Denford Triac Mill

Hi folks,

I may have the opportunity to buy a Denford Triac mill, I know nothing about this brand. Could anyone share if this is a mill worth investing in? The controller looks dauntingly outdated, I was considering removing the controller completely and rebuilding that aspect using Mach 3 or 4. Although that will be an adventure all of its own as I have no experience. What would be sensible money for this mill in decent condition?

Any advice appreciated!

Hi Mark

Triacs are well built and have a useful working envelope, some had autotoolchanging facility using BT30 or BT35 holders, without the ATC spindle was usually R8 located by drawbar as opposed to ball nut of the BT type.

Although the machine may be using old style programming it does have many cyclic operations built into the programs so may achieve all you need without converting to Mach or other operating system.

If in good working condition expect to pay from £1000 upwards, latest models with full 3 axis software and ATC will make 2k plus.

If it has been in an industrial environment it may be thrashed to death and need new ballscrews to eliminate excessive backlash, careful examination may reveal other faults but it's best to see it working cutting material if possible.

Some were 3 phase machines so check the nameplate.

Emgee

Edited By Emgee on 02/10/2017 22:22:01

Mark, check in my picture album where you can view some of the variants of the Triac, link below should take you there.

http://www.model-engineer.co.uk/albums/member_album.asp?a=42512

Emgee

Edited By Emgee on 03/10/2017 13:49:11

There is heaps of information available on the Denforddata forum.

I have a Novamill (smaller brother to Triac) - I did a half way house conversion, kept the existing driver board/cabinet, but removed the processor board and linked to the parallel port of a computer running LinuxCNC (or Mach3).

I have had a triac for 10 years or so. They were built for education (who invariably didn't use them) and are very well put together. If the capacity of the machine is enough for your needs I would say that you are unlikely to find anything better. As for the control, yes it is outdated but refitting them is not complicated and there is loads of information about how to carry this out.

Which of Emgees photos does it look like?

Regards.

David.

Mark

I have an Orac lathe from the same era (1983) and still using the original G&M code control system, does all I need as a model engineer so if it aint broke why not continue to use it.
Programming info can be found on the Denford Forum for the model you have, it will allow you to write or edit programs on a computer and then send the program via a cable link to the machine.
You may have to Register to get access to all forum information.

I believe all Triacs were fitted with steppers in std form. If you want to draw the part and then use a CAM program to send the cutting program to the mill you will need to upgrade the system to accept the program.

Emgee

I believe all Triacs were fitted with steppers in std form

Not all of them.

I have an ex-industrial Triac that is different to those shown above - it is on a twin pedestal base, with a removable swarf bin between the legs, with the gas strut balanced, full width lift up front guard. The electrical cabinet is full width across the rear on the pedestals. Control system was a Heidenhain TNC355 (operator station mounted on a swinging arm from the base), with brushless servo drives (can't recall the make, but not "main stream" to all axes. Spinde is BT30 with an Erickson locknut & no ATC. Spindle drive is a 2.2Kw squirrel cage motor directly connected to the spindle with a polyvee belt - it originally had an IMO inverter drive. The machine was bought in to scrap for the electronic parts where I used to work & I bought the carcass for £100.

The Fanuc Triac shown above would also have had servo drives - type dependant upon the exact model of Fanuc 0M fitted (the "A" models were analogue interface, "B" & " C" models were all digital & could only use Fanuc's own brushelss servos).

I really should make room in the garage to get it out of storage - it's only been there 11 years now ! I have the stepper motors, stepper drives, PC break-out board & an inverter already bought in to get it up & running again. I planned to remove the rear mounted cabinet to save floor space & cut out the side of one of the pedestals to let in a smaller box (also already to hand). Unfortunately the lift-up guard & the swarf bin had already gone out in a skip before I got the OK to buy it.

Have fun with yours,

Nigel B

Edited By Mark Slatter on 03/10/2017 20:14:45

Mark, states 0.01mm resolution on the specification sheet, seems that was typical for lathes and mills across the range at that time. I find it best to run a program through the machine a few times before cutting material so it attains working temperature, accuracy and repeatability is then pretty good.

Emgee

Mark

To get your Triac machine running quickly the original DOS software can be found at the link below.

**LINK**

You will of course need to use a computer capable of running DOS.

Emgee

I would strongly advise you to update the hardware / software to something more modern. The first triac I owned was a working non atc version. I had it for 2 / 3 years and hardly used it. I then came across the one I have now which was a non working Fanuc one with an atc. I refitted it to run Mach 3 and I started to use it all the time. It has remained unchanged ever since. Although converting it may seem complicated it is in reality not that difficult and you would be following a path that many others have trodden. The Denford software is rubbish and will only frustrate you. The memory in the older machines is very limiting and although you can drip feed (send one line of code at a time) it is very very slow. That and the fact that any modern cam package is unlikely to have a Denford post processor that will suit your machine and there is a dwindling number of people familiar with it to help you.

Whatever you choose to do good luck with it and I guarantee you will learn something new .

Regards.

David.

Triac and Novamill used a similar arrangement to lock holders in spindle when ATC was fitted. If you dig around the Denforddata site you'll probably find some drawings of the arrangement.

Mark

It will be helpful for you to get the machine up and running with the original software, you may find it suits your needs without converting.

Sounds like your mill has a Coventry Easy Change toolholder fitted in the R8 spindle, various heads on short tapers fit into the holder. Usefull for quick changing tools but has the disadvantage of reducing the tool to table distance and the heads are very expensive but still available should you have deep pockets.

The toolholder used when the machine was equpped with ATC was kept in place with a stack of disc washers bearing on the ball stud, this pressure was released by an air cylinder. As stated earlier the arbor on those toolholders was BT30 or 35, I am not sure if any R8 spindles were equipped with truly quick change tooling but it may be posible to do so.

Emgee

Added link to Easy Change info.

http://www.coveng.co.uk/group/coventry-toolholders/products/toolholders-for-manual-machines/easy-change.html

Power Drawbar PDF drawing, (you may have to register for access).

http://www.denfordata.com/bb/viewforum.php?f=47

Edited By Emgee on 05/10/2017 14:33:46

Edited By Emgee on 05/10/2017 14:49:01

Sounds like your mill has a Coventry Easy Change toolholder

MSC Industrial Supply carry these **LINK**

Make sure you are sitting down before looking at the prices !

Nigel B

Many thanks for the replies Nigel, David and Emgee, sorry for only acknowledging it now I've been a bit under the weather. Just as well Ive been lying in bed...those prices for the Easy Change toolholders are shocking!! I managed to get a few tooldholders with the mill however:

It includes a ER32, ER25 and two ER16 collet holders, and a couple of other holders. A few hundred quids worth just in that lot! The owner was saying he might want something for the tooling...with those prices for extras I think I might consider selling them and making up some Tormach TTS style holders...it would work out cheaper in the long run I reckon.

What do you think this is...I havnt had a chance to open it up and see what the collet looks like...but if its just a collet holder it seems a strange shape?

Edited By Mark Slatter on 08/10/2017 18:46:48

Edited By Mark Slatter on 08/10/2017 18:49:03

Edited By Mark Slatter on 08/10/2017 18:55:37

Since I only had one easy change holder with my Novamill, I removed all the easy change stuff and instead substituted an ER collet chuck using the original manual drawbar.