[Trimix]

I hesitate between these two plans !

Machine Tool Camp 4'x8'
(http://www.machinetoolcamp.com/4x8.htm)

Cad Cut CNC 4'x8' Router
(http://www.inshorepowerboats.com/cnc.../CNCROUTER.htm)


The first reason is that they are together in imperial units and I'll have to convert them into metric units because it would be hard for me to procure parts in imperial !

Second, I'll need a strong CNC because I want to cut 1' MDF.

What are the advantages and drawbacks of each ?
Anyone can send me some pictures about its CNC based on these plans ?

Thanks for your time on my post

Trimix

[samualt]

I have read the instructions for both machines. But, I haven't built either yet. Both would cost about the same to build.

The Machine Tool Camp 4'x8' is a light-weight machine. The instructions are detailed but more of a connect-the-dots type deal rather than a tutorial. Metric or emperial is irrelevant here because you would probably order most of your parts from this company.
Pros:
1. Easy to assemble once you have all the parts (Order from them. Its cheaper and easier.)
2. Light-weight so could be moved around, within reason.
Cons:
1. Light-weight causes vibration during use.
2. Light-weight material may deflect (bend or bow) slightly during use.
3. Less precision.
4. Might be hard to cut aluminum frame members to the tolerances listed.
5. I would have liked more of a tutorial in the instructions rather than just connect-the-dots. Instructions need more large pictures.

Cad Cut CNC 4'x8' Router is a heavy duty machine. It is as close to an industrial machine as you will ever get. The instructions are pretty good with lots of big drawings as well as tutorial. This is a big heavy machine. If you are looking for precision then this is it. I think this one would be easier to do in metirc than the other, if you feel you must.
Pros:
1. Very high precision machine.
2. Heavy weight means no vibration during use.
3. This machine is stout! No deflection here. No bending of frame or gantry during use.
Cons:
1. Big heavy machine.
2. You must weld frame. (Any cheap stick-welder will do. Mine costs less than $100. It looks pretty easy to do.)
3. Takes two people to man-handle some of the pieces during assembly.

And now a few words about the big routers in general.
1. You should go to the garage with two yardsticks (meter-sticks?) taped together and see if you really have 6'x11' clearance somewhere. These machines are really large! You are talking about a permanent fixture that can't be easily moved. These things are as big as a car!
2. Small motors are better. They can still be powerful but the smaller and more lightweight the better. You don't want to weigh the gantry down with big heavy motors like I have. It's a headache.
3. You should consider if you really have the money for one of the large machines. It adds up. Expect to spend $5000+ US before all is said and done.
4. I don't plan on using Gecko's for the controllers. I am going to use Rutex because they look like they have more bells and whistles and there is less wiring to be done. In my case, the schematic parts of all the "Plans" are useless. You should consider if you will follow the schematics or not.

Second, I'll need a strong CNC because I want to cut 1' MDF.

Is that one foot? Yikes! Neither machine above has a 12 inch Z-axis. That is really large. Most industrial machines don't have a Z-axis that large. The longer the Z-axis the less precision you have. Talk to Tom at CadCut and see what he says. It might be possible.

Hope some of my drivel has helped!

[Trimix]

Thanks a lot Samualt

It's 1" MDF !

Your analyses of these two CNC is close to mine.

Concerning Cad Cut

Can you tell me more about the motors ? (type and torque)

I read there's a joystick ! What can you tell me about this ? I can't imagine how it works ! Ability System don't mention it in its LPT solutions capabilities!

If you have pictures of yours, I'll be happy to them !

Thanks again

[samualt]

1" MDF is a piece of cake. No problem there at all.

The motors seem to be 470 oz-in by MicroKinetics, model 34M470. They look pretty heavy duty to me. Step angle 1.8 deg. They are not tiny motors so I imagine you could get more powerful ones of the same size if you liked.

Can't tell you much about the electronics and joystick. I was going in a different direction completely with the Rutex controllers. I see the joystick switches in the Cadcut schematic though. It doesn't look like there is any special circuitry.

I don't have any pictures yet. I haven't got that far. I still have to build the frame. And, I was thinking about helping a friend with a T-Slots design first. It might just help fund my machine.



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"We're lost but were making good time." - Yogi Berra

[Trimix]

Another question !

What is the speed of this Cad Cut CNC ?
MTC claims 350+ inches/minutes (in load or not ???).
What about Cad Cut ones (with 470 oz.in steppers) ?

Could you explain your motor choice ? I wan't to use DC brushed servo with Gecko 320.

Thanks

[samualt]

I very much doubt the MTC machine could even get close to 350 inch-minute. I bet it's more like 10-50 inch-minute. I'm sure the CadCut machine could go faster than the MTC in any case.

As far as the choice of motors you would have to ask the designer, Tom (ninewgt on this board. See the CadCut forum here just under this one.)
My choice of motors is some giant nema 42, 1500 oz-in DC servos that I picked up super cheap. Electronics Goldmine is out of them though so I couldn't pick up any spares, darn it! They are really overkill and too big...but cheap.
I was going to use the Rutex controllers instead of the Gecko's because it looked easier to hook up.

Sorry I couldn't help more!

[dcd121]

Heres real world. I cut 3/4 mdf 1 pass at 75 in per min. with 3/8 spiral bit on 3.35 hp porter cable mounted on a machinetoolcamp 4 x 8 . Rapid traverse is 350 in per min.