If you want to cut steel, its a whole different ballgame. The rigidity required goes up with depth of cut and with how much acceleration you set the machine to, so you can cut anything if you're willing to make enough passes - but hey, that's why you built a robot to do that. On 6061 aluminum, I usually use a DOC of .050 or so and use a .125 in single flute "O" type cutter made for routing aluminum. As long as making 100s of them isn't a requirement (like on the production machines you mentioned), you can finesse a lot of things.
Happy to answer questions. What voltage is your supply right now?
BTW, I fumbled the shift key before. Its www.liming.org/espcopter
From: bbass408 <bbass408@yahoo.com>
To: GrizHFMinimill@yahoogroups.com
Sent: Thursday, February 2, 2012 4:56 PM
Subject: [GrizHFMinimill] Re: Just finished my "stupid" power feed. :)
Sounds interesting. It's just opinions anyway.
It seems like it's a not-so-simple physics problem. As it gets bigger in every dimension, it wants to wobble more so you have to do more to add rigidity. If you look at the differences between a sub-10K 4' X 4' router (like the Shop Bot) Vs. one that goes for 35K+ (I was exaggerating on the 100K), a lot of the differences are really just increased mass and structural reinforcement on the joints.
I saw your setup. Very cool -- especially for under 2K. I also notice you used lots of big aluminum U channel members for what I think are the parts that need to be the strongest. That's got to be a good thing.
I'm thinking of upgrading at least my power supply and maybe even the motors. If I do, hopefully you'll take some questions based on your experiences.
As someone who did most of my early woodworking with hand tools, I still get bored watching it cut. That's just me. I also made a nice dust collection setup so that should bring the dust down. MDF dust is some nasty stuff.
What bits, speeds, depths, and feeds to you use to cut aluminum? When I tried using a single flute carbide bit at about 15K RPM at low (30 ipm) feed rates on aluminum, that was loud. My router itself is really loud but a nice spindle would make that go away.
--- In GrizHFMinimill@yahoogroups.com, Gary Liming <g_liming@...> wrote:
>
>
>
> Well, I built a CNC router, and I love it.
>
> 1. Serious "coin" is relative, but I built mine for less than a Carvewright.
> 2. I routinely get 1-2 thou tolerance and I made mine from mostly dimension lumber.
> 3. How much dust depends on what you cut. Not much from aluminum. Lots from MDF.
>
> Get a DC system anyway if you have a router, CNC or not..
> 4. Only thing that is loud is the fan in the router. Get a quiet router or use a PID control system.
> 5. I have made lots of stuff with it, and I am still fascinated by just standing there, watching it cut.
>
>
> But then, that's just me.
>
> If you would like more info:
>
> For a log of building it, see www.liming.org/cnc
> For a log of cutting something from aluminum, see www.liming.org/ESPcopter
> For a log of cutting wood items, see www.liming.org/orrey
>
> Just my 2 cents, your mileage may vary.
>
>
>
>
>
> ________________________________
>
>
>
> I have 4X4 foot CNC router. I say, "Don't do it. It's a trap!!!" :) I ended up coughing up serious coin and time on that thing and I bought most of it premade. I ended up hating that thing for so many reasons. It's been tarped for over 5 years.
>
> Some observations:
> 1. If you make it yourself, it's going to be rickety no matter what compared to a 100K rig. You might be talking about 20-30 thou accuracy which I can get with hand tools on a good day.
> 2. It's loud and dusty. Dusty is somewhat solvable.
> 3. I love woodworking. Watching a robot do it for me was interesting for about 5 minutes then got really boring.
>
> But, that's just me...
>
It seems like it's a not-so-simple physics problem. As it gets bigger in every dimension, it wants to wobble more so you have to do more to add rigidity. If you look at the differences between a sub-10K 4' X 4' router (like the Shop Bot) Vs. one that goes for 35K+ (I was exaggerating on the 100K), a lot of the differences are really just increased mass and structural reinforcement on the joints.
I saw your setup. Very cool -- especially for under 2K. I also notice you used lots of big aluminum U channel members for what I think are the parts that need to be the strongest. That's got to be a good thing.
I'm thinking of upgrading at least my power supply and maybe even the motors. If I do, hopefully you'll take some questions based on your experiences.
As someone who did most of my early woodworking with hand tools, I still get bored watching it cut. That's just me. I also made a nice dust collection setup so that should bring the dust down. MDF dust is some nasty stuff.
What bits, speeds, depths, and feeds to you use to cut aluminum? When I tried using a single flute carbide bit at about 15K RPM at low (30 ipm) feed rates on aluminum, that was loud. My router itself is really loud but a nice spindle would make that go away.
--- In GrizHFMinimill@yahoogroups.com, Gary Liming <g_liming@...> wrote:
>
>
>
> Well, I built a CNC router, and I love it.
>
> 1. Serious "coin" is relative, but I built mine for less than a Carvewright.
> 2. I routinely get 1-2 thou tolerance and I made mine from mostly dimension lumber.
> 3. How much dust depends on what you cut. Not much from aluminum. Lots from MDF.
>
> Get a DC system anyway if you have a router, CNC or not..
> 4. Only thing that is loud is the fan in the router. Get a quiet router or use a PID control system.
> 5. I have made lots of stuff with it, and I am still fascinated by just standing there, watching it cut.
>
>
> But then, that's just me.
>
> If you would like more info:
>
> For a log of building it, see www.liming.org/cnc
> For a log of cutting something from aluminum, see www.liming.org/ESPcopter
> For a log of cutting wood items, see www.liming.org/orrey
>
> Just my 2 cents, your mileage may vary.
>
>
>
>
>
> ________________________________
>
>
>
> I have 4X4 foot CNC router. I say, "Don't do it. It's a trap!!!" :) I ended up coughing up serious coin and time on that thing and I bought most of it premade. I ended up hating that thing for so many reasons. It's been tarped for over 5 years.
>
> Some observations:
> 1. If you make it yourself, it's going to be rickety no matter what compared to a 100K rig. You might be talking about 20-30 thou accuracy which I can get with hand tools on a good day.
> 2. It's loud and dusty. Dusty is somewhat solvable.
> 3. I love woodworking. Watching a robot do it for me was interesting for about 5 minutes then got really boring.
>
> But, that's just me...
>
__._,_.___