CNC Mill made from Polyethylene

polyethylene plastic mill

I spent some time getting the electrical going for the Polyethylene mill.

The electrical is a Nema 23, 3-Axis.

I wired it up with some nice long wires so I can add the drag chains later. I decided to just run it for a while before installing the drag chains.

I just used a dremel as a spinle motor. Not perfect but when you think of it, it’s great value overall.

It runs nice.

DIY Mill made from HDPE

mill

I just picked up an interesting mill. Here are the specifications and a couple of pictures.

I found it on ebay.

I saw other DIY mills from the seller.

I was surprised to learn that they were made in Quebec. I messaged them to find out if I could pick it up to avoid the 100.00 delivery charge.

They said no.

So I kept shopping and exploring.

I recently asked another question (how much does it weigh). No answer. Now I understand the ebay feedback on “do they answer questions”.

I saw one that was for auction so I placed a bid and this evening I won it.

Too bad I can’t pick it up since they are only just outside of Montreal. That would be gas to Montreal+ and more.

I look forward to getting it running and reviewing it!

The specifications are:

-Durable HDPE (High Density Polyethylene)
-0.75″ shaft with super-oilite self-lubricating bronze bushings (inside HDPE bloc)
-1/2-10 Acme Lead Screws
-24 t-nuts threaded steel (1/4-20) inserts for convenient fastening of the workpiece.
-Router mounts included (e-mail for your choice).
-This model allows you to change the sleeves blocks for real  bearings block (TWA12UU, SPB12 etc).
-Table size: 26 x 20.5 (inches)
-Travels: X-13.0 Y-16.0 Z-4.0 (Inches)

Ouch

Early this morning I was looking at my CNC mill since the last time I ran it, it started missing steps like mad. It was intermittent.

The problem is on the X-Axis. I’ve already fixed a connection on that axis right after the machine was delivered. I’ll have a look at it tonight.

I have a complete backup electrical system for it so I’ll deploy that (probably a day’s work) if I can’t get to the bottom of it right away. My backup system is a great deal better than the one it came with so I’ll just leave that on it and then use the electrical it came with on another project.

3 Axis Nema 17 Electrical for CNC projects

controller

I just received (minutes ago) the electrical parts for the Marauder and other CNC projects! Wohoo!

I bought the power supplies separately.

I’ll be testing this stuff out over the next short while!

I need to order some bearings for the Marauder project!

Marauder Extruder/Mill

flake

I realize that it’s pretty involved to make even a simple CNC mill for cutting plastics and wood. There are nice open source projects such as the Mantis. But for some reason, there is still a high enough complexity that projects are not getting done in my community (despite the low cost of the project). Perhaps the functionality of these projects isn’t compelling enough for people to make the commitment.

So I am setting out to make an open source design that is both a CNC cutter AND a plastic extruder (like a reprap or a makerbot-cupcake (thing-o-matic)). It will have both an endmill and a spindle.

Here’s the plan as it stands (feedback, ideas and collaborators welcome!):

  • Marauder will have a work area of about 11 x 8.5 x 3″.
  • It will be possible to tote it around.
  • It will be based on inexpensive parts.
  • Construction methods will use common tools.

I expect to build many prototypes during the design phase. I’m supposing I’ll sell a few of them during the process.

I have no set timeline. I’ve been working on this for about a month.

Marauder is the current project working name. Naming the project isn’t a priority but I’m sure something will drop out of the process.

CNC is great for drilling repetitive holes

I needed a lot of holes drilled to make a jig. The holes all had specific measurements.

I was cutting some unknown plastic I found in the scrap bin at Canus Plastics in Ottawa.

At first it was melting. What I found was that I needed to decrease the spindle speed and increase the feed speed. As you can see by the end of the video I had it working very well on the second attempt to make the part.

