A Preface CNC DSA.docx

8/11/2019 A Preface CNC DSA.docx

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A. PREFACE

After I read the book "CNC Robotic - Build Your Own Workshop Bot", I bumped to the KELLYWARE home page . into that link, I bumped to many sites thatmade me very impressive by the creation of many CNC machines by self made(Majosofts Hobby Site ). Especially of the John's site : John C Kleinbauer's UniquePlans for Hobbyists , it was very-very impressive. Starting from that, I then started to

build my own CNC table. Because I didn't have skill much in mechanical section,didn't have many tools, still in a new starter and up to my purpose, ie; drill and millthe PCB, I only made the smaller table for this uses. Searching on the net, at last Ifound Zoltar machine plan that I think, I could make it by myself besides that the partcould be found on the local market. It has size about 60mm x 40mm. Perfect size!!!

First, I search for the important materials, ie: stepper motor drive, thread rods,and mechanic driving. An exception of another parts will be build by myself. I foundcheaper thread rods, but the threads very few. I bought 3 of them each with 1 meterlength; each of has pitch like 6mm (1/4") with thread about 26 tpi (turn per inch),8mm with thread about 20 tpi and 10mm (3/8") with thread about 17 tpi. It will driveslower, but I think it's ok for the beginning. I found used stepper motor NEMA-23standard, but the spec for 5-phase coils, not quiet the same with the other making, like2 phase bipolar or 2 phase unipolar (the spec like stepper disk drive). At first I think, Icould found the schematic controller from the net. Searching the net, but I could notfound any related with this kind of stepper. Disk drive stepper has NEMA-17 standard(it is about 1.7" dimension). The torque is very small, only can drive small load.

Nema-23 standard (2.3" dimension) has more torque to drive. It can drive CNC tablewith size about 1 meter x 0.5 meter or below. Up to it is NEMA-34 (3.4" dimension)can drive about 2 meters x 1 meter or below. Up to that is NEMA-42, and so on ... soon ... I put email in the stepper motor discussion news group, but don't have anyreplay or answers. So I think I must search for the new ones with the same spec andabandon all what I have or make my own controller for this stepper motor. I prefer thesecond choice because it is more challenge, besides that I already bought those stuff.For the mechanical driving, I will use ball bearing slide drawers rather than usinglinier rails with roller bearing. It is more cheaper and easy to get from hardware store(like : ace hardware or home depot/depo bangunan).

First, I try to hacking the connection of the stepper motor.

Motor Spec is : Vexta, 5-phase Stepping Motor, 6-cable, Type : A2487-9215, 0.75A,4 Ohm, 0.72Deg/Step, FH7-1413, Under license of Berger Lahr, Vexta, OrientalMotor Co. Ltd., Made in Japan.

I found the connection is star connection with one cable is the centre tap.

http://www.kellyware.com/



http://wwww.majosoft.com/



http://www.kleinbauer.com/




http://www.rcmodels.net/cnc/



http://dsaprojects.110mb.com/electronics/cnc/5-phase_stepper_constr.gif











Searching the net how to run the stepper, I found Prof. Douglas W. Jones tutorial , show algorithm how to run the star type stepper motor for 5-phase coils. I make someexperiment on my PC, using parallel port to drive this stepper. Until I am sure themotor could make its run, then I think how to controlled it using programmed chip. Ihave microcontroller knowledge, I think it is now to try my PIC-micro project. Formore explanation about this stuff go to electronic section . While I still experiment, Ialso built the mechanical section of the CNC table. Here are the progress ...

B. COLLECTING THE PARTS

First I collect the parts that I think could be used for this purpose :

2 kind of angle bars, plain type size of 35mm x 35mm x 6000mm and thickness about3mm. The hole type size of 35mm x 35mm x 3000mm and thickness about 2mm

http://www.cs.uiowa.edu/~jones/step/software.html



http://dsaprojects.110mb.com/electronics/cnc/cnc_ctrl.html







3 kind of thread rods, 6mm with 26 tpi, 8mm with 20 tpi, and 10mm with 16 tpi. Eachof 1 meter length. I don't know yet which one is the match. And some of nuts.



