Newbie- ZAY7045 + Gecko G540?

[BobWarfield]

If everything is properly lapped, adjusted, and lubricated, the head should move just fine on 640 oz in.

Consider that the stock IH servos are only about 500 oz in.

Further consider that you don't need the Z-axis to be a 150 IPM speed demon. Fine for X and Y, but Z can move at half that speed and be very happy.

Lastly consider that Tormach is a 65 IPM machine.

Just go forward with it. If you're unhappy with the performance, you can always by a single Gecko drive and bigger servo or stepper later. You could also
counterweight the head and radically improve performance that way too.

Best,

BW

PS I haven't seen anything remotely like 0.006" slop in my quill. It needs to be locked anyway while cutting, and once the head is motorized, it may as well just stay locked.

[HimyKabibble]

Originally Posted by arizonavideo I don't see anyway 640oz stepper with the G540 will lift the head. It's not just the 250LB but there is a lot of drag on the slide too. For any kind of accurate work you want to run the gibb fairly tight which will make lots of drag but even if you can get the head to lift the acceleration will be real bad. Buy one servo driver for the Z and you might try steppers for the table. I have a new Gecko servo driver and an extra used servo and pulliy for the Z if you can't find a deal anywhere. I could pre test the setup for you and put it in a box. I got my ballscrew on eBay, I just got lucky, bad picture and the " I think is is a ballscrew" sales pitch. The nut does have backlash but that is not really a problem unless the head sticks.

You NEVER want to run gibs tight enough to cause drag. If you do, you will induce backlash, due to "stiction". If it's necessary to run the gibs that tight to get accurate movement, then you need to lap your ways. When the ways are in good shape, the gibs should be only tight enough to take *almost* all of the slop out of the movement, and the axis should still move very freely. On my knee mill, I can disconnect the ballscrew and push the 49" table end to end fairly easily.

I move the 500+ pound knee of my mill with an 850 oz-in peak/140 oz-in continuous servo motor, and it'll do 75 IPM. A 640 oz-in stepper should be plenty for an RF-45.

Regards,
Ray L.

[BobWarfield]

Originally Posted by HimyKabibble You NEVER want to run gibs tight enough to cause drag. If you do, you will induce backlash, due to "stiction". If it's necessary to run the gibs that tight to get accurate movement, then you need to lap your ways. When the ways are in good shape, the gibs should be only tight enough to take *almost* all of the slop out of the movement, and the axis should still move very freely. On my knee mill, I can disconnect the ballscrew and push the 49" table end to end fairly easily. I move the 500+ pound knee of my mill with an 850 oz-in peak/140 oz-in continuous servo motor, and it'll do 75 IPM. A 640 oz-in stepper should be plenty for an RF-45. Regards, Ray L.

Matters of degree there. You want them as tight as they can be without causing the backlash. In fact, tightening until measured backlash starts to bump up and then backing off a tad is one way to adjust the gibs.

It turns out, that if you lap the ways and run a one shot oiler, you can run them pretty darned tight without adding any backlash. This is beneficial to rigidity.

I run mine tighter than X or Y, for example. I can move X or Y by hand pretty easily, but not Z. The cantilevering of the head is partially responsible.

If I don't remember to pump the one shot after the mill has sat for a while, I can almost guarantee a servo fault on Z at some point in a CNC job, particularly if it is a small move (sure sign of stiction!).

All this has made me a huge believer in having a one shot, BTW. Let's me run the machine a lot tighter.

Cheers,

BW

[bogus105]

you were really lucky Arizonavideo, pls check if your set manage with Z head and pls tell me how much you want for it? i'll check then if i have enough money to purchase such a thing or have to wait and collect more funds...

have you fellas consider counterwieght in the back of the column to make life easier for the Z motor? i know that this solution will increase head assembly inertia but it also decrease stresses on leading screw/nut/bearings and decrease motor Nm requirement

and one more thing: where can i get one shot oiler? how much is it? is there any thred on how to do one shot oiled mod of the mill (rich with photos)??

