[gfacer]

Bought an old Gerber 404 that was in service up to the time of the sale. Perske spindle.

Plan- shorter term is to rewire to closed loop steppers and UCCNC controller (I was planning acorn but I had UCCNC hardware around). I will reuse the OEM limits and Spindle wiring.

Using 3NM Nema 23 motors with 8mm shafts. I am hoping to then use a rigid coupler, machined to 11mm OD, to mate up with the OEM pulleys.

The slightly longer term plan is to change out the lead screws with 20mm10 Pitch ball screws/nuts. I was told that you can't buy the 404 Y screws and they are 2KUSD each regardless, which is insane. From looking around, I don't see anyone that has made that switch before, which is strange to me as it seems relatively simple.

I am pulling off the OEM servos, related wiring, and will not use the main controller box at all. I'll probably keep the VFD box. If anyone is interested in those bits, let me know.

I have previously had an even older Techno Isle machine that had similar mechanics (with ball screws) and that was a great machine. My main machine has moved on to a 5x10 Chinese ATC, this is just a secondary unit.

Another question.....those 20mm linear bearings must have a non-Gerber version somewhere, I would love to know that information!

[gfacer]

Ok, So I have ordered a ton of bits and pieces. It looks like I can just get gt2 pulleys that fit on 8mm shafts and not use or modify to the oem pulleys. Easier is good.

I have also started my enquiry to getting a set of c5 ball screws made up to match the existing lead screw sizes and pitch (20mm size, 10mm pitch). I need to check the lead nut size that nests inside the gantry beam (underneath) though, and I expect I will make some 1/4"-1/2" adapter plates for the nuts to match existing holes with the ballnut holes but I think there is clearance. I'm asking for the SFA style from TBI.

The Z will need a nut housing as well. Same idea. I'll need either a adapter plate or spacing plate and drill and tap the required holes in the new block. None of the current screws *need* replacing so I am reassembling after measuring. But, I will probably swap out before it's in production. DSG12H is the block size.

I'm also trying to order a bigger screw to replace the one on my 5x10 ATC machine, so that will be nice. I have been working with a home-made urethane cast part to keep it running. That is a SFYA bearing with 3232 size and apparently rolled not ground. I don't love that but it's probably what I have and I need to keep the rotating nut hardware.

I'm also ordering a set of 4 sbr20uu bearings to see what I would need to make those work in place of the OEM bearings. Just as a backup / cheaper / longer term available option than the OEM parts. If you swap all 4 then, again with an adapter plate, I think the worst would be a slight increase in height. That is OK on Y, not sure about the other axis.

[gfacer]

I have reviewed a bit more, and think the rolled ball screws will be fine. Pricing is about what I expected with express delivery and I imagine it might take a month to get them in. I might not be done the electronics by then!

I have bought a Panasonic tough book for the UCCNC, got the semi-finished control box I had picked up on marketplace talking to it, and will start bench testing a similar motor to what I intend on using. I'll have to rebuild a control box (probably to fit on top of the VFD box of the Gerber) and want to test the limit switches and estops early if the actual motors haven't arrived.

[arturod]

What Panasonic servos do you have? I think we can help you. Please open a ticket in our website and send pictures and part numbers and we can put together a list of parts for you.
https://www.cnc4pc.com/contactus

Arturo Duncan
https://cnc4pc.com

[gfacer]

What Panasonic servos do you have? I think we can help you. Please open a ticket in our website and send pictures and part numbers and we can put together a list of parts for you.
https://www.cnc4pc.com/contactus

Arturo Duncan
https://cnc4pc.com

No, the laptop is Panasonic. I'm moving to closed loop steppers as using the old servos is more work than starting with new motors.

I am using some of your bits, and some came with the control I bought used.

[arturod]

What you are saying about the old servos is true, but we have connector boards for about 100 different old and new servos that many times make using the old servos very easy, and you do not have to deal with the mechanics of replacing the motors. That is why I asked about opening a ticket and sending pictures of the machine and electronics, and we should be able to send you a suggested list of parts: https://www.cnc4pc.com/contact

Arturo Duncan
https://cnc4pc.com

[gfacer]

I will consider and send when I can. Although if the steppers (on the way) work fine then I might not look to switch back to the servos. The good news is that I'm not planning any modifications to the motor pulleys so other than the steps/rev on one axis (gave up trying to find a different # of teeth for the Z), presumably I could drop them back in. But I might upgrade / try Centroid Acorn if I go to that trouble.