I don't know yet this purpose, aluminum rails, usually used for electrical panel, size of30mm x 10mm x 1000mm and thickness about 1mm. The white plastic is mothers

plate usually used for chopping meats and vegetables. I plan to build the z-plateholder from this material. I need also aluminum plate to make small part. The sizedepends as the purpose. I can get the 1mm plate. I think this is enough.





Needs some nuts and bolts of course. Also some washers and spring washers. BecauseI don't used welding. By using the nuts and bolts, I can adjust the leveling accuratelyand besides that I don't have the capability of welding yet.

I got these used stepper motors from

refurbished market. But a pity it was a 5-phase type. Hard to find the controller to runit. It is very good resolution indeed, 0.72 ° / step, I hope that I could make thecontroller.

What next ...???

C. WORKING SECTION



Start to design what it should be like and how??? Here is my plan , complete!!!

http://dsaprojects.110mb.com/handicrafts/cnc/cnc_plan_final.pdf






First, I cut the plain angle bar with length 400mm - 4 pcs, and 600mm - 2 pcs, thesewill be made for table top. There is still half bar left. Make a hole for each corner to

joint it with bolt. I don't used welding, I don't know it and I don't have the tools. Alsonot shown that for the leg, length of about 100mm - 4 pcs. The white bars are the partsafter finishing.



I cut the hole angle bar to several size; 500mm - 3 pcs, 300mm - 4 pcs, and 50mm - 6 pcs, total of 3000mm length. Try to see how it looks like. It seem stiff enough. I don'tknow yet, the motor could drive this steel. If this is too bulky then I think I must cut ita little more.



Then I try to modified 60mm slide drawer to become 435mm. and the rest modified toz driving. I cut 2 of these drawer sliders. Cut the others drawer sliders with the size of435mm. This is for y-axle drive. Joint it to the y-frame. The rest of this drawer usedfor z traveling, after modified. Its only has about 6cm stroke. I think its enough forPCB drill and router uses for z-axle travel.

Now I still working for the z-axle drive. Still thinking for the ideas .....!!!



At last, the z-axle drive complete. Complete build the z-axle, and then working to thethread rod. It is quiet difficult also. Then make the connection for the rest 2 axles.Here are the rest ...



The nut I make from 6mm hex nut put 2 top and bottom, the middle fill with plastictube to sustain the hex nuts.

Then working to x-drive ...

It needs aluminum plate to make the motor frame support.

Here are the x-motor frame support and the thread rod support.



Put the drawer sliders beside the table bed. One of each side. This is for the x-axledrive. Joint the y-axle frame to this drawer sliders. Also it can be seen the x thread rodalready put.

Now working for coupling thread rods to motors. I cannot found a perfect materialyet. Because I don't have a lathe machine!

Still thinking ...!!!

Solving the problems for rods couplings, I got the perfect coupling using a cup of plastic marker pen. Its diameter size fit the 10mm rod. I used it for the 8mm too, usingthe reducer from a wall nut (small anchor nut). The top cup drilled to the size of motoraces. The rest 6mm using cable tube. All of the materials easy to find and can bereplace at any moment if worn out. The dial I used from 3 1/5" disk drive rotary plate.

Here could be seen also limit switch for x-drive. I put it at the moving frame, so thewiring can be made simple. I made it from a push on switch and a micro switch.





You see, now I know the used for aluminum bar, I make it for x and y drive nutmounting. The nut made from wood. For y-drive I used 8mm claw nut, planted to thewood. For the x-drive I used the standard 10mm hex nut also planted to the wood.

Working to the y-drive axis, this is the easier part to do compare to the other axis.Here How I mount the thread rod and limit switch. Limit switch made from a micro

push on switch, usually used for PCB reset function.



I moved a little far, design the table for this CNC machine and the result can be seenhere. Also a few tests and calibrate using pen for a starting, still perform till now ...

Here are the complete machine ...

http://dsaprojects.110mb.com/handicrafts/cnc/cnc_rack.pdf






The complete machine!



Because the space for this Z-drive is verylittle, the limiter using a dial beside the drive. The limit switch put on the top. I madethis from 3 1/5" disk drive micro switch detecting the disk hole. It's cool!

