Nice looking machine.
Newbie first build of hobby wood CNC mill, have been reading a lot here and other site, these are the decision I made. I also wanted parts that could be used if I upgraded/bigger my build. See picture of the design that I build. The useable bed is 19” x 15” and all is driven by 1/2” 13 threads per inch and I am using a full size router.
I bought this stepper motor
KL23H2100-35-4B 381 oz In. Hybrid Motor 1.8° /200 Steps Per Rev. 3.5 Amps Current Per Phase, Inductance 2.8 mH, 0.73 ohms.
4-wire 2.55 rated volts Bi-polar, NEMA 23 Frame
NEMA23 381oz/in 3.5A Dual Shaft Stepper Motor KL23H2100-35-4B | Automation Technology Inc
Reading found the following rules of thumb need 300 to 400 oz-in and the lower the Inductance the lower the drive voltage could be. Another rule was the needed power supply voltage, should be 20 time the coil rating. So went looking for a max power supply voltage of ( 20 x 2.55 ) 51 volts.
The driver that I was going to use was a 6064: 4AMP Stepper Motor Driver Kit. Drives 4.5 Amps (peak) and 4 Amp sustained at 50 volts. This is a new driver that is now being offer. Also used their 4Axis5: BOB/Pulse/Power. Note if you are going to use the 5 v reg on the BOB board it has a 35 V max input.
THB6064 MassMind Stepper Motor Driver Kit
Because of the above, I was looking for a power supply that could be adjusted from 30 to 50 volts.
I ended up with this from ebay 32V-40V Adjust DC 9.7A 350W Regulated Switching Power Supply
32V 40V Adjust DC 9 7A 350W Regulated Switching Power Supply Quality from USA | eBay
Had an old XP desk top computer and went with Mach3. Seem like everybody uses Mach3.
Software & Downloads - Newfangled Solutions
I am still at a lost as to what Cam software to get as I have an old copy of Solidworks that I would like to use. Here is a site that has a good list of what is being used by others.
The Results are in on the CAM Package Survey - CNCCookbook CNC Blog CNCCookbook CNC Blog
Summary:
The power supply had the pot gliped with a strong paint and I damage the pot trying to adjust. So had to take apart the supply and install a new pot ( voided warranty) . I have it set at 33volts and seem to be working well. ( 2 volts under the 35 V max of the 5v reg.)
The 3 stepper motors looked new but one had been drop and cut the wires coming out of the housing. There is a sharp edge that will do this easily if not handle carefully. I was able to repair. The motor run warm but not hot. The current is set at 3.5 amp at the driver. The chips that drive the motors are running cool. On the bench I was able to drive the stepper at 950 RPM if I was doing the calculation right.
The driver are a kit that you have to put together, I got the kit that had 3 driver and BOB board with cables and reg and did the assy. All the part were there and the instruction are well done. The PC boards are good and will take a lot of heat without the pads lifting. Part location is by part designator or value, would have liked to see all part designator. The driver and stepper motor play well together. The biggest problem I had was getting the Mach3 set up to drive them ( I am not good at reading instruction). The driver board needs 3 signals: step, direction, and enable signal. Having got the BOB board/cables was a great aid, it was also a kit, again all parts were there but you need a heat sink for the 5 v reg. Also one part, the leads were to big to fit the mounting holes. Also since I was using the motor supply voltage to the 5 Vreg I need to place 280 ohms 2 watt in the supply line to dissipate some of the heat. The 3 driver board were pulling .08 amp total.
All is working great and the system tops out at at 75 ipm at 10 micro steps but have been running at 50 ipm. I was hoping for .01 accuracy and think I am getting better then that so all is good.
All vendors deliver very quickly and I was sent notice when they had ship, I did not contact any vendor so do not know how they respond e-mails.
I am writing this to give other an idea what has work for me, as I pulled a lot of information from a lot of place and still was not sure if I was making the right decision. I hope the above information helps someone who is looking to build their first CNC.
Similar Threads:
Nice looking machine.
Nice write up. I'm at the point of adding motors to my MDF build right now, I'm going with the same 381oz-in. Nice to know what kind of speeds you're getting out of that setup with 1/2-13 threaded rod as I'll be doing the same to start with to save on costs. Nice build over all. Any other pictures of the machine would be nice to see aswell. Good work.
Sorry about the time delay. I have been on the road.
Notes:
The 4 hex bolt heads that can be seen adjust the x axis bearing there are t nuts that allow them to be driven into the wood holing the bearing assembly.
The SS tube are filled with epoxy, thinking it would make them stiffer, they work good on the Z axis but the 30 inch tubes for the Y axis move a little when I push on the unit.
The nylon coupler from stepper to ½ in thread rod are being replaced with aluminum as the set screw have stripped and slip.
