Redesign of JGRO in Denmark.

[pulsar200]

Hello everyone.

So I have been reading the forums for some time now with great interest. Especially the JGRO design which was possible for me to build with the tools I have access to. But since all messurements in the plans where imperial I had a hard time adapting it to the the things we have available in hardware-stores here in Denmark.
So, since I really wanted to build the cnc-router, I made a new set of drawings from scratch.
Heres a snapshot of the almost finished drawings in SW:


I have been working in my parents garage for two weeks now. Cutting and assembling it. Here are some pictures of my progress:




This last bit I did today. The rails aren't fixed to the bridge yet but i really wanted to see how the rails worked, so I put them on anyway:

This is also the router i want to use.

Closeup of a rail:


One last picture with the top on:


So I just wanted to tell you all how it was going..

[snooper]

Looks impressive, what size is it?

[txcowdog]

That is a lot of work considering you had to convert everything to metric.If you have done the converting, you should post the metric version of the plans so others can start a machine. I'm sure the task of converting has kept a lot of people from starting their own machine.

[pulsar200]

The machine is (x,y,z) 84x65x63 cm.. So it's not the biggest, but I dimensioned it to take a cutting material of 35x53x7cm, which is enough for me. It should be small enough to fit in the back of a car as it has to be moved a bit.

As to the posting of the plans - I will do so, shortly. I really want to make the plans as complete as possible, maybe even with some instructions. I am not a woodworker by trade (studieing control engineering), so I had to figure techniques out by myself for making it as accurate as possible. It's really hard work when you don't own a table saw Maybe instructions would be helpfull to people in a similar situation. I am thinking about starting a free wiki-site so the build process could be refined and optimized. I think a lot of people would be interested in building and owning such a woodworking machine without having to do it almost from scratch, as I did. Yes, I used JGRO ideas with the rail system and adjusters, but redesigning it to metric really took a lot of time. It was easier starting from scratch and incorporating my own ideas in the process.

Best Regards
Martin Holm Pedersen
Denmark

[epineh]

Nice work, keep the pics coming...

Russell.

[pulsar200]

So I have finally been able to get some work done on my project. Eventhough I still need some assembling of the router i thought i would get started on the electronics.

I have ripped some steppers out of an old copier that i got for nothing. It had two usable motors(I think) and a lot of other small thingies, some of which I can use(limitswitches etc..). One Unipolar 1,27Nm MF 2A 1.8 deg motor and a smaller one which i couldn't find any info on.



Anyone know what is needed to control these motors? I have seen some drivers around but im not quite sure what i need. The big one has 6 wires and the small one 5 wires.

Best Regars
Martin H. Pedersen
Denmark

[thunterman]

Five, six and eight wire steppers are wired "uni-polar". See this link for details on the motors: http://www.cs.uiowa.edu/~jones/step/...s.html#practvr. One source for a driver for these is HobbyCNC at http://www.hobbycnc.com/. Another is http://pminmo.com/.
I also built the jgro. You can see it on my web site at http://cnc-hobby-site/cnc.
Keep the pictures coming! Good work so far...

Thunterman

[Jason Marsha]

Good work on the machine. I like the steppers, if the serial number on the motor is shown more clearly I may be able to get some info.

Jason

[txcowdog]

thunterman

The link to your build does not work.

[pulsar200]

Okay. The serial numbers are:
The big square one:
TYPE 103H7522-8221
LOT NO 01720
AX060124
The round one:
TYPE 103H7126-0413
AX060117B

I found a little info on the square one, but not much. No wireing but i found that it must be a unipolar 2-phase model.

The round one I haven't found any info on yet.

If anyone can help it will be greatly appriciated..

I thought about building something similar to:
http://pminmo.com/discrete/discrete.htm

which uses discrete components rather than chips. I also thought about using the L297+L298N combo. But im not sure that will run a unipolar stepper.


Regards
Martin

[paul3112]

The 5 wire are not the go, the six is the better option. have a lookat the Gecko page on motor basics. http://www.geckodrive.com/photos/Step_motor_basics.pdf
I use gecko's with six wire steppers and they work a treat,

[thunterman]

The link to your build does not work.

Yup, I fat fingered the link. It should be http://cnc.hobby-site.com/cnc.htm

Thunterman