6 or 7 years ago, I started gathering parts to build a 100 watt, 24" X 48" laser. Have the main frame about done, but just wasn't satisfied with the open rail with Delrin wheels. After it sits for a while, they seam to get flat spots on them (they go away within a few hours of use) when checked with a dial indicator. I've been told that I'm just too much of a perfectionist. Anyway, back in 2016, my wife got a K40 for me as a birthday present and the build has just sat since. I've learned a great workflow system for the K40 using Sketchup (Pro) and Inkscape using the stock electronics. I've upgraded it to a homemade honeycomb bed, new pot, and few other things. Went to use it last week and had no laser beam, so I figured it was the tube. Ordered a new tube and got it installed, and still nothing. Ordered a new power supply and it should be her early next week. It has served me well. The cutting area and power are a big drawback to the K40. The K40 is in my small basement workshop area, along with my 3D printers (resin and FDM) and I want something small enough that would fit in the space the K40 is in. Being a model railroader, the basement workshop is small and is used as a lounge area during OP's sessions. This new one will have HGH 15 linear rails, take 18"X36" stock, moveable Z axis, and 60 watt tube. Here is what I've designed so far. It's just the outside main case. Outside dimensions are 28"X 50" Have enough materials on hand to get this much done now. I have some more parts on order from China and hope they get here in the next week or so.
Worked a little more on it X and Y axis. Need to get the motors and belts mounted. If my plan works, I'll have 2 shafts on the X. One will be the drive and the other will have pulleys on it riding in bearings. I've seen one other done this way and it never gets out of square and no missed steps. The belt tighters will be like the one on on the Y.
If I can throw my 2ยข in, HGH15 is overkill to the point of being detrimental. Unless you already have it, you can step down to MGN15 or MGN12. (I have MGN12 for my 2'x4' build.) You would save a little money, but more importantly, weight. The HGH15 also has a higher resistance than the MGN15/12. Continuing with the idea of weight, you should even be able to use a 2020 instead of a 2040 for the X axis. Looking good so far. Keep it up!
Kevon, Thanks for your input and encouragement. I already have the rail, but I just ordered a 1000mm MGM12 from Amazon. I'll use it on the X axis and use the HGH on the Y axis. I can get more MGM12 and change them out if they are too stiff after it's up and cutting. BTW, I've been following along on your build as well.
I'm waiting on mirror mounts and head set coming from China. Other than that, I think I'll have everything by Thursday. I bought a used LightObject X7 controller a few years ago for the big laser and will use it on this one for now. I plan on getting a Ruida RDC6445G within a few of months. Going to assemble what I have drawn up now and see how well everything fits. First thing will be to get a few plates milled out. Right now my Bridgeport is set up for cutting gears and I need to cut one more set before I can take it down and set the vise back up on it. So I guess I'll get that done first today.
Last night got the rails mounted for the "Y" axis. It was 1500mm long single piece and needed cut, so I threw it in my bandsaw to cut it. It ruined the $60 blade in seconds. Got grinder with cutoff disk and got the job done. Started on the X gantry mounting plates. I milled one side so that they have a no interference (tight) fit in the slots of the 2040. On the other side I milled them so the ground edge of the blocks will fit tight against a true edge. By doing this, it should be a almost perfect 90 degree to the Y axis. Waiting on a M4 tap and drill bit (that should get here later today) to get the block mounting holes done. I'll do the rail mounting holes at the same time. Ground edge of the bearing block.
Made some progress. Don't have enough M3X8 screws to finish bolting the X rail down. I'm working on both X and Y motor mounts along with the idlers. With the MGM 12 rail, I need to make a adapter block for the head to mount onto the bearing block. The tracking from China says that my head set with mirrors, the 4, 40 tooth pulleys and 3600 closed loop GT2 belt is in customs here in the US.
Which head set did you go with? I can upload the skp model of the one I have if it saves a little design time.
I went with this one US $77.46 6% OFF|Startnow CO2 Laser Head Kit 20mm Focus Lens & 25mm Mo Si Mirror Mount Holder For DIY CNC Cutting Machine Metal Base Spare Parts|Woodworking Machinery Parts| - AliExpress It has all the dimensions I need but the thickness of the head plate itself. I guessamated it would be around .200". I needed that so I could make the motor mount high enough the 15mm wide belt will clear.
Motors are mounted. I made the mounts so they lock into the T slots like the "Y to X" blocks. I did this so that the "Y" motor shaft was perfectly straight with the rail cause I'm going to use solid couplings to the drive shafts. The adapter plate for the head to bolt to
A change in plans for the drive of the Y axis. I will be using a 282oz nema 23 that will be driven 2 to 1. Just ordered the belt and pulleys from China, so it'll be, I'm guessing 2 weeks before I see them. After some research seeing @Kevon Ritter build, I see most commercial lasers are made this way. With the weight of the X axis, the bigger motor and gear reduction should work better. While I'm waiting for them, I try to make the motor and shaft mounts. I'll use 8mm shaft for the pulleys to mount on and then use a 12mm driveshaft between to two. I think 12mm is large enough that it shouldn't do any whipping.
