CNC for acrylic projects

[DonW]

I got stuck on my stand build due to the lack of some bearings that have to be custom made. Instead of waiting for the shop I decided to go ahead and just build a cnc. This is just a quick simple project, I've already done two for friends, so I might as well have one for myself.
The cnc is built from Rockcliff cnc plans and uses the largest possible size stepper motors to cut acrylic up to a inch thick. The cutter is a dewalt trimmer that I have laying around.
I'll cut up the pieces this week-end and post some pics.

Don

 

[Scooterman]

Man someone has lots of time on their hands
I guess that is good for us because you help out everyone when their in need of just about anything! You know that may be a sign of experience, which If I'm not mistaken comes with time/age:shock: so this may be a dead giveaway huh!:lol:

 

[DonW]

Man someone has lots of time on their hands
I guess that is good for us because you help out everyone when their in need of just about anything! You know that may be a sign of experience, which If I'm not mistaken comes with time/age:shock: so this may be a dead giveaway huh!:lol:

Be nice. I thought everyone needed a cnc machine.

Don

 

[DonW]

Time to get going on this thing. Ive got all the parts comming so I can get started on the main sections.
First a quick explanation. Why a cnc router in a reefkeeping diy forum? There are many folks that believe they cant have exactly what they want because they cant afford a 10K cnc machine. I'm one of them, until I started building these little units. What can it be used for? A short list would be skimmer flanges, threaded lids, electronics and even the trim work on a nice stand, of course many others.
Is it complex? Well only if you make it that way. What I mean is, there are plenty of things that can be learned but for me I like to keep it simple. I dont know how to draw complex drawing to feed the cnc. But like most people I have friends that can draw for me in their spare time. I also use wizards that are built into many software applications. The main one is called Mach3. There is a wizard that will make just about anything that a reefer may want to make.
Is it expensive? IMO under 400 for a shop tool is pretty darn cheap.

Now for terminology:(no high tech terms)
To avoid confusion all directionals are with the operator standing in line with the machine facing the cutterhead.

Axis- A axis is nothing more tha a plane of travel. Your kitchen drawers move on one axis.
Z axis- also refered to as zed. Z is the up and down movement of the cutter head.
X axis- is the side to side or left to right movement of the of the cutter head
Y axis- is the front to back movement of the cutter head.


Parts and suppliers:
The plans were made by Rockcliff that I modified to make what I concider better. The plans are cheap only $20. Please get them from Rockcliff if your up to a project like this. I will not give out copies of mine. Rockcliff worked hard to come up with these and the $20 is well deserved. They are downloaded so no waiting.

Most parts are made from plain everyday 3/4" MDF. MDF is cheap from Home Depot. Do not buy more than you intend to use in one session. For example If all you have time to do today is build the base just buy a 2'x4' section from home depot. Why? Simple you dont want any of these parts to warp at all. Each major section should be cut and sealed ASAP. This is a cnc and we dont want even .001" of warp. Trust me on this one, it only takes one cold night to ruin a piece.

Motors Driver boards and electronics. These are readily availibe in sets ready to go. This is the kit I like http://www.stepperworld.com/FET3hobbyist.htm

Rails and beaings these are all Mcmaster parts and are very inexpensive.

Many parts can be had on ebay for cheap but do not run out and buy motors because they were a good deal. There are different types so you have to do your homework. A mistake I made one was I got a great deal on new motors for $5 ea on ebay. Come to fine out they needed a $500 driver board so I was just out the motors.

Now off to home depot for chunk of mdf. ( but only half)
Don

 

[Curtswearing]

LOL

I have a number of clients that are screw machine shops that have CNC lathes and equipment. However, none of them BUILT THEIR OWN!!!

 

[DonW]

LOL

I have a number of clients that are screw machine shops that have CNC lathes and equipment. However, none of them BUILT THEIR OWN!!!

Yup and as you know they owe their soles, first born....... to a bank or investors. Of couse those machines are on a much larger scale.
Also would like to point out that having clients that run these sort machine is another way to keep it simple. I'm sure you may be able to get them to machine parts at a discount but i'm also sure you could get one of them to draw up a flange file for free. I spent 3 weeks on mine and never got it right. My brother did it in ten minutes and its perfect.

