To get the best possible CNC driver / firmware setup, in combination with the CAD and CAM programs that are required, I tested the following setups with the Indymill hardware:

I have a setup running on the CMC Indymill with Duet wifi BUT I just can’t get enough current to my Nema23 stepper motors.

Therefore, I made the final choice to also test OPENCNC: https://blog.altholtmann.com/open-cnc-shield/

I am building this together as you can see in the below pictures, where the driver boards will be replaced with 6600 pro drivers.

In this post, some other possible choices are presented:

1) Reprap 3.3 & the Duet2wifi.  STL’s are made with OpenScad and then converted either online or with Estlcam to Gcode (.nc files).  The Gcode is then uploaded via Duet webinterface and run on the local reprap driver board.  Not chosen by me beacause it proved impossible to run a gcode stream online from the PC to the USB interface of the Duet2wifi board.  It is, however, possible to attach a serial handwheel to the Duet2wifi and manually control the CNC setup.  And dual axis squaring is also easily made possible.  Actually, the Duet reprap CNC setup is very mature and customizable.  I still have this setup as backup and by switching the connectors from the Indymill over, I can easily switch to this setup.  Some advantages of this setup are a.o.  the webinterface and the ease of having an automatic squaring gantry on the 2 Y axes with individual endstops.  I also learned that Estlcam can generate Gcode that I can then send via the webinterface to the Indymill CNC machine which works very well.  (I make my designs in Openscad and save this as .STL files. Estlcam can then convert these .stl files to .nc files…, using the machine configuration to get the code properly generated for the Indymill’s dimensions and hardware settings)

2) GRBL, Estlcam & Openscad, Marlin & GT2560 (A) board; This is also working out of the box and emulates a GRBL driver board. The main reason to NOT use this is the fact that the GT2560 board just has not got enough pins available onboard for things like a handwheel and other outputs for accessories.  The second thing that prevents me from going this way is the fact that it proved impossible to have a functional LCD attached that shows things like position, speed, status et cetera.

3) Mach3, FreeCad & USB CNC ‘barebone’ .  This is actually a very solid and reliable solution BUT I could not get it to do any way of squaring my dual Y axis setup.  Still investigating this…

4) GRBL, Estlcam & Openscad & MKS DLCV2.1 board with TFT 3.5 “;  Also for this setup: No option for squaring the dual Y axis setup.  But- this is a very neat solution for smaller machines.  or larger, if you use external drivers.  The nice option of this setup is the 3.5 inch LCD that also comes preconfigured for CNC.  I use this for my small 3018 CNC.

5) GRBL, Estlcam& Openscad & Mega2560 & RAMPS 1.6 shield. 

DUET2WIFI clone Mellow FLY-CDY-V2

MACH-3 with a generic USB-CNC converter

I also have an original USB Mach3 interface with a. o. a handwheel unit. This works very straight forward but needs a PC to keep a stream of Gcode commands running to the USB controller. I am not very fond of this solution since a little mishap will destroy your objects that is being carved.  But- this appears to work very well for many people so I have set this up after I had the FLY-CDY-V2 with the reprap 3.3 and the Duet webinterface running, to get to know the differences.  I must admit it works straight forward without any problem.  I decided to have this setup available next to the GRBL Mega2560/GRBL shield solution.  The thing that keeps me from the USB-CNC solution is primarily the fact that this setup cannot auto-square my dual Y axis gantry. The Mega 2560/GRBL shield solution does this squaring very well.

GRBL with MKS-DLCV2.1 and the TFT screen

And- the most in use hobbyist solution: The GRBL boards like the above shown setup from MKS.  I have this running on my old 3018 CNC milling machine and it always works well. This particular setup utilizes the preconfigured  KMS DLC 2.1 board and the preconfigured MKS TFT for CNC.  All is very neat and since the drivers can be adde externally as well as interanlly, it is possible to drive real high currents if you want that.  These boards don’t do sensorless homing and usually put the 2 Y steppers in serial.  This means that you will never be sure that they are well aligned.

RAMPS shield for Arduino UNO and Mega2560 (and DUE?)

