Author Topic: Cnc minimill  (Read 12064 times)

Offline chipenter

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Cnc minimill
« on: December 12, 2015, 01:52:38 PM »
Some 18 monthe ago I bought a microscope plotter at a boot fair , presision instrument but the head could be lifted and wobled , then on ebay I bought a Arduino 3d reprap board and 5 stepper drivers , so now to mod the head to make it firm enugh for a mill  200mm X 100m X 100m .
Jeff

Offline chipenter

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Re: Cnc minimill
« Reply #1 on: December 12, 2015, 02:02:08 PM »
First job was to mill a groove in the cast iron body , then fit some small bearings on excentrics , turned down the X leadscrew and fitted bearings , made a dummy for the Y leadscrew to clock off and milled a groove in the bronze X table and some more bearings .
Jeff

Offline RotarySMP

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Re: Cnc minimill
« Reply #2 on: December 12, 2015, 04:52:04 PM »
Nice bit of recycling

Mark

Offline chipenter

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Re: Cnc minimill
« Reply #3 on: December 13, 2015, 03:57:00 AM »
The Arduino arrived last week I found easy cnc on the nett , dowloaded then it wanted firmware and that needed processing and was written in Java , my computer is 32 bit XP Java does not run on 32 bit and no support anymore , back to square one Makersmith do a cnc that runs but can't see the encoders as there is no pins defined so far , just got to find how to do that to test everything .
Jeff

Offline SteveT

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Re: Cnc minimill
« Reply #4 on: December 13, 2015, 04:57:16 AM »
Nice project looking forward to seeing the end results.
I use Linuxcnc http://www.linuxcnc.org/ running on Debian to drive my CNC mill it works a treat and is free; also will run on a old computer with no problems.
Steven Tyrer
lives in Cardiff South Wales

Offline chipenter

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Re: Cnc minimill
« Reply #5 on: December 13, 2015, 06:08:11 AM »
Thaks Steve I bought a new laptop on cyber monday half price in a supermarket , there was 3 left out of a hundred by 9 am . have Ubatu to load on the old laptop used to run Mandrake Linux years ago , the learning curve is getting very steep . 
Jeff

Offline SteveT

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Re: Cnc minimill
« Reply #6 on: December 13, 2015, 07:09:39 AM »
When I converted my mill about 18 months ago the mechanical bits was easy then I got to the software/electronics and the learning curve became a vertical cliff  :scratch:
But the guy's on the Linuxcnc forum gave a lot of help and we got to the top of the cliff  :D
Still learning but the cnc conversions was well worth the effort
 
Steven Tyrer
lives in Cardiff South Wales

Offline chipenter

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Re: Cnc minimill
« Reply #7 on: December 13, 2015, 10:54:03 AM »
Finished the spindle housing today from a hydroulic ram EN8 I think , the ER16 straight shank collet chuck I bought is to long  :Doh: reduces the height by 35mm and puts side pressure on the X axis lead screw two bearings required under the housing instead of one , I have some 6mm watchmacers collets but not a 3/32" one http://www.levinlathe.com/page23b.htm  :bugeye: , I will have to make a spindle and a collet to take dentist burrs .
Jeff

Offline chipenter

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Re: Cnc minimill
« Reply #8 on: December 27, 2015, 03:40:41 AM »
Got a peice of 10mm plate for the table filled two 1/2" holes with weld , skimed the face and squred the edges one side was cut with a torch with some hard bits that chipped the end mill ,
started on the spindle using anouther hydrolic ram as they are usualy EN8 , this one wears the edge off the insert pretty quickly even at 250 rpm with coolant .
Jeff

Offline chipenter

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Re: Cnc minimill
« Reply #9 on: December 29, 2015, 09:34:51 AM »
Got the spindle finished and pressed on to the bearings , no photos left the SD card in the pc  :doh: , made two collets drilled reamed and slit next is a draw bar then I can test the run out .
Jeff

Offline PK

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Re: Cnc minimill
« Reply #10 on: December 29, 2015, 05:54:31 PM »
FYI, my own spindle experiences...
http://www.caswa.com/cncathome/spindles.html

I should add that I now exclusively use Chinese water cooled spindles >24000 RPM. These are game changers for small machines.
My latest.