Mill Calibration

measure

Following Michal Zalewski’s advice I have made two Squares. One with outside cut and the other with inside cut. I used google Sketchup to make two 1″ squares. I used Phlatboyz Plugin to add an outside and inside cut.

SquareTest Source Files

Square with outside cut:
X = .935
Y = .931

Square with inside cut:
X = .993
Y = .995

Endmill diameter at end across flutes: .1230

Endmill diameter at chuck side: .1235

I’m supposing this suggest I need to make a small change in Mach3?

3D CNC milling

3d

Today managed to cut a 3D part using my CNC mill (rather than 2.5D like the other stuff I’ve done so far).

Here are the source files: balsaholder

I did the design drawing up in Google Sketchup.

The file was exported from Sketchup to STL format using an STL Exporter plugin in Sketchup.

The STL was processed into g-code using FreeMill.

The g-code was then run in the CNC machine to produce the part.

If you get this error in FreeMill, it's because you have to run the program as admin. Cannot find the c:Program FilesMecSoft CorporationFreeMILL emp.acl file. Do you want to create a new file?

I got stuck on Freemill for a while. You have to run it as administrator (right click then “run as admin”). If you don’t it will fail when you get to the end because it tries to write the g-code into it’s own program directory where there isn’t sufficient privilege for the program process.

I used pretty well all of the defaults of FreeMill except I put in the specific dimensions of my endmill (1/8 diameter, ball radius 0, length 1).

measure

Part dimensions: The measurements of the part do not match the measurements of the drawing from Sketchup. I suspect I have to calibrate the machine (Mach3) or there is something wrong with how I made the g-code.

The 4 1/2″ measure in Sketchup is 4 1/16th” on the part. The 12 1/2″ measure in Sketchup is about 12 1/8″ (measured with ruler). So those two came out a little shy.

I find this puzzling because the 1×1″ square in Sketchup is 1 3/8 x 1 7/16″ (1 3/8″ side is in the direction of the 12 1/2″ measure).

Something is fishy that the 12 1/2″ came out shy but the 1″ along the same line came out long.

Feed Rate: It took really long. Next time I will us a feed rate that is much faster. I’m supposing next time I’ll try a feed rate that is about 5 or 10 times faster. I was running on full override and it was still crawling.

Holes: It seemed to miss the holes. I think I made them right in Sketchup but they didn’t come out on the part.

Multi-pass: The g-code is quite simple. It removes all material in one pass. When it made the edges it plunged about .6″ and cut across the board at that depth. I will look in FreeMill to see if there is a feature to have it remove material in layers.

Clamping: I had to move a clamp and the workpiece shifted a bit. The piece has to really be clamped well. I’m going to get more hardware for clamping.

Dust: This is still an issue. I don’t like lording over the piece with a vacuum. I went out and got some hose so I vacuum near the spindle automatically. I wound up with some 1 1/4″ ID pool hose. It’s pretty light and flexible. I got enough to mount it on the machine. I now need to make a mount for the spindle and a mount for the base so I can just plug the vacuum in when I want.

CO2 Laser Mounting Brackets

brackets

I learned more about the operation of Sketchup and Phlatboyz plugin. I was able to design and cut out the second laser mounting bracket in one sitting.

I ran the first parts on a faster speed to see if cutting would be quieter. I also changed the multipass depth to .05″ from .10″.  I noticed it was just as loud, maybe worse at the faster feed rate despite the smaller depth.

I noticed that on one pass when it was taking less than .05″ it was quite quiet. Perhaps next time I cut cast acrylic I will try .03″ per pass. It might take longer but it will be easier on the ears.

I did have an incident where one of the parts came unclamped. It took me a moment to figure out I had to go for the emergency stop button. No damage done to the machine or the work piece. It’s amazing the punishment a carbide endmill can take.

parts

So I now have two mounts. One that is adjustable and one that isn’t. The non-adjustable mount has three little tabs that will contact the laser tube. The adjustable one will be drilled and threaded to 1/4-20 so that three nylon bolts will contact the laser. This will provide a fine adjustment of the direction of the laser.

