gives several AC voltages.

The Spindle speed controller can be re-used but you'll need Controller or BOB that can provide 0-10V signal.

The Contactors and Relays can often be reused, as can most of the other bit's n bobs inside.!

Not difficult to do but Not something I'd encourage anyone who as NO experience to take on.!!

Thanks. Understood. I'm happy to do the electronics, sounds like a perfect match for a lot of new kit.

Trying to find some details of the spindle etc to see if it matches what I need in terms of speed / power.

[JohnHaine]

Look for denfordata on google to get the mill details as well as lots of info from people who have probably converted them to Mach 3 and / or modern drivers etc. for guidance I spent less than £200 on new drivers, a BoB and smps to get my Novamill working, using the original motors. All the electronics from China via eBay, 2m542 drivers. Psu is 36volt. There were no electronics at all with my mill so also had to use a KB electronics motor drive I already had, but you can use the one in the mill if it's working. Caution however, if it's a dc motor thyristor drive it is NOT isolated from the mains and you will need an isolating circuit to link the drive to your BoB.