CNC-2116 - Up and running, sort of (2015-03-21)

[Yvan256]

Sorry for the lack of updates but this whole project is driving me nuts, in a good way. People who have a CNC machine probably know what I mean. 

I've done a few tests on my old Roland MDX-3 and found that it can cut MDF pretty easily but I have to go extremely slowly and with extremely thin cuts. We're talking about 0.005mm deep cuts at something around 30 cm per minute. Doing a 20cm hole in 3/8" MDF takes around 15 to 30 minutes... I forgot to time it so let's round the value to "forever".

The reason it's so painfully slow is because this machine wasn't designed for such hard materials and the spindle motor is barely up to the task. Using a 3.175mm end mill surely doesn't help but it's all I could find locally.

I still don't know how to use Mach3 or LinuxCNC but since the MDX-3 is basically a printer that you send text files to, I did the test cuts with a PHP program I wrote. I plan on making the whole thing available as a "dirt simple 2D" program. I'll try to have it able to export both g-code as well as Roland's own format. I'm also writing a "2D Roland Web Simulator" to have a top-view of paths for 2D-only Roland Modela files. It's great for debugging.

Seeing the results with such a weak spindle, however, has led me to rethink my bigger machine. The first version will use my Dremel 395, I already bought the bits #115 and #650 for resurfacing and milling, respectively. The planned upgrade is to switch to a Black & Decker RTX.

Since both the Dremel 395 and the Black & Decker RTX are extremely lightweight, the whole CNC will not require to be built like a tank, helping keep its weight down and helping with the portability factor. Ideally I'm trying to have the whole thing designed as an oversized briefcase so it's easier to carry around.

Given all this new information, the goal is again to have a milling area of 20x24x1 inches, the shorter Z axis should make it easier to keep it strong and as flat as possible to keep it "briefcase-like", with removable Dremel/RTX. Yes I know, a 24x28x8 inches briefcase is going to be huge...

Attached are test cuts done on a variety of materials such as old membership cards, hardboard and recycled plastic containers. As you can see from the photos, some tests went better than others. 

But at least, I'm having fun! 


2012-12-17-4.jpg is a NEMA 17 motor mount gone terribly wrong.

[TopJimmyCooks]

subscribe 

[Yvan256]

The MDX-3 was busy yesterday after my last post, cutting a test part out of 3/8" (~10mm) MDF.

The motor was taken from an old 5 1/4" floppy drive.

[tightwad]

I love your progress and I am working on re-working my mini-cnc machine.  It has never had the accuracy I wanted and the Z axis had play in it which wrecked havok cutting anything more than foam.  I needed to see various bearing options.  I found great prices on the 608ZZ bearings on ebay...I think I paid about $0.50 each for the ones I bought in the past.

[Yvan256]

Yesterday I noticed that the horizontal cuts were not at 90 degrees. The MDX-3 had some slack in the horizontal axis assembly so I had to disassemble part of it just to access the bolt that had gotten loose. Really bad design as far as maintenance is concerned.

After tightening the bolt and putting it all back again the results were much better. I have not measured it but at least just looking at it you can't tell if the edges are straight or not. A great improvement!

I asked the neighbors below if the noise of the machine was annoying and their reply was "what machine?" I told them that if it ever was a problem to simply come and tell me. The fact that the machine is sitting on five layers of oversized bubble wrap sheets seems to prevent the vibrations from reaching the table it's on.

Since I can run the machine all day from my apartment, I plan on making the new bigger machine completely with the MDX-3 using smaller plates that bolt together. The bigger machine, once assembled, will be able to cut continuous replacement panels for itself if needed. The MDX-3 can only cut parts about 150x100mm, so that's quite a challenge indeed. The more I design and build, the more I'll see if it's possible. The number of panels will be high to say the least.

So this morning I started to design my new machine, starting with the Dremel 395 mount. I plan on designing and cutting the machine from the inside-out, going from the tool holder to the Z axis (top/bottom), then the X axis (left/right) followed by the Y axis (back/front).

The photos below are the first version of the bottom Dremel mount holder but I will have to cut it again. The two small round holes were supposed to be for cross-dowels but these were made for 5/8" panels and I'm using 3/8" MDF because of the cutting height of my end mill bit.

I'm currently cutting bolt+washer+nut assembly test plates so that the next Dremel plates will have the proper assembly holes.