For the spindle, I got the perfect type, it much, the same as dremel pro tool (maybe alicense one) from Krisbow maker. I bought it for Rp.200.000,- include with a few ofits accessories bits. Variable speed, 0 ~ 35.000RPM, selectable adjuster(1 ~ 6 speed).But not implemented yet! I will use it! Another kind is a wood router, one speed30.000RPM, this is more cheaper Rp.120.000,- I think this is to fast to used for PCBdrill and mill. It also fit for wood working project. I bought also a few of its router bitsfor Rp.6.500,- each. The bits are big, 3mm ~ 6mm standard type. Maybe this is for thenext dream!

http://www.acehardware.co.id/






http://dsaprojects.110mb.com/handicrafts/cnc/krisbow.jpg



This is how I mount this mini grinder tool ...





D. CONTROLLER

As told before I made all of the controller using PIC Microcontroller, thesimplest one type is PIC-16F84A. For detail explanation about this stuff goto electronic section . Here are some of the pictures.

http://dsaprojects.110mb.com/handicrafts/cnc/boards_layout.gif














Controller bits setup ( LPT I/O port bits ) with selected bit function (basedon KCAM drawing example) :

1. X-Drive Step Pulse = pin- 2 (DP-0), active low 2. X-Drive Dir ection = pin- 3 (DP-1), active low 3. X-Drive En able = pin- 4 (DP-2), active low 4. Y-Drive Step Pulse = pin- 5 (DP-3), active low 5. Y-Drive Dir ection = pin- 6 (DP-4), active low 6. Y-Drive En able = pin- 7 (DP-5), active low 7. Z -Drive Step Pulse = pin- 8 (DP-6), active low 8. Z -Drive Dir ection = pin- 9 (DP-7), active low 9. Z -Drive En able = pin- 16 (PC-2), active low (I used this since it is not inv.)10. X-Drive L imit Switch = pin- 10 (PS-6), active high (I used this since it is not

inv. and I used Normally C losed contact LS (series connection), if you used a Normally Open LS (parallel connection), set this to active low)

11. Y-Drive L imit Switch = pin- 12 (PS-5), active high (the same as above)12. Z -Drive L imit Switch = pin- 13 (PS-4), active high (the same as above)13. Spindle ON Control Relay = pin- 1 (PC-0), active low (This is an inv. output)14. Aux. Control Relay 1 (for coolant or vacuum) = pin- 14 (PC-1),

active low (This is an inv. output, I plan to run a vacuum next)15. Aux. Control Relay 2 (for coolant) = pin- 17 (PC-3), active low (Also an inv.

output)16. Spare Input Control 1 = pin- 15 (PS-3), non inv. input17. Spare Input Control 2 = pin- 11 (PS-7), inv. input

E. SOFTWARE

To run the CNC machine, first I tried to use Kelly "KCAM" Software . But notsucceed, even when tried to configure the port setting (it's a little bit confused). Themotor didn't want to start. I think this is because the PC is too slow. At last I foundthat to run this software it needs 500MHz PC!!! Then I used TurboCNC (DOS based) . This is more friendly. But without the graph display. The result more than I expected.It can run perfectly. My configurations are like these :

IBM PC Compatible, 80486-DX2/66 (already included Math-Co, because thissoftware need it! It can't run on my another 80486-SX/33, where there is nomatch-co with it)

RAM 32MB, VGA 1MB, Hard Disk about 2.1GB, Partitioned with seagateextended partition (hard disk manager).

Use second LPT card as port $278. MSDOS Win98 SE TurboCNC Ver 3.1a.

http://dsaprojects.110mb.com/electronics/cnc/kcam.gif






http://www.dakeng.com/








The specification for TurboCNC parameters are like these :

1. Axes Setup :X-Axle Drive :

Steps per Rev. = 500 (My 5-phase stepper resolution)TPI of Screw = 17 (This is for the big rod, 10mm) ---> changed to 16.9 MicroStepping = 1 (Standard controller)Reduction = 1 (Direct coupling)

Y-Axle Drive :Steps per Rev. = 500 (My 5-phase stepper resolution)TPI of Screw = 20 (This is for the middle rod, 8mm) ---> changed to 19.9 MicroStepping = 1 (Standard controller)Reduction = 1 (Direct coupling)

