[travis_farmer]

I realize this is the DIY part of the forum, but i thought i would post a quick note here as that is where i got so much research help in the past.

it is a Techno/Isel table, 48" X 48" X 5" working area. it has servos, but no drivers, and a Perske VS 60.11-2 5HP, 3-phase spindle. no controllers, or drivers, but i bought it as a fixer-upper to get me going strong. right now it is under a tarp on the trailer still, but when i make room for it, i will be able to take detailed pictures, and research parts for it. overall, i am pleased with it, and it only cost me $500. (i think it is a good deal...)
Anyway, as i learn more about it, i will post in the correct forum about it. or is it considered DIY to rebuild a CNC router?

Anyway, thanks for all the help in the recent past, and i look forward to getting this machine up and going. :cheers:

~Travis

[Jim Dawson]

Looking forward to seeing the pictures. Sounds like a fun project. For $500, if it's in reasonably good mechanical shape I would say you got a deal. :cheers:

[wizard]

That is one hell of a bargain.

Updating the electronics, effectively replacing all the missing stuff, will take some time and money but there are few well designed frames that you could do for $500.

[louieatienza]

It would be a good deal for the spindle alone!

[travis_farmer]

I took a few pics to show my new (to me) router.

it is still on the trailer, and yes, i know it is perched rather scary for transport. that is what happens when you know the frame width of the CNC is 5 foot, and you foolishly think a 5 foot wide trailer, is actually as advertised.

so anyway, it currently sits under a heavy duty tarp while i make room for it. but it is home

~Travis

[AMG Guitars]

Travis,
You got a really good machine there at a phenomenal price. I know. I bought one new. The servo motors on there are very good.
Keep them! They'll probably be cheaper to rebuild. It looks like it came with a pretty good spindle as well. All you need to get this thing to go is the controller box. I have the old style ISA slot controller (which works fine BTW) but Techno uses a newer style controller box these days. If you come across any of the older style boxes please let me know. I'd like to add a 4th axis to mine.

You should contact ISEL USA as this is an older machine. Isel makes the linear components in Germany (and you can still get all the parts you need BTW). You will need a special lubricant for this machine. There is a special grease and a special oil. I suggest you inspect, clean, and lube before you do anything. Then you'll have to reassemble everything. After that you should be able to push on the gantry by hand and see that it all slides good. One thing to note is that the Z axis has a brake, but if you have a power failure it will drop a little before the brake engages.

The Techno company in Hicksville NY can get you some of the special lubricant but they mostly do the electronics as far as I know. The mechanicals are ISEL (usa), and the're very good. This machine uses ball screws and when everything is working right it's smooth as silk. You can hear the balls drop as they cycle through. This is normal. This is a very capable machine but you should be aware that if you program arcs on a helix (you know, to engage the part as you come down into it) you will have to set your software to output lines on that helix because this machine will not do arcs like that. In fact I just spoke to one of their reps and even the newer machines will not do that. But it's not really a problem, just something you need to be aware of when you program. You can still ramp or helicaly engage a pocket but you must set your software to output lines instead of arcs. The machine will only run arcs in any of three planes.

I wish you the best of luck with your new machine and if you know a place where I can get used parts for cheap like you did!!! For one of these machines, please let me know. I'm particularly interested in getting another controller card for a fourth axis. My box has an extra slot for just that, but I never got one. The amplifier box I have has a cable that runs to an ISA card in the computer and I use Gcode Ver. 105c to run the machine. If you need a copy of this older software or post processor, let me know. It shouldn't be too hard to get it going though. Lately I've been experimenting with F-Engrave, G-Code Ripper, and Dmap2Gcode from Scorch Works. These are some really nice free programs and I was pleasantly surprised that they are totally compatible with the Techno. You just change the file extension to .NCD and you can use them to program your machine. If you use V-Carve note that it comes with 2 types of post processors for your machine for the older (ISA) and newer (PCI) cards.

Alex

[travis_farmer]

just for reference, what size stepper do you all think i would be looking at? just a rough idea. right now, it has brushed DC servo motors, though the encoders are floppy, so i doubt i will want to re-use them.

the spindle, being 5HP, 3-phase. i assume i need something like a VFD unit? admitedly, i know very little about 3-phase motors.

~Travis

[Jim Dawson]

Why not use the existing DC servo motors? The drives are only slightly more expensive than the cheapest stepper drives. Not sure what you mean by the encoders being ''floppy''

Yes, you will need a VFD to run the spindle. If you don't have 3 phase in your shop, you will need a 5hp VFD that will accept a single phase input.

[louieatienza]

You should be able to run those servos with Gecko G320; just need to figure out rated voltage for a PSU. Don't know if the encoders are compatible, but you can replace them.

[travis_farmer]

the problem i have with the servos on it are that i can't read any of the info on the specifications sticker. so i know nothing about them, other than that they are DC brushed.

i looked up the Gecko G320, and they are outside of my price range for now. i may have to use a cheap Chinese driver, and upgrade later.

how do DC brushed servos take a "step" without coasting past? also, how do they hold position?

~Travis

[louieatienza]

the problem i have with the servos on it are that i can't read any of the info on the specifications sticker. so i know nothing about them, other than that they are DC brushed.

i looked up the Gecko G320, and they are outside of my price range for now. i may have to use a cheap Chinese driver, and upgrade later.

how do DC brushed servos take a "step" without coasting past? also, how do they hold position?