I have it on video when the work came unbolted but I didn’t show it in my video below since I’m to embarrassed to show what a klutz looks like in real time. I guess if somebody asks I’ll put it up.

I think I’ll be making a lot of parts in the next while. I won’t post stuff except when I make new discoveries.

More parts from CNC

yippie! parts!

I learned a few things making my first part earlier.

I had the feed rate too fast in the g-code, the tabs were too big, I had Z-zero set too high so it didn’t cut right through, and I didn’t have a vacuum cleaner.

This is very exciting for me. I know all the holes for the bolts will line up nicely. And everything will fit together. When I was making parts by hand before it was rather time consuming and frustrating.

I made a trip to the store to get some longer bolts for my hold-downs but they were too long for this application.

I was able to function with the bolts that came with the machine.

CNC pocket milling

pocket

I was thinking of making some model planes on my mill. I went out and bought a 1/32 endmill hoping that it would not waste much wood. Also a small bit like that probably wouldn’t generate much sawdust.

The problem is that the sheets of wood that I want to cut have no space for clamping. So I decided that I should cut a pocket into a board that is the same size as the balsa. I’m betting it might be able to sit in there without clamping. Or perhaps I can have a small clamp the covers the very edge that holds the wood into the pocket. I think it’s okay if the machine cuts the clamp a bit.

Perhaps some sort of vacuum might work too. If I drilled some holes in the pocket and then drilled holes in the side of the board, then I could connect some sort of vacuum.

Making a cardboard box

Cardboard box design

I’m making a box to practice using my CNC machine. It’s a great example of 2D CAD and cutting.

The tools I’m using are:

Google Sketchup: To draw the box.

Phlatboyz Plugin: To mark the cuts and scores on the box. They actually have a tool called “fold” which does exactly what I want. This plugin also generates the g-code.

Mach III: CNC control software (to run the g-code and carry out the cutting)

The image shows the design. In a nutshell I want to score all the lines that are on the inside and cut completely through the cardboard on the entire outside. I added a couple of tabs so the cardboard would stay put while it’s being cut.

The scored lines will be folds. Notice the folds are not all in-line. This is because of the thickness of cardboard and the geometry of folding.

Challenge: I can’t seem to get the cuts and folds to be on all the lines I need.

I know this is just a matter of learning Google Sketchup (and the plugin) but I’m so anxious to make a box. 🙂 Any input is very welcome. 🙂

This is the smallest box I will make. The long lines are 12.5″. The base and top are 3″ wide. The height is 2″.

Update: 2am, Jan 4, 2010

Okay, I’ve been fooling around with this problem and I’ve managed to get some boxes made.

I’m still having a lot of problems figuring out Sketchup and the Phlatboyz plugin. For one thing I couldn’t get the box object to accept an outside cut. I had to redraw it. For some reason the second time I drew it, it accepted the cut. I also couldn’t get the folds (partial cuts) in the same g-code file as the outside cuts.

I’ll need to try this again.

The boxes are already taking less time to make and of course they are highly accurate compared to my hand cut ones! And it’s more fun!

Here’s a video. As you can see by the end I had the speed up a bit higher plus I was getting the dept of the bit right.

Here are the boxes I made in the first run:

CNC router/mill Testing

Okay, my CNC has arrived and I am in the process of configuring it. The manual shows how to configure with Mach III but I want to use EMC2.

I went through each setting in the manual for Mach III and then went to the corresponding place in EMC2 and changed the setting. cnc manual.

The spindle works great but when I operate the steppers they are rough in one direction. Actually the Z axis only works in one direction. I’m pretty sure it’s the settings in EMC2. The defaults are probably different than the Mach III defaults and the machine prefers the Mach III defaults.

