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General Category => General Shop Discussions => Topic started by: 4GSR on May 04, 2024, 03:20 PM

Title: CNC Retrofit Kits
Post by: 4GSR on May 04, 2024, 03:20 PM
Has anyone messed with one of these CNC retrofit kits they are starting to come out with for the "budgeted" minded guys like myself? Here's a couple that I'm looking at for future play.

https://www.alibaba.com/product-detail/4-axis-cnc-milling-lathe-controller_1600276726036.html?spm=a2700.pccps_detail.0.0.117b13a0QpPe4p

https://www.alibaba.com/product-detail/cnc-control-4-axis-and-5_1600413555808.html?spm=a2700.wholesale.popular_products.4.45473ce4Yt1cqY

Ken
Title: Re: CNC Retrofit Kits
Post by: TerryWerm on May 04, 2024, 03:49 PM
Oh no...      :o   we might be losing another one to "the dark side".   :smiley_XD:
Title: Re: CNC Retrofit Kits
Post by: Piggiron on May 04, 2024, 04:00 PM
No experience, but a bit of knowledge from looking into it myself a while back.
Looking at it, I see a couple issues. It shows 380v 3 phase as the supply for the system.
I also see it lists servo motors and spindle motor, but no specs for them. Servo motors can present their own challenge of the tuning process, but do have advantages over stepper motors.
I didn't see any info about it being a closed or open loop system on the motors. Generally, servo motors are closed loop since it requires the feedback signal for it to operate and keep position.
On the plus side is the price. It would also give me pause since servo kits tend to be pricier than servo kits and that one is listed cheaper than most stepper kits I've seen unless the motors are very low power.
Title: Re: CNC Retrofit Kits
Post by: 4GSR on May 04, 2024, 05:06 PM
From what I've read about them, the power supply is adjustable for the voltage you need it for.  Could be wrong.
They mentioned using a servomotor for the spindle motor.  I believe that is not correct.  What you do here is have your motor running on a VFD.  The feed back parameters are fed to the VFD to control the motor and I guess if you wanted to put a feed back loop on the motor, it may be an option.  IDK just guessing here.
Title: Re: CNC Retrofit Kits
Post by: Adasha_Machining on May 04, 2024, 06:04 PM
All I know is when I priced a retrofit for our Cincinnati arrow 1000 it was over $12,000...

My concern with the cheaper systems would be power, accuracy, failsafes, and linear correction. If you tell it to 16" and it goes 16.050" and you cannot correct for that, that's a problem.
Title: Re: CNC Retrofit Kits
Post by: Adasha_Machining on May 04, 2024, 06:08 PM
Although, if someone dropped a Bridgeport cnc or a TRAK mill in my lap, if still eat it up in a heart beat. Some things are practical in a VMC, somethings are practical on a manual, and there are still many things that fall in between... bolt patterns, for example, a radius on an already machined part... etc.
Title: Re: CNC Retrofit Kits
Post by: Piggiron on May 04, 2024, 08:15 PM
Now that I looked closer, I believe that price is just for the control panel. All the other power supplies, motor controllers, cables, and motors would be extra.
In some instances it might be a better option vs a computer, but it appears to me that all the programming is through pre-coded G-code keys. Might work if you're a wiz at G-code.
Title: Re: CNC Retrofit Kits
Post by: Adasha_Machining on May 04, 2024, 08:33 PM
You don't need to be a Wiz with G-code now a days. There are so many CAM programs out there that deal with all the G-code. And once you have a program do the leg work for you, it doesn't take long to understand what's on the screen.
If I can do it, jeez, anyone can...
I often hand write lathe programs now because it's easier and faster than designing a model and setting tool paths for a simple process.
Title: Re: CNC Retrofit Kits
Post by: Piggiron on May 04, 2024, 08:45 PM
Don't sell yourself short Shawn. My impression was you dug into CNC, CAD, CAM, and G-code like an Arkansas tick.
Title: Re: CNC Retrofit Kits
Post by: Adasha_Machining on May 05, 2024, 10:32 AM
I assume that means deep? Lol
Out of necessity, yes. But it's still a very useful tool in a home shop, I think. I will often turn a hand-back of napkin sketch into a model and generate a 2D print just because; 1-it helps me get a better understanding of the part. 2-just darn easier to read...
Title: Re: CNC Retrofit Kits
Post by: Piggiron on May 05, 2024, 10:43 AM
Quote from: Adasha_Machining on May 05, 2024, 10:32 AMI assume that means deep? Lol
Out of necessity, yes. But it's still a very useful tool in a home shop, I think. I will often turn a hand-back of napkin sketch into a model and generate a 2D print just because; 1-it helps me get a better understanding of the part. 2-just darn easier to read...

Watch the movie "Predator" with Arnold Schwarzenegger.
Title: Re: CNC Retrofit Kits
Post by: 4GSR on May 05, 2024, 01:04 PM
Yeah, my G-code learning goes back a half a century ago, right after stone tablet and chisel days.  Where you wrote each line of code starting with "001", "002", and so on.

The listings at Ailbaba is just the controller. You still have to buy the servo drives kits.  Those are listed all over eBay.  Here's one I've been following.
 https://www.ebay.com/itm/193049372979