[Deano7/11]

that seems pretty good value really.

more than likely you will set up with a new cnc mill for under 15k

not bad value at all

[Deano7/11]

how are you planing to cnc the z axis? quill or knee?

[BMSTECH]

I will focus on the X and Y axis first. There is a lot that can be done with just that working properly. Proto Trak sell just a 2 axis system as a basic CNC conversion and their 3 axis system controls the Quill. I have posted a photo of a Proto Trak Quill Conversion here:
http://www.cnczone.com/forums/attach...3&d=1274575780

The Quill on these machines must be rigid enough for a Quill conversion. There is around 140mm travel in the Quill. A Knee conversion makes some sense on a machine with a horizontal spindle.

I am preparing the drive enclosure for the 3rd drive but the mechanics of drivinig the Quill will wait on the wish list.

[Deano7/11]

that makes sense and to be honest probably the way i would go if i go the cnc path.

i would love to no what is in that box and how it is all done.

do you now how they do the quill?

[BMSTECH]

The Serve motor cables run in flexible conduits from the drive enclosure. Cable glands need to be mounted at both ends of the conduit. Assembling the encoder cable drive connectors has required hours of careful soldering and heat shrinking using a magnifying head set to see the tiny contacts. The motor end will be assembled once the cable is threaded through the conduit.

[BMSTECH]

The drives mounted on the enclosure base plate.

[chich2]

Just Stumbled across your thread. VERY nice machine you have there. Can't wait to see a video of it running. It's nice to know I have inspired others to convert their knee mills.

Keep up the good work,

Chich

[Deano7/11]

looking good. why did you go with ac servo over DC servo and steppers?

[BMSTECH]

Deano,

I asked the same question early on in this thread. See Ray Gardiner's response on the first page. The Motors are smaller for their relative output and brushless. The Drives are more complex and expensive. My Used motors and drives have probably been removed from a critical production machine during a scheduled maintenance period in order to minimise the chance of failure. The only wearing part in the motors is the bearings. The drives have large capacitors that can eventually leak/breakdown. My kit was tested by the seller in Korea. I am yet to power them up and confirm proper operation. AC servos seem to be the choice for most professional industrial control applications but come at a premium cost. It is only that the used kit I purchased from Korea is now much more affordable that I could consider the advantages over DC Servos. Steppers are not recommended for machines of this size.

[Deano7/11]

cool mate

i will be intrested to see how you go setting up the ac servos. i assume you got them off ebay, noticed a sell in korea that is selling kits similiar to what you posted.

any more progress?

[BMSTECH]

I have eventually found a good crankshaft for my Honda S600 restoration project and my focus has shifted back to get some progress happening with that. If you know these little cars you maybe interested to follow my build thread here: http://honda-tech.com/showthread.php?t=2460545
I would like mine to look as good as this one.

[Desertrunner]

Hi all I have some good news, I managed to get the cover off the quill on a KRV-3000SL machine and get a photo of the setup. I also have let my head go and purchased a KRV-3000 that I intend to convert to CNC using servos. It has all the ball screws etc the same as the machine here its just a bigger one. I have converted a X3 in the past to CNC I need the bigger table. Looked sriously at the X7 but the table was far to small thats why I went with the King Rich I also had them check the tolerance of the mill and they claim .01 of a mm. In my case I will be happy if its .05 just to get the bigger table.
When the cover was off I took some rough measurements of the mounting plate. Over the next month I will draft up the design and post it on the forum.
Hope this helps the project. Have a great day.
Tony

[Desertrunner]

It was pointed out to me that its difficult to see the detail of how the servo motor drives the ball screw. So what I have done is crop the high res image this one came from to show more detail of the ball screw.
At the very top of the ball screw is a black belt and pulley this is above the ball screw bearing carrier. Hope the new image helps. The manual adjust leaver just drives a encoder that feeds back to the control computer. There is no phsyical connection between the lever and the ball screw.
Have a great day.
Tony

[BMSTECH]

Tony,

Here are the circuit modifications I needed to make, to run the Mill as supplied in manual mode.

[Desertrunner]

It might take me a while to get my head around it, thanks for that its a great help.
Tony

[Desertrunner]

John here is a photo of the inside of the electrical box on my 3000 is it the same as yours?
Tony

[BMSTECH]

http://www.cnczone.com/forums/knee_v...ch_3000_a.html

Tony has got his mill operational, including the Z axis, in just a few weeks.
He has started his own build thread and inspired me to get my project back on track. He makes it look simple, well worth a look.

Well done!

John

[Desertrunner]

Hi John,
Can you check your control card and see if the resistor on the inputs terminals goes to the gnd rail or the plus 24V.
1 input is connected to both limit switchs with them wired in series, This enables home to be sorted as well. Based on the resister we will configue Mach3 to be high or low.

Here is a photo of the box I built to fit card, plug limit switchs, motor cables & control motor & coolant.
The 25 pin plug may not be need.

Also download the Mach3 if you haven't already so you can start configing the program as you go. Its lines of code is limited to 500 till you buy it.

PS I gave you a bum steer today you need to configure the drives for 1,000 pulses. As I remember you have 3 to 1 reduction is that correct?
Tony

[BMSTECH]

I see that you have used the existing X and Y limit switches (same as mine) to signal the computer to stop or home. I was thinking of using them to E-stop the machine in case the software hung. I was then going to use some small optical sensors for home position and limits for the interface board. My servo kit came with some. Do you think this is over kill? I hate the idea that a motor could possibly run-on uncontrolled. It's a "belt and braces" approach.

John

[Desertrunner]

John it would be over kill. The servo drives have built in motor protection so the moment the encoder reads that the motor is out greater then a preset it shuts power to the motor so no damage is down, its quicker then the limit switch would be,
You only need 1 input for the 2 limit switchs & home. I was like you I thought that the home was used all the time but it is not. The program only uses it during a set up or receck of home position. How it works is in Mack3 you hit the button marked "Ref Home" and program move one axis at a time back till it hits the limit switch/Home switch then it move forward till the switch is not on. The abasoluate ref is then zeroed.
Hope that helps.
Tony