Sieg X3 Conversion

I'm starting the conversion my Sieg X3 to CNC using the CNCFusion kit and about to order the remaining stuff from Zapp.

I'm looking to use the CSMIO/IP-M and EM806 with two Nema 23 and one Nema 34, or possibly the Easy Servo Closed Loop system (ES-D808 and Easy Servo motors).

This is my first CNC and will be for hobby use mostly. I have a few questions:

- Firstly,is a closed loop system worth the ~60% increase in cost? I don't want to waste money which could be directed elsewhere obviously.
- The ability to cut threads would be useful on the converted machine (occasional use). What's options are there to accomplish this?

A closed loop is always better, because the control unit knows the actual positin of any axe. But instead of the so called Easy servo, I would better buy a really servo system. This is better in every part. You have much more speed and accuracy. But real servo systems are not cheap.

With the IP/A or S you can buy a separate addition ENC module with this part you can make threads. At least, if you believe their website.
Experiences with this are not available.

The CNCFusion kit seems a good place to start. But I imagine you will probably be better served learning how to mill manually first.

Another point to note is that if you are going to spend money on a CSMio controller you may as well buy the best ballscrews you can. I have a feeling that the kit includes C7 accuracy screws based on the quick look I had on their site. C7 accuracy does not lend itself to milling machines as you cannot preload effectively. You should be looking at C5 or if you can afford C3. Then you should also match the bearings to that accuracy.

If you do not go full hog and get servos, then the closed loop steppers are a very positive step in the direction of eliminating lost steps. I would recommend you get the better branded ones though.

As for threading, if it is thread milling you are interested in as opposed to using the mill like a vertical lathe of sorts, then using a single point thread mill will get you any internal or external thread you need. No need for extra hardware.

May I ask if you have considered buying a ready made system? With the price of a X3 + screws+ electronic+motors, you may be in the region of buying a ready Syil CNC machine.

Hi, I already have the mill and use it occasionally. The CNC Fusion kit on order is the 'Small-Mill Deluxe CNC kit with Premium Ballscrews', although there doesn't seem to be mention of the ballscrew accurary: http://www.cncfusion.com/smallmill1.html

The more I read the less certain I am with regards to closed loop. What's the advantage if a servo misses steps but corrects itself, presumably the damage could already have been done?

The single point thread mill looks interesting, thanks.

There is no need to go to C3 on a machine like the X3, C5 will be nice, but you will need to talk to cnc fusion, because you cant just buy some C5 screws that will fit the existing nuts, unless you get the smae brand, then you will need to pre load it.
This can be done quite easily on a double ballnut, but if they are single nuts then you will need to use over sized balls and re ball the nuts.
If you need C3, you can get them from stock at Zap, but expect to pay real prices for them.
Adding the threading module will only be part of the problem, there are other issues with the X3 electronics that will need to be looked into.
For threading in CNC you need to interpolate between the rotary and Z axis and with the current spindle motor you cant do this.

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Originally Posted by dodgygeeza

For threading in CNC you need to interpolate between the rotary and Z axis and with the current spindle motor you cant do this.

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Gary at Zapp mentioned this, however I wondered why using a single point thread mill wouldn't work? http://www.youtube.com/watch?v=JA_osyWIEFY

You are right, damage can be done if the steps are lost but at least you will be able to tell and the drives can be wired in such a way to tell the control software that they lost the steps. Servs will have this too to some extent

To reduce the likelyhood of having lost steps in the first place, you have the motion controller.

It goes without saying that you will need to buy the ballnuts and screws as a matched pair like dodgygeeza notes.

What I don't get is why they say you need to index the spindle to the z-axis, unless of course you are doing rigid tapping. Mach3 cannot do this anyway unless you treat the spindle as another axis or use a servo. Even tormach agrees http://www.tormach.com/blog/getting-...hread-milling/

NYC CNC also use a multiflute threadmill on a Tormach:

https://www.youtube.com/watch?v=TSBaHLmnJ-s

I was referring to rigid tapping and that is why you would use the encoder module, but to use this, you would need the S version that is considerably more expensive.
I have not done this myself, but know someone who has and he used a servo motor for the spindle.