[Yvan256]

Here's the test for the bolt+washer+nut assembly method. The hole for the bolt was just a bit too small and the rectangular hole for the nut and washer just a bit too wide and tall. Still works fine but I'll fine-tune the measurements when cutting these holes on actual parts.

The MDX-3 is currently busy cutting the upper panel for the Dremel 395 mount, I'll post an update in the next few hours.

[Yvan256]

Here is more pictures of the Dremel 395 mount.

The first image is my web-based "design" software, currently written in PHP and HTML5 (using Canvas), showing the part to be cut. The lines are extra-wide because they represent the cutting diameter of the end mill (1/8 inch or 3.175mm). The light grey line represents the cutting area of the machine.

The other photos are the MDX-3 about one minute before it finished cutting the plate. I still need to get a proper cutting plate with rails and clamps.

The last three photos show the Dremel inside the plate and a small cut I had to do because I incorrectly measured the diameter of the body. Still some mistakes to correct so I'll be re-cutting these two plates tomorrow with the required corrections as well as the back plate for them. In 24 hours I should have a proper Dremel 395 mount with mounting holes, ready to be attached to my yet-to-be-designed machine.

I don't mind re-cutting all the plates again because the CNC does all the work.   

It's really amazing to design something on the computer and holding the part in your hands a few minutes/hours later. It's kind of the reverse of "Tron", taking something from the digital world and bringing it to the real world.

[Yvan256]

Good thing I was still making new joints tests and the Dremel 395 mount was on hold, because yesterday my brother gave me this as a Christmas gift!   

The RTX is rated at 2 amps compared to the 1.15 amps of the Dremel 395. If you judge by the numbers it means it should be almost twice as powerful but from the torque alone you would think the RTX is almost three to four times better. It's also a lot quieter at the slower speeds, which is extremely good. And it's more or less the same weight so I won't need an over-engineered gantry to support it.

Step motors: check
Electronics to drive the step motors: check
Linear slides: check
End mill bits: check
Powerful and lightweight spindle: check!

[Yvan256]

After looking at a few dozen types of CNC joints, I choose the type with tabs because it allows the parts to align themselves in all three axes. A simple manual drilling in one part is required but centering is done by a CNC'ed hole in the other part in front. Kind of hard to mess it up. 

Can't wait to finish my CNC machine and start making actual arcade projects, I know it must be boring reading about all these changes after over a year since I started this thread.

Well, here's a few photos, feel free to leave replies, suggestions and ideas!

[crashwg]

That's pretty neat.  I'll have to remember that method for machine #2.

[Yvan256]

While designing the new CNC machine, I had to find a way to hold those LM8UU linear bearings for the Z-axis. The most compact way to mount them is parallel to the sheet material (MDF or otherwise) so I had to create something simple, compact and easy to mill. Easy for my current little CNC anyway. People with 3D printers make clamp-style holders but with flat sheet material you need to think differently.

I made a rectangular hole, 4mm deep, with four holes for cable ties. The bone-shaped rectangle is to make sure the inside corners are actually square without the diameter of the cutting tool.

The more I move the small plate by hand, the more I think those linear bearings are worthless. Instead of a smooth glide I feel some resistance. The skate bearings assembly feels a hundred times better by comparison. The size and weight difference between the two assemblies, however, is far from negligible. Using the LM8UU will allow me to build a very compact and lightweight Z-axis.

And since I'm starting with the Z-axis assembly anyway, I'll be able to decide if it's good enough once I have it working with a stepper motor and the RTX. Maybe with the stepper motor and the screw moving the plate it won't make much of a difference compared to the skate bearings. So many people use the LM8UU linear bearings with their 3D printers that they can't be that bad.

[Yvan256]

Since I can only cut panels 140x90mm with the MDX-3 (150x100mm minus the diameter of the tool all around the perimeter), the design of the bigger machine has to be made from a lot of small panels.

This is what I've come up with for the sides, to fit within the 140x90mm limits and to still get something bigger and yet sturdy enough for the bigger CNC. Twelve panels, 20 bolts, 20 nuts and 40 washers are required for each side. The material used will be 3/8" MDF since the MDX-3 seems to have no trouble cutting it, albeit slowly.

Am I the only one who thinks it kind of looks like a building with windows, from the game Rampage?

