How fast is your homemade CNC?

[Khalid]

MY G00 = 135 FOR X AND Y AND G00=100 FOR Z

[LeeWay]

On my little Cutty Shark router, I usually cut 3/16" lexan 1/16" deep and through cuts. I can cut straight cuts @ 150 IPM. Can set the rapids to 300, but set @ 200. I have to slow doen on tight curves to 80 IPM. 2 cuts gets me through the lexan using a PC 690 router, Thompson single nut ball screws, roller skate bearings on X and Y. Little THK RSR 12's on the Z. 425 oz 23's and 3 Gecko 203V's running on a 62 VDC 6 amp lab power supply and an IBM Thinkpad laptop.


I cut steel and aluminum on my mill. Steel sheet, I can run coated cheap EM's @ 6600 RPM feeding 25 IPM with .025 DOC. I use Koolmist 77 and a cheap HF solvent tank for the coolant system.
I can cut 6061 aluminum with a 3 flute coated EM @ 50 IPM. 1/4" mill drill for engraving, spotting and edging @ about 40 for edging and 150 IPM for engraving and spotting. Same speeds in steel for this.

The mill is using THK linear rails and preloaded ground ball screws. (Thanks EBAY)
The Z axis has a ready built IKO cast iron slide with the same NSK ground ball screws.
495 oz Keling motors withe 3 Gecko 203V's running off a Keling 72 VDC 12 amp PS.
It has an X2 R8 spindle running off a 2.5 HP treadmill motor.

I am very happy with both of these.
My little 7/12 conversion works well too, but not as strong as these two. Smaller motors, smaller PS and stock screws so far. I have another treadmill motor fotr it. Then I will be able to up the speeds. Right now I often stall the OEM motor. Undesireable anytime, but especially so for cnc.

[dertsap]

i keep mine set at 500 ipm , this is an old test vid from the developement stages , routers been replaced and a number of mods done but overall table performance is the same , lately ive been testing aluminum pocketing at 500 ipm the depth of cut is only .015" but it doesnt take long to cut a 6"x6" thru 3/8 plate with a 1/2 endmill , its neat to watch , the load on the tool is basically nothing , normally i'll cut it at .05 depth at 50ipm ,
what the heck sometimes its fun just making pointless holes

"http://www.youtube.com/watch?v=qPFA0qpnonc"]YouTube - homemade cnc router test run

[Herbertkabi]

My selfmade gantry mill: X-1000mm, Y - 400mm, Z-180mm, all Aluminium,
Hiwin 15mm rails, 4 cars per axle, 16/5mm ballscrews, Closed Loop Servo Kit-4 www.imsrv.com, max speed up to 350 ipm ...
Selfmade high speed spindle High Speed Spindle for SIEG X2 Mill - getting technical ... Coolant ... I use cooland every time - alu, carbon, plastics ...
Very different cutting speeds, depends what Im doing, what material ...
Mostly I cut 4, 5 and 6mm 7075 sheet then 1/16" 2 flute endmill (1,6mm) , spindle ca 30.0000 RPM, then 200...300 mm per minut , ca 1,8mm deep ...
Too slow? For me its normal.
Herbert

[Haydn]

I can run my diy machine at 13,500mm/min or 531"/min without stalling and with plenty of motor torque left. Can't go any quicker as I can only get this with 45k pulse frequency in mach with fixed 10x microstepping. 10mm pitch ball screws directly driven by steppers from homeshopcnc and gecko201 drives. Don't need to go any quicker as it would only wreck the ball nuts/screws. Typically runs at 3000-6000mm/min with wood unless its a small part. Rapids usually set to 8000mm/min.

"http://www.youtube.com/watch?v=3_qdZB9iGhU"]YouTube - CNC Stepper Motor Demonstration

[1041448]

Hi all.
I'm building a CNC wood router machine , but i'm a little stuck with the mechanical things . I am trying to get the acme threaded lead screw and the stepper motors , but i dont know the specifications, which should i get first?? how to choose it's specification???
what should the speed of motion on each axis Be??
My machine is a 3 axis wood router , i'll be drilling MDF wood.
Y-axis : 4 feet long ,25 lbs horizantal movement
X-axis : 2.3 feet ,14 lbs horizantal
Z-axis : .6 feet ,11 lbs vertical

Help please ,thanks.

[marting]

Hi to all,
I'm not sure if anyone has ever come across this sort of problem but here we go.. I have built my own cnc router about 3 years ago, as most of you guys did on this forum and have a small setback that
has been bothering me for a while, so I was wondering if anyone on the forum has ever come across this one. My cnc
router runs perfectly fine in all aspects when running at a cutting speed below 28mm/sec. As soon as I take it up to
say 50 or 60mm/sec, my cutting path gets messed up.
My current configuration / setup is as follows:
1 - PC Pentium4 core II 2
2 - Servo drivers from Rutex R990 type
3 - running software Mach3 at max clock speed on OS WinXP
4 - encoders on servos 500ppr
5 - cnc structure mild steel
6 - driver motors - servos rated at 6000rpm at 60V and supply voltage 58V DC (As seen here
ElectroCraft Electric Brush Type DC Servo Motor )
7 - gantry driven by belt and pulley at a step down ratio of 4:1
8 - Using ball screws 10 travel per rev and gantry sliding on brass bushings
9 - working area 750mm x 550mm x 250mm


Now the problem is that when running at "higher cutting speed" the cutting path seems to initially loose orientation
but then comes back to the right path as can be seen in the attached photos showing "V" gap between cutting path. According to my calculations I should
be running at least 200mm/sec.

I have thought the following but could not figure out what could be wrong:
1- There doesn't seem to be any lagging between the gantry and the signal from the driver cards cause the gantry
starts going back a short distance clearly indicating it's way out of line.
2- I have tried a higher encoder resolution - no improvement
3- running mach3 at a lower clock speed - no improvement
4- checked servo actual running voltage - OK
5- Changed servo bearing the whole gantry movement to a more powerful one (type
http://www.kelinginc.net/KL34-170-90.pdf ) but running at voltage of 58V DC.

That's as far I have gone but to no avail and the only against me is the weight of the gantry which is about 20Kg
but nothing the motors cant handle.

Any comments please.
Thanks

[stewi]

Martin,
at 6,000 rpm of your motor and 500 ppr from your encoder (that is 1,000 of track A and B) you are getting 100 kHz pulses to your servo. I don't know your Rutex servo driver, but I would check for max frequency of encoder input.