Z -Axle Drive :Steps per Rev. = 500 (My 5-phase stepper resolution)TPI of Screw = 26 (This is for the little rod, 6mm)MicroStepping = 1 (Standard controller)Reduction = 1 (Direct coupling)

2. Motion Setup :For all of axles ( X-Y-Z)Max Speed (Hz) = 2000 Acceleration (Hz/s) = 1500 Max Start (Hz) = 500 Pulse Width (us) = 1 Backlash Comp = none

3. Home Switch Setup :For all of axles ( X-Y-Z)Home State = Active High (I used an NC contact limit switch)Home Direction = Negative Home Position = 0,0

4. Misc ellaneous I/O Setup :Spindle-On State = Active High

I could get up to 2000 Hz speed possible, up to this speed the motor start to buzzingand the drive lost steps. But I satisfied with this result. It's enough to run & drill PCBor maybe mill too. For 2000 Hz max speed, I can go about as fast as 12 IPM (Inch PerMinute) = 2000 (Hz) / 500 (steps/rev) / 20 (TPI) * 60 (sec).

F. TEST



So far the test are so good. But I tried it using a pen, not a really tool. I don'tknow yet the precision and the result when the real feed rate applied. Still need moreexperiment ...

I will put the result when the test complete!

Here are some pictures, when I make the first test .....

The distance for x-,y-axis not the same (1/32" more), so I changed the TPI screw parameters.

This is when I wrong setting, put the axle rotate. The result made as if it go from the back.

http://dsaprojects.110mb.com/handicrafts/cnc/square_test.jpg







Here after I put a pen mounting and set it back to normal setting and make some tests program .

G. RESULT

To milling a PCB layout, it takes more than just to run the machine. It needs aCAD/CAM works too. Some program out there can translate PCB layout from *.PCBto GCode or DXF file. I search the net to find how to make an outline drawing GCodefrom *.PCB file.

One is the very good result from Scott page , mechanical etching PCB, using the popular Eagle CAD drawing to translate it to GCode file. Eagle CAD has thecapability to run a user define script program (*.ULP), and with the outlines.ulp (orother modified outlines*.ulp) can generate engrave drawing of PCB layout and the

software is free for a limited edition. This file then stuff to CNC mill program (likeTurboCNC, or any other programs). But it only can take the eagle format, not like theother PCB CAD like protel, orcad, etc. For this CAD, it must be transferred(imported) first to eagle CAD format.

Second way, to translate it from an image file (*.GIF, *.JPG, or any other formats) to become GCode file. Many software programs can do it, but the results almost thesame all, they can translate it to generate a curve drawing (not an engrave drawing).At last I found one, DeskCNC software, can do such an outline drawing (engravedrawing). This is a shareware program (30 days trial). I try this and the result is also

pretty good. Here some of my examples : 5-phase stepper board and washingcontroller board .

http://dsaprojects.110mb.com/handicrafts/cnc/tests_prg.zip




http://mynock.dhs.org/pcbmilling/



http://www.cadsoft.de/



http://www.deskcnc.com/



http://dsaprojects.110mb.com/handicrafts/cnc/5-phase_pcb_prg.zip



http://dsaprojects.110mb.com/handicrafts/cnc/wash_pcb_prg.zip














These samples taken from DeskCNC software program.

H. REFERENCE LINKS

Here are some reference links about CNC and PCB drills & routers, others builtout there :

Campbell design , router using aluminum extrusion, also CNC plan, drill bit, shop tool, carbide drill bits, router bits, end mills, hobby tools @ Drill

Bit City! , any kind of drill & router bits, hardware links-CNC @ Home ! , Zoltar CNC machine that inspired me, hobbycnclinks , Majosofts Hobby Site , majosoft's hobby site , Majosoft links,

many kind of CNC creations, Homebuild Basic Plotter - Engraver - Vinyl-cutter - PCB-drill , Good for starter,

Luberth self made plotter, http--www.geocities.com-crankorgan-index.html , another John site, cheaperCNC plan,