Still to discover:  ESP-based CNC board 6-axis on Openbuilds is very promising!

This is my test setup for a 1.4 RAMPS shield on top of an Arduino Mega with TMC2209 drivers, optical endstops and individually homing of dual Yaxes PLUS an LCD that shows the exact XYZ locations anytime.

Firstly, I must admit that this option was initially NOT on my list bacause I felt this was a pure hobby-like option.  BUT- as my requirements list grew and other options got less and less, I ordered a Ramps 1.6 shield and plugged one of my Mega2560 boards under it.  Then- the search began to get a working fork of GRBL for arduino that both accomodated the Mega 2560 and my requirements list.  On this list: GRBL, Squaring my gantry, LCD with useful data, Handwheel connection, Preconfigurable buttons on the handwheel (stop, define as zero, probe here, et cetera).  The fork that does this all is: GRBL-Mega-edge.  The last comment is of April, 2020 and the fork was updated last in 2019.  But- it works straight out of the box and the documentation is very well maintained. 

Since it works under the Arduino IDE and has its own library, I foresee little problems in the future.  Everything is freely configurable and it might even be possible to put an Arduino Due in place of the Mega2560 in this setup, with some tweaking of pins and speeds.    And- tweaking is required for the hardware as well. The Ramps boards were never designed for 24 Volts, so this needs to be taken care of.  One might of course use 12 Volts and use external driver modules, but I intend to keep everything very small and make use of an external PSU, and a small handwheel-like box for the Mega2560, Ramps, drivers, LCD, buttons and handwheel knob.  By the way: For getting my designs I already had from my 3d printer background towards the CNC I bought Estlcam (CAM program). This really does a great job at converting it to Gcode and sending it to my Grbl- Mega 2560/RAMPS setup.

Afterthoughts 2021-06-22:  When connecting Estlcam to the Mega2560 and RAMPS1.6 shield, Estlcam can program the RAMPS / Mega2560 configuration, including dual X and Y axis.  This works straight out of the box including endstops. Actually this is easier than first compiling GRBL on RAMPS with Arduino’s compiler.  BUT- it seems that autosquaring does either not work or I did not install Estlcam’s options correctly since the endstops on the dual axis appear to function in parallel instead of indicvidually per axle.

24 Volts connecting is not possible on a RAMPS shield just like that. I removed D1 and powered the Mega2560 with a 9 Volts PSU, and the shield seperately with 24 Volts.  For the Arduino DUE, dedicated RAMPS boards are already available (Smart ramps that compensates for the 3.3 volts in/out Voltage of the Arduino Due)!.

Another option for Estlcam is to program the Mega2560 without RAMPS shield and connect everything directly to the Mega2560 with jumpers.  If this is done, Estlcam will do the bare programming of the Mega and Estlcam can steer almost everything.  Since I bought a license for Estlcam I will, at a later stage, try this as well.  SEE THIS POST

After configuring the reprap Mellow FLY-CDY-V2 motherboard for CNC including the webinterface and installing Mellow’s TMC2209 driver units I got  sensorless homing setup for the Indymill.

It took a lot of time to get it all tuned, as the 3 axes act entirely different due to their different inertia.  The weight that is carried is obviously higher for the Y- than for the X axis.  And the 4 kilogram weighing spindle engine made it pretty difficult to get the Z axis tuned.

The resulting config file is provided in this post.  Use this with caution, since every machine is different, and the used stepper motors, cabling, steppers and PSU all have influence on the CNC’s behaviour and thus on the config settings.

To have the original Mellow FLY TMC2209 drivers work with sensorless homing, set the underneath dip switch to ON

(Diag pin will then be connected).  It took me some time to find out that this is different than other TMC2209 drivers, where the Diag pin is activated by jumper settings on the motherboard.  No idea what happens when you use non-Fly TMC2209’s on the Fly board, but I expect this will not work for sensorless homing.

What I experience on the Y axis is that if you have real problems with homing or skipping steps, the steel Y carriage plates may bend and cause a non-square Y carriage that will never align any more.  I repaired this but preventing is better.

