04-24-2009
Well, the machine is working splendidly, so I decided it was about time to cut a new dust shoe for the bigger dust collector hose. To that end, I ordered up some half-inch thick acrylic online. It came in earlier this week, so today I clamped it down and cut out my new dust collector shoe.
Here it is, hot (literally) off the table. The paper is purely for protection from scratches.
Here is a view of the edge, after cutting. I am quite impressed with the quality of the cut. This was done with a 1/4 inch 2-flute up-spiral bit, running at about 22000 rpm, taking off 0.05 inches per pass.
Here is the shoe without the paper. It's very nice.
Now the bad news. After peeling off the paper, I got to looking at the iece and thinking that it did not look quite right. So I got out my calipers and measured the diameter of the inside holes. Low-and-behold, they're all half an inch too big! It turns out that I accidentally cut outside the circle in the plans, rather than inside.Thus, since the bit is 1/4 inch, the hole is 1/2 inch too big.
So, now I have to come up with a new piece of acrylic. So, unless I can find someone locally who has the sutff (unlikely), there goes $14 + S&H. Sigh. At least it cuts nicely.
04-17-2009
I have been using the machine for a while now and have added a few more upgrades.
I finally got and installed some IGUS e-chain to manage all the wires. So the white hinged arm is gone, as are the hanging cables on the side. You can also see a black pipe running vertically in the background. That goes to my dust-collector. Now I have to install some 3-inch flex hose to the cutting head. The hose off of my shop-vac just dosn't provide enough airflow.
I also added homing and limit switches. This is incredibly helpful for re-zeroing the machine, and allows for automatic squaring of the gantry, ensuring that the left and right motors for the Y axis are synchronized. I'll try to get some video posted here soon of it cutting something.
01-25-2009
I spent this afternoon designing and then build a dust shoe that will allow me to hook my shop vac up to the router.
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The plate is cut out of 3/4" particle board that I got out of the Home Depot scrap bin for $0.50. It took about 90 seconds to cut. The plastic is a piece of "Garage Door Weather Strip" that I cut the lower lip off of and then slit to make the little flaps. The rubber is held to the plate with staples for most of the perimiter, and the last quarter with velcro, allowing access to change bits. The whole plate is held to the router mount with a piece of 1/2" threaded rod so that the height can be adjusted with respect to the router.
I need to get a real dust collector to replace the shop vac, and when that happens, I will make a new plate out of clear acrylic so that I can see what's going on.
01-12-2009
I managed to get the MDF work surface installed and a hinged arm installed to help keep the cables under control.
I still intend to switch to the IGUS chain when I ge the chance, but this works for now. For the time being, the wires are just hanging off the right hand side of the Y axis.
And here is my first cut. It is the Roadrunner sampe file from Mach3 cut in a scrap of wood from an old entertainment center. It's a pretty simple thing, but it sure seems like a huge achievement. And here is video(5M) of the machine doing its thing.
01-10-2009
Well, two more days of working on the mill, and it's nearing completion.
All three axes are now mechanically complete and mobile. I have to come up with a wire management solution. I suspect it will be IGUS chain.
I went ahead and mounted the reconditioned router I purchaced. It is mounted to the Z axis via a mount from K2.
Video to come.
01-08-2009
Well, I went on vacation, but I am back now. There has been alot of progress, so this will be a pretty lengthy post.
While I was gone, the connectors I had ordered to wire up the motors arrived. I already had the cable I plan to use. They are 4 conductor, polarized, screw-together connectors. I bought 50 sets of one bulkhead-mount male and one cable-mount female on eBay. I should only need 8 sets for this project, but I'm sure I will find some use for the rest of them.
I spent the last two evenings working on this rat's nest of wires. The box contains all the control electronics for the mill. On the left is the paralell breakout board through which the controls arrive. The breakout board is sitting on top of the 36 volt power supply. To the lower-left is the back end of the emergency stop button.In the middle are the four motor KL-4030 controllers from Keling Technology. On the right are two bus-bars, which are connected to +5 volts and ground. On the far right is the cheapest power strip I could find at Home Depot at 8:30 last night. The whole assemblage is built into what used to be an Onyko stereo receiver, which had died, hence the random circuitry still inside the front (top of the picture).
The blue wires are for movement pulses, the yellow for direction. The black wires are all grounds. The red wires are all +36 volts. The small white wires are all +5 volts. The large multi-conductor cables go to the motor connection jacks on the box.
The documentation for this stuff is virtually non-existant, but through much reading of the Joe's 4x4 forum, I was able to figure it out eventually.
The next step was to wire up the motors. I soldered the male bulkhead connectors to the wires hanging out of the steppers, then mounted the motors to the machine. I make a short test cable to connect the male connector on the motor to the one on the control box for testing.
Then came the big moment. I flipped the switch. And nothing caught fire. It was a moment of rejoicing. My glee was somewhat tempered when nothing worked though. So I set about trying to figure out how to configure Mach3 to correctly drive the machine. It is pretty convoluted, but eventually I discovered got all the stuff in the "Ports and Pins" configuration page set up correctly.
