Proxxon Tool Holder PCB MIlling

Hi all,

I was wondering if anyone here has tried using a Proxxon rotary tool to mill PCBs using their Mendel?

If so would they be able to share their design of tool holder? Reading through the RepRap Wiki somebody has definately made one:

[reprap.org]

But they have not posted the model file for it. I am not adverse to making my own, but if somebody has got one that works already it would save me a bit of time.

Cheers

Andy

... search in Thingiverse for "dremel" - [www.thingiverse.com]

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Viktor
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Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

Victor,

Thanks, but I was after a tool holder for a Proxxon tool, not a Dremel. Dremels are not really any good for milling as the bearings are generally quite poor.

Quote

Reading through the RepRap Wiki somebody has definately made one:

Coincidentaly, I've reviewed this page just yesterday and added a few experiences.

To my experience, a Dremel has better bearings than a Micromot. The problem of the Dremel is it's larger diameter, though, which leads to substantially more vibrations (and also more noise).

To get something in the heritage of RepRap ideas, you might want ot design something like the Mantis spindle, also on this page. This design could be fitted right into a Mendel tool carriage.

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Generation 7 Electronics	Teacup Firmware	RepRap DIY

Hi Traumflug,

Thanks for the information on the updated page, I had not realised that it was more about the size of the dremel.

I would love to make a spindle myself, in the vein of the Mantis one. I did find a great article on the internet about making your own spindle but I cannot seem to find it anymore. My problem is that I lack the metal working tools to do it well and it would just end up taking months before it was ready to use - maybe someday, but for the time being I thought the easiest way to get up and running would be to use the tool I already have and just print a toolholder for it, then see how that turns out. Hence asking for an already designed tool holder.

I sort of hoped that the author of that wiki page who placed the photos would be kind enough to share his, perhaps it would be a good idea to post it on thingiverse and link to it from the wiki.

But since he has not I shall see if I can design my own and post it.

Cheers

Andy

You mean these instructions: [makeyourbot.org] ?

The tiny bit I'm currently scratching my head about is how to get this 4 mm PVC tube over a 6 mm shaft. Probably I simply have to try. In case you're in the metric world, an equivalent bearing is a 626-2Z and the aluminium tube can be a 25x3 mm (19 mm inside, available off the shelf).

Regarding the Micromot, I found it's bearing solution to be not sturdy enough. Every other Gen7 PCB I have to open the spindle to get rid of play. No idea how often I can do that before complete failure. Looking at the recommended loads of roller bearings this is no wonder, the smaller the spheres in a bearing, the lower is the acceptable load. A 8x12 bearing can accept some 10% of the forces of a 6x19 one. Also a smaller bearing outside means a higher pressure where it connects to the housing, of course.

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Generation 7 Electronics	Teacup Firmware	RepRap DIY

Traumflug Wrote:
-------------------------------------------------------
> The problem of the Dremel is it's
> larger diameter, though, which leads to
> substantially more vibrations (and also more
> noise).

I'm using the flex-shaft (less moving weight, decoupled from the motor)
and am gripping it along all of it's length instead of just 3 or 2x3 bolts.
No problems with vibration at all.

> This design could be
> fitted right into a Mendel tool carriage.

I think the Mendel tool-carriagre is way too small and
there is not even remotely enough headroom in the mendel
(as opposed to a Darwin) for a Dremel.
Also the tool carriage seems to be design with not a single
thought about changing tools at all.
Both mechanically and in terms of an electronics connector.

So I won't use a Mendel for this or seriously re-design it.
(wider too-carriage, quick-release of the tool that is accurate enough
to need no extensive re-calibration after a tool-change, connector
for the tool to the electronics, resistor to identify what toolhead is currently
mounted to the electronics,...)

I'm thinking of modifying the RepMan dual-head upgrade to accomodate
a Dremel flex-shaft in combination to the 2 extruders with a servo or threaded
rod to lower/raise the Dremel when (not) in use.

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What's about the dirt / dust appearing while milling?
I guess, little copper pieces between smooth rods and linear bearings of your Mendel might not be the best for the health of it?

... I'm cooling the millbit and binding/consolidating the dust by spraying some soapy water+alcohol in the path ...

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Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

I mounted a small bathtub on my WolfStrap: [reprap.org]

Works nicely, if the mill bit angle is 30deg or smaller and there isn't too much water inside. Just a millimeter over the copper, or you get a nice fountain effect, spraying all the water everywhere.

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Generation 7 Electronics	Teacup Firmware	RepRap DIY

oo nice. ive not thought about milling PCB tracks before (its hard to get etch stuff in my country, the authorities fear u can make explosives)

may i know what kind of software combi u use to "convert" circuit to tracks or is that what to call it?

must the bath need to be absolutely soapy? or just water will do?

the part where the bed zeros, have you tried to just have a light springed wire touch the smooth part of the drill bit?

hmmm this is exciting, looks like i will def have to try to fit my dremel into my yet to be done machine

Edited 2 time(s). Last edit at 09/01/2012 08:00PM by redreprap.

... I'm creating CNC-paths for isolation-milling mostly with Target (free edition limited to 2 sides and 250 pads), but it's no problem to use Eagle with an outline-ULP - read here for more: [reprap.org]

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Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

Quote

may i know what kind of software combi u use to "convert" circuit to tracks or is that what to call it?

Quote
http://pcb.geda-project.org/
gEDA/PCB

comes with an G-code exporter which makes excellent drill files and reasonable isolation-mill files. Make sure to get the latest git sources, as this exporter received a lot of attention the last few weeks.

For isolation milling, I use Visolate 3.

Quote

must the bath need to be absolutely soapy? or just water will do?

It'll work dry, too, but water reduces dust development and tool wear.

Quote

the part where the bed zeros, have you tried to just have a light springed wire touch the smooth part of the drill bit?

Recently I've soldered a wire to the motor inside the Proxxon, an appropriate soldering lug is already there. This should solve the problem of clamping the wire on and off all the time. Yet to be tested, though, in production I'm pretty conservative, aka "never change a running system".

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Generation 7 Electronics	Teacup Firmware	RepRap DIY