[nemesismachine]

If the cable ties ever start to loosen or eat into the MDF, you could always go with pillow block bearings. You can order them online, or a lot of tractor supply stores carry them. I used a few for a wheel polisher I made.

[TopJimmyCooks]

Wow - you're going to cut 10 pieces of MDF and ~20 bolts.  I can't help but think that four full sized pieces would give better, cheaper, more rigid results.  Do you have a friend with a tablesaw? 

It does look like a good solution to cutting pieces only with the smaller CNC.  I don't want to be super negative, but if you're working MDF, you have to have a way to cut larger pieces.  It comes 48 or 49" x 96 or 97". 

[CoryBee]

Love this build!

[mcseforsale]

Subscribed...

AJ

[Yvan256]

Wow - you're going to cut 10 pieces of MDF and ~20 bolts.  I can't help but think that four full sized pieces would give better, cheaper, more rigid results.  Do you have a friend with a tablesaw? 

It does look like a good solution to cutting pieces only with the smaller CNC.  I don't want to be super negative, but if you're working MDF, you have to have a way to cut larger pieces.  It comes 48 or 49" x 96 or 97".

I think the result will be at least as strong as a single piece of 5/8" MDF, if not more. Using the two small "tabs test" panels as a guide, I can tell you that it's extremely rigid. The goal is to prevent warping from side loads and I think it will be more than enough for that goal.

I will be able to use the finished machine to cut new parts for itself once it's assembled, to gain some space in the Y axis (curved sides). None of the people I know have a scrollsaw and I don't want to cut complex shapes by hand. This is why I'm building the CNC in the first place.

Also, the sides need holes for the motor, the rod, bearings, etc. All the people I know aren't equipped to drill half-depth round pockets so going with CNC'ed panels removes that problem.

The base and surface of the machine will be cut with a tablesaw (5/8" MDF) since it's only plain rectangles and I have someone who will help me cut a big sheet of 3/8" MDF into 140 small panels for my MDX-3... I just calculated that the pile of panels will be more than 1.3 meter high. 

My biggest problem at the moment is finding a place where I could buy a small 28x14cm piece of slatwall, all they have is 4x8 feet sheets. 

[tightwad]

at what linear speed and depth are you able to cut?  what kind of bit do you use?  How do you secure the piece to the table?

[Yvan256]

at what linear speed and depth are you able to cut?  what kind of bit do you use?  How do you secure the piece to the table?

Are you talking about the Roland MDX-3? The speed is set to "5" (I think it means 5 mm per second, although it seems faster than that to me). The cutting depth is 0.02mm.

The bit is a 1/8", 1-flute straight end mill (the website says 3/4" for the cutting length but it's wrong, it's around 1/2"). I could probably go faster or cut deeper on each pass with a 1/16" bit, but most places I find online don't have 1/16" bits with 1/4" shanks that can cut 1/2" deep. And the places that do have those bits sell them for 40$ or more, plus shipping, etc. It's not worth the cost.

I have a 1-slot slatwall MDF panel instead of the flat plastic sheet that comes with the MDX-3. To secure the piece I use bolts and big washers and the piece is held on two sides by the edge of the washers which are at about 45 degrees once they hold the piece. I'm trying to get a larger piece of slatwall and I plan on making better clamps to hold the panels in place.

Cutting the smallest panel in the side panel assembly shown above will probably take 2 to 3 hours, the bigger ones will probably take 5 to 6 hours. Doesn't really matter, I'm not in a hurry to complete it. I'm just happy to be able to use a small CNC to cut parts for my bigger CNC.

The machine I'm building will use a Black & Decker RTX with a Dremel #650 bit.

[Bender]

I'm just happy to be able to use a small CNC to cut parts for my bigger CNC.

  That my friend is how the robot apocalypse starts

I love it!

[Yvan256]

I'm just happy to be able to use a small CNC to cut parts for my bigger CNC.

  That my friend is how the robot apocalypse starts

I love it!

Nah, we're safe, I won't let the bigger CNC machine cut another even bigger CNC machine. 

[Yvan256]

Yesterday I bought a 3/8 inch thick, 49x97 inches MDF panel and cut it into smaller panels that can fit inside the Roland MDX-3. I ended up with 120 panels of 17x11cm and 40 smaller panels roughly 9~10x11cm.