~Travis

Only things I foresee is that the steppers may not mount to the servo mounts, and their shafts to the couplings. So by the time you buy new couplings and motor mounts, you could have just gotten the three drives.

[ger21]

how do DC brushed servos take a "step" without coasting past? also, how do they hold position?

They have encoders on them. The encoder tells the drive where the shaft is, and the drive holds it there.

[Jim Dawson]

We can probably help figure out what the motor specifications are, should be pretty easy to figure out. It looks like Techno/Ise may still be in business, with a US phone #. At least the web site mostly works with a few broken links.

Brushed DC Servos don't really take a step, rather they are told by the controller to rotate at some speed, and the controller keeps track of the position by encoder counts. When the commanded position, in encoder counts, is reached the motor is locked in position by the controller/drive. BTW, this is not a totally correct explanation of how it works but close enough for right now.

[travis_farmer]

i pulled one of the servos (from on the gantry itself) to take a few measurements.
the mount holes are 47mm centers, and the shaft has a 6.32mm diameter, and 6mm at the flat.

what pictures or measurements can i take to help get the specs of these servos?
I have some Gecko G320 drivers in my ebay watch-list, and i can get them via PayPal Credit. but i want to make absolutely sure they will work, and that i know how to hook them up before i spend credit.

now, regarding the spindle. all the VFDs i found require 220/240Vac, at about 18 - 20A. that is a bit more than the current service to my "CNC trailer" (old camper, in process of conversion) can handle. actually, it is the whole of the service to the trailer (L14-20 connection). if i buy/make a mount for my Makita RF1101 router, other than feed rate, what compromises would i have to make to downgrade the router? (the 5HP spindle may be up for sale... )

there is a remote possibility of upgrading the trailer power to 220V/50A service, but that would require a lot more money.

~Travis

[AMG Guitars]

They give positional accuracy and feedback to the controller. If you have servo's already, stick with the servos. If there's something wrong with them they can be rebuilt. Contact ISEL USA. But let's talk about that spindle, you really don't want it? PM me.

[travis_farmer]

i still have the servos, and at the moment i am keeping the spindle for when i have a proper shop to move the CNC into.
I went for steppers as i have become intrigued by the sounds they make when working, but i will likely put the servos back on when i can afford to upgrade the drivers. i understand that i could have saved money buying the servo drivers, but like i said, i kind of fell in love with stepper "music".
I still have the original ISA interface card, but no servo controllers. i have the servo encoder cables (pretty beat up), but no motor cables. so i can at least use those in the future.

as the only space i had available to put the CNC was to modify a camper, i had to reduce my power consumption to what can travel over the power cord (30A 220V). and that includes an air-conditioner. the VFDs i found to fit the spindle required 20A, 220V, and left no room for the A/C (it gets very hot in the camper).

for others following along, i have the new roof on the camper. or at least the rafters, and Advantech sheeting, and a temporary waterproofing layer (tarp). so all that's left is the actual roofing membrane, and finishing up the interior of the camper. things are definitely coming along.
I apologize for the lack of updates for a while, but i had to get the camper done, before making much more big moves on the CNC itself. it currently works, it self homes (via LinuxCNC), and i can even run a program on it now. as more progress is made, i will update with pictures.

~Travis

[travis_farmer]

Been a while since i posted a real update.

today i mounted my router into the machine, and loaded in a cheap Chinese PCB router bit (sharp and pointy, for less drag on the test). then, after homing, and zeroing the machine to the piece of plywood (i used the sheet of paper method to zero the Z-axis), i timidly hit the go button, and delighted as the machine started carving away.

what i learned:

the router is too heavy for the Z-axis, only when it is un-powered (it settles with very little effort).
perhaps adding a spring to help support the axis in the event of a power failure.

the router is loud in such an enclosed space.
when i add a sound buffer wall to separate the machine from me, with a viewing window, it should help.

the stepper drivers get fairly warm.
perhaps adding a fan to the control box will aid in cooling.

all in all, i think the project is coming along fairly well. It was very pleasing to watch the machine working (with hearing protection on, of course).

~Travis

[AMG Guitars]

I'm glad you're having fun with your project. +on the hearing protection. Been thinking about taming my beast lately with a spring loaded drag engraving tool.
Best of luck with that.
Alex

[Jim Dawson]

I'm running a Porter Cable 7518 router motor on my 4x8. Like you, I don't have enough power in my shop to run the original 10 HP spindle. The only real difference is you just have to cut a bit slower. Other than that it works just fine.

Regarding your servos, some good pictures would help. If you have a local motor shop maybe a trip over to them would be in order. They may be able to identify the motor, and should be able to figure out the voltage, most of them are rated at 140V, but I have seen them rated at 320V. Some of the newer ones are rated at 80V. The RPM is dependant on voltage, the torque is roughly dependent on the current. A call to the router manufacturer, if they are still around, might be helpful.

I have brushed DC servos on my mill, they are rated at 140V, they were originally running on 100V, and I am now running them on 75V and they are working just fine, I don't need 400 IPM rapids, 150 IPM is just fine. I checked the voltage to them at 100 IPM and they were only being fed 37 volts to run at that speed.

[travis_farmer]

out of curiosity, i happened to find steppers with the correct mount, and shaft size, and 400oz/in (2.83Nm) holding torque. would those be a working fall-back, if the servos don't pan out? (also, i kinda like the sound of the steppers working...)

I will take some detailed pictures after work of the servos.

~Travis