Re: [CAD_CAM_EDM_DRO] Re: Routers

Yes, I understand that the accuracy is the sum of the system. This is
why I'm asking about the accuracy of routers. My mill is assembled from
Aerotech slides. They have decent specs and appear to be in good shape.
I'll have the final structure for the machine done soon in something
more rigid than MDF and I expect it to be solid. The completed machine
is expected to weigh ~500Lb for 12x12x6" travels. On paper I have
.002mm resolution, haven't checked the actual table resolution yet
though. The Geckos still need to be tuned. I also need to come up with
a decent milling table that will fit my 12x12 travels.

The question is will a Seig Minimill head have better accuracy than a
router? And can I get enough RPM to do a decent job in aluminum with a
1/8" ball nose endmill? Changing the motor should not be a problem, but
will it hold up?

Thanks for the lead on the collet adapter Steven.

Coolant does worry me a bit with a router, it's going to be messy. Is
compressed air and a dust collection setup enough?

Thanks guys!

Greg


caudlet wrote:

> --- In CAD_CAM_EDM_DRO@yahoogroups.com, Gregory Kamysz
> <smsupply@a...> wrote:
>
>>How many of you are using routers for cutting metal? Can you get
>
> enough
>
>>accuracy from a router? <snip>
>
>
> Accuracy is an elusive concept in CNC. It is a combination of a lot
> of things. There are certain things you can say: One is that your
> accuracy can never be greater than the sum of your inaccuracies and
> that one inaccurate component will spoil the total system accuracy.
>
> Will a router be more accurate than a roto zip? theoreticaly it
> should, since it has larger bearings and should have better run-out.
> Now we have to ask if the rest of the machine has the ridigity to
> handle the larger router/weight and the added forces.
>
> Several of the list members have been using routers to machine
> aluminum. Like all material there is an optimum feed and speed for a
> given cutter size and geometry. The needed RPM will diminish with
> the metal and as you point out the speed control is essential. One
> byproduct of pure voltage speed control is that reduced voltage also
> brings reduced power and torque, often when you need it most.
>
> Chip removal in cutting metal is more important especially if finish
> is important. Most metal cutting operations are done using a coolant
> of some form (mostly mist or flood) to not only cool the cutting tool
> but to lubricate and help remove the chips. At the very least a
> stream of compressed air blown to help remove chips is needed.
> Aluminum cut at the wrong speed tends to "gum" and that can make for
> some ugly cuts.
>
> Even in routing woods of different types, users have found a vast
> difference just by changing the router bit geometry. A 2 flute
> spiral cut bit with uplift works better on dense woods or manmade
> composites that have glue type binders. I had my worst experiences
> when cutting relatively soft wood like pine and then hitting a patch
> of sticky sapwood...instant bit snap.
>
> If you want to use 1/8" shank bits with 1/4" router collets you can
> pickup some Adapter Bushings from MLCS (www.mlcswoodworking.com) for
> 4.00 each.
>
> So tell us a little bit about your machine and how it is built and
> the accuracy answer can be a little more accurate....did I say that?
>
> Tom C
>
>
>
>
>
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--
Gregory Kamysz
Crystal Lake, IL
USA

Electric Ducted Fans
www.edfinfo.com