And now... IT'S ALIVE!!!!!!!!!!!
Admittedly, only one axis is hooked up, and my table is a terrible mess, but it's something. I still have to complete the Z axis, and make the hookup cables for the motors, and mount the actual table surface and come up with a cover for the control box, etc... But it's getting there. I hope to have all three axes moving by the end of the weekend. We'll see if that actually happens.
12-14-2008
Another day of work, more progress.
I got the X axis carriage built and installed, as well as getting the X axis beam propertly mounted to the Y axis carriages. That proved to be quite a challenge, as the T-nuts for the bolts had to be slid in from the side and then the bolts threaded through them. Since I went with the "Economy T-Nuts", they are not perfect fits in the slot and tend to slop around a bit. This meant that I had to spend a few minutes prodding each one into position with a piece of heavy wire before they lined up with the bolts.
Of course, once I had all the bolts tightened and everything was ready to go, I realized that I had the X 8020 beam upside down, meaning that the steel rails were on the wrong side of the 8020 beam. This was not a major issue for the top rail, as I could just loosen all the bolts, slide the rail out, turn it around and slide it into the correct slot on the 8020. The bottom rail on the other hand was trapped between the Y carriages, so it had to be completele removed the T nuts slid out (more fun with the sitff wire), and the whole processed reversed to mount the rail correctly (yet more fun with the wire).
12-13-2008
I spent most of today working on the machine, just like yesterday. Got a lot done.
I got the Y-axis carriages built and mounted, and most of the X-axis rail built. I also got the X-axis carriage assembled, but not yet mounted, as the glue was still drying.
The carriages are all assembled out of MDF, secured with 12" pieces of threaded rod. The threaded rod keeps the entire carriage assembly under tension, which makes it very rigid.
Assembly of the X gantry is not yet complete. There dosn't seem to be any way to get the T nuts into the 8020 to support the bolts that should go in the empty holes in the left picture (blue circles). The other snag I ran into was that the bolts highlighted in the right picture (red circle) were nearly impossible to tighten due to the very small space they are in. I spent probably 20 minutes on each of the four of them getting them to snug up, turning them about 10 degrees at a time.
12-12-2008
Well, I spent most of today working on the machine, and here's where it stands:
I spent much of the daylight hours painting the MDF parts, and drilling then cleaning up the steel for the rails.
I did encounter a couple of gotchas. The short steel pieces for the Z axis are not duplicates. I drilled them both only to realize that they are not to be drilled the same. They need to be mirrored. So I ended up drilling one of the rails twice. It will have to serve until I can come up with another piece of 3/4" steel angle.
I also accidentally purchased these crazy nuts. They look just like regular zinc plated hex nuts, but they have little square stampings embedded on 3 of the flat sides. These nuts are made so that they can be forced on, but do not come off again. This, of course, was not what I wanted, so I had to go back to the store to get more of them. I also discovered another product that my local Home Depot does not keep in sufficient stock: 1/4" lock washer. I blew though the 50 or so I had on hand and tried to get more, only to discover that they only had about 30, loose, in a bin. I bought what they had and am getting as far as I can.
I then spent the rest of my day drilling and tapping the various High Density Poly-Ethelene (HDPE) parts that had come with the kit. After working with the hand tapping tool for a few hours, I don't know if my hands will ever un-cramp.
More will be done tomorrow.
12-09-2008
Well, when I got home from work today, I found a large box waiting for me on the doorstep. From the holes I could tell that it was the long awaited kit from Joe of Joe's CNC. It had been pretty badly treated during shipping. Opening the box revealed a sea of packing peanuts and lots of little pieces.
I freed the pieces from their fluffy white tomb and began to sort them out. I have not yet done a full inventory, so at this point I'm just hoping that no little bits escaped through the gaping hole FedEx was kind enough to add to the box. Hopefully I will have some time this weekend to begin assembly.
I also got all the parts for the computer (no pics, it's just a computer) to run the whole machine. It's assembled and humming along nicely.
12-07-2008
The 3/4" angle iron for the X and Y axes came in on Friday, so I went and picked it up. I was planning on drilling it all yesterday (Saturday), but wound up working on other people's projects all day. So today, I drilled.
I drilled my holes with a 3/16" Rigid brand "Metal" drill from Home Depot. I have no idea what it's made of or coated with, but it worked well. I spritzed it with WD-40 before drilling each hole to provide some lubrication, and that is what you see burning off and producing smoke in the first picture. I backed the angle with a scrap of wood from building the table to ensure that once the bit went through it would not hot the vise. All the drilling was done on my small CNC Mill. I just set it to low speed and ran it at about 1/3 speed and it worked wonderfully.
I marked all six sticks of angle iron the same, but happily realized my mistake before drilling the last two pieces. They will be used on the X-axis, and will be shorter than, and have a different hole pattern than, the four used on the Y axis.
