hacking a PCB milling machine to become a boot strap

Dear all,

as I am currently in China I think about buying this PCB milling machine and modify it to become a boot strap machine.

[item.taobao.com]

I plan to keep the 4 pol stepper motors, but replace the complete electronics and also add the opto end stops. Of course I would also need the extruder, but mechanical fixation seems to be easy to realize.

What I am affraid of are the needed software adjustments for machine calibration. Could such a spindle drive with shaft joints be accurately controlled by the software? I probably would need add some code and compile it again, right?

Please just help me to give a general estimation of feasability.

Thanks in advance! Grettings from the middle kingdom,
Peter

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I plan to keep the 4 pol stepper motors, but replace the complete electronics and also add the opto end stops.

Sounds like a good plan. You might want to keep the Stepper Motor Drivers as well and replace the central computing unit only.

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What I am affraid of are the needed software adjustments for machine calibration. Could such a spindle drive with shaft joints be accurately controlled by the software? I probably would need add some code and compile it again, right?

Yes, you'd have to adjust firmware settings for your mechanics. A step RepRap's firmware is well prepared for. (Re-)compilation is also a commodity, as there doesn't even exist a binary distribution. Everybody is compiling, and it's only a matter of installing the Arduino IDE plus code download plus a few clicks: [reprap.org]

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Generation 7 Electronics	Teacup Firmware	RepRap DIY

Peter, where in china?
Asia RepRap User Groups

A few other questions:
1: What's the vertical clearance of that machine?
2: Are you buying anything from our Official RepRap-China Supplier™
3: What are the fastest traverses you can get with that machine?
4: Have you thought about a WolfStrap?
5: Does it use unipolar or bipolar stepper motors?

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-Sebastien, RepRap.org library gnome.

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Remember, you're all RepRap developers (once you've joined the super-secret developer mailing list), and the wiki, RepRap.org, [reprap.org] is for everyone and everything!

SebastienBailard Wrote:
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> Peter, where in china?
I am located close to Shanghai in Nanjing.

> Asia RepRap User Groups
>
> A few other questions:
> 1: What's the vertical clearance of that machine?
75mm. Maybe 65 mm with endstops. Should be enough for all mendel parts, right?

> 2: Are you buying anything from our Official
> RepRap-China Supplier™
I also saw this offer, but decided to save some money.

> 3: What are the fastest traverses you can get with
> that machine?
Good question. Haven't thought about this. After online research for typical machines like this I would say up to 15mm/s. But I will check with the persons who sells the milling machine and give a more accurate value later. What is the minimum usable axis speed for printing? Is the quality increasing or decreasing with slower speeds? I am also worried that the complete different acceleration and deceleration characteristics might cause problems.

> 4: Have you thought about a WolfStrap?
Yes! If it is not possible to hack the milling machine, I would probably go for a solution like that.

> 5: Does it use unipolar or bipolar stepper motors?
The motor controller shows 4pins. So they are bipolar.

Hey everyone. Digged out this old post to share with you that I did it. It slow like hell, but tomorrow I will have my meshball print finished... MUHAHAHA

check out my just started blog (photo album): http://tangsob.blogspot.com/

Looks real good Tang. Congratulations!