Here's a photo of the piles of panels next to the Roland MDX-3 cutting the very first panel of the bigger CNC machine, sitting on five layers of big bubblewrap sheets to eliminate the vibration. The old IBM ThinkPad 760XL is sitting on top of the three piles of 17x11cm panels.

I'm still making the cutting files manually in Google Sketchup by measuring the coordinates of the tool and typing them inside my custom MDX program made in PHP. It's slow but at least there's no costly software involved.

The second photo is an attempt of taking a close-up of the tool cutting one of the holes in the panel. I think I'll need to tape a flashlight on my Nintendo DSi.

edit: the third photo shows cutting progress two hours later.

edit: the fourth photo shows the finished panel four hours and twenty minutes later. Did I mention patience was required to cut MDF with the MDX-3? 

[kahlid74]

I like where you are going so far.  I too am building a CNC machine but I decided with a 4x6 cutting area and a mobile base that folds up so the machine can be moved around.

Keep up the good work!

[Yvan256]

I like where you are going so far.  I too am building a CNC machine but I decided with a 4x6 cutting area and a mobile base that folds up so the machine can be moved around.

Keep up the good work!

Thanks!

Do you mean 4x6 cm, 4x6 inches or 4x6 feet?

I like the folding/mobile idea, do you have a thread for your build?

Update on my build: the MDX-3 is currently busing cutting the second panel of the bigger CNC machine. Same as the first one above except with two holes for bolts.

[kahlid74]

I like where you are going so far.  I too am building a CNC machine but I decided with a 4x6 cutting area and a mobile base that folds up so the machine can be moved around.

Keep up the good work!

Thanks!

Do you mean 4x6 cm, 4x6 inches or 4x6 feet?

I like the folding/mobile idea, do you have a thread for your build?

Update on my build: the MDX-3 is currently busing cutting the second panel of the bigger CNC machine. Same as the first one above except with two holes for bolts.

No thread yet, I'm procuring all of the parts now.  It's a 5 feet by 6.5 feet totaling a cutting area of 4 feet by 6 feet.  I wanted to be able to mill a side of a regular arcade cabinet or as close to the standard size as possible while still being mobile.  The base is 11ga steel 2" square tubing welded together.  There are two cross beams that will stabilize the whole getup.

The design I'm using is on Joe's CNC board which you have to pay to join.  Here's a picture of the guy's machine I'm modeling mine after:
It's Dkohfeld's CNC machine and he is actually a frequent of these boards as well including Mountain, whose CNC machine is the stuff of legend.

[Yvan256]

No thread yet, I'm procuring all of the parts now.  It's a 5 feet by 6.5 feet totaling a cutting area of 4 feet by 6 feet.  I wanted to be able to mill a side of a regular arcade cabinet or as close to the standard size as possible while still being mobile.  The base is 11ga steel 2" square tubing welded together.  There are two cross beams that will stabilize the whole getup.

The design I'm using is on Joe's CNC board which you have to pay to join.  Here's a picture of the guy's machine I'm modeling mine after:
It's Dkohfeld's CNC machine and he is actually a frequent of these boards as well including Mountain, whose CNC machine is the stuff of legend.

That's a pretty neat idea to have it fold that way, takes a lot less room when not in use. 

Mine is going to be big enough to make desktop cabinets yet small enough to carry by myself. It won't be lightweight but not heavy enough that I can't carry it and get it in the back seat of my car.

[Yvan256]

Yesterday's panel now has a slightly modified clone... the holes are for #10-24 bolts.

A third clone should be completed in a little more than four hours.

You can see the precision in the second photo, with the two panels inserted into one of the test assembly plates. I can't even slide a thin sheet of paper vertically between the two parts. 

edit: it's triplets!

[Yvan256]

I needed to modify the plate holder and make new clamps to hold the bigger 17x11 cm panels. Here's a photo in case someone else with a Roland MDX-3 needs to see how I've done it. There's a part bolted at the bottom that holds the panel in place since I'm leaving the whole holder in the machine at all times. Two bolts+washers+MDF spacer assemblies are on the sides of the panel to be cut, I simply tighten those to hold the panel in place against the holder.