Idler mount for the "Y" is done. Note the peenning around the bearing. These new bearings I got were .001" under on the OD. This works in most cases if the gap is not too big.
Love this, reminds me of my laser build. The satisfaction of machining your own hardware is immense (if a little on the slow side sometimes) Is there a reason you can't mount the X rail on the vertical face of the 2040 for convenient plate/head mounting, then fasten the belt up top off an angle plate? System looks plenty rigid enough that it won't bind up.
Thanks Rob, This is the head set I have coming. It more of convenience to just bolt it in place on the bearing block.
Got one idler done for the Y. I was working on both sides, but I messed the other side up. I got redo it from scratch. Still need to trim the shaft up before I call it done.
I've been thinking about changing the stepper motors. I ran across this video while looking at Automation Technology's hybird steppers. It really shows how much torque is lost a high RPM's in stepper motors. Moving up the the hybird stepper is going to add about $200 to $300 (depending on where I get them) to my build and will have to wait about a month or two before I can get them. I have a nema 17 on the X right now and hope if I change, I won't run into problems with the length of the hybird motor. Looking at one of these two for the Y https://www.amazon.com/RTELLIGENT-Stepp ... 1VBW&psc=1 https://www.automationtechnologiesinc.c ... e-kl-5080h There is a big price difference between to two, but the bottom one has a 1/4" shaft and I have the pulleys for it already. It's also uses a plugin cable for the encoder. BTW, this is the only one I've found that has the 1/4" shaft. The upper one has 8mm shaft and will need to buy a pulley for it. Have to wire the encoder to the driver. Trying to deiced between a 17 or 23 on the X. Really don't need power cause all it's driving is the weight of the bearing block and head. Which one would you go with??? Will I have signal interference running the cable with limit switches wiring in the drag chain??? Thanks
Just get it running with what you have. If it needs more, get more, but you don't know what it actually needs without giving it something to need from.
I have closed-loop steppers on my machines and love them, wouldn't use anything else except servo... But I have open-loop NEMA 17s on my laser. At 24V, there's really no reason to have anything bigger than a NEMA17 (maybe a very small NEMA23 for a single-motor-dual-Y) on a machine with effectively zero cutting force.
Thanks Kevon, That makes more sense really than try to fix something that hasn't happened yet. Thanks Rob From what I can see, those closed loop stepper are nice.
Did get a little more done. I got the Z axis bearing plates and the Z nuts made. I need to wait till I get the bed and frame made before I cut the 3/8" Amce rods to length and turn the ends down. The bearings are 8mm ID and the rods end will get turned to fit. The tops of the rods will get drilled and threaded M4 so I can get a small amount of pre-load on the bearings with a M4 bolt.
When I saw the picture with the bearings my first thought was 'it would be ideal to have it made for thrust bearings but I guess he doesn't need them'. Then I read that you plan to pre-load the bearings and I went back to 'why didn't he make it with thrust bearings?'.
Going with what I have on hand. On second thought, I might have some thrust bearings. I'll have to go check my stock.
Well I don't have any in stock. It'll work fine the way I got it planed. The Z axis only needs to stay level and don't need any real speed. The table weighs less than 8 pounds and with 8 bearings carrying the load, there won't be any problems.
When I installed the honeycomb bed in my K40, I made so it was a down draft fume extraction as I mostly only cut with it. It uses a 12V 360 CFM inline blower that is controlled with a 10amp, 16 volt model railroad transformer to make it variable speed. Most of the time when just cutting, I have the speed controller set about 20 to 25%. Once I have the stock for cutting in place on the table, I cover all exposed parts of the honeycomb with paper. Another advantage is the vacuum holds the stock in place and any thin warped wood gets sucks flat. It works so well, I sometimes forget to turn the air on and even then, I don't see or smell any smoke at all. When I do engraving, I just leave small amount of the bed exposed close to the stock and turn the speed of the blower up to about 60%. I'll be trying this type of fume extraction on this build. Making some progress Table frame is put together. With 1" honeycomb setting on it (I found this it in the trash several years ago). I need to go to the aluminum getting place tomorrow to get a sheet for the bottom and some pieces for the sides. Starting on the framework.
That was at least 25 years ago and at the time, I had no idea what I was going to do with it. It was in a fab shop aluminum recycle bin. I ask the shipping- receiving guy if I could buy it and he said "Go ahead and take it". So yea, it was a great find.