The z axis screw is only held at one end with the bearing that can be seen. The white plastic that can be seen at the top of the Z axis block is the home-made antic backlash nut. It is 1 ¼ inches long, 1 inch Dia. and threaded the whole length. It is cut down the length to within a ¼ inch of the end then it has a o-ring that clamps it to the thread.
Using the number 12 screws to mount the motors seem to be working OK.
Notes:
I used some paper print outs for hole location, Using spray-on glue to hold them.
The white square is just holding the bearing in place, used skate bearing.
The screw with the nut on it laying on the side support is to show the hardware that was used to hold the X-axis to the side support. The nuts were bought here, but I think I have seen them somewhere cheaper.
Woodworking Assembly Hardware - Cross Dowels
The dark brown blocks that can be seem in the last picture is something I tried that if I had to do it again would not. They seem to bind when all is thighten down. There are 3 bearing at 120 degree apart at each end. The top bearing is adjustable with set screws. As said before the tube flex a little when I push on the unit but does not seem to effect the running of the machine.
I have been meaning to update what I think I now know. Well as most say as soon as you finish your first CNC you are looking at you second build or redesign. Well I have redesign the first build. I now have a working bed of 15 inches by 26 inches. I have stayed with the thread all 13 by ½ inch. I have changed the full size router to a RouterZip ( smaller diameter and ¼ to 1/8 shaft bits). I can still go back to bigger router,.
I am happy with all the hardware that I bought.
At the time of my last post, I said
“All is working great and the system tops out at at 75 ipm at 10 micro steps but have been running at 50 ipm. I was hoping for .01 accuracy and think I am getting better then that so all is good.”
Well if that had been true I would not have done a redesign ( I though it was true when I posted it ). I started losing steps and the frame and rails were not rigid enough. Not sure what the accuracy was ( it was not .01”) and I am still not sure how you would measure it. If you cut butter it mite of been 0.01” real hard wood maybe 0.1”. The new machine is more like .02” in real hard wood. It will run at 170 ipm without losing steps.
The 2 biggest mistakes I made on the first build was the long 30” unsupported tube rails on the y axis ( I am thinking now any thing over 12 inches is bad and that may be too long) and I used direct coupler/no flex on the stepper motor to the screws. I was getting so much binding that it was causing lost steps at speed as slow as 30 ipm.
Since I was losing steps I troubleshot it first. I add 1/8 rubber pads under the mounting screws that held the stepper motor and that help some then I tried rubber hose to couple the shafts to the drive screws. At that point I could run at 170 ipm without lost steps. I did not like the twist in the holes. I cut a hose clamp and used the metal band on the outside of the hose and clamp it. That stop the twist, it worked so good I have not gotten around an ordering store bought coupler.
The more I used the first design, the more I want it to be more rigid. The long 30 inch tubes flexing and the gantry being supported at the bottom just seem bad all round. So I did a new base. As you can see in the pictures, I built a 5 inch by 1 ½ rails that are glued to the 1 ½” thick table top. It is a good fix.
The only other thing that I could do to this design is to use 2 stepper on the Y axiz as the center drive is letting the frame rack a little.
Not sure what else could be done to this design to make it more ridged when using wood and home made bearing blocks and rails.
The learning curve has been steep but fun.
I guess the other thing to add to this update is software.
Mach 3 is working good.
I have been using the free version of CamBam, and I will be buying a copy of the latest version
The following are on my computer, not sure how many I will keep/use/buy.
DraftSight x64
DeskEngrave
HeeksCNC
G-code viewer
Inkscape
Punch! ViaCAD 3D v8
f-engrave
Microcarve V4
VisualCADCAM 2014 their FreeMill
Estlcam
It will be interesting to see how the Zip Router holds up.
Accuracy is hard to achieve in an all wood router, 0.02" isn't bad at all in this sort of design.At the time of my last post, I said
“All is working great and the system tops out at at 75 ipm at 10 micro steps but have been running at 50 ipm. I was hoping for .01 accuracy and think I am getting better then that so all is good.”
Well if that had been true I would not have done a redesign ( I though it was true when I posted it ). I started losing steps and the frame and rails were not rigid enough. Not sure what the accuracy was ( it was not .01”) and I am still not sure how you would measure it. If you cut butter it mite of been 0.01” real hard wood maybe 0.1”. The new machine is more like .02” in real hard wood. It will run at 170 ipm without losing steps.
I kissed that arrangement in your first post. Unsupported rails are almost universally bad. Not to mention alignment is tough too.The 2 biggest mistakes I made on the first build was the long 30” unsupported tube rails on the y axis ( I am thinking now any thing over 12 inches is bad and that may be too long) and I used direct coupler/no flex on the stepper motor to the screws. I was getting so much binding that it was causing lost steps at speed as slow as 30 ipm.