Back on topic, the MDX-3 is now cutting the plate that will hold the X-axis motor (Sketchup screenshot shown below, second image). It should be ready by the end of the day tomorrow. I'll update with a new photo once it's completed, assembled with the two smaller plates shown above as well as the motor itself with the coupler and the threaded rod, as seen in the third image.

After three days of cutting I'll be happy to see some progress!

edit: even if I have to go extremely slowly to cut MDF with the MDX-3, I'm beginning to understand the feeling of owning a CNC.   

edit2: I really under-estimated the cutting time, so I had to stop it for the night. The CNC always returns at the same position when starting, so I'll just send it another file to cut the outer edge. Attached is a photo of the progress so far.

edit3: I added two bolt holes for another plate in my design, so I cut those two extra holes before cutting the outline, which is what the MDX-3 is doing right now. It was already half-done so I would expect to have the plate ready before lunch, in roughly an hour and a half.

[Yvan256]

Talk about slow... it takes about 5 hours and 30 minutes to cut the outer perimeter of a big 14x9 cm panel. 

I don't want to push the MDX-3 to cut faster and deeper, however, because of the noise and the risk of breaking the machine.

It's currently busy cutting a 4th small panel with tabs as shown above, but for the moment here's two photos of the completed panel that holds the stepper motor for the X axis of the big CNC. I still need to drill holes into the small panels with tabs to be able to bolt those panels together but that will come later once more panels are ready for assembly.

The first photo is from the "outside" and the second photo is from the "inside" with a home-made fuel line coupler.

[Yvan256]

I started building the Z-axis today, the MDX-3 is busy cutting the outline of the top panel, right below the motor, shown in the assembly below. It should be done cutting the panel in less than two hours. The motor is a NEMA17 from an old floppy drive. The sticker says 1.8 degree but manually I count 50 steps. I'll need to test it to know more, once this whole assembly is completed.

The first two images are the 3D models of the complete Z-axis assembly, apart from the missing bearing for the threaded rod in the bottom plate and the plate that will hold the RTX.

The third image shows the MDX-3 cutting the top plate of this assembly.

I just calculated the cutting speed at roughly 3.4 mm per second.   

edit: the plate is cut. The fourth and fifth images show the finished plate, and the plate upside-down with the motor, bolts and 8 mm rods. I should be able to cut the bottom plate tomorrow.

[Yvan256]

The bottom plate of the Z axis assembly is done. There's a notch in the corner because I'm still not using milling tabs to hold the part when cutting and I was away when the MDX-3 was done cutting. 

You can see the top and bottom panel in the photos below. The bottom plate has half-depth holes for the 8 mm rods just so they won't fall down when the machine is working, although they would probably hold in place by friction alone. I didn't take the picture with the rods in place because I need to cut them to the proper length.

I'm still missing the three vertical panels that will go between them, I should be able to start cutting those tomorrow.

The MDX-3 is currently busy cutting a long panel with tabs for the X-axis assembly, I'm hoping it will be done before bedtime...

[Yvan256]

One of the four long panels with tabs is now done, but I was getting tired of looking at this MDF-colored assembly... boring. 

Since the little Hang-On Shop Vac is red and black and the Black & Decker RTX is also red and black, I started painting the panels. I've decided the panels with their face visible from the side would be red and the panels with their face visible from the front, top or bottom would be black.

I've also decided to paint the side of the parts the same color as the panel itself instead of the face of the joined panel to get an interesting effect, to show off the assembly method of the whole machine instead of trying to hide it (i.e. the tabs will show up in black through the panels).

And here are the results so far. It looks better in real life than in those photos, I guess the close-ups really magnify the defects and the texture of the MDF.

For reference, the paint used is Crafter's Acrylic from DecoArt, Bright Red DCA22 and Black DCA47. I'll be applying two or three coats of gloss varnish DS13 after two coats of paint. In those photos, the red panel has two coats of paint and the black panels only one.

Photo 1 shows the left side of the X-axis assembly so far, upside-down to be able to take the picture.

Photos 1, 2 and 3 shows the "interesting effect" I was talking about, showing off the assembly method (tabs are in black) instead of trying to hide it by having all the side red.

Photos 3 and 4 show the bolt+washers+nut assembly method discussed in a previous post, from both sides. Since the MDX-3 can only cut perpendicular to the panel itself, I need to carefully drill the holes for the bolts, manually.

