CNC Routers - who would be interested....

[Chris DeHut]

Greetings again fellow woodworkers.

During the last couple of years we have been designing and refining a shop made CNC router. This machine is just now starting to appear in the magazine as we have it running pretty good. Our original goal with the CNC router was to present a "How to build a CNC router" story series in the magazine.

Here are its current specs...

Computer required - Pentium running at 1 ghz with Windows XP
Power supply to run machine 110 Volt
Cost to construct (excluding, router, computer, and base cabinet) $1700.00
Travels - 5 inches Z axis, 28" Y axis, 38" X axis
Speeds, 150 Inches per minute maximum
Recommended router - 1 1/2 Hp to 3 Hp

While commercial routers are generally priced at the bottom end around $6,000.00, don't think that this machine is a toy by comparision. The machine performs equally with larger industrial machines, jut a little bit slower on top end cutting speeds. The price of $1,700.00 is still a rough estimate as there are changes planned, some of which will increase cost, some which will reduce costs.

If you don't mind, could you offer some: opinions, thoughts, suggestions, or any other comments about CNC routers. Of particular importance, I am wondering if there is enough appeal in the home woodworker market to justify running such an article in the magazine.

Thanks for your time and I look forward to hearing your comments.

Chris DeHut

[Kurt Aebi]

Chris,

It's a good idea.

I think it would really be better; though, if the computer could be of a lesser grade. That way, maybe we could use up some of the old 486's and Pentium 75's that are still working, but no longer have viable uses. This would be right up the alley of a use for one of the Old Clunkers.

[Keith Christopher]

I would love to see this. The shop made tools are so awesome!

[Bob Aquino]

Sounds interesting. Curious about the software for it. Is it commercial, open source or yet to be developed? What type of 3d file does it take to run? How about the mechanism to move the router in all axis; where does this come from?

As for the cost, I dont think that would be an issue. Lots of people have been spending past 2k on bandsaws and more than that on euro combo equipment. Probably would be a boon to small shops that do commerical work.

[Chris DeHut]

Actually, the overall design would allow for the use of either a DOS based computer or a Windows Xp computer. The software we are currently testing is available in several different versions to accomodate various levels of computer power.

In the story, we will focus on the "current' version of whichever software package we select but also point out other options. Also, CNC machines do require a substantial amount of computing power, so those old 486s probably are not the best choice for good performance.

Chris

Chris,

It's a good idea.

I think it would really be better; though, if the computer could be of a lesser grade. That way, maybe we could use up some of the old 486's and Pentium 75's that are still working, but no longer have viable uses. This would be right up the alley of a use for one of the Old Clunkers.

[Chris DeHut]

I too love shop made tools - this was a major driving force to create this machine.

Chris

I would love to see this. The shop made tools are so awesome!

[Chris DeHut]

Yes, the software is "Off the shelf" and is priced very resonable for the features it offers. In fact, if you are familar with CNC, then you are probably aware of FANUC controls. The software we are currently testing rivals many of the features of that control - in some regards, exceeds the features.

The control software allows for the direct import of DXF files. However, it will not work directly with 3D DXF files (I beleive). Doing 3D work generally requires both CAD and CAM software to generate the 3D geometry needed to run CNC machines.

For motion control we are using ball screws and stepper motors. Servo motors are just too expensive for this application. We are currently testing the second driver board and are very impressed with it, very smooth motion, high speed, good power range, and low cost. The drawback to this particular board though is that it has to be soldered - it only took about an hour to solder it up though as there are a minimum of components.

I agree on the cost issue. Comparatively, a good table saw is about in this price range, many band saws are, and heck, I think there are some folks that have spent more than that on their router table setups.

Chris

Sounds interesting. Curious about the software for it. Is it commercial, open source or yet to be developed? What type of 3d file does it take to run? How about the mechanism to move the router in all axis; where does this come from?

As for the cost, I dont think that would be an issue. Lots of people have been spending past 2k on bandsaws and more than that on euro combo equipment. Probably would be a boon to small shops that do commerical work.

[JayStPeter]

I'm interested. I have been thinking about doing that myself. I'd be interested to see what pitfalls you've overcome along the way.

What kind of accuracy to you get with the stepper motors?

I hate to tell you all this, but 1G machines are well on their way to being clunkers. Most companies are now replacing anything less. In another year or so ... Anyway, figure you could add the 1G computer to the $1700 CNC machine for about $150 used. Sheesh, just throw away the 486s already.

Jay

[Kurt Aebi]

Jay,

Just trying to find a use for these rather than becoming some more Toxic waste in an already over toxic wasted environment - OKAY??

