EasiTurn Mach Conversion - Any ideas?

[SimonRafferty]

I have an Easiturn Lathe with a NEE controller, which, to be honest is a bit basic and out-dated. The lathe itself is fantastic and very solid - so worth some effort and cash!

I have been offered a Heidenhain (sp?) controller by a friend - but I'm not sure this is going to be any easier than going for Mach - and at least Mach is well supported.

My question is: Have any of you converted one of these? I have the circuit diagrams from the Manual, and it looks like the stepper driver boards could be re-used as they have a Step/Direction input (though I'm not sure what voltage levels they expect - probably TTL?). They also have a 'Boost' input - any ideas what this is for?

Failing that, what are the most sensible stepper drivers for the machine. The steppers have been painted green and I can see no indication of any ratings - voltage or current?

The spindle drive is another matter. The machine is single phase, but the motor is 3 phase, fed through a variable frequency inverter drive. The inputs to this are a bit more mysterious with just Acronyms which are un-obvious on the circuit diagram. It looks like the speed is controlled by an analogue voltage from 0 to 10v (as there is a 10v reference provided). There is an input that could be direction - and a couple of other mystery ones. Is there a board which will talk to the inverter - or do I have to replace it as well? If so, again, what is the best option?

To bring it all together, is there a break-out / isolator board which will talk to all the above plus the spindle encoder and limit switches and present it to the parallel port in a Mach friendly way?

I'm pretty technically competent - but have very little time for projects like this - so need it to be as simple as possible! (and low cost)

Any help would be much appreciated!

Si

[davidimurray]

Go Mach !!!

You get such a degree of customisation and support that you will never get with the Heidenhain. Also if you do hit a problem you can often delve into the inner workings of mach and find the cause.

You can see the details of my Starturn conversion here - viewtopic.php?t=452&highlight=starturn

Do you know what stepper drivers you have - are they SD2s or SD3s by any chance?

Spindle drive is probably a Brown Pestell of a Parajust unit. You should be able to interface these quite easily using a digispeed from peter Homann or similar.

For breakout boards etc have a look at CNC4PC

Hope that gets you started

Cheers

Dave

[SimonRafferty]

Thanks Dave, that was an interesting read!

The StarTurn looks pretty similar to the EasiTurn - just half the size!

Not sure what control cards I have - I'll have a look when I get home.

Do you know if the connectors used inside Denfords can be sourced these days? It loos like the interfaces to the boards all have nice connectors on - it would make sense to keep these and build something that just plugs it - then if I need to I can revert to the original control in a matter of minutes!

I'm really impressed with the machine. Last night I made 16 stainless bushes (simple, but they all needed to be the same) - and it managed a near mirror finish. I'd take a photo - but they are now holding the 8 wishbones on to my truck!

Si

[Triac whizz]

Going with mach will be a lot cheaper and a lot more people know how to play with it than Hiedenhan.

The connectors can be got from rs - trident connectors I think.
The drives can be reused with the little board designed by david. The drives use 12v.

The drive on mine was a KEB. You'll probably get it working under mach and then a week later it dies - at least mine did!

basically straightforward but needs some quality time to do it all.

[SimonRafferty]

peter Homann or similar. For breakout boards etc have a look at CNC4PC

CNC4PC sell a board with the 0-10v analogue output as well as all the breakouts. Still, people seem to recommend the peter Homann varispeed.

Is the latter a better option than the CNC4PC, or is the CNC4PC board too new for many people to have tried it?

Collecting everything together on the same board appeals to me!

Si

[davidimurray]

I've seen those boards and they look very good.

I used Peters board as there was no other on the market at the time and Peter is great with tech support etc.

One thing to check is that they are fully isolated units. A lot of the parajust, brown Pestell etc unit have their earth volatge around +130V and then use a range of 0-10V (i.e 130-14V)

Probably the best place to ask for advice is on the Mach yahoo groups.

Cheers

Dave

[SimonRafferty]

I've ordered one of the CNC4PC boards.

All the inputs and outputs are opto-isolated - and appear to be able to talk directly to the driver boards in the EasiTurn.

When it arrives I'll start a thread for the conversion - cos there's almost nothing on the web about what is actually a bloody good machine - even though the NEE controllers are a bit lacing in functionality.

I replaced the toolpost with a "PISTON TYPE QUICK CHANGE TOOLPOST - MEDIUM" from Chronos. Although it took a bit of adapting (cutting a new thread on the post and the block which mounts on the cross slide - I'm pretty impressed with it. £99 delivered inc 5 tool holders and it's rigid as hell. No chatter or movement.

If anyone would like the old toolpost (one of the Swiss made things with the corrugated profile) and/or the one tool holder I have - drop me a line and you can have it for the cost of the shipping!

Si