Also, when I received the machine the spindle shaft was bent. I was able to correct this by slapping it with a hammer. I suspect that this was caused during shipping. I have opened an investigation with the courier company. They said they will come and inspect it and also the packaging to see if they are at fault or not.

January 1st, 2011 update:

I found a better manual. CNC 6040 Router Engraver System Installation Manual

This manual is for a similar machine. It has EMC2 directions in it as well.

I followed the directions in this manual and here’s the outcome:

X) Moves both ways. Very rough in one direction.

Y) Moves both ways. Rough in one direction as well.

Z) Moves in one direction smoothly.

My controller is a little different than the one in the manual. Mine doesn’t seem to have limit/home switches.

I don’t think there is a problem with the bearings or anything mechanical. All the axis move very freely and smoothly. Also, if I move plug the Z motor into the X axis it works exactly like the X axis motor.

Still a little stumped.

Janyary 1st, 2001 Second Update:

I don’t believe there are any mechanical issues. The screws are really easy to turn in both directions. I am keeping one of the motors disengaged from the mechanical of the machine as to make sure I’m sure. Earlier when I had the motors running with EMC2, when I changed the motors around from axis to axis, any problems stayed with the axis (rather than moving around with the motor).

I grabbed one of backup computers that has Windows and installed Mach III. I then used the manual that came with the router (cnc manual) since it talks about Mack III.

I went through all the step and now I can’t move any motors at all.

I know the parallel port is working since I am able to press the panic button and that comes up in the Mach III software when I press it.

I try to press the “RESET” button and also make sure the manual jog is enabled. I then press the cursor keys and PgUp and PgDn keys. The X, Y and Z numbers on the screen change but the motors just sit there.

So I’m guessing that I still have something missing from the Mach III configuration since I can no longer move the steppers.

January 2nd (just after midnight of the 1st)

I received this message from cncZone user Lanthan:

Re: 6040 from China
Hi Darcy,

I use my 6040 (from the pics in your site I can confirm it is identical to the one you got) exclusively with EMC2/Axis, and it works perfectly.
Just get your hands on the configuration manual prepared by DIYCNC, launch stepconf and copy the settings.
Just in case, here is a link to my copy of that manual.
http://dl.dropbox.com/u/3772847/CNC%206040%20Router%20Engraver%20System%20Installation%20Manual-ebay.pdf CNC 6040 Router Engraver System Installation Manual-ebay

This manual looks just like one of the ones I already have (the software configuration portion that is).

I think I already tried all those settings since they look the same as one of the other manuals I have.

January 3rd update

Okay, after spending a lot of time fooling around with software (assuming the machine was manufactured okay) I finally started to look at the electrical. I knew the mechanical was sound.

I phoned Micheal Grant and he suggested changing the motors around a bit and the pin configuration and we were able to isolate the issue to one of the three stepper controllers. I then took a multimeter to start to verify the connections going from the breakout board to the controller and found a bad wire. Jackpot!

CNC Router, Milling, Engraving

I’ve been wanting to get a CNC mill or router since I started the laser project. I’ve done a lot of research and contemplation about what I want and need. Here’s a great article on CNC: http://lcamtuf.coredump.cx/guerrilla_cnc1.shtml

I’ve been borrowing my friend Guy’s (from the Ottawa Robotics group) a bit and I have other offers from guys like Micheal in Smiths Falls.

I initially thought of building one thinking it could save money. Micheal (also of Ottawa Robotics) was helpful in finding some parts online and with local suppliers. Guy has been successful at building one of his own.

