21 replies to this topic

[Michael_Molnar]

Before I took a sabbatical early this year I was asked to show some photos of the cabinet housing my CNC. Here they are.

The cabinet is made out of MDF sheets. There are only six screws holding this together.



The panel corners are built up by gluing MDF strips to form mated slat corners. MDF is great for containing noise, but I added white ceiling panels to the interior which helps even more.



Air is pulled across the work from the five left vent holes.



Wood chips and dust are drawn into the large vacuum port seen behind the gantry in the photo.



The front door is lifted into place and mates with the corner slats. The window is very useful to check on the CNC.



The aluminum bar running across the from door stops the door panel buckling inwards when the vacuum is on.
The rubber strip above the door protects my bare bald head from striking the cabinet roof edge when the door is off.

[James Ansara]

Very interesting. Do you have any pics. of work done with this machine? What parts do you intend to make with it?

James

[Stonehedge]

Michael, what software are you using with this CNC?

[Anders Buen]

Noise insulation 101: http://m.youtube.com...h?v=TmAX6zqw4wc

[Wm. Johnston]

For reducing the noise from my cnc machine I built a large enclosure, similar to Molnar's, from 3/4" thick plywood. That helped reduce the noise a lot. Then, since I had some plywood leftover, I attached rectangular plywood stiffeners to the box which also helped. I thought about adding foam inside the box too but decided that it would collect too much sawdust. Now the CNC and router are more than quiet enough, the problem is that my dust collector makes much more noise than the router. However it's less noisy than the nieghbor's washing machine so I call it good enough. I live in a duplex so reducing the noise to a reasonable level had to be done.

[Johnmasters]

My machine has travel of about 22", 32", 4" in x,y,z. X is a moving table. The rails are ground steel rods with linear bearings. I was concerned with the heavy z-carriage loading the Y rails, so above and out of sight is a traveling linear bearing on a 1" rod. This has a double pulley block and tackle to hold up the z carriage. There is a counter weight a few feet to the right. When the z carriage is not mounted on the rails, the balance is neutral. The X rails have a support in the center. Because these are 48" long, the center support limits X travel to the 22". It was designed to make cellos (If I ever get the ambition.)

Dust collection is by a collar that goes around the work support (adjustable 3/4" x 12" x 18" jig plate). Over this is the other device fixed as the collar slides under it. The router works through a slot, and there is a 2" vacuum hose attached to the top. Most of the debris is taken into the vacuum. One problem is that the exhaust of the router blows cuttings around a bit. But all lands on the machine table, or on the floor nearby. A broom is sufficient to take care of the floor.

[Johnmasters]

The cost of the CNC above was about $2500 plus some duplicate parts I bought as experiments. That does not include all the parts from two pantographs.

The 1" rails and bearings were originally in a pantograph. In the background, one can see a larger pantograph with 48"x1" rails. This was never finished, but I had nearly all the aluminum plate needed for the CNC from these two machines. A bit more aluminum was bought at scrap prices from a local metals junkyard.



Two 1" rails went into the CNC proper, and the third one is attached to the ceiling to carry the traveling pulley system that holds up the z carriage.

[Michael_Molnar]

Very interesting. Do you have any pics. of work done with this machine? What parts do you intend to make with it?

James

I make bellies (including ff's and purfling channel), backs, garland forms, scrolls, and even fingerboards.

I'll get around to taking some photos.

Stay Tuned.
Mike

[Michael_Molnar]

Michael, what software are you using with this CNC?

I use MACH 3 by ArtSoft USA for controlling the CNC. I use an old version 21 of BobCAD for drawing and generating G-Code. (I write some G-code subroutines by hand.)

[Michael_Molnar]

For reducing the noise from my cnc machine I built a large enclosure, similar to Molnar's, from 3/4" thick plywood. That helped reduce the noise a lot. Then, since I had some plywood leftover, I attached rectangular plywood stiffeners to the box which also helped. I thought about adding foam inside the box too but decided that it would collect too much sawdust. Now the CNC and router are more than quiet enough, the problem is that my dust collector makes much more noise than the router. However it's less noisy than the nieghbor's washing machine so I call it good enough. I live in a duplex so reducing the noise to a reasonable level had to be done.

Dust collectors are, indeed, noisy. My wife complains about that and not the CNC.

[Michael_Molnar]

Noise insulation 101:

Anders,

My Swedish is rusty. Could you please translate the captions? Looks very educational.

[Michael_Molnar]

The cost of the CNC above was about $2500 plus some duplicate parts I bought as experiments. That does not include all the parts from two pantographs.

...

Wow, John. You leave me in the dust.

I'm attaching a photo you and William should appreciate. The Y-axis bearing wore out a month ago. Instead of replacing it, I replaced the entire ball-screw assembly with a higher pitch thread and larger diameter. I felt this would get me even smoother curves which it did.

The photo shows the table removed so you can look at the y-axis assembly. I placed the old thin screw above the new one for comparison. Even though the new screw is not as long, I positioned it to get the same coverage over the table. (The gantry displacement let me do that.) My CNC really now zips out details even better than before.

[Johnmasters]

Wow, John. You leave me in the dust.

I thought you did not have any dust........... For anyone interested, Ebay has new stores now that will provide ballscrews and machine the ends and supply matching bearings. I got mine all new by looking at Ebay for several weeks. I had to make end bearings for two axes, with wooden blocks and thick aluminum angle in a sandwich. But it works smoothly.


Your X screw is very similar to my Y-screw, slightly smaller... But yes, I think the higher pitch and larger ball bearings is a good idea. My motors microstep 20 times for each 1/180 revolution. It duplicates to about a thou or two.

[Anders Buen]

Anders,

My Swedish is rusty. Could you please translate the captions? Looks very educational.

Michael,

Will do when I come home again to my wireless network.

Best,
Anders

[DBurns]

Dust collectors are, indeed, noisy. My wife complains about that and not the CNC.

Now the CNC and router are more than quiet enough, the problem is that my dust collector makes much more noise than the router. However it's less noisy than the nieghbor's washing machine so I call it good enough. I live in a duplex so reducing the noise to a reasonable level had to be done.

Picture from Muffler for shop vac


Picture from Project 2: Shop vacuum muffler box



Picture from Shop Vac Enclosure

[DBurns]

There is also this method which is less material.



Picture from Shop Vac Noise Reduction: Muffler and Panelling

[catnip]

Michael, Can your CNC machine read and record an existing violin plate and then carve a duplicate?
How do or did you enter the g-code for a violin plate?

Just curious.

[Anders Buen]

Anders,

My Swedish is rusty. Could you please translate the captions? Looks very educational.

Drill directly on the table - 79 dBA
Drill on vibration insulation - 79 dBA
Drill on vibration insulation and sound absoprtion - 76 dBA
Drill on vibration insulation and sound insulation - 71 dBA
Drill on vibration insulation, sound insulation and absorption - 61 dBA
As above but without the vibration insulation - 73dBA

[Michael_Molnar]

Thanks, Anders. I think some people forget how important it is to have an insulated base or support. That effect was very obvious in the film.

[Michael_Molnar]

Michael, Can your CNC machine read and record an existing violin plate and then carve a duplicate?
How do or did you enter the g-code for a violin plate?

Just curious.

There is a probe that measures and digitizes contours. It is mounted on a CNC machine in place of the tool end mill. I do not have that because I draw all my patterns from scratch. That is, I make a CAD drawing, say, of a top plate. Then I run an application (usually a CAM feature within the CAD program) that generates the plate contour G-code. The G-code file is then read by MACH 3 to control the CNC.

Hope that helps.