nice to hear there is some progress.
you want to use a 540 motor i guess.
i can only suggest to go for a 600 size instead.
those 540 size is only used because of limitations by club/ racing
guidelines for cars.
I suggest using the jamara venti series. these motors cost maybe 20% more
(so 12 eur instead of 10 at expensive model parts shop) but have a built in
fan. they really run very cool with that fan inside (think about it....).
there are new high speed series from jamara which go up to nice 20krpm
drilling speeds.
the 600 size costs the same and is much more efficient because of longer
magnets and rotor.
the idea with the own spindle is good, i saw a nice one on the web (sorry
hav no url).
the guy used two counterloared bearings and got much better results than
with a dremel (because
of which there was the need for a new spindle).
i saw the own spindle coupled with a piece of compressor airhose.
i would prefer that over a "metal" cardan. better for high speed i think.
(addition to the usefulness of plans: here in europe it may be much harder
to get
the needed items, so it makes additional sense to not sell it here)
the non-moving table has the following advantages:
you can rise/lower it more easy to take thicker parts (objects to mill one
side).
you can try other milling methods like edm and similar stuff.
i see with drawer slides there is much advantage in mounting with a moving
workpiece setup (in one directon).
but with the pipes/bearings ther is not so much advantage left (they can
support themselves etc...).
i am still not sure which way to go...
your control setup sounds very interesting, but maybe a bit too complicated
for me.
(i hoped there are free dos based tools for parallel port drive available)
have you done software research? what is available?
i will check today - ignored the software until now totally....
regards
stefan
On Sun, 05 Oct 2003 12:27:35 +0200, Markus Zingg <m.zingg@...> wrote:
> Hi Stefan
>
>> I would not buy his plans even if i could.
>> The hardest for me is not how to make it, but how to get the needed
>> material.
>> The plans don't do the work for me.
>> Making some errors during development i something i risk, but i doubt i
>> would be satisfied
>> with any plans. (you have to search for the specific parts then also...)
>>
>>
>> I think it is good possible to see from the pictures of his machines
>> which principles he
>> uses, (e.g. which rail mechanism). For someone with a bit understanding
>> of mechanics there are no dimensiones etc. required.
>>
>>
>> Look he too uses the ball bearing on pipes/rods...
>> i located a big length of stainless pipe (maybe flag pole or similar)
>> at a relatives shed.. have to inspect for surface quality but if it is
>> ok i am sure
>> i can get it..
>>
>> another source for good rails is ebay..
>> at ebay.de (for markus....) there are always a lot of "linearführungen".
>> often ground steel profiles with ball or roller beared carriages. no
>> play.
>> also acme threads with ball-beared nuts ("kugelumlaufspindel") are
>> sold..
>
> I already do have all materials I think I need for my machine and also
> started construction. I had to cease working on it cause I'm held busy
> job wise at the moment. I'm looking foreward to continue the work and
> once there is a stage where I can take some picutres I will do so and
> post a link to them here.
>
> With regard to John's plans - they most likely will be worth the money
> for those also able to organize the parts. He's concept for the
> machines seems ok for hobby use from what one can see on the pcitures.
> I do agree though that the value of plans is more than questionable if
> the parts shown there can't be bought easily. This is of course true
> for all these kind of plans. Especially for those that want to build
> such a machin "on the cheap" it's very important that they can be
> flexible with what parts they use. However, this flexibility actually
> then destroys the value of a plan...
>
>> it is not as cheap as pipes or steel profiles but a lot more precise.
>>
>>
>> I was thinking about the cnc for some time now, not really having time
>> to build one
>> but gathering information..
>>
>> i initially wanted to make a steady table with the spindle moving all
>> three axis..
>> now i think it is easier to move the workpiece the one direction (x),
>> the spindle y and z on a vertical mount (like seen on many designs,
>> including kleinbauers).
>> Not sure what's better...
>
> I also will do it like this. I.e. a moving x direction and a stand
> with y and z mounted to it. IMHO this is is the simplest aproach also
> giving a fairly stable result. I will only used threaded rods that
> drive a plastic nut. Surely enough precise and stable for the purpose
> of my machine (drilling only).
>
>> I want to use the machine not only for pcb making (and there maybe only
>> for drilling)
>> so i have dome extra requirements.
>
> Mine will be restricted to drilling only. That's what I need most at
> the moment - well, it's the only need I had so far. Based on the
> experience made and provided the need arises here I then may build
> another machine for milling.
>
>> if i make "ball bearing" slides (and not buy good oned from ebay) they
>> need to be steel.
>> a ball bearing only conacts the rail on one small point (ok a lne with a
>> flat rail).
>> if you use aluminium bearings and want to mill aluminium this may not be
>> sturdy enough.
>> ball bearing rails have the disadvantage of small contact points. (i
>> think because of this
>> on other tools like lathes/mills dovetails are preferred).
>
> My (drilling only) machine will be equiped with those special
> drawerslides I mentioned earlyer. They have no play at all, are stable
> in all directions (as oposed to standard drawer slides) but of course
> have a limitted stiffness because they are just drawer slides. Again,
> for the sole purpose of drilling PCB's they are perfect. I'm also sure
> that they are sufficient for light milling jobs like wood or plastics
> etc. Experience will show.
>
>> i have a lot of other ideas.. but i don't want to bore you...
>
> Instead of using a redy made drill for the motor (I.e. proxxon) I will
> build one on my own based on a cheap electro motor as it's used for RC
> racing cars. This motor delivers a high enough RPM and torque. An
> extra spindle made of a silver steel rod then will be centerd / held
> with ball bearings and the motor is then driving this spindle over a
> cardan. Like this the motor can be mounted in a way to avoid
> virbrations being transported to the machine frame thereby reducing
> noise. The home made spindle will be threaded on it's end so as the
> Proxxon keyless chuck can be monted to it.
>
> So far the materials I bought are way below $100 - including the
> stepper motors bought from e-bay. I will most likely also build my own
> controller cirquit cause I don't intend to use a DOS based PC but a
> microcontroller for controlling the machine. The drill / mill data
> then will be transfered to the machine over a standard ethernet
> connection. I happen to have a working single computer network enabled
> design I made for another purpose that should be up to the task to
> form the base of this controller unit. The machine then can be
> controlled using a built in webserver. The costs for the controller
> therefore are also within strict limits - I don't expect them to raise
> above $80.
>
> Markus
>
>
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