Yup, this big arm is nice. I’ve got the power section working again, now I need to see how the rest of the electronics are working.
But…… this arm is too big for doing smaller pieces on my bench top. So I want to use the lessons learned so far to make my own. I have the Langmuir MR-1 cnc to make my aluminum parts, and I can buy carbon fiber tubes. Most of the hard work will be making sure there isn’t any slop in the joints.
This is the MR-1 cnc in the shop…
Gantry style 3 axis with tool measurement and touch probe. I’m really happy with this machine.
I started laying out the structures for the joints. I’m using encoders and carbon tubes available from Amazon. Who knows, someones else may want to build one and specialty suppliers are no fun.
Rhino 3D, the only CAD program I like to use. I have experience in Solid Works, Sketchup, Fusion 360. Rhino is the only one you buy and use, no subscriptions. Used Rhino4 for years up till a few months ago. Upgraded to Rhino8 commercial for less than a year of Fusion.
As you can see, picked up some nice looking carbon tube and started cutting pieces. Watch for future updates, when its running I will make a parts list. Maybe make a couple arms to sell if there are people wanting them.
Ok, it’s been a while since my last post again. I may make a separate post with all the details, all the changes, jobs, experiences, ect. But it isn’t this post. This post is about an arm…..
This is a CMM arm, or a coordinate measurement machine. This arm is incomplete and broke, but that has never stopped me from making useful tools from unloved parts piles. The purpose of this arm is that you fix the base firmly in space (like to a table where it won’t move), and you use the other end to probe an objects shape.
This is the end the probe goes in, I’m gonna have to build one. This arm is so old you can’t get parts for it unless you luck out on Ebay or some other online antique shop. Once you have the probe up against the object you want to measure, press the button. This will cause the software (don’t have that either, lol) to measure the angle of al the joints in the arm and create a data point in 3D space using the fixed base as the reference point. Move the probe to another spot on the object to be measure and press the button. Doing this repeatedly creates a Point Cloud that is a digital outline of the object that can be used in modern CAD software. It’s a very useful tool to digitize large parts like the missing pieces of my various projects. If there is a left side part on my project, but I am missing the right side, I can digitize the side I have, and then mirror it in software and have one of my machines make the missing part.
So why but a broken arm missing pieces with no software? Because these arms new go for tens of thousands of dollars. Used arms go for multiple thousands of dollars. This arm was a couple hundred dollars, with a bunch of metal bits I don’t have to machine from raw stock, and expensive encoders that measure the angles in the joints for accurate point data. Bonus is the arm has carbon fiber tubes that make the machine accurate in almost any temperature or humidity level. So……
I pulled it apart to see how bad it is.
Not gonna lie, it’s a mixed bag. On the bright side it’s a known major manufacturer, using good hardware, so that’s a win. On the down side, it’s going to need some major work. I applied power to the unit and checked voltages. It should use 12VDC in, which is knocked down to 10VDC using a LM33T, followed by a 78M05 to give me 5VDC. The 10VDC and 5VDC test pads are showing the full 12VDC. The whole arm is getting unregulated voltage that may have wiped out sensitive components elsewhere in the arm electronics.
First things first, have to get my voltage under control. So I will be replacing the LM338, the 78M05, and any other item I find out of spec in the power regulation section. Once I have done that, I will continue posting the progress on this. I may also make a smaller arm from scratch using the ideas I see in this arm for inspiration. It will have much simpler electronics though……
Another project in the long string of micro-manufacturing and prototype work I love to do. I needed to make replicas of certain parts of aircraft for a simulator project I was working on. This particular cockpit was using King Bendix KX155 nav/coms. A friend of mine who works on aviation radios happened to have a KX155 that he was repairing and allowed me to borrow a very badly damaged lens to base my reproductions on.
The upper right lens is the original that I borrowed, it literally was in pieces. The lower left lens is one of my reproductions. Here is a couple pics of the the reproduction lens next to the radio that donated the loaner lens.
As you can see, the remaining lens in the real radio is starting to de-laminate like the loaner lens.
I’m still trying to figure out which it is. Maybe it’s both… a grown-up toy that’s a cool tool. I have to admit I was pretty excited when the delivery guy pulled up out front and rolled up the door on the trailer. I took the day off just to make sure I was there. We got it off the truck and stashed it in the garage and that is when I realized…
That this is a lot bigger than I thought it would be. Yeah, 4 feet long and over 2 feet on the other dimensions. Crap…..I don’t have any room for something this big. Hmm, maybe it’s all packing space and foam to insure the trip from China is a good one.
Nope, it’s all machine. One big, fat , awe inspiring 50 watt cnc laser cutter/engraver. So, I guess there is only one thing I can do…. re-arrange the garage and make room to squeeze it in. It fit in it’s new spot but barely. No pictures of it’s area until I make a decent stand for it, right now it’s on cinder blocks and portions of the packing crate. There is some redneck in the blood somewhere, at least it’s not my house on blocks. 😉
Of course it couldn’t be smooth sailing and laser light shows. Being a chinese product from mainland China I gave it a serious and thorough once over to make sure everything looked like it was in generally the right place. As soon as I plugged it in to the socket something cooked and the breaker to the garage popped. Not good. Turned out the culprit was the primary power supply for the electronics, not any of the expensive laser stuff yet.
Mmmm…. Toasty. Well, it gave me a good chance to see if the 3 year warranty was worth it. The people I had to talk with were in Hong Taiwan or something like that, so all correspondence was answered at 3 in the morning. They are paying for the replacement part and some time to do the work. Check is in the mail they say. We will see if it shows up. In the mean time, I needed to get this thing working, so a new power supply went in , got wired up, and turned on. All checked out, the laser powered up and smoked holes through some popsicle sticks I had laying around so it was time to try something. The very first attempt to cut a file turned out like this….
I’d say that was a success. Mom’s favorite embroidery file and a little text engraved, a square cut out to finish. The one thats right side up in the pic is actually in the hole it was cut from. The laser cuts a very very fine line.
One was cut from 1/16″ ply and the other from 1/8″ ply. The engraving in the 1/16th” ply went almost all the way through, leaving a thin layer about the thickness of a half sheet of paper. It looks kinda cool if you backlight it.
Each of those took under a minute to cut. It’s a lot quicker than using my cnc mills to do this kind of work. This last pic is a piece I just cut, a little over 10″ from top to bottom. Took about 2 minutes to cut and I’m really liking this machine.
This will be short, but I just had to throw it on the blog.
First off, I did a little rework on the small cnc machine I keep in the third bedroom/office area. I built this one to do small parts inside without having to go out in the garage and fire up the monster cnc converted mill out there. That thing eats energy at a prodigious rate and most things I make are smaller. Anyway, I built in a new circuit in my home made controller board and added automated Z axis part height. Everyone out there can roll their eyes at the geekiness but it saves me a TON of setup work that I had to do before. Here’s a pic of the machine, built from the cabinet up from parts I had laying around.
It’s kinda Frankenstein, but it works great. This pic is after the mods and a test pattern run to check performance. The pattern was a simple DXF file of a chicken I had laying around and had Mach3 do a quick convert on. The results were really nice though, ‘specially after I ran some stain in the cuts and sanded the top down.
I had a scrap of oak to run the file on. It looks good, so I may have to cut it down and route the edge to clean up the block and give it to mom.
If my friend at ThisRusticSoul.com sees this and ever gets her blog up then maybe you will see some of the work she does. LOL!