Don

 

[DonW]

Here is a shot of the machine base.

 

[Krish]

Very cool Don!

 

[Reefdaddy1]

Iam very intersted in this thread, Been meaning to build one myself. Would like to see the final outcome of this project for sure.

 

[plack]

I work in a large machine shop and am curious .What is the machines travel length on the little guys ?

 

[DonW]

I work in a large machine shop and am curious .What is the machines travel length on the little guys ?

I should be able to get 13 on the y 12 on the x and 5 on z. Obviously you could get much more just by going with larger hardware. The biggest Ive seen personaly is 48 x 96.
How are your cad skills? I'd like to put together a public library of dxf files just for flanges and thing of that sort.

Don

 

[DonW]

Iam very intersted in this thread, Been meaning to build one myself. Would like to see the final outcome of this project for sure.

They really are a simple device. All the one Ive done so far are still working fine. One guy makes signs and alot of them and we built his for $500.

Don

 

[Reefdaddy1]

What kinda Cutting motor you put on these Don? Is it a standard router? Or more like chucked motor?

 

[DonW]

What kinda Cutting motor you put on these Don? Is it a standard router? Or more like chucked motor?

I like the pc690 routers but you have to beef the whole thing up to use a router. If you go light/medium duty I like the dewalt trimmers and trim routers. I may just make this one strong enough for the big router it just depends on what sort of deals I can get on rails. The normal duty unit uses bronze bearings. To make it heavier you need pillow blocks and linear bearing. These add about 500 bucks to the price of doing a build. I'm bidding on a full set of 20mm rails and bearings on ebay so we'll see what happens.
If you go the rockcliff site you can see pictures of the finished units.
http://www.rockcliffmachine.com/cnchome.htm

Don

 

[Reefdaddy1]

Would a rotozip work? I currently own one. Iam really gonna have to check this out, I want one really bad.

 

[DonW]

Would a rotozip work? I currently own one. Iam really gonna have to check this out, I want one really bad.

Sure you just have to cut and peck slow. The light duty version will handle a rotozip just fine. Ive seen alot of them with dremels.

Don

 

[Reefdaddy1]

Dremels? Really? Well thats surprising. Can you do Acrylic with a dremel? I thought the were to fast and to small a cutting surface.

 

[DonW]

Dremels? Really? Well thats surprising. Can you do Acrylic with a dremel? I thought the were to fast and to small a cutting surface.

I really doubt you could do more than 1/4 with a dremmel. My understanding is that alot of these are using a router type speed control instead of the cnc software to control spindle speed. I was just going to use a regular pc speed control that I have laying around. You are also using upcut bits, so I guess that may help a little with burning.


Don

 

[IAP Brian]

You can work on 1" with a dremel, just have to be careful and slow or you will snap the bit. Yes, upcut bits work the best when your not penetrating all the way through the material (pulls cuttings away from work area). I primarily use Amana bits. Made in Israel and expensive, but they last a long time and stay sharp longer.

This is a really cool project Don. I'm gonna have to stay tuned to see how this works out. I have quite a few CNC plans with an engineering firm, perhaps I can get them on disk. I have CAD but they did in 5 min what I was trying to do for days.:lol:

Now, you just have to show me the best way to make a large scale acrylic oven and I'll be set! (no more Keltech)

 

[DonW]

You can work on 1" with a dremel, just have to be careful and slow or you will snap the bit. Yes, upcut bits work the best when your not penetrating all the way through the material (pulls cuttings away from work area). I primarily use Amana bits. Made in Israel and expensive, but they last a long time and stay sharp longer.

This is a really cool project Don. I'm gonna have to stay tuned to see how this works out. I have quite a few CNC plans with an engineering firm, perhaps I can get them on disk. I have CAD but they did in 5 min what I was trying to do for days.:lol:

Now, you just have to show me the best way to make a large scale acrylic oven and I'll be set! (no more Keltech)

Brian,
If you go to the yearly woodworkers show up in seattle you can pick up Amana bits for about 1/3 the cost that they are normally.

I guess if you cut slow enough a dremel may do the job. Even with drilling since your really not drilling your just pecking at the material. Personally I MUST to have more horsepower.

Don