Photo 5 shows, once again, a close-up of the home-made fuel line coupler that attaches the motor shaft to the threaded rod.

[Yvan256]

Some parts require manual drilling on the edge of the panel. Messing up one of those hole would mean re-cutting a part and wasting another 4 to 12 hours of CNC time depending on the size of the panel. Some panels have zero holes to drill manually but others may have four or more, that increases the chance of messing up when doing things manually.

So right now the MDX-3 is currently busy cutting a drilling jig to make sure all my manual drilling is spot-on, every time. First image is the design in Sketchup, with the four panels to cut in the back, the complete drilling jig in the middle and the jig without the top panel on the right to see how it will lock in place for the panels with tabs. The big round hole in the middle of the two top panels is for a drill bushing insert (Lee Valley Tools Item 25K6220). The first photo is the MDX-3 cutting those four panels.

edit: the MDX-3 is done cutting all the holes in the four panels and is now starting to cut the outlines.


Progress on the Z-axis assembly. I still need to cut the back panel and the panel that will actually move the RTX up and down. The second photo shows what it looks like so far with the panels held in place by gravity, until my drilling jig is complete. I still need to apply varnish for the final touch.

[Yvan256]

Just to recap things since I've joined BYOAC, I'm building a CNC machine to be able to cut parts for my arcade projects.

But I need to apologize to everyone who reads my threads.

My MVS-99-6 and ColeCade projects have been on hold practically forever.

My CNC256 project is taking forever to properly start and my perfectionism means I keep starting over. Since these are personal projects I can allow myself to aim for perfection. There is no set deadline, no launch date to meet and no budget to speak of except my own spare time.

Having the MDX-3 to cut parts, however, is helping me to concentrate on the designs in Sketchup and have perfectly cut parts on my desk a few many hours later. This was the missing tool in my process.

But... the MDX-3 is old and was probably never designed to cut MDF with a 1/8" end mill bit, so the panels are taking forever to cut. What should be a 15-20 minutes job is taking 6-8 hours.

So I decided to make "CNC64", a smaller machine with the same cutting envelope as the MDX-3 so that I don't have to trash the 100+ small MDF panels that I have.

And since CNC64 will only be built using panels as big as it can cut, I guess it could become the "reprap" of the CNC world. I guess I'll build a second CNC64 with the first one just to prove the concept and to see how long it takes for it to "replicate" itself.

The smaller CNC64 will require fewer panels (current count is only 37 CNC-cut panel) and a simple rectangular table saw/hand cut base with not much precision required and thus will be ready in a much shorter time than CNC256. Without counting the base and without optimization of cutting multiple smaller parts on a single 6x4" panel, the MDF cost is currently around 8$CAD for one CNC64 machine. That's without counting the machining or design time, however.

It also means I can practice some design ideas on a smaller scale and in the end I will have two faster machines to cut more panels at the same time, if needed. At the very least it will give me a more portable machine for when I only need to cut smaller panels.


Back to the topic of my previous post, the two side panels of the drilling jig would have required a drilling jig to make precise holes. The first hole I drilled on the side wasn't exactly centered and the second hole just split open the MDF because I tried to drill too fast. 

I also messed up the two side panels of the Z-axis assembly, once assembled the whole assembly wasn't even level. Not a good start for a CNC machine. 

So, from all this came a new joint method. The method I showed earlier is based on the joint method used by the first version of diylilcnc but since 3/8" MDF is a much thicker material I decided to combine the tab and the bolt coupling in a single, compact part with no post-machining drilling to do. Take the panels, join them, bolt them. The only way I can mess that up is by doing a mistake in the Sketchup design.

In the five photos below you can see that each joint requires six parts:

• A tab with a channel for the bolt and a hole for the nut and washer
• A hole for the tab and a hole for the bolt
• A bolt
• A nut
• Two washers (to make sure that the MDF doesn't get twisted and ripped apart while tightening the bolt)

The channel for the bolt is not cut all the way through, so there is an "inside" and "outside" for the panel. I'm doing it this way for two reasons:

• It looks cleaner from outside
• It makes a stronger joint because there is more material for the washer and nut to sit on.

