Re: [CAD_CAM_EDM_DRO] Re: CNC machine building without scads of tools

I was going to suggest that that was a real possibility, but the
designer took care of that.

The problem is two fold as I see it. One you want to cover a rather
large area and two you would need to maintain accuracy over a large area
on various materials.

The large area means long travels on at least one axis. If you build a
gantry type mill this implies that at least part of the table is longer
than the 19 inches of the panels you want to cut. Even a conventional
mill would require a long table to cover 19 inch panels. Probally the
best choice for this type of Application would be some sort of gantry
device given that you can keep it square and flat. It will not
however be easy to build such a machine with limited tooling, your best
bet MIGHT be extruded aluminum sections.

The problem with accuracy is significant even when milling PC boards.
Ideally you don't want to remove anything more than the cladding.
This implies rather tight tolerances with respect to spindle hieght.
Some of this tolerance concern can be elminated buy having the spindle
plane the mounting table. When it comes to metal machining accuracy
is important as is a stiff machine to keep chatter an a minimum. It
may be that a PCB board mill is within you tooling capabilities but that
a machine capable of handling metal is not. If you really need the
metal machining capability, there is always the possibility of engaging
somebody locally to help with the project. It may cost you a bit be be
worthwhile in the end.

Do consider searching the net for other plans.

Dave


ab2pn wrote:

>I emailed him and he said hes machines are not suited for what I want
>to do.
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>--- In CAD_CAM_EDM_DRO@yahoogroups.com, "Ron" <veeguy@y...> wrote:
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>>>From: "ab2pn" <ab2pn@y...>
>>>Subject: CNC for PC boards?
>>>
>>>
>>>I'm looking to be able to mill PB boards and front panels for
>>>electronic equipment, I would think that the largest PC board I
>>>would ever do would be 12" square.
>>>
>>>
>>>I would also like to be able to mill a standard rack panel (19"
>>>wide x 8" tall max).
>>>
>>>
>>>I currently only have a drill press and a small band saw and
>>>typical hand tools (files, wrenches etc), I'd rather not have to
>>>buy too many tools to be able to build a CNC machine.
>>>
>>>
>>You should take a look at www.crankorgan.com
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>>The guy has plans for several well thought out CNC machines. His
>>plans can all be built with hand tools except for maybe an
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>electric
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>>drill or drill press.
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>>The site has a lot of pictures of machines that have been built
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>with
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>>his plans, and they look pretty nice as well as functional.
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>>The plans are like $40.-, the only downside being that he doesn't
>>take Paypal or credit cards for ordering. (I've gotten so lazy, if
>>a site doesn't take plastic, it takes an act of congress to get me
>>out of my shop to buy a money order and lick a stamp!)
>>
>>Take a look!
>>
>>PS.- I have no connection to this guy, or his site or most anyone
>>else for that matter. I do however, intend to send away for a set
>>of plans for his "Brute" CNC machine, as soon ai I do that whole
>>stamp/money order thing.
>>
>>veeguy
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