Offline chipenter

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Re: Cnc minimill
« Reply #11 on: December 30, 2015, 02:39:14 PM »
FYI, my own spindle experiences...
Thanks for the info 275 and I am to late for Christmas .
Jeff

Offline chipenter

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Re: Cnc minimill
« Reply #12 on: December 31, 2015, 09:01:32 AM »
Made the draw bar and set up to test the run out 4/10 of a tho out , a closer inspection a bit of swarf in one of the slots , a small burr and a bit of a wobble of the thread cleaned off and a retest less than .5 of a tenth  :thumbup: phew .
Jeff

Offline chipenter

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Re: Cnc minimill
« Reply #13 on: January 17, 2016, 03:40:01 PM »
Not had a lot of time one this project , bought a pair of ball bearing kitchen drawer runners and cut one in half , to get 100 mm of travel the runner needs to be 140mm , I will machine a slot and an angle bracket in the base plate when it warms up a bit , fitted the board into a cliplock box bolted on a small fan , as for the sofwhare one step forward and two back it wants netframework 4 , java , python , wxpython , repetier host , g code sender and arduino cnc host .
Jeff

Offline chipenter

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Re: Cnc minimill
« Reply #14 on: January 31, 2016, 01:32:50 PM »
Finaly got back on this setting up has been dificult to say the least , trying to sort the nots out it's not straight flat square or parralell , made the base and Z axsis screws from 8mm studding to fit bronze bearings , it's been apart so many times now but is getting there , sorted the software in the warm and ran a test the steppers all worked at last something went right .
Jeff

Offline chipenter

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Re: Cnc minimill
« Reply #15 on: February 04, 2016, 02:37:38 PM »
Marked out the table limits and drilled 4.2mm for 5mm clamps , to thin for te slots all I have to do now is counersinc and tap 180 holes .
Jeff

Offline chipenter

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Re: Cnc minimill
« Reply #16 on: February 08, 2016, 03:29:01 PM »
Finaly finished tapping the holes glad to see the back of that job , I was supriesed how ridgid the bed felt so I won't be fitting the drawer runner as a linnier bearing .
Jeff

Offline chipenter

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Re: Cnc minimill
« Reply #17 on: February 21, 2016, 11:34:11 AM »
Not had a lot of time lately just the odd half hour made some small bright mild steel clamps for the table , remade the bearing holders and the exsentrics for the X and Y , glad to say this has made it much firmer , the pullys turned up from China that will be the next job .
Jeff

Offline chipenter

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Re: Cnc minimill
« Reply #18 on: February 28, 2016, 09:56:12 AM »
It's 8 degrees C in my shed and the machines are about 2 degrees so I don't stay there long , got some bronze pullys and started on some mounts for them , drilled and taped 3mm other end threaded 5mm may do the outher three when I warm up , John Stephenson kindly coverted a image to g code for me , it's for Mack 3 Marlin works on buffered g code command I can edit the code in the warm .
Jeff

Offline chipenter

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Re: Cnc minimill
« Reply #19 on: February 29, 2016, 01:56:53 PM »
Got the idler pullys finished and started on the stepper motor mounts , I found I have no 3mm washers may have to make some .
Jeff

Offline chipenter

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Re: Cnc minimill
« Reply #20 on: March 01, 2016, 12:16:20 PM »
Drilled and taped for the idlers and motor mounts , got to figure a way of joining the drive belt all I have come up with is gluing 2 peices back to back , make some feet next now I know the height .
Jeff

Offline chipenter

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Re: Cnc minimill
« Reply #21 on: March 06, 2016, 01:31:45 PM »
Time to fit a motor a peice of 2 X 1/4" black iron was mounted , and slotted for the motor and driled for the spindle , the ends were radiused , started turning a peice of 2" bms for a spacer before the temperature droped like a stone with the sleet shower .
Jeff

