This is going to be a tough one!

[tommylight]

Hi there and thank you all for a great forum and a wealth of information. I have been thinking and trying to build a CNC for a loooooong time but due to problems sourcing the parts here in Kosovo i was not able to till some days ago when i accidentally bumped on a pair of 1 1/2" (3,75 Cm) lead screws and complementary ball screws. The good thing is these are huge and very heavy, the bad- to damn short for my taste, i was aiming for a 3X1.5m (10X5'), so i have to make some modifications to the frame. Will post pictures tomorrow so any advice would be very much appreciated.
I still have to order and hopefully receive the motors and drivers.
Again, thanks a bunch.
Tom. ( there is another tom here as far as i know )

[tommylight]

Here it is as i unloaded it from my wan

http://www.shpalljetevogla.com/downl...1062009113.jpg

those 2 big bulky parts weight over 200 kg each, i lost 5 kg sweating while unloading them, luckily i still have all the fingers and toes !

Here's one of the ball nuts with the added measure but due to pictures being low quality it is 20 cm long ( 8" ) and weights in at over 10 Kg , 2 other nut holder weigh over 30 Kg each! DAYYYMN.

http://www.shpalljetevogla.com/downl...1062009114.jpg

This is the other nut holder , do i need to say it again, it is VERY heavy.

http://www.shpalljetevogla.com/downl...1062009115.jpg

After a lot of cleaning and some 3 hours of pain and suffering i managed to remove the short lead screw and the nut, but i could not remove the nut holder ( there are over 70 ball bearings inside the nut ).

http://www.shpalljetevogla.com/downl...3062009116.jpg

Here is the Y axis that is now rendered useless since it is to thin/weak to hold the screw/nut/holder combo, so more work and the frame definitely has to go and a much biger frame made from truck chassis beams, if i manage to snatch them from a friend of mine.

http://www.shpalljetevogla.com/downl...3062009118.jpg

That is all for the time being, more to come so stay tuned.
P.S.
Admins, i think this is the wrong place for this post so can please move it to DIY section if you think that it belongs there. Thank you and sorry for the trouble.

[tommylight]

Went to the local junk yard today and spent 4 hours dismantling an old AGFA mini lab, got 2 steppers and drivers on separate boards with L297/L298 IC's , a nice big and REGULATED 24V/8A power supply with 4 separate current/temperature/anything limiters, a nice big helium neon laser with power supply and 5 mW of power, and some other stuff. The motors are as follows : one 6V/0.8A 2 phase bipolar 4 wire, 1.8 degree step. The other is NEMA 23 1.4V/3.6A 2 phase bipolar 8 wire 0.9 degree step.
I already managed to connect the small one to the driver and made the power supply work perfectly, made the motor move one step at a time on both directions, connected another motor from a canon printer to that driver and it worked, connected the laser and did all that with no smoke at all !!!
Pictures tomorrow, i did not want to use the crappy camera on my nokia so i will get my NIKON back from my brother.
Regards and thanks for taking the time to read this.

[analogman]

Looks very interesting Tom, keep on posting those pics!

[tommylight]

I am really sorry for not posting more pics, but been very busy lately, still i managed to put together a small CNC the X and Y axes are ready with some 38cm (15") of movement on both axes and no Z as i intend to use this with a plasma cutter to cut parts for the bigger CNC. i am still waiting on the electronics and some bigger motors as i don't believe that the steppers i got will be able to move the big lead screws ( again FYI they are very heavy at over 30 KG with the mounting on one side. Oh i did find the missing balls for the big ball screws, the same ones are used on bicycles with a diameter of 6.32 mm ( fill in inches ). On the other side since i was doing electronics since i was 9 i started gathering parts for the drivers and BOB and been researching a lot on servo control . The idea is to use used car alternators with 3 phase electronic speed control and do some other electronic that will magnetise the rotor at a higher level when spining slowly and at a lover level when spining fast so you get huge amount of torque even at very slow speeds, and they can do 12 to 18000 RPM easily and have over 2 KW of power, they are light compared to ready made servos and have cooling built in, etc etc. Anyway since i am unemployed at the moment i have to wait till i sell my AUDI so i can invest more on the machine, for now i am broke but i manage to gather stuff all the time and next week i should to a billboard conversion from CFL to LED and it is 50 meters long and 0.6 meters wide so i will be busy all week.
Thanks for reading and again sorry for the delay.