GO TO THE INDYMILL & Reprap Driver POST 

Since this setup with sensorless homing never gave me good speed ratings, I disassembled this setup and continued with endstop setup.  If you want to know how to setup sensorless homing with reprap, please look at my sensorless homing setup on my dual carriage 3d printer, where this works perfect!

Just ordered me a new case for the Indymill’s electronics from Thomann.de.

The idea is to get everything mounted in the cases, and use the control case with the lid open.  The control case gets connected to the Indymill case with multicables and – connectors. When not used, the cables get disconnected from the Indymill and from the control case and go in the Indymill’s case.  The electronics controls will be mounted in the lower part of the control case and the connectors are placed on top of the control panel that gets mounted flush with the  top rails of the bottom part of the controller’s flighcase.  When closed, everything is neatly stored and can be  transported damage-free.

I intend to store the controller case inside the Indymill case, but when moving it around the controller case will be separated from the Indymill case to prevent any possible damage to the mill.

This is only the lower part of the newly built flightcase for the Indymill.  It is 15cm high, 75 cm deep and 80 cm wide, all measured on the inside.

The top of the case is 22 cm high on the inside and it will get perspex windows at the front and top.  Wheels will get mounted at the rear so the case can be moved standing upright.

The Indymill will be mounted in rubbers underneath and on the sides of the frame.  The connectors to the electronics will be mounted in flightcase shells at the front.  When all is positioned correctly and connected, the Indymill will be placed in my garage where I will use it in my large(r) shop.

With the 1.5 Kw spindle I intend to mill aluminium and brass, but mainly aluminium.

1st Job will be to machine ‘flat’ the 8mm aluminium plate I have bought some time ago for the heated bed of my Voron 3d printer. The plate is 310x310mm wide and was not entirely flat when I received it, due to the way it was stamped instead of saw’d.  Now, I will be able to get it done right.  I will use the boring head from my other mill to get this done.  My other mill can only work with smaller objects, not anything as large like the Indymill can handle.

The Indymill’s Z-axis uses a lead screw  by design , and not a ballscrew as I would like.  But- that will be changed later.

For now, the lead screw solution will be OK because I will first build the Indymill machine and use the 500 Watt DC engine I already have for my CNC3018 setup.

The leadscrew of the Indymill is an 8mm leadscrew with a brass nut mounted in a 3d printed part that is mounted on the vertical rear of the Z-plate.

And- the drive stepper motor is mounted hanging on a horizontal plate on top of the Z-plate.

The required motion is exchanged to the leadscrew with a pair of 8x10x22  treehed wheels that are coupled with a GT2-10 mm wide 200 mm long belt.

The change I made to the original setup is to use an original 8mm lead screw bearing on top, under the horizontal plate.

I did not particularly like the original setup with an 8mm bearing in a 3d printed holder, and an 8 mm lockup ring under and above this bearing.

I had to machine the pro-bearing to fit the Indymill’s mounting holes and get  the threaded drive screw nicely centered.

In this post, you can see how I changed the original Indymill to more rigidity by using the original 1605 aluminium nut holders for the 1605 ball bearing screws of the Y axis, and how I made use of the BK12 and BF12 ball bearing blocks instead of the 3d printed parts like in the original build.

When building the frame, make sure that you do not initially screw anything tight.  Follow the steps that apply to any build:

