cncconversionkit.com???

[ethank]

Has anyone had any experience with this company? any Reviews or thoughts???

cnc kit, diy router, mini mill, x2, x3, build, milling machine, machines, home made, used, woodwork, make your own, low cost - Taig Ballscrew BF20 Mill milling routing machine machines

Hello CNC zone , my name is Ethan.I work in steel, doing architectural installations. You can see my site here http://www.midnightmetalworks.com
I would like to try scaling down my work and so I am interested in buying a small bench top cnc mill for carving wax for jewelry.
I am considering a taig!!! I am looking for advice on wether this taig would work well for me...

This page details a taig adapted for a 5th axis:
Taig mill 5 axis with ball screw - Taig Ballscrew BF20 Mill milling routing machine machines

indexed 5 Axis Machine
Included
Taig mill with ball screw
Trunnion Table with 2 sherline rotary table
5 x Gecko g201 cnc driver redy to go
5 x nema23 270 oz motors
configurable post-processor
mach 3 up to 6 axis

Thanks in advance for your help!
I have also been considering some other brands so if you have any other ideas I should look at please let me know...

[lsces]

Ethan
The Taig mill is more than capable as it comes, so there has been a long discussion on the taigtools list as to the advantages 2nd otherwise of ballscrew conversion. I have many customers who do very fine work with the bog standard machine, once they have become used to keeping it 'well tuned'. As for the fifth axis being supplied on the bed of the taig - again, the design of the Taig provides a good amount of clearance over the bed to do that, but providing the fifth asis by simply mounting a second rotary table on the back of the spindle gives a MUCH bigger working foot print.
Nothing against cncconversions - he is trying to do a good job, but his targets just seem to be wrong at present.

[wildwestpat]

Hi Ethan

Nice sculptures. Suggest you define the size length - width - depth you wish to 'carve'.

The problem comes when you add extra axis. The extra axis require support bearing structures and motors all of which can eat into the envelope of a 3 axis machine to leave very little room between the cutter and the work. I know this is obvious but adding the fifth axis reduces the total envelope that can be cut considerably.

As well as a suitable machine you need software that can translate a 3D conceptual computer generated graphic into code to drive the various axis to deliver a the surface as a reproduction of the computer graphic but in solid form.

The CNC axis motors have to drive the extra mass added by the forth and fifth axis. Acceleration and maximum traverse rates act with the inertia caused by the total mass being moved along with losses due to friction to determine the motor size required. 270 oz inch torque sounds very low. Motors that are too small will stall and wreck the work as the axis become uncoordinated. Motors that are too large can suffer resonance problems. Closed loop servos are much to be preferred where the need is for fast slewing of the part under the cutter.

I would be suspicious of any source of hardware that makes a point of slagging off their competition and not giving the basis for that comparison. When comparing ball screws be-aware that there are not only different specifications but there are also various ways of minimising the backlash. The drives for the first three axis might be linear and ball screw candidates the extra axis are rotational and will involve rotary not linear motion. There are some weird and wonderful machines with videos on YouTube that employ cantilever leg type construction to get the cutter into position - these machines are large compared to the actual envelope of the work they can do.

Good luck - Regards - Pat

PS - IMHO what you might be looking for is a smaller edition of this one http://www.doughtydrive.com/productc.html rather than a conversion job on a small bench top mill/drill.

[darrellatg]

I looked at your metal art on your website, very nice!

I called up the guy at cncconversionkit a few days ago to get more info on his ballscrew upgrades. I dont really need ballscrews for what I do, but I love tweaking and upgrading my toys. I think I will buy the kit after some more checks come in. He said he started working on this kit for his son, who is a jeweler, to carve wax. So it might be ideal for what you want to do. Call him up and talk to him.

One other Taig to look at is here: MicroMill DSLS 3000 Its a taig with servos instead of steppers. Servos are generally thought to be more accurate since they are closed loop.

[lsces]

One other Taig to look at is here: MicroMill DSLS 3000 Its a taig with servos instead of steppers. Servos are generally thought to be more accurate since they are closed loop.

Correction to that!!!
The DSLS3000 is still stepper motors. It just adds an encoder to the shaft of the stepper motor and does provide some protection against missing steps but is no more accurate than the standard 2000 model. If anything it is ACTUALLY less accurate unless you run at slower speeds. The main problem with it is that Mach3 does not know that the 'correction' mechanism is working, so if a long move on one axis is still happening when Mach3 changes direction, corners get distorted.
The idea is good, but being practical, a good bipolar drive setup is a much better 'upgrade' and has to be recommended as a first choice if one is starting out.
And while I'm still running a DSLS3000 controller on the demo mill here, I know it's quirks which took some time to appreciate. One has enough trouble with the basics of CNC without adding other variables when starting out.

[lsces]

mine is hooked up right to my tv with out going through a converter
that would be your best option

Any chance you can explain what you are talking about?

[wildwestpat]

Stepper motors when over loaded miss steps and the problem is that once they start to stall feeding extra steps to try and correct is of no practical use. With open loop drives it is essential to have sufficient power (torque) for all circumstances.

If an encoder is used to check that each step has been made then simply detecting the missed step and adding an extra one is not a viable solution as more power is needed not extra steps.

Detecting missed step might have use to halt the machine or warn the operator of the malfunction.

Suggest you ask the vendor DSL for a detailed explanation of how their system works. It is just possible they have had that Eureka moment and found a way out of the lost step quagmire. If so why have they not used linear scales so that the table is driven to the precise position instead of putting a rotary encoder on the motor shaft?

Power servos with linear scales cost around ten to twenty times the price of a stepper drive and have different motion controller needs.

Regards - Pat

[lsces]

Stepper motors when over loaded miss steps and the problem is that once they start to stall feeding extra steps to try and correct is of no practical use. With open loop drives it is essential to have sufficient power (torque) for all circumstances.
Regards - Pat

Totally correct, which is why Kurt's closed loop approach does not work that way. He is able to adjust the width of the pulse applied, and continues to apply power until the motor moves. This approach actually works very well, and gives a usable reliable speed increase over the identical open loop package. The problem with the system is simply that since the pulse width is varied, following pulses have to be buffered, and as I have already said, Mach3 does not know about that correction process, and so looses position on it's own display. To work well, this approach has to be integrated into Mach3, which is not practical, but it could be handled properly in EMC2 where the encoder output can be used directly by EMC2.

In practice, replacing the DSLS3000 controller with a good bipolar driver package is currently a lot more practical.

[wildwestpat]

Hi Lester Thanks for the explanation. With the price of hybrid motors and modern shaped current drives now I know I am not missing out.


Regards - Pat

[cameraguy]

Back to the Ballscrew thing;

Cutting waxes and small camera parts is right along my lines, so this looks good. For years people have talked about how difficult it is to convert a Taig to ballscrew. It seems pretty straightforward and nearly a bolt-on from what I can see, and this conversion kit looks that way too. What am I missing?

1)Is it really as easy as it looks?, and

2)What parts is he using to do it? Has anyone who has done it put any details online?

[Rift]

The price for this is just bonkers. I don't get it. The options make no sense either. Both of them look like they want you to send parts over there but the last one is saying that after your Y axis and X axis stuff is received you will get a ballscrew kit sent to you what the heck?

In either case I don't think this is worth the price of another Taig Mill.

[cameraguy]

In either case I don't think this is worth the price of another Taig Mill.

I would agree, which is why I want to know what screws, nuts, and bearing blocks he is using.

I have a workshop, I can do it myself. Much cheaper as well I would imagine.