[tommylight]

Again, i am really sorry for the delay, but there have been some new developments lately so here it goes:

I've spent most of last week scouring through junk yards and found some old XEROX photocopiers so as any normal techno junkie i removed anything worth wasting time on, so a lot of driver boards some very strange, a lot of stepper motors 2 of them NEMA 34 and over 30 NEMA 23 and NEMA 18, 4 servo motors with built in encoders, 5 power suplly 2 of them over 700 wats, some drawer ball bearing rails and a lot of small things. The good things in all this ??? All of this costed me 175 euros and i have a working SLA7026 driver board and the SLA7024 is pin compatible soooooo ........ oh hell it is a 2 sided board so drawing schematics is going to be a pain in the a.r.s.e. I will try to get to doing that but i am pressed for time, and since i have some 12 SLA7024/26 on useless boards i am going to have to take the plunge. i will also take pictures of the board and try to figure out the traces on both sides. In addition to SLA it uses a 74LS95 and a 74HC04 and a few other parts so it's fairly simple. I also have 3 driver boards with STK6713 but they behave strangely, strange being the motor turns only on 1 side. I will try to post the pictures and other stuff whenever i can so stay tuned.
P.S.
the above was posted on another thread on this forum but somewhere under the electronic section. I am sorry if that causes any inconvenience and i will remove the post if necessary.
Regards,
Tom.

[Hdale85]

Wow wish we had junk yards like that around here!

[harryn]

Very impressive actually. If my build went this fast, I would not be making any appologies. Well - I don't even though mine is much slower.

[tommylight]

Hi there,

Here are some pictures i just took with a warning: they are big at over 2 MB each so you can see the details if interested.
First off here are some of the drives, most of the with SLA7024 and SLA7026 and 2 smaller power supplies
http://shpalljetevogla.com/downloads/DSC_2625.JPG

Some more boards with L298 and STK6713BMK4 and 3 different steppers, the one with the smallest stepper and a NEC controller already tested and working, the one with the big heat sink and a VEXTA motor on top has 2 DAC ( digital to analogue converters and 2 PROM's so i still have to figure out how it works because it does not use L297 as the other board, and the third one on the left has STK6713 and 2 logic circuits also tested and found the ENABLE and STEP pins but no DIR pin........wierd.
http://shpalljetevogla.com/downloads/DSC_2626.JPG

Here are the smaller steppers and there are more where i got them, but i didn't bother taking them out.
http://shpalljetevogla.com/downloads/DSC_2627.JPG

Now this is the grand price: NEMA 23 steppers some very powerful and some less, but i am not complaining since i got them at 5 euros a piece, also notice 3 gold colored ones are SERVO's with built in encoders but at 30W of power i doubt they can do much.
I am skipping technical specs since they wary a lot.
http://shpalljetevogla.com/downloads/DSC_2628.JPG

I also found these 2 puppies: NEMA 34 2.5V 4.6A 1.8 DEG steppers and a crappy servo with a low resolution opto sensor. I've put my trusty Logitech MX700 for size comparison and since the MX700 is anything but small, you figure the size of them or if it is of any use, they are over 4 inches or 10 cm deep.
http://shpalljetevogla.com/downloads/DSC_2631.JPG

This is the drive for the big ones, but i could not find the other one so i have 1 drive and 2 steppers........and that ...blows ! This one is a life saver since it uses SLA7026 and it works perfectly with STEP and DIR pins and at 5A peak or 3A standard current capability it is just what the doctor ordered! . If any one is interested, i can make a video of it driving the big stepper connected directly to the parallel port.
http://shpalljetevogla.com/downloads/DSC_2632.JPG