Oh Yea - I Still have a couple of Simpson Analog Voltmeters as well. The response time of the needle has saved my butt when troubleshooitng some New >1GHz computer systems that a New Super Powered DVM would have missed due to it's limited Sample Rate. Don't disregard older technology as passe, as it may be even better than some of today's!


SORRY for trying to be Frugle and environmentally concious! Sheesh!
__________________________________________________ _______________

Sorry for responding in this manner, but the tone of the thread above is getting to happen more & more often and rubs me th ewrong way. Opinions are great and should be heard, bu tth etone - please think about that.

Chris - Thank you for answering my computer use question - it was clear, concise and I thank you very much for taking the time to respond. I needed no more explaination than that.

Again, I appoogize for going off - topic and messing up this very interesting thread. I will try to have broader shoulders next time.


Thanks,

Kurt

[Jackie Outten]

Gentlemen,

Let's stick to the topic at hand please.

Jackie

[George Grubaugh]

I would be more interested in a manual X,Y,Z setup that's accurate & built with parts that could be readily ordered & would max out at $500.00.

Maybe that would only get an X,Y setup if it used bearings & steel rods?

Just my $.02

[Dean Baumgartner]

I would be more interested in a manual X,Y,Z setup that's accurate & built with parts that could be readily ordered & would max out at $500.00.

Maybe that would only get an X,Y setup if it used bearings & steel rods?

Just my $.02

George, do a google for the copy carver. You need to have a full scale pattern but other than that it sould work well. I ordered the plans, just haven't gotten around to building the thing yet.

Dean

[Mike Kelly]

Chris, I have what I consider is a shop built CNC machine which is rather crude by today's standards, but it works for what I use it for. I can do small signs, plaques for things I make, and board games that I can put people's names on.
I use the original Compaq Portable with an 8086 processor, a full 64 MB of RAM and a "huge" 10 MB hard disk. The driver for this is an old HPGL plotter, "Sweet P", made by Enter Computer. I had to slow down the pen-up/down command to allow for raising and lowering the overkill 3 1/4 HP router which is driven by an air solenoid controlled by a relay driven from the logic on the board. This was an overarm pin router made by Porta-Nails in Wilmington, NC. I had a 6" aluminum riser block added to the arm so the X-Y Table would fit under it. The table is made with Thompson ball screws and slides with homemade end plates and stepper mounting things. The table is an aluminum plate drilled for vacuum so a vacuum chuck can be used for hold down. A vacuum motor from Edmonds Scientific gives adequate suck for most objects. The X-Y travel is about 16" x 16" and fixed Z axis movement has about 6 inches of adjustability. It is under computer control, but just up or down. It has 32,000 x 32,000 matrix for X-Y travel so accuracy is not an issue.
I had a catastrophy happen a couple of years ago. My original hard drive froze finally which shut me down. I had been letting the computer warm up and then drop the front of the computer about 3 inches, reboot and it would wind up and work. This worked for about 2 years. Couldn't find replacement hard drive for sure, so I looked on EBay and found several old Compaq's in very good condition and working so I bid on them. Natcherally I won all of them! None of them cost over $10 or $15, but the $30 shipping on each one ate my lunch. I have a closet full of spares now!

[Chris DeHut]

Most of the pitfalls so far have been along the lines of buying/trying products for the router that simply don't perform well. As I have an extensive background in CNC machine tools, my expectations are pretty high regarding performance and accuracy. In other words, if I could make this into a CNC machining center, I would, but that won't happen in the budget range we are aiming for.

As for accuracy with steppers, that is a small part of the accuracy equation. As configured right now, the steppers are giving me a theoretical linear accuracy (based on motor rotation and ball screw) of .00025". However, as you may suspect, actually accuracy and repeatability are not that good. The ball nuts for example are not pre-loaded so they have a little backlash. In testing last week, the machine was moving within an accuracy of .0035 and a repeatability of .001" over 38 inches of X axis travel. So far so good on accuracy and repeatability.


As for those old computers, I know what you mean but it sure is hard to throw them away :-)

Chris

I'm interested. I have been thinking about doing that myself. I'd be interested to see what pitfalls you've overcome along the way.

What kind of accuracy to you get with the stepper motors?

I hate to tell you all this, but 1G machines are well on their way to being clunkers. Most companies are now replacing anything less. In another year or so ... Anyway, figure you could add the 1G computer to the $1700 CNC machine for about $150 used. Sheesh, just throw away the 486s already.

Jay

[Chris DeHut]

That is another type of machine I have been considering. With machines like the "Multi router" costing even more than your price point, I believe there is a good market for a shop build "Router/milling machine".

Keep an eye on our website to see if that develops.

Chris

I would be more interested in a manual X,Y,Z setup that's accurate & built with parts that could be readily ordered & would max out at $500.00.

Maybe that would only get an X,Y setup if it used bearings & steel rods?

Just my $.02