Offline chipenter

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Re: Cnc minimill
« Reply #22 on: March 08, 2016, 10:15:29 AM »
Turned a spacer to go between the motor mount and the spindle , just straight turning .
Jeff

Offline chipenter

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Re: Cnc minimill
« Reply #23 on: March 08, 2016, 10:27:05 AM »
Ran out of head room to drill and tap the spindle and mount , I will have to pitch a dormer in the roof to get the mill up to full height , just enugh room to spot for the screws , I have an old chuck without a backplate that works well for holding round things for drilling , I am thinking of useing a O ring to drive it got to work out the pullys next .
Jeff

Offline awemawson

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Re: Cnc minimill
« Reply #24 on: March 08, 2016, 11:08:14 AM »
Whip the chuck off the drill, and use an MT shank drill to reduce headroom. If you don't have a suitable drill, pop a hole in an MT blank of drill size, with an axial locking screw.

Andrew Mawson
East Sussex

Offline mattinker

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Re: Cnc minimill
« Reply #25 on: March 08, 2016, 11:57:04 AM »
Cut down a drill bit from both ends ie cut the chuck end and the cutting end an resharpen. Mount the bit in a collet chuck.

Regards, Matthew.

Offline chipenter

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Re: Cnc minimill
« Reply #26 on: March 08, 2016, 01:46:04 PM »
2.5 mm for 3mm screws and 3.2 clearance  it lined up nicely , I need to raise the roof to get full travel on the mill , I was a carpenter for 50 years should still remember how to do one, a dormer will raise it by 400mm a job for the summer .
Jeff

Offline chipenter

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Re: Cnc minimill
« Reply #27 on: April 02, 2016, 02:36:16 PM »
The belt was a complete falure it came apart before I could get it on the pullys , ordered two NFX525 from the local bearing shop and got NFX52 about 900mm short , reordered hopfully the right ones this time , changed the bearings on the X carridge and fitted the stop switches for the Y caridge , had to modify the scale on the X to get full travel because of the new bearing set up .
Jeff

Offline chipenter

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Re: Cnc minimill
« Reply #28 on: July 22, 2016, 10:48:42 AM »
It's taken a while to get belts for the Z axis the supplier failed to supply after some arguments and failing to get my money back , I went for a pair of MXL belts from China more delay , fitted the belts but the Z felt stiff so made hand knobs and will put an index line in case of droped steps , I also bought a Mac3 board and driver to try .
Jeff

Offline chipenter

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Re: Cnc minimill
« Reply #29 on: July 25, 2016, 08:41:34 AM »
Now I have the belts on laveled the bed and fitted stop swithes , had to fit a micro micro switch for the top of the Z because of the clearance , I will cut up a bear can to make cable clips to route the wiring and connect to the board .
Jeff

Offline chipenter

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Re: Cnc minimill
« Reply #30 on: July 26, 2016, 03:39:31 PM »
Got the end stops wired to the board and as tidy as it is going get , the Z gets realy tight at the bottom of the travel so it's apart again to fix that .
Jeff

Offline chipenter

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Re: Cnc minimill
« Reply #31 on: June 22, 2017, 06:55:28 AM »
It's been a while this project has gone though a lot of changes and delays, fried the board changing stepper connections with power still on , stepper motors changed for more powerfull ones ,and made larger pullys  witch needed longer belts , went for LCD screen with the new ramps board , more learning screen only works with Marlin 3d printer software , got it sort of workin will print from SD but steppers just squeel moving axis using the screen , havent found the right feed jerk and alseleration yet .
Jeff

Offline chipenter

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Re: Cnc minimill
« Reply #32 on: June 29, 2017, 08:38:43 AM »
It's alive sort of it wont do rapid moves G0 G28 or G92 , keep changing the setting but onlt does slow .
Jeff