Here is how it is going to look if i manage to make the STK6713 drives work. I will add the 24V power supply (bottom) and the drives on top, there is already a 80mm ventilator on the left and the 120mm on the back of the case. The loose connector on the left with yellow/black wires is from the PC power supply and can provide 12V @ 18A, so i have been using it for testing the drives and motors with the computer on and had no problems at all. The serial ( rs 232 ) ports on the table will be used for connecting the motors to the case so all the wiring and electronic will be in one place.
http://shpalljetevogla.com/downloads/DSC_2634.JPG

Here's another problem, i have 2 of these power supplies with the output clearly wisible on the picture and the interesting part is 25V 17A, but, all the other voltages work normally and it needs the yellow wire to be connected to 5V to activate the 25V output and it does, but only after starting it, in other words, if the 25V is active before connecting the mains, the power supply doesn't work !!! Now i have to make a delay for starting the 25V rail. BTW, this costed me 10 euros a piece.
http://shpalljetevogla.com/downloads/DSC_2636.JPG

20 euros worth of drawer steel ball bearing rails !!! NICE !!! i intend to use them for a small table router mostly for making PCB for my needs, but i know some of them had over 35 KG weight on them when completely opened, so they can take a lot and there is no give in them, at least i can not produce enough force with my hands to notice any give. I also need ideas on how to put them together since they go out when moving.
http://shpalljetevogla.com/downloads/DSC_2637.JPG

Detail of the ball bearings, notice there are 2 moving rails in 1 set, and they move 60 cm or 24" out.
http://shpalljetevogla.com/downloads/DSC_2638.JPG

That is all for now, thanks for everything, and any ideas are welcome.
Regards,
Tom.

[Arquibaldo]

I make mine Hdale85's words ("Wow wish we had junk yards like that around here!")

"my" junkyard has a big sign posted at the entrance: "no admittance carrying tools" -
if you see something you like, you have to take everything home, gambling on what you'll
find inside...

[tommylight]

Damn, the camera on NOKIA E71 sucks big time !!!
This is suposed to be the small CNC router/plasma cutter that i've put together one afternoon some time ago. It looks even worse in reality but it moves and i am amazed that the angles where spot on since i used only my eyes to align it. I plan to use this only until i manage to build the big one or, since i started gathering parts for a small mill also. It is still missing the motors till i get the time to do some couplings and it will be running only as X Y plasma due to the fact i only have 2 working drivers so far.

http://shpalljetevogla.com/downloads/23112009134.jpg
The motor is a crappy NEMA 23 size i got out of a printer, for size comparison.


http://shpalljetevogla.com/downloads/23112009135.jpg
Again, that kid is there for size comparison . That is my brothers daughter, she is 18 months old and interested in anything moving.

http://shpalljetevogla.com/downloads/23112009136.jpg
This is the ball nut, i used only one but they are double for every screw i have. While this nut/screw assembly was mounted on an industrial mill, i was able to move the work plate turning it by hand easily but when i got tis out, that work plate moved only after 10 minutes of me hammering it !!!

http://shpalljetevogla.com/downloads/23112009137.jpg
This is the lead screw holder with preloaded axial ball bearing. The tension on it must be pretty hi since moving it by hand requires some force, but the rotation is smoooooooooth.

More to come.

Regards,
Tom

[tommylight]

It is alive and moving and it did it's first baby steps yesterday morning drawing "EMC2 AXIS" on a pica box. Did some testing and tuning and since i used inappropriate belts to drive the lead screws, i had to slow it down to a crawl to avoid missed steps. I also tested stopping the gantry by hand while it was moving but the frame started bending, so it has plenty of power for milling whatever. BTW i've put the NEMA 34 on it, i wasn't sure the 23's would have enough power, but now i know they do so soon i will be moving on the big one, or since i am stuck in the shop and my garage is 4 Km away, i may start the mill first. Here are some more of the crappy NOKIA pictures:

http://shpalljetevogla.com/downloads/01122009138.jpg

Here you can the amazing work that went into arranging the cabling
http://shpalljetevogla.com/downloads/01122009139.jpg

Here is the first half successful try, half because it was backwards. Just reverse the wiring on one side of the motor and everything was cool. Left it working 4 hours and it worked flawlessly . Now some more work on the box, wiring, motor connectors etc.
http://shpalljetevogla.com/downloads/01122009140.jpg

regards, Tom