I'm surprised that you stayed with All thread in your upgrade. ACME lead screws and real couplings would go a long way to reducing motor load.Since I was losing steps I troubleshot it first. I add 1/8 rubber pads under the mounting screws that held the stepper motor and that help some then I tried rubber hose to couple the shafts to the drive screws. At that point I could run at 170 ipm without lost steps. I did not like the twist in the holes. I cut a hose clamp and used the metal band on the outside of the hose and clamp it. That stop the twist, it worked so good I have not gotten around an ordering store bought coupler.
The more I used the first design, the more I want it to be more rigid. The long 30 inch tubes flexing and the gantry being supported at the bottom just seem bad all round. So I did a new base. As you can see in the pictures, I built a 5 inch by 1 ½ rails that are glued to the 1 ½” thick table top. It is a good fix.
Spreading the bearings out more might help but then you need to make your axis longer. Eventually the accuracy of your rail alignments impact the ability to tighten things up.The only other thing that I could do to this design is to use 2 stepper on the Y axiz as the center drive is letting the frame rack a little.
Not sure what else could be done to this design to make it more ridged when using wood and home made bearing blocks and rails.
Again a nice build followed up by some nice improvements.The learning curve has been steep but fun.
I guess the other thing to add to this update is software.
Mach 3 is working good.
I have been using the free version of CamBam, and I will be buying a copy of the latest version
The following are on my computer, not sure how many I will keep/use/buy.
DraftSight x64
DeskEngrave
HeeksCNC
G-code viewer
Inkscape
Punch! ViaCAD 3D v8
f-engrave
Microcarve V4
VisualCADCAM 2014 their FreeMill
Estlcam
Wizard thanks for the comments.
About the !/2 inch ACME screw. When building the table and with all the reading I had done, I was thinking the screw would have to go, but I was surprise at how well they are working and see no need to replace them. One of the thing I did was smooth the screw over a Brass Wire Wheel on a bench grinder, also the 1/2 inch size does not seem to wip around at higher RPM as smaller size are said to do. I may have luck out using the bigger size, the main reason I went with the 1/2 inch was it only had 13 threads per inch as a oppose to 20 for 1/4 inch.
About the Zip Router, I will post if it die. I am guessing I have about 30 hours on it.
I can not believe it been 3 years since the last updated.
Well I did think of some changes to make it better.
I will start with the RouterZip , the bearing went out when I was cutting Aluminum. I was able to get parts and repaired. I replaced it in May of 2016 with DEWALT DWP611 1.25 HP Max Torque Variable Speed Compact Router with Dual LEDs. I like this new router, The LED,s are a little dim and the Bit nut only has 2 flats so the wrench will only go on at 180 degrees.
The CNC needed to be more rigid.
The Z axles was redesign. The Z is now driven by 3/8 inch thread rod and all Aluminum. It is working well.
Re-did the bottom cross members.
Re-did X drive.
Here is what I am using for nuts on thread rod. The hose clam is only tight enough to keep nut from skipping threads.
I am going to split this post for the last 2 pictures.
I did go to store bought coupler because the rubber tube started slipping, what I bought.
https://www.amazon.com/BQLZR-Flexibl...Z1RPN4ME30X22X
I have just changed the stepper motor drive ( X an Y ) from direct drive to gearing, it now has the stepper turning 1 time to the screw turning 4 times. I now have a IPM of 250 when it start lossing steps. ( I figure the stepper motor is doing about 812 RPM). Used a 16 tooth 32 Pitch Shaft Mount Pinion Gear and 64 tooth 32 Pitch Shaft Mount gear
Got them from Servocity
https://www.servocity.com/motion-com.../rotary-motion
I doubt I will be able to run faster then 100 IPM as the machine is starting to jump around as it start and stops. I guess that what happen when the machine get rigid. I am not sure I can make it any more rigid using wood.
Machine accuracy? It mite be .015 now, it is getting harder to improve, each mod has improved it but I now know more, how to look at accuracy. I think this is all the accuracy I need for what I do.
Ok Parts.
Still using the same steppers, drivers, power supply and Mach3. ( I am thinking of a new power supply that will run at 48V as the drives that I have will handle it.) I would run the Z off the old power supply and X and Y off the new supply.
I am now using Fusion 360 for CAD and CAM and NC Corrector v4.0 to view G-code, ( I know fusion will do this )
I have not had a need for Inkscape but I could see a need later for it.
Nice looking machine. Glad it's holding up. My machine's made of MDF and if it holds up like yours, I'll be happy.
Curiosity did you 3d print some of your brackets and if so how are they holding up, and what have you managed to machine?
Designer-Prototyper-Maker
Make My Ideas = https://makemyideas.uk/
No, did not 3D print.
I did machine all the black parts on early rev machine of tis CNC plus some drill press, I think the material is ABS it does not like to be machine it melts, if the bit cuts to much or too slow.
Also did some of the aluminum cut out and I do most of pilot holes on the CNC. The gear box sides were done on the CNC. The upright wood sides were cut out on the machine plus the holes line up so much better when the CNC does them..