Older Shopbot desktop build

[yeeter]

Hello,

I am exploring the idea of updating my older Shopbot desktop to an Acorn controller. I will post pictures as I go.

Motivation: Flexibility of more industry standard/open design. This will allow me flexibility for customization and also I will be learning on something more universal. Note I am a pure hobbiest and do not push the machine in terms of performance. It will be a learning curve for me but looks possible.

Current machine: Stock Shopbot 24/18 Desktop. (note this is not the newer Desktop, nor the Desktop max.
Current electronics and drives: stock shopbot
Current software: SB3 version 3.8.5 (running on a windows 95 computer that amazingly has been working fine for years)
Spindle: stock 800W spindle (HSD, 220V, 200Hz)
Current VFD: Delta VFD007S11B (110v input)
Steppers: Ametek K57M4Y-007, C1523
Indexer: I do have, and want to continue using an indexer

Note the VFD and spindle speed is controlled manually not from the software.
First upgrade capability I would like to enable is to control the spindle speed via the software.
Once that is working I would like to consider adding ATC. (either pneumatic or rapidchange atc) - as a second phase upgrade

From what I have learned so far, the AcornCNC controller should suffice for basic operation.
I would couple this with a Leadshine 4660 4 channel stepper driver
And a DuraPulse GS20 VFD for the spindle
I can use the original power supply

I am only getting started so welcome any insights, reference links, or criticisms.

Thank you

[Gary Campbell]

Your project is more than doable.
I have done a small format drilling machine with that exact combo and would suggest, that since you don't need, and therefore don't need to pay for, all of the IO features on the MX-4660. I would recommend the LeadShine DM-542E at $35 each ($140 total) rather than the MX-4660 at $379.
http://www.americanmotiontech.com/produ ... e-50v-4.2a

The Acorn will give you far more than basic operation, as it is light years ahead of what you are now using. There is no reason to swap the VFD, that Delta is capable of controlling spindle speed via analog 0-10 control.
You should be able to find a good computer on the cheap. Many of us on here have been using refurbished Lenovo M93 tiny. Around $100 with windows10 pro.
You will need to find a small ATC spindle as those motors are not overly powerful.
How many amps/watts is the OEM power supply, if I remember correctly, it is 48 volts. Can you verify?
You should work at improving the limit switches and make sure that there is one on the Z axis.
If you do upgrade the spindle, the GS2 is a good choice.

Good luck, start a build thread when you get your parts, and find answers to your questions here if you get stuck

[yeeter]

Thanks Gary, for the encouragement.

And in particular for the specific design recommendations.

The power supply is 48V as you remember. 6.7A
Again as a hobbiest on a small machine I am not pushing the limits.

I will look into limit switch upgrades. Should be plenty of choices but if you have a known accurate/reliable recommendation I welcome it.

I have plenty of pc choices - was just noting how well the W95 system has served me but its past time for an upgrade.

I still have to decide how to do zeroing. The current setup uses a plate and a tool automatically advances until it 'touches' (and alligator clip on the spindle to complete an electrical circuit - perhaps nothing more than a limit switch?? This is the type of thing I need to learn about). But the macro to find an inside or outside corner is handy so I will want to do that. I have a corner plate I could touch off on.

More to come, I am slow but will share more specifics and photos as I get into it.

[Gary Campbell]

The power supply is 48V as you remember. 6.7A

I believe those Haydon Kerk motors draw 2 amps, so 6.7A on the PS should be good

I will look into limit switch upgrades. Should be plenty of choices but if you have a known accurate/reliable recommendation I welcome it.

I prefer proximity sensors. I would look at the 5 or 8mm round varieties. The square block flat mounted versons might work well also. Don't forget to implement one on the Z axis.

I have plenty of pc choices - was just noting how well the W95 system has served me but its past time for an upgrade.

It was past time for an upgrade a decade ago.

I still have to decide how to do zeroing. The current setup uses a plate and a tool automatically advances until it 'touches' (and alligator clip on the spindle to complete an electrical circuit - perhaps nothing more than a limit switch?? This is the type of thing I need to learn about). But the macro to find an inside or outside corner is handy so I will want to do that. I have a corner plate I could touch off on.

Any method for Z setting that is available on the hobby grade controllers is available, and undoubtably works a bit better on Centroid software. There are built in macros for conductive plate Z setters and if the corner zero versions are not included in the install package, they should be soon.