For reference, the small test assembly shown in the last photo is only 30 mm wide (left to right), 20 mm deep (front to back) and 30 mm tall (bottom to top, without the bolt head). The tab itself is 15 mm wide and 3 mm tall but I'm switching to 5 mm tall for the final parts for an even stronger joint. This means the tab inserts more or less 50% into the thickness of the other panel (I measured the thickness of the MDF a around 9.7 mm).

I'm calling this joint "100% CNC-Cut Compact Joint", or "100CNCCCJ" for short.

... okay, I need a better acronym, not to mention that it probably already exists and already has a name.

Hopefully, CNC64 won't take too long to build, then CNC256 and then I will finally be back to posting about arcade projects!

[mcseforsale]

Cool...a place for your nuts!

Love the build so far.

AJ

[Yvan256]

Thanks for the feedback, mcseforsale.


The MDX-3 is has been cutting the first panel of CNC64 for about two hours from an estimated cutting time of around three hours. I need twelve of those plates for CNC64, which means roughly 36 hours to cut these simple assembly plates. 

Now you see why I'm building CNC64!

edit: It took the MDX-3 about 2 hours and 28 minutes to cut this small plate (shorter than my 3 hours estimate), meaning twelve plates will take around 30 hours, so 27 hours and 30 minutes to go for the other eleven plates. The rounded corners certainly didn't help the cutting time but I was getting tired of making rectangle plates. Nothing says "CNC" like rounded corners! CNC64 completion countdown: 36 panels to go.

edit2: here's a partial preview of CNC64 in Sketchup. You can see where those 12 plates go.

[Yvan256]

I forgot to mention that I modified the RTX by following these instructions (thanks cre8er!) because the speed dial was really hard to turn, I couldn't imagine turning that dial once the RTX would be in place in the CNC mount. After that small and easy modification, the speed dial is now very easy to turn. 


I now have four panels ready to build CNC64, those are small panels used to join other panels end-to-end. The holes are a bit smaller than the bolts to allow the threads to run into the MDF and prevent any movement once assembled. I had to dump the first plate with the rounded corners because the holes were 0.5 mm too big in diameter.

I switched back to rectangular plates to save about 10 minutes of cutting time per plate and because the MDX-3 was doing weird noises while cutting the rounded corners. I'll let CNC64 make rounded corners when cutting the parts for its clone.

I promise the next few parts will be more interesting to look at.

That's 4 plates done out of... 42.

[Yvan256]

(cheesy TV announcer voice) "Tired of looking at small rectangles with round holes? How about looking at a longer rectangle with holes and tabs?"

As seen in the Sketchup render in a previous post, this is one of the two side panels.

The first image is the 3D render in Sketchup, the second image is the 2D render in Sketchup with the milling bit circles all around the part to calculate the polygon outline coordinates. The third image shows the cutting outline path in my own web-based "CAD" program, if you can even call it that. The photo shows the MDX-3 cutting the panel.

edit: the last two photos show the beginning of the assembly. Don't mind the small part at the front of the panel in the 5th photo, it's just my test plate for the new joint I talked about. The MDX-3 is busy cutting the same panel again for the right side of CNC64. The next two panels to be cut will be either the other half of the sides or the front of the machine. Five plates done, 40+ to go. I'm also going to need longer bolts for assembling these small plates...

edit 2: the very last photo shows the six panels that are ready and assembled and the two sides roughly at the correct distance from each other if all parts were there. I also need to paint the other side of the long panels as well as the edges of all six panels. I know it's not an arcade cabinet, but I just can't wait to add more panels for the base! 

[Yvan256]

I'm not sure people still read this thread judging by the lack of comments, but then again there's not much to comment on. I apologize for those boring updates. 

The MDX-3 is cutting the first front corner panel that will connect with the long panel from yesterday.

edit: wow, 6400 views 

edit2: added a photo of the final part, the MDX-3 is busy cutting another for the other side.

edit3: another photo, the front left corner of the first CNC64 is complete! The other Sketchup screen capture shows a corner that will be added to the first CNC64 clone for added strength. I made this update while the second long panel was still being cut yesterday, we'll see if I need to cut them again to add these corners once it's complete.

[Drnick]

Don't apologise for Boring updates, At least you keep giving us updates.  Gonna be fun when you finally have 2 cnc 64s busy making up the big brother cnc256.

And on top of that, reading this is still better then staring at ping traces trying to work out why we keep losing connection to one of our DNS Servers.    I am sure that the problem is in the routing