After all the drilling, I realized that I didn't have any bolts short enough to mount the rails to the machine's bed. So off to Home Depot I went again. Once there, I discovered that they did not have any bolts short enough either. I eventually found one sad little bag of 1/4"-20 1/2" long slot-head machine screws. They worked perfectly, but sadly there were only 10 of them in the whole store, and I will need about 80. So, I spoke with the folks at the service desk about getting more, only to be informed that the earliest they would be available would be January. I bought the 10 they had, just so I could make sure that the rails were properly drilled. I will be looking around online to order a box of the needed screws.
11-30-2008
Got the Superstrut bed mounted to the table this afternoon.
It is now fixed to one end of the table, so that when the machine is done, it will be able to work over one half of the table space.
I experimented with using 1/4" spring nuts, sans springs, as the hold down mechanism, but ended up going with carriage bolts run up from below, with two fender washers and a regular hex nut. It seems very solid. By grabbing one of the 8020 members, I was able to lift one whole side of the table.
11-29-2008
Spent some more time on the machine today. I spent a few hours fighting with the 8020 extrusion and the Superstrut, and was able to get the router bed built.
The little yellow bins contain all the various losable bits and pieces I have gathered up. I need to get more of them, and find somewhere to mount them all. They're handy little boogers.
This is how I eventually decided to mount the angle bracket that connects the 8020 to the superstrut. The bracket is held to the superstrut by a half-inch bolt with a lock washer and a half-inch spring nut inside the superstrut. The 8020 is then held to the bracket by 3/4" long 1/4"x20 bolt, going through a lock nut, and two fender washers, and finally an economy T-nut inside the 8020. The plans called for a "Unistrut Nut" instead of the two fender washers, but I could not find those at my local Home Depot.
Here's a view down the Superstrut. Here you can see the other tie the 8020 has to the superstrut via another 3/4" long 1/4"x20 bolt passing through a lock washer, two fender washers, and finally another economy T-nut. Again, the plans called for the ever elusive "Unistrut Nut", so the fender washers replaced it.
All this hardware is, of course, replicated eleven more times (six Superstrut cross-members, two ends each). If pursuing this sort of build yourself, I HIGHLY recommend having another person around to help get everything lined up. My father helped me, and without his invaluable aid, this would have taken easily twice as long as it did.
11-28-2008
Started working on a much larger version of the previous CNC Milling Machine project. That mill, in it's final state, had a working volume of approximately 6"x5"x6", which rather limits the types of things that it can make. It is also pretty slow, moving each axis at a maximum of 15 inches per minute (IPM). This further limited the sorts of things I could make, as more complicated stuff would frequently take a very, very long time (think days) to make. This bigger mill should change all that. I have chosen to build a variant of Joe's 4x4 Hybrid machine.
I have been ordering parts for about two weeks now, and stuff has begun to arrive. I have the motors and motor controllers, the 8020 aluminum, the lead screws, the anti-backlash nuts, the V-bearings, the router itself, the ... Wow. I don't even remember what all I have. Anyway, it's a lot of stuff. The big thing I am waiting on is The Kit. The Kit is a box full of all the custom parts required to make the machine, ordered directly from the eponymous Joe.
I started actual construction today, by building the table the whole thing will sit on. The machine will have a 4'x4' working area, so the plans call for an appropriate sized table. I chose to over-do things and built a 4'x8' table. I figure, I will need all the workspace I can get.
Here is all the lumber in the back of my truck, fresh back from Home Depot. I have here two sheets of wafer-board, nine 8' two-by-sixes, and one eight foot two-by-four. In addition, I picked up enough Superstrut (seen on top of the left tool box) to build the basic framework of the machine.
Here is the table top. It is at this point just a box with a piece of wafer-board screwed and glued to the top.
Next, the box was flipped, and a two-by-four brace was installed. This brace will eventually serve to support the table backing, and will be an integral part of the table's anti-racking structure.
The table legs were added next. The legs are made from two 32" sections, joined in an "L" shape.
Bracing was then added to the legs. These braces will keep the legs evenly spaced, as well as supporting a handy shelf. Additionally, the back of the bracing will be attached to the previously added two-by-four brace to stiffen the table.
A half-sheet (2'x8') of wafer-board is used as backing for the shelf. More importantly, it will also keep the table from racking along it's long axis.
The table, was then flipped upright, so the other half of the wafer-board sheet could be added as a shelf. This shelf, while handy, will help to further stiffen the overall structure.
Of course, as with any flat surface in a garage, the instant the table was finished, stuff was piled upon it. Here, the table has much of the machine's future parts on it, as well as various garage items on the lower shelf. In the background of this picture, you can see my little mill in the corner. It is a converted Harbor Freight micro-mill.
You may have noticed that the machine on Joe's website has metal legs. Well, getting that much metal here would be very, very expensive, if I could even come up with it. So I built my table out of wood. The table is framed entirely from two-by-sixes, so it should be plenty strong enough. I will put the Superstrut bed on top of the table, and build the machine from there.
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