[pete from TN]

I did a one shot oiler setup on my mill and I think there are quite a few photos of it on my thread " finally getting started" in this forum. It is not real difficult but you do have to do some thinking about where the table is and where you can and cannot drill for the threaded fittings. I used my other mill to do the drilling and tapping for the cnc and I think it is a very worthwhile endeavor. It does take some time tho. As far as the one shot oiler itself. I used an asian copy of a Bijur type oiler I got off ebay new and it is more than enough for this machine. They also sell automatic oilers which are pretty neat but I think rather unnecessary for a machine like this. I just usually give the one shot a crank whenever I start the machine up and If I wind up running it for a long while I may give it another tug. The whole system cost me like less than a hundred dollars I think so there is really no reason not to do it. I do think I can crank down on my gibs a little tighter and still run nice and free which I think helps in the rigidity dept. Could not do that without good lubrication. Peace....

Pete

[bogus105]

hi,
2 days ago i believed that sun shines above me and i've found servos for my mill... but i didn't... my mate have couple of sets of servo packages for sell. Each package contain:
1pc. INDRAMAT SERVO CONTROLLER MODEL DKC01 1-040-7-FW
1pc. INDRAMAT SERVO MODEL MKD071B-061-KG1-KN
1pc. INDRAMAT FILTER NFD 02.1-480-08

unfortunatelly i don't have a 3 phase power supply in my house! Indramat controller need 3phase supply for operation.

Because of power supply problem in my house these beauties are for sell. Do you guys know a person that needs such a nice babes?

I don't know how much is it worth for one set (mains filter+controller+servo motor)? What you guys think about it?

Units are in perfect working condition. Units was professionally removed from a decomissioned machine.

Here are links for tech data:
- servo controller:
http://www.boschrexroth-us.com/count...-11.1_PRJ3.pdf

-servo motor:
http://www.boschrexroth-us.com/count...D/MKD_PR07.pdf


These motors have a 9Nm(1275 oz-in) stall torque! Max is 12Nm. Motor speed 4500rpm, max 6000rpm. Motor weight 9.8kg. Motors are equipped with resolver and encoder and 5Nm brake (automatically controlled by controller).

Controller is conected directly to 3phase supply (380...480VAC) so you don't need any additional power supply unit. Position can be commanded using couple different methods (for example it has 3 different ways to controll motor position via stepper interface - quadrature-signals, forward-backwards-signals and step-direction-signals). AC filter blocks any electrical noises. A real proffesional thing.

How much $$$ can i take for one axle set (mains filter+servo controller+servo motor)???

[bogus105]

hi,
i've purchased 2 servos for x an y axis. Servos made by ElectroCraft, model E240.

* 0.22 Nm (32oz-in)Stall Torque
* 1.7 Nm (240oz-in)Peak Torque
* 3.1 Amps Stall Current
* 24.5 Peak Current
* 4700 RPM Max Speed
* 48 VDC Max Voltage
* 1.1 kg Weight
* 4.5 kg Radial Load
* 2.3 kg Axial Load
* 7.8 v/kRPM Voltage Const

is it good idea to drive x and y axis with such servos? i consider 1:3 or 1:4 pulley ratio.

also i found bigger servo i consider to drive z axis. Manofacturedby Aerotech, 1000dc series, model 1210-01-1601-03. It has 3000rpm, 210oz-in stall torque, 1000oz-in peak torque, Nema42 sized. Pretty heavy - 5kg. Is it strong enough for z axis?
What timing pulley ratio will be the best?
below link with this motor scpecs (model 1210):
http://www.aerotech.com/products/motors/1000specs.html

all axises have a Boschrexroth ballscrews - 25mm dia and 10mm pitch!!! note the pitch. I know that 5mm (approx. 5tpi) would be the best but i can't find such screws for resonable price. I can get 570mm long, 25mm dia and 10mm pitch ballscrew for about US$55. is it good price?

please tell me if these motors will be fine for my zay7045 with 10mm pitch ballscrews