Offline vtsteam

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Re: Cnc minimill
« Reply #33 on: June 29, 2017, 10:07:11 AM »
I'm impressed with all the hard work that you've put into this, chipenter, good to see that you've got it working.  :thumbup: I really hope that you can iron out the remaining bugs -- I think you will.  :beer:
I love it when a Plan B comes together!
Steve
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Offline chipenter

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Re: Cnc minimill
« Reply #34 on: June 29, 2017, 02:28:37 PM »
It's dead fried the power supply so on hold until I can get another .
Jeff

Offline awemawson

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Re: Cnc minimill
« Reply #35 on: June 29, 2017, 03:04:17 PM »
Bad luck - and it was coming along so nicely !
Andrew Mawson
East Sussex

Offline chipenter

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Re: Cnc minimill
« Reply #36 on: July 02, 2017, 07:11:38 AM »
I have found a pre atx power suppy but has les power than the one I fried , can't use it for the spindle as well as the board so only temperary , spent a frustrating amount of time on the forth axis both soft and hardware , got it to turn with a temperary risistor arangment crocodile clips and leads .
Jeff

Offline vtsteam

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Re: Cnc minimill
« Reply #37 on: July 02, 2017, 10:03:43 AM »
Persistence pays off! :thumbup:
I love it when a Plan B comes together!
Steve
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Offline chipenter

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Re: Cnc minimill
« Reply #38 on: July 15, 2017, 10:33:02 AM »
Succes it made its first part today , an indexing dial for my mill .
Jeff

Offline awemawson

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Re: Cnc minimill
« Reply #39 on: July 15, 2017, 10:41:13 AM »
Very nice Jeff  :thumbup:
Andrew Mawson
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Offline chipenter

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Re: Cnc minimill
« Reply #40 on: July 28, 2017, 09:53:32 AM »
I have changed the stepper driver for the Z axis for a 3.5 amp one , set at 2.5 amps has enugh power to dive the Z without dropping steps at last , also bought and fitted a speed controle for the spindle , and a shelf on the power supply for the screen , had to fit a fan over the board as it was overheating a dropping steps ( themal overload ) .
Jeff

Offline chipenter

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Re: Cnc minimill
« Reply #41 on: August 02, 2017, 03:35:15 PM »
At long last I have solved the issue of the negative movements not working , Marlin is made up from over 120 small programs , and it has taken me weeks to find " enable sofware endstops " once I got rid of them the maching worked as it should , but I havent found a way to set the speed of fast moves from the screen , I ran a program to cut a small clock dial and had a bo bo , no feed speed on the first line and the stepper just howled with no movement , this was a clearence move processor thinks its moved up 3mm next line puts a cut of 1.5mm on , results in a 4.5mm cut lots of dust but it cut well no droped steps so I let it run , just as well I was using 10mm MDF for the test .
Jeff

Offline chipenter

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Re: Cnc minimill
« Reply #42 on: August 03, 2017, 03:23:56 AM »
Found another setting , #define ENDSTOPS_ONLY_FOR_HOMING // If defined the endstops will only be used for homing , why risk damage by having this set as default ? having disabled this the print will stop and a message will say press to continue or reset to abort iff an endstop is hit .
Jeff

Offline chipenter

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Re: Cnc minimill
« Reply #43 on: August 05, 2017, 02:28:34 PM »
I have found the speed controle for the screen  , it was listed as ( 50*60 50*60 40*60 60 ) witch is 3000mm per minet if I changed the 60 this was ignored , finished with 1*60 or 60mm per minet I now no longer need my laptop to set up . :thumbup:
Jeff

Offline chipenter

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Re: Cnc minimill
« Reply #44 on: August 19, 2017, 06:08:40 AM »
 This morning I broke the tip of a BS1 centre drill before I threw it in the bin , I looked and saw it had some rake on the futes , ground it in my engraveg relife tool and a test cut on cast brass plumbig fitting worked , nice clean lines apart from its not in the centre I am pleased with the result .
Jeff