Perhaps different too if the motors and wires were not already pulled, but they are.

[gfacer]

So, I guess I didn't save my last update. The acorn board came it and I did a one motor bench test with it. Not as quick as I hoped as I a) didn't really read up too much on the acorn and b) the stepper driver wiring (and estop wiring too I think) has a different design than the ucccnc stuff. This is where the library of schematics and YouTube videos help and I saw what I needed to change.

Today I worked on the computer size. The toughbook has more of a 4:3 ratio screen so I had to eventually figure out that changing the resolution to the recommended 16:9 was the way to go and made the virtual control panel useable. In the end, I think I will love the toughbook in just it's tablet form as the control. Touchscreen, maybe even resistive, Ethernet connection is there (will streamline the cable), and can take power to the tablet side, and has hot keys for the onscreen keyboard when needed.

[gfacer]

Ok, I am overdue for posting updates but I have been focused on the machine.

I changed over to the ball screws. My dimensions were slightly off on the Y but the motion gets locked into the frame on the Y low (front) side, and the other side could tolerate a few mm of variance.

I also did not consider how the ball nut had to be assembled to the screw and the factory put it on (no doubt how I asked) the same way as the X which is 180 degrees of what is needed for the Y. they say users can't take the nut off themselves but it is merely a huge pain. I don't believe I lost any individual ball bearings even.

And while I haven't checked that Y low limit yet, I did have to go as slim as possible for the adapter plate I made, about 6mm thick. Ideally I would have had countersink style 4mm machine screws to mount the adaptive plate but I hacked it with 8-32 screws and JB weld in the threads.

Z axis needed a .26" thick spacer and 4 new flat countersunk holes in the Z mounting plate to use a standard chinese ballnut housing. X axis across the gantry was an easy adapter ring.

With those bits done, on to the motors. I though the mounts were nema 23....they were not. Drilling out the oem holes a touch made it work. I tapped the motor side holes for a 6mm cap screw and I'm using washers and lock washers. The 30 tooth pulleys for the motors worked fine, I think, for the X and Y, although i really do need to find a 40 tooth to match the oem diameter for the Z. Or a slightly smaller belt, whatever I find first.

Today was wiring up the control box and testing axis. If I remember the OEM specs for these have 1000ipm travel speeds but that seems insane for any screw type system. Limit switches are separate for high and low side of the axis but otherwise simply enough to wire one side to power and one side to common on the acorn board. I am currently putting all the limits and the estop on one breakout style db9 plug. It works but I might change that to make trouble shooting easier in the future.

I'm also having an issue with the motors doing a sort of cutting out thing if I try to go too fast. If I set my jog and max to 500 ipm, The motor will respond for a half second maybe and then fall back to a slower speed. Up to about 350ipm is OK. I presume it might be a driver issue, but could be something else. I will google.

Next step is to make sure everything is greased up, make it tidy, and move on to the spindle and control of it.

I also seem to easily go past the limits at high jog speeds too easily. The motors maybe are decelerating but not stopping as fast as needed. The limit switch position and the "crash" position are very close together!

[gfacer]

Well, I flipped the "step filter" dip switch on the drivers and lubed up the screws and rails and 450ipm is ok and that's good enough for me, its not like I have a linear atc or something.

Homing works in Acorn but I don't love how it's wizard isn't really documented. The existince of limit switches and home switches as pre-labeled inputs in the wizard made me wonder if I was going to crash without my limits designated as home switches. I guess the wizard is smart enough to know but it's an opaque process. I left the Z out of the Homing sequence for now, but if I'm losing Z position with the power off I will add it back in. Which would solve the possible issue of Z clearance on the homing sequence.

I am now waiting on some more little bits to make the limit / home / tool touch off sensor / connections more understandable and easier. to do: position and level the table, mount the spindle and tram it, wire up the spindle power and get the acorn controlling it.
I think I will mount a laser diode to the spindle as well for workpiece reference using an offset.