I decided after shopping around that it might be a good idea to get a small one to start with. At least if I want to make one I can use the CNC mill to help. 🙂

Here’s what I’m looking at:

XYZ axis: 60x40x6.5cm
Driving Units: 1605 Ball Screws (20, 16, 13mm)
Machine Weight: 60KG

Here’s what the supplier quoted:

Power: 110V
Working area: 580mmX400mmX60mm
Max thickness of the material: 790mm (distance between Z axis and bottom of work station)
Work station: 750*480mm
Dimension: 900*650*450mm
6061 aluminum alloy + 6063 Industrial aluminum
Slide unit: X axis 20mm Chrome circular orbit, Y axis 16mm supporting rail, Z axis 13mm Chrome circular orbit
Stepper motor: New 2.8A two-phase 57 stepper motor
Drive unit: 1605 ball bearing linear + cased muff coupling
Spindle motor: C57 300W DC motor, used, from USA, super-low noise, speed 3000-9000, ER11 3.175 collet
Spindle accuracy: radial runout 0.03mm
Engraving accuracy: better than 0.04mm, has been tested
Resetting accuracy: better than 0.03mm
Idle load speed: 0-5000mm/min
Engraving speed: 0-2500mm/min
Control box (electrical): 3977 3-axis control box with the power supply + spindle speed regulator
Weight: 60KG

It comes with a spindle and spindle controller. I had the supplier strip all electrical so I will use my own. This saves on shipping and I was able to get it cheaper.

I realize that’s a pretty low powered spindle but I think it’s a great starting point for a hobby shmuck like me. 🙂


I may use my own steppers and controllers. I have already acquired all the parts and am starting assembly now. If I do that, I will take the electrical off this and use it with my Mantis project.

Here’s a video of the 6040.

Here’s another option:

http://romaxxcnc.com/hsproduct.html

Convert engraver (Roland CAMM-2 PNC-2000) to mill?

Okay, I got a lead on an old engraver. It’s a Roland 20x14x1cm with a small belt driven spindle.  Quite small but it might make a fun learning project for me.

Seller claims it’s working but when I went to look at it, it doesn’t. Spindle motor does not run plus the spindle belt drive is fried. I was able to power up the controller but knowing this thing is about 24 years old, I don’t think it would run on a current computer system. (Besides, the software’s not included).

Another challenge is that I’m not sure this works like a CNC machine exactly. I think it works like a printer. You set the depth and you print to it from your computer. I’m not sure about this but I noticed that there were people on the internet looking for printer drivers for this machine. If this is true, then the only real option to get it to behave like a CNC is probably to replace all the electrical with something compatible with Mach III or EMC2. Or perhaps there is some special software that will allow it to be used like a CNC machine.

I just checked the EMC2 compatibility at http://wiki.linuxcnc.org/emcinfo.pl?EMC2_Supported_Hardware and I don’t see anything from Roland listed.

Challenge: I think if I got it, I could gut the electrical and electronics and try and run the hardware off of some newer electronics.

What do you think? The machine specifications are at: http://www.e-engraving.com/machines/roland/Roland_PNC-2000.htm

Monday afternoon will be decision time for this machine!

It is a Roland CAMM-2 PNC-2000.

Update Dec 6 (pictures from my visit last week)

Not sure how clear this is but you can see that the belt is sagging. I suspect it isn’t an expensive part but it makes me wonder what else could be wrong.

Update: I was outbid at the auction so looks like I will not be able to do this project.

The bitter who outbid me was under the impression it was working as is so they will be thrilled to find out it needs a spindle belt, the spindle to be fixed and may need all the electronics replaced to act as a mill. I suppose they could have purchased it for parts if they already have the same one and it needs service too.

Mantis CNC router build

Toronto hack lab are interested in building this CNC router. I managed to come up with 5 people in Ottawa Artengine and OttawaRobotics so we will be making 10 of these!

Apparently the Mantis can be made for less than 100 bucks not including the controllers and steppers and such. I think this is a great project because it can do all sorts of cool stuff like cutting PCB circuit boards, cutting plastics and wood. What a great platform for learning about CAD, CAM, CNC and such. Not to mention going to town cutting things.