How to compile edit run the mgui cstep source , Luberth CSTEP, free sourcecode,

Kellyware Favorite Links , KCAM software, shareware windows based, Parts at CNC Linx , cheap source for important CNC parts, but not for me at all!




http://www.campbelldesigns.com/


http://www.store.yahoo.com/drillcity/index.html





http://www.rcmodels.net/cnc/hardw/hardw.html


http://213.10.73.60/majosoft/hobbycnclinks/body_hobbycnclinks.html





http://www.geocities.com/majosoft/



http://www.geocities.com/siliconvalley/lab/3685/plotter/plotter.htm


http://www.geocities.com/crankorgan/index.html


http://www.microsoft.com%[email protected]/cstep/


http://www.kellyware.com/links/links.shtml


http://store.yahoo.com/cnclinx/

















PCB Milling - PC Boards For Electronic Hobbyists & Professionals , PCB Milling with CNC , how to make PCB milling with small budget, PCB Router , Jonathan self made PCB router, Some pictures from my new automatic foam cutting machine , self made CNC

foam cutter, The CNC Desktop Machine Information Center , all explanation about milling,

lathes, etc., CNC Routers & Plasma Cutters for Wood & Metal. Get started for $70. , CNC

plan using aluminum extrusion, Piezo Gyro Prototypes , Scott Stephens CNC drill, Quick Turn Printed Circuit Boards You Make With No Chemicals ,

Commercial product PCB milling, DESKAM , sharewares & freewares DOS and windows based, Andy Shaw CNC drill & mill , modification type from milford selling CNC

drill, Building a mill from a drill , convert a small drilling machine to milling

machine, Home made CNC drilling machine , self made PCB drill, TurboCNC , freeware DOS based, Data-Cut.com The BEST CNC Router and Engraver PLANS ! , commercial

CNC builder, Adam Kumpf @ MIT - Innovative Projects , cool self made PCB drill and mill, Hazir urunler PCB cnc , Scott PCB milling technique, Mechanical Etching of PC Boards , How to, step

by step PCB milling, very good result! Milling a One-Sided PCB in Etcheverry , How to, step by step PCB milling, PCB workshop Info , How to, step by step PCB milling, Prototype Machining Products from MicroKinetics , The Low Cost Equipment Project , How to, step by step PCB milling, The official DANCAD3D (tm) Beta Test Web site. , graph design, LPKF Laser & Electronics of North America - PCB Prototyping and Circuit

Board Manufacturing Solutions , commercial CNC PCB mill, very good result! Wood CNC machine , self made CNC from mechanic printer, DeskCNC , CNC router making, this software program can make engraving

outline for PCB milling, I already try it! Also very good in wood working project,

References :

http://www.pcbmilling.com/


http://www.lce.org/cnc/


http://cryolite.ath.cx/i/pcb-router


http://www.8linx.com/cnc/cnc.htm


http://www.desktopcnc.com/index.htm


http://www.machinetoolcamp.com/


http://home.comcast.net/~scottxs/pcbcnc/cncindex.htm


http://www.pcb2go.com/


http://www.deskam.com/


http://homepage.ntlworld.com/gloomy-place/cnc.htm


http://www.pathcom.com/~vhchan/cnc/cnc.html


http://www.bioelectrifier.com/drill.htm




http://www.data-cut.com/Index.html


http://web.mit.edu/kumpf/www/kumpf-projects.html


http://www.geocities.com/cnc_designer/




http://www.eecs.berkeley.edu/~sbergbre/Milling/


http://www.electronics.oulu.fi/pcb/


http://www.microkinetics.com/pcbproto.htm


http://www.lce.org/

http://www.lce.org/

http://www.dancad3d.com/S0302600.HTM


http://www.lpkfusa.com/





http://www.storm.ca/~rheslip/cnc.htm









http://www.lce.org/























1. CNC Robotics : Build Your Own Workshop Bot, by : GeoffreyWilliams, Mc. Graw Hill

2. PC Hardware Projects : Volume 2, by : James J. Barbarello, 1997, 1998,Prompt Publications, Howard W. Sams & Co

3. Microcomputer Applications in Manufacturing, by : A. Galip Ulsoy,Warrent R. DeVries, 1989, John Willey & Sons

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A Preface CNC DSA.docx