1. Make the footprint square by measuring either with a good 90 degrees angled measuring hook OR measure the diagonals against each other and make them alike.  Then, tighten all corner screws .
2. Re-measure the footprint’s left against right length and also front/rear length. If there is any difference here,  a) take everything apart and b) make sure you have equal sizes for your build where this is required.  OR, if you have a non-standard build, make sure you build according to specs sizes. The, do 1. again.
3. For a lineair rail: use a ruler that is specifically made for your type of rail  You can 3d print one or buy two aluminium ones.  ALWAYS use at least 2 rulers!  With the rulers in place at 20% from left and 20% from the right,  after you have installed the rail loosely with the screw in the nuts, tighten the screw a bit but not too stiff..  We will get back to these screws at a later stage.
4. Put the connecting piece on the motor’s axle (8mm side) and tighten this well.  Preferably, use some loctite on the axle but don’t overdo it.  Be aware that you need to testfit the BK12 first.  make sure that the connecting piece almost touches the BK12’s nut!
5. Put the stepper motor and the BK12 connector together, using the 3d printed thin NEMA23 adapter plate between motor and steel plate. Do not yet tighten this too much.
6. Make an original aluminium 1605 nut holder block shorter to fit exactly.  See the picture.
7. Fit the aluminium nut holder block including the entire assembly of the 600 mm long 1605 ball bearing screw on the machine, and superglue the block in the correct position.  Let it dry so it won/t come off. Demount verything except the steel sideplate and the glued aluminium nut holder.
8. clamp the nut holder to the steel plate with a grip vice, just to make sure it all keeps together.
9. Drill 3 new 4mm holes through the steel plate’s lower part ,  drill through the aluminium block as far as possible.  2 holes on the lower side and 1 just between 2 of the top 3 holes,  NOT where the existing hole of the aluminium nut holder block exists.
10. Get the nut holder block loose, if it has not already come off.
11. Tap M5 in the holes of the nut holder block.  You will have come through the big center hole (for the nut) with 2 holes, make sure this gets cleaned up on the inside.
12. Drill the new holes in the sideplates with 5.5 mm drill (to give you mounting clearance)
13. Place the sideplate on the 2 bearing blocks of the linear rail with 4 outer M3 x8 (or x10) screws.
14. Put everything loosely together
15. Mill an end baring block to fit the 1605 ‘s screw end at the front an mount this at the exact center of the small front plate.
16. Now, connect your nema 23 engine to a motor steering device so you can test the setup.  First, turn the screw by hand and it should run smooth.
17. Since you want to have an even height of the side plates, do not alter these unless it needs to be done on both sides equally.
18. Your fixation point is the only non-movable position, at the rear of the frame.
19. Move the carriage to the rear and now, see if you have slack on the M3 screws of the slide bearings AND on of the 3x M5 screw the rear of the aluminium nut holder. If so, first tighten the M3 screws.  Then tighten the M5 screws.  If not, loosen ALL of the linear rails screws ans move the rail a little. If this is possible, tighten the M3 screws of the linear rail’s bearing blocks.  Then, try to get as much clearance on the linear rail’s movement up/down as you can and tighten the 3x M5 screws of the nut holder block.
20. Now, tighten 1 screw only of the linear rail, at the position above the nut holder.
21. Move the carriage entirely forward position.
22. Tighten the linear rail’s M3 screw that is exactly in position above the nut holder (of the ball bearing screw)
23. Now, tighten all screws of the linear rail.
24. You’re done!
25. Check the other side and if the linear rail’s height differs from the other side,  the only thing to do is to start over again, where your slack is in the 5.5 mm holes of the steel plate’s screw holes for the  nut block.  If you play with this, and then adjust the linear rail’s height, you can get it all even.  At least’eventually I got mine right but it took some time.  Have fun!

Things to bear in mind: You don’t want anything out of parallel like a linear rail that is uneven to the aluminium profile on which it is mounted or a ball bearing screw that gets under tension.  There is also another way to see what is happening while you are tweaking the hardware/frame: take the front bearing off and see what happens to the end of your ball bearing screw in the hole up front when you move the carriage.  It can tell you much about what is happening…  It should always stay perfectly centered but I’ve seen it up, down and all other directions.. -)

And- I must say, this build goes quite well. The materials are OK, and the guideline from the build description was very good. Although I never use it anymore.  The build is quite self-explanatory once you start building the Indymill CNC machine.  I also cahnged quite some parts, and made alterations where I felt this would improve the machine to fit my purpose better.

Since Corona was still around (May, 2021) , I had some time available to spend on other things than just work.

I already had an upgraded 3018 CNC-machine with a 0.5 kW spindle motor,

and a simple GRBL 3- axis board that works very well.  But- it would be nice to make a CNC machine that can really work with aluminium and possibly also with copper and brass.  I have already done some research in the past about what sort of CNC machine would be right for my goals. And the IndyMill CNC macine was already on my mind for over half a year.  So-last week I ordered the manual and the steel plates

for the build and ordered some other parts from Ali.  I also have quite a lot of parts on stock, from my 3d printer supplies.  The Nema23- motors and the extrusion, motherboard, drivers, power supply, switches and probes are already available.

