CNC Mill options

This forum is dedicated to those Hobbyists Interested in CNC machining & 3D Printing in their home shops. (Digital Read Outs are also topical, as is CAD/CAM as it relates to CNC)

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WJH
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CNC Mill options

Post by WJH »

I have a Sieg X3 mill from Grizzly with an asian glass scale DRO. I was thinking about getting the Fusion CNC deluxe conversion kit with the high precision ball screws.
But again I am also thinking about getting a ready to go Taig CNC mill.
The whole purpose behind needing a CNC mill is that I've come up with a plastic part that is nothing more than a cam wheel for sewing machines. Basically recreating a part that is hard to find that no one makes anymore, and is in demand for certain Kenmore sewing machines. I want to machine it out of ABS plastic.

Real life situation is that I do not have much time with my job and a new born baby due in August. I am thinking that the Taig is more than enough to cut the cam profile. Should this endeavor pay out decently, I will CNC my Sieg X3 down the road anyhow.

Am I accurate to assume the X3 CNC conversion will run close to 3000$?
And just because I have a million ideas running through my head, is it possible to create a closed loop system using those glass scales and with what controllers?
hobgobbln
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Re: CNC Mill options

Post by hobgobbln »

It depends on if you go stepper or servo. I did my X3 a few months ago with steppers. Cost me around $2200 by the time I was done not including the cost of the machine or software. I have no idea what servos would run.

Just a bit of a heads up, buy the zero backlash couplings and be prepared to do a lot of tweaking. I'm still working the kinks out of mine because my circular pockets aren't coming out round.

As far as closed loop is concerned, you'll have to probably go with LinuxCNC (EMC2). Mach3 doesn't do closed loop. I'm starting to wonder if Mach4 is ever going to come out.

Griz
WJH
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Re: CNC Mill options

Post by WJH »

As I understand it, its the hardware driver boards that handle the closed loop function, not mach 3 or emc? Well its quite clear that if turning my X3 into cnc costs the same as a taig cnc mill, the x3 would make more sense. I need to do much more research, even visit some one with the setups in question
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Dave_C
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Re: CNC Mill options

Post by Dave_C »

I think RB211 is correct as I am running mach3 with closed loop hybrid servos. Be prepared to spend some money on the motors as you get what you pay for!

My setup includes hybrid servos with feedback pots, the matching controllers and Mach3.

Dave C.
I learn something new every day! Problem is I forget two.
hobgobbln
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Re: CNC Mill options

Post by hobgobbln »

DrDavo wrote:My setup includes hybrid servos with feedback pots, the matching controllers and Mach3.
But will the hardware boards read from the glass scales? I thought that was what RB was trying to do.

Griz
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Dave_C
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Re: CNC Mill options

Post by Dave_C »

Griz,

No, the breakout board for Mach 3 does not read the feedback encoders. I have no idea how the two servos will stay in sync if I overload one and not the other. It doesn't make any sense to me.

The Hype on the "hybrid Servos" is that the feedback encoder on the back of the motor won't let the motor lose a step. The literature says that it can slow the motor [to a point of more torque] rather than let it stall. Ok, let's say it does that. With no feedback to Mach3, there is no way to keep the motors cutting the proper arc or whatever. If you slow one motor you have to slow the others proportionally. Mach three will not make cuts faster than the slowest motor but that is based on the setup data in Mach 3 and not real time feedback from the encoders.

So my solution was 1,200 In LB motors which is way more than I need on a lathe [most of the time I think]

Dave C.
I learn something new every day! Problem is I forget two.
WJH
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Re: CNC Mill options

Post by WJH »

Mach3 only sends direction and step signals to the controller boards. It is the job of the controller boards to make sure the hybrid steppers do not lose a step. It is the driver boards that work the magic, not mach3. Mach3 does not care what the driver boards are doing.
If I want to use feedback from glass scales, I need to find driver boards that will do this. I think Kflop has a system for this. It doesn't matter if I use EMC or Mach 3, as long as the driver boards can work with step and direction commands from the parallel port. I am going to try EMC as it is free.
Mind you all, I was hit hard in the face with reality and current finances by my lovely bean counting wife, so it will be at least three years before any of this can happen, short of a nice raise from work which is coming when I upgrade to Captain... That could be this December.
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Rex
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Re: CNC Mill options

Post by Rex »

How about an alternative?

Lately - this month - I have discovered the training mills based on Sherline machines. D&M, Lab-Volt, and Denford all had machines sold to schools all over the world. Now they have become basically obsolete for the purpose and schools are off-loading them for cheap. I acquired 3 for less than $1000.
500px-Denford.JPG
The issue with them is the electronics and software pretty much has to be replaced. You can use the steppers
So, you buy a breakout board ($100) and stepper drive boards ) ($55 - $150?) some 6-strand wire, and run it on EMC or Mach3.
I am working on one now. I'll have about $600 in it if all goes well.
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Marty_Escarcega
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Re: CNC Mill options

Post by Marty_Escarcega »

These machines could be easily retrofitted. Good chance that the stepper drivers could be used. After trying several different stepper drivers, I've settled on GeckG540 almost have everything you need add stepper motors and Mach3, a little time, and you are off to the races.
"Jack of all Trades, Master of None"
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DICKEYBIRD
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Re: CNC Mill options

Post by DICKEYBIRD »

This note is to anyone that's retrofits one of the above pictured Denford training mills or lathes and opts to replace the controller with something more modern. Please contact me 1st before trashing the old SmartStep3 or DenStep controller as I have a good home for one.:)
Milton in Tennessee

"Accuracy is the sum total of your compensating mistakes."
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