A MDF (Medium Density fiberboard) CNC router

Construction photos, video and log: NEW -  09/30/2006

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VIDEOS:

"First Movement video"

"First Cut video"

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Started build April 2005.  Completed build in January 2006

CNC Information log:

Software:

Building the CNC router is one thing. That's the easy (well not really) part! Buying and learning the software is another! Buying all the software will probably cost as much or much more than building the machine! First, you need some sort of CAD software. You can use a simple vector based graphics program to create the required dxf files.  I like using CorelDraw for this.  A full CAD program is also something to consider for creating more complex parts. I have a copy of BobCAD.  This program is OK, but has a steep learning curve. Once you have a part designed and the toolpaths created, you need to send it to a CAM program to create the g code. Now, BobCAD has this capability, but there are many others to choose from. I have demo copies of Sheetcam(2D) and Meshcam (3D). These both do a good job and the price for these is fairly cheap. Another program I like for creating "carvings" is VCarve and Photocarve .  Then you'll need software to actually interpret the g code. There are two program that I have been testing, TurboCNC and Mach2/3.  TurboCNC is a DOS based program so it can run on older hardware. Mach2/3 is a very nice Windows program. So, you can see that learning the software is also a large task not to mention learning the g code to control the router!

3-23-06

After some testing,  a problem with the long "Y" axis" has shown up. There is some shaking when the axis moves during fast rapids. It appears that some of the axis bearings are binding sometimes! I will be taking apart this axis to replace the four bearings on the leadscrew this weekend (3-25-06). Hopefully this will correct the problem.

I have been attempting to cut a pocket with three letters (CNC) raised (islands) in the pocket . After four attempts using "Turbocnc" software, I have decided that this software has problems! It does not have "constant velocity" on the arcs that are being cut. Since I don't have a speed controller on my spindle and the lack of constant velocity on Turbocnc, there has been burning on the wood from the slow transit  speed of the router bit. The solution is to buy Mach2 or Mach3 controller software. This software does have constant velocity on arcs. I have run the demo version and the results are pretty impressive compared to Turbocnc.  Turbocnc is OK for straight cuts, but is lacking on arcs. However, the price for Turbocnc is about a third of Mach2/3.  Mach3 will be my choice for controller software. Price is around $160 as of March 2006.

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3-25-06

I believe I have corrected the Y axis shaking problem. Readjusted the leadscrew bearings and tightened the nuts on the end of the leadscrew. Seems to rapid smooth now.

I was a little premature in pointing my finger at Turbocnc having a  problem with arcs. I was using the G2/G3 commands with "r" (radius). This does run very slow, however switching to absolute "i" and "j" commands on the G2/G3 speeds up the arc cutting considerably!  I've only "cut air" testing this. The real test will come when I cut some wood.

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4-06-06

 I'm still having bearing problems on the Y axis. I am in the process of replacing the two end bearings on the Y axis with better bearings. The current bearings have just too much end to end play. Almost 0.030! These bearings were purchased at the local hardware store. It's hard to cut a perfect circle when there is that much play! The new bearings (purchased off EBay) have virtually no play at all. However, the new bearings are smaller in diameter.  I have attached some picture showing the old and new bearings.

The old bearing is a "flange type" bearing. The new one has no flange.

The old bearing inner race is very loose. It has 0.030" play in it!

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5-29-06

I designed a bearing block that works like a charm. I used BobCad to design and produce the G code. Cut out eight of these blocks and then painted them blue. You can see them on the finished machine at the very bottom of this page. I used a "upcut spiral" bit to cut out these blocks

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6-16-06

I have now suspended all cutting with the CNC router until I can come up with a dust collection system to control the very fine dust created by this beast! Moving the machine outside and having a fan blow the dust away from me will work although the neighbors may complain about the noise. When the weather turns cold this fall, I'll need a dust collector for indoor use. I'll be spending my time this summer working on a dust collection system.

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9-22-06

I have been working on designing a dust collection system this Summer for the CNC Router. I am designing it after seeing one made my Beezer on the CNC Zone web site.  This thing does make a lot of dust! I have a working prototype. Just need to cut the final out of Lexan and UHMW plastic and order the lower brushes. I will be using 4" pipe and a 650CFM Jet dust collector to pickup most of the chips and dust that is created by this beast.

In the mean time I started to become interested in wooden clocks. After finding some wood clock plans on the net ( Gary's wooden clocks & Brian Law's  Thanks Brian for the dxf files!).  I decided that I would attempt to build one of these clocks. I downloaded the dxf files and cut out one of the gears as a test. You can see the gear here in the following three photos:

Click on a picture to enlarge it.

The gear is 7 inches in diameter 1/2 thick mdf and took about 20 minutes at 30ipm to cut. I used a 1/4 inch straight bit. Now I need to buy some 1/8 inch mdf and then start cutting (after the dust collector is finished of course!)

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9-30-06

Here are some pictures of my working prototype dust collection system. The router clamps and dust pickup head are made from MDF. The final working design will be made from UHMW plastic. I have cut one UHMW router clamp. I have added a chip separator to the dust collection system. It acts as a mini cyclone separator.  Works fairly well as most of the chips and larger dust particles will fall into the plastic waste can. Hardly any dust goes into the Jet dust collector! The dust pickup head will be attached to the router clamps via a 1/2" rod that will have set screws to tightened to the pickup head and router clamps. The pickup skirt is made from some flexible plastic that I purchased. The final design will have brushes.

Click on a picture to enlarge it

Build Photos:

Place your mouse pointer over a picture for a description and then click to enlarge.