Re: Dremel alternatives

Hi Ian,
Just use two steppers, one at each end of the leadscrew. Use
rubber tubing to connect the motors to the screwrod. Use a floating
nut assembly to fix alignment and warped screwrod problems. The whole
machine can be built for under $125 US not counting the Dremel. See
the link below for all kinds of builder links. Anybody can buy a CNC
machine. The real fun is building one!

http://users.bart.nl/~majosoft/

John

--- In CAD_CAM_EDM_DRO@y..., chapmani@m... wrote:
> In the next month I will be joining those of you who have built
their
> own home brew, small CNC device. As a result, I am trying to decide
> what tool to mount on the darn thing.
>
> As I browsed the web, I noticed that most of the small ones I saw
> used a Dremel, and had just about decided that was what I'd use.
> Then I started reading this group, hit upon this thread, and it made
> me start to re-think my initial plan.
>
> So, I want you guys to help me decide what to purchase to do my
> projects.
>
> I realize you "high end, more power, Tim Taylor" guys will laugh at
> me. So will you former professional, steel shaping, converted heavy
> duty industrial mill guys. Just realize I'm at the bottom end of
the
> spectrum, and on a very small fixed income.
>
> Firstly I'd better describe what I'm building. It will be a fairly
> low end, bridge style machine, built out of MDF. It will be my
"mark
> 1" version, hence using low end parts that are easy to obtain
> locally. For example, the "screws" are going to be stainless steel
> threaded rods available at home depot. Steppers for this one are
> only going to be Nema 17 size, 12v (yea I know probably too small)
> [Off topic question though - If I remember my high school physics, a
> pulley makes 1/2 the force required to move an object. Am I correct
> in assuming that gearing, or gear and timing belt type options
> increase my torque forces similarly?]. I plan on very light "bites",
> slow speed, and multiple passes.
>
> Secondly, my applications. I want to try everything! :{) Well
> really, a little circuit board milling and drilling. Routing some
> signs and shapes in wood (pine, MDF & plywood probably). Cutting
> some shapes and rear milling plexiglass. Oh yea - cutting some
> shapes out of tin (roof flashing type of thickness). Basically very
> light duty stuff. Eventually I might try a little glass engraving
or
> maybe even routing ice.
>
> Thirdly, budget and choices. I want to keep the tool down to around
> $100 Canadian or lower if possible. Listed below are some of the
> choices I've seen around, along with some of the pluses and minuses
> of each.
>
> Dremel like
> - 5 speed Dremel - $85 - 5,000 to 30,000 RPM - 5 year warranty
> - Black and Decker Rotary Kit - $89 - 8,000 to 24,000 RPM - 55
pieces
> and case
> - Mastercraft Rotary Kit (Canadian Tire house brand) - $99 - 5,000
to
> 35,000 RPM
> 100 pieces + Case
>
> Router
> - Mastercraft plunge router - $99 - 30,000 RPM - 5.6 amp, 1.25 HP -
> 1/4" collet,
> detachable body leaving nice cylindrical tool - 3 year warranty
>
> Drywall Cut Out
> - Porter-Cable Drywall Cut Out - $99 - 28,000 RPM - 3.4 amp - 1/4" &
> 1/8" bits
> - Rotozip 4A Cut Out tool - $139 - 30,000 RPM - 1/4" & 1/8" collets
> - DeWalt Cut Out tool - $129 - 30,000 RPM - 6 amp - keyless bit
> changes
> 1 year warranty
>
> Laminate Trimmer
> - No-name Laminate Trimmer - $120 - 28,000 RPM - 3.3 amp - 1/4"
collet
> - Porter-Cable Laminate Trimmer - $143 - 30,000 RPM - 5.6
> amp "industrial" motor,
> 1/4" collet
>
> The "single speed" devices may make it difficult to handle the
> plastics. Could possibly add a "router speed control" for about $40
> to get lower speeds.
>
> 1/4" collet won't take the small, inexpensive Dremel bits (or maybe
> can with an adapter?)
>
> The Dremel type tools may be shorter lived than the bigger power
> tools.
>
> What is the expected single sitting running time for some of these
> tools. For example are some of the bigger tools designed to be used
> in short spirts? Dremel implies longer usage as in their "Wood
> Carving" examples. Though I suppose the more powerful tools would
> shorten the time to do a job.
>
> Ok guys, have at it. Tell me what choice you think gives me the
best
> price/performance ratio. Pick my idea's apart. Just don't pick me
> apart!
>
> Ian C.