The required printed parts are being printed right now (early May-2021). I am printing all the upgraded STL’s, latest version as these are freely available  on Thingiverse (just search for IndyMill) .  And then you see the power of sharing: the design was already great, and with the upgrades it got even better.  The upgraded versions of the mounts for the linear bearings are really a lot sturdier than the original design and the new endstop holders are very handy to have.

I roughly calculated the costs for building this machine and it was a lot cheaper than buying a similar CNC machine of this size.  If you purchase wisely, the costs for all materials can be just under Euro 1000, if you follow the original BOM and including the 1.5 KW air-cooled spindle motor with regulator…

If you want to install another board than the standard Arduino UNO with the standard Arduino CNC shield,  this can set you back an additional amount of 120 to 500 Euro’s.  I use a FLY_CDY_V2 with Mellow’s original TMC2209 stepper drivers. DO NOT FORGET to set the switches on the underside of these steppers to ON if you want to use sensorless homing!

My add-ons  to the original build:

1. Currently I use a 10 Amps detachable 24V PSU, will become a 30 Amps one.
2. Sesorless homing with the use of a FLY-CDY-V2 motherboard and TMC2209 stepper drivers.  This works awesome but I moved on to add endstops and make a more stable and exchangeable setup.
3. Original  mounts and usage of the ball bearing screw nut’s holder, and of the BK12 nd BF12 original bearing holders to keep the ball bearing screw from moving the wrong way.
4. Altered Z axis setup with a better nut holder, and a better top bearing
5. .
6. Closed loop NEMA23 stepper motors drivers MKS Servo57A V1.0 will be fitted to the rear of the steppers, still to be mounted but will conflict with sensorless homing

   

7. 10 mm GT2 200mm belt between the Z motor and the Z-leadscrew with GT2 10mm wide 16-teethed wheels
8. Add a ‘CNC pendant’ manual control device.
   • On the Duet support website a project is available to convert such a device to a serial interface, with a programmed Arduino (pro) mircro or -nano built-in the device:
9. Solid connection plate between the rear side of the upper and lower linear rails of the X-axis. Still to come.
10. Piezo-probes on all axes’s start- en end positions, instead I first setup the FLY CDY V2 reprap board with TMC2209 and sensorless homing, and later with mechanical endstops.
11. Coolant mist installation and fluid gathering-, pump, reservoir et cetera is ordered. Stll to be installed, and the pumps were not supplying sufficient pressure for the flood mist, have to look for another solution.
12. Independantly driven (and independantly finetuned homing) Y-motors to prevent any possible problems between left and right. This works flawless with the FLY_CDU_V2 reprap setup but it took me quite some hours of finetuning to work with the 3.5 kilogram heavy spindle motor…
13. 2080 profiles all around (also front and rear) with 4 extra-wide corner brackets underneath.  I chose to implement this differently with 3 additional bottom connections and corner brackets, since I need the front of the frame to be low and give way to the spindle vacuum hose.

    

14. Smart enclosure with Scheppach vacuum cleaner connection like this example from https://www.shophacks.com/cncenclosure.html#/  THIS IS REALLY NEEDED!

    

15. Protecting guards for all leadscrews and linear rails (ordered in China)
16. Later if possible: Wheels on the rear or on 1 side and a handle on the front (or other side) to stow and store the machine easier
17. Easily detachable control unit(s) with solid connectors

I started with a FLY_CDY-V2 reprap board to experiment with reprap CNC and the webinterface that has been developed for this setup.

This is achieved with  smart dual homing of the dual Y axes, and gives me a lot more control on the machine. It is also already possible to just send GRBL-based Gcode to the USB port of the machine and use the reprap FLY board simply as gcode-interpreter to steer the machine.  But for now I use the webinterface to upload and run any gcode.nc CNC file, which works perfect!

Picture of the CNC-adapted and already available webinterface for reprap, especially tailored for CNC (by Sindarius, work ongoing):

Pictures are already published about this build!