For steppers and control I have a 30V 5A power supply I picked up on the cheap on ebay (used). Also, I managed to find some nice Nema 23 stepper motors from an Ottawa Robotics member. The same member also sold me three controllers. The wiring came from the generosity of Guy of Ottawa Robotics. This configuration might be overkill for the project but I was already building a CNC mill so I have this stuff on hand. (The 4-axis controller you see in the background of the stepper detail is the controller for my CNC laser cutter).

http://makeyourbot.org/
http://makeyourbot.org/mantis9-1
http://makeyourbot.org/mantis9-build
http://www.artengine.ca/modlab/index.php/Mantis_CNC_Build_2011
http://hacklab.to/

I’m thinking of extending one of the axis of the machine. That might be interesting for cutting larger wood and platic parts.

Here is the BOM for one supplier McMaster-Carr according to Leigh who is championing this project:

1 Machine:   $170.74
2 Machines: $221.17 [$110.59 ea]
3 Machines: $271.60 [$90.53 ea]
4 Machines: $322.03 [$80.51 ea]
5 Machines: $372.46 [$74.49 ea]

The incremental cost per machine is $50.43, for any number from 2-5

Here is a breakdown of the BOM For the shared, and unshared portions

Unshared parts:
Part#        Description                            Qty    Price      Ext
60355K503    R4 .25" ID .625" OD bearing              2     4.71     9.42
2868T17      .625x.75x1" bronze bushing               1     0.93     0.93
9414T6       .25" shaft collar                        1     0.58     0.58
6061K108     .375x10" precision rod                   4     4.86    19.44
6061K422     .375x7" precision rod                    2     4.17     8.34
2868T72      .375x.5x.625" 863 bronze bushings       12     0.56     6.72
98935A817    3/8-12 lead screw 36" 2G                 1     5.00     5.00
----
50.43

Shared Parts: [for up to 5 units]
Part#        Description                                 Qty    Price      Ext
5234K72      Nylon/silicone tubing - 1ft                   1     1.01     1.01
94639A189    .09x.25x.3125" spacer [100pcs]            1/100     7.99     7.99
1817T13      5/8 O.D.-1/4 I.D. Delrin AF tubing - 1ft      1    14.60    14.60
90283A112    4-40x.625" flat pan head screws [100pcs]  8/100     1.56     1.56
92949A199    8-32x1" screws allen button head [100pcs] 7/100     8.05     8.05
90975A012    8-32 tee nuts [100pcs]                    7/100     6.74     6.74
90126A512    8-32 washer [100pcs]                      7/100     1.29     1.29
90252A104    #6x.75" plywood screw phillips [100pcs]  17/100     6.66     6.66
25345A42     ACME 3/8-12 Tap                               1    72.41    72.41
----
120.31

Whups… I forgot, there is an error in my BOM. The R4 bearing is incorrect. The bearings are supposed to be shielded. The proper part should be: 60355K43 [replaces 60355K503] They are only slightly more at $5.10 ea from the 4.71 ea in the BOM.

Tom Burns (Dec 6) of Ottawa found a nice independent build log at http://trackhacker.com/archives/430

There is a much better BOM: bom-9

Tom Burns (Dec 8th) sent this link: http://crevicereamer.com/Page_2.html

Project Update: I think the Mantis project isn’t really attractive enough for people to get over the time it takes to make it. The Toronto group didn’t actually do the bulk order for parts that they talked about. The Ottawa group isn’t really hot on it either.  I decided to just do this on my own but not follow the Mantis plans. Instead, I’ll go to a slightly larger cutting area and a few other improvements. I’ve already ordered a pair of Nema 17, 3-axes systems with motors. They came without power supplies but I’ve already bought a supply for one of them. I’m still shopping for the second supply. I’m now working on some ideas for the linear bearings. I ordered 150 bearings from VXB to try some of the ideas I use on my laser cutter. I have a telephone meeting with a linear bearing sales person on Wednesday. They have some plastic bearings. I will consider that. I think I’ll publish the plans and have pinged around for a name for the project. Any ideas? Feb 6, 2011