[newguy1985]

hello im a newbie to forums and building cnc routers, but my first table is done and i need help with a software/hardware issue. i want to start a thread for my issue, but i cannot figure out how...thank you for your help

[PaulRowntree]

hello im a newbie to forums and building cnc routers, but my first table is done and i need help with a software/hardware issue. i want to start a thread for my issue, but i cannot figure out how...thank you for your help

Welcome!

Well, you have your thread now ... what is the issue that you are having trouble with?

[newguy1985]

ok..hopefully sometime soon i will be able to post some pictures of the machine....first i will list basics so everyone knows what im working with
-win xp sp3
-mach 3 demo
-pci parallel port card
-1x...24 v power supply
-3x...d2hb882mb drivers
-3x...34hs5435c-02b2 3.5a 1600oz/in steppers
-1x...x220826 BOB
as previously mentioned i am a cnc newbie. so sorry for any stupidity that may proceed from this point..lol...
this 3 axis cnc kit was purchased from longs-motor of ebay...now im starting to think that i should have joined this forum before i made the purchase
i have everything wired up according to their provided schematic witch has all the same model numbers on it...and the parallel port was only supplying 3.5v to the BOB so i added a 5+ source from my pc. i do need to confirm the dipswitch settings on the drivers still, but besides the switches on the drivers, i think it is wired properly.
is it normal for the motors to get warm just from being plugged in?(motors have never turned via software. i CANNOT get them to turn with mach 3)
i am starting to think that my problem may be the parallel port. after the pci parallel card was installed, i went to device manager and looked at the i/o range and the first setting says "EC00". so i then went into mach 3, set up my units for inches. then i set up ports and pins. is Ox necessary? the default value is Ox378, from what i understand, thats a generic parallel port address. if just enter EC00 then hit apply or ok and go back into ports and pins, it changes itself to OxEC00. not sure if the parallel port is the issue, but thats where im going to start. ANY SUGGESTIONS??????

[ger21]

is it normal for the motors to get warm just from being plugged in?

Yes

if just enter EC00 then hit apply or ok and go back into ports and pins, it changes itself to 0xEC00

That's OK. Make sure on the motor pins, that the pins are assigned to port 1.

[zool]

The only stupid questions I know of are the ones that you do not ask when you are confused.

[newguy1985]

Pictures by newguy1985 - Photobucket


here is a link to some screenshots i took and the schematic i used.
screenshots show configuration. i think the motor pins are set to port 1

[newguy1985]

thats true...im so happy i joined because no one i know has the knowledge to help. much appreciated

[newguy1985]

-the mdf bed is 6ft x 6 ft
-frame is 3"x3"x1/4" tubing(i did all the fab/welding/machining at my work then assembled it in my basement...it is very rigid, yet it breaks down to fit all pieces through a 30" wide door)
-3/4" thompsons hardened shafting and shaft rails
-thompsons linear bearings(8 open block, 4 closed block)
-porter cable 7518 15hp production router
-nook industries 5/8-10 acme screws
-custom machined hubs

Pictures by newguy1985 - Photobucket

[doorknob]

A few notes to consider:

a) It looks like your breakout board has optoisolators for the signals from your parallel port.

b) It also looks like your stepper motor drivers have optoisolated inputs.

c) It may not be a good idea to put each of your step and direction and enable signals through two optoisolators inline, because that could lead to degradation of the signal (that is, you may end up with "soft" transitions on the signal edges, which could cause timing problems). So you may want to consider getting a simple breakout board that merely buffers the parallel port signals, instead of one that isolates those signals (note, however, that you still may want some of the breakout board signals to be optoisolated, namely the signal that may be used to control a spindle power relay, and possibly also the signals for home and limit switches). Maybe someone else can recommend a different breakout board that will be suitable.

d) While I'm not sure whether or not to raise a concern about this (because it will probably just work OK as-is), it's probably at least worth mentioning that if your parallel port is only designed for 3.5 volt signals instead of handling 5 volt signals, then you may want to double check the specs of your breakout board to make sure that it will work properly with 3.5 volt signals.

In addition, as even less of a concern, depending on the design of the specific breakout board that you end up using, it may also be a good idea to examine whether the breakout board and your parallel port can handle 5 volt signals coming from the drivers, or whether they can only handle 3.5 volts, and if so, determine whether that is OK (for example, if you change to a very simple breakout board that just uses direct wiring between the parallel port and the terminal strips, is it OK to "pull up" those pins closer to 5 volts from the driver inputs - it may be just fine, especially since you will have a LED voltage drop through the optoisolator inputs, and there's probably a series resistor in there as well, and your hookup is sinking current from the optos). Again, it's probably not a concern.

e) To verify that Mach3 is talking to your parallel port, you may want to check the voltage on the direction pins for each axis, to see whether the voltage changes (from a logic "high" to a logic "low", or vice-versa) when you jog each axis in one direction or the other.

f) Finally, 24 volts is a very low voltage for those motors (which may have a rated winding inductance of 22 mH). I'm not sure what the maximum voltage rating of your drivers is, but you could probably benefit from using a much higher motor voltage than 24 volts.

[newguy1985]

im honestly not sure what i did, but must have been a bad connection somewhere on the bob, but my motors are responding now!!!!!!! the drivers are 24v-80 v input, what power supply would be recommended for my application?

[doorknob]

Glad to hear that things have started working for you.

If the 22 mH winding inductance is correct, and your driver's max voltage is 80, you might want to try using a 72-volt power supply. (The motor could handle an even greater voltage, but your driver would be the limiting factor.)

[newguy1985]

ok ill look into that. could the power supply also then be why after i set it up for my 10 threads per inch, motor starts slipping as if it had a clutch after it acceleratets....it "slips"

[doorknob]

A higher motor voltage should give you more torque when the motor is turning at higher speeds.

So, yes, it is possible that what you are seeing could be fixed by increasing the voltage.

(There are other factors that could affect the maximum achievable speed, but it sounds like that's not what you are experiencing right now.)

[Dan911]

The schematic you used shows motors wired in series, you may have better results with them wired with parallel connection. Here's the schematic I used, the middle 1 is series and the last is parallel.


The slipping your experiencing is the motor stalling, lower your velocity in motor tuning in Mach 3. Getting higher volt power supply like Doorknob suggested I'm sure would help, he helped/taught me allot with my setup.

Also take a look at this thread, I also purchased a Long Motor Kit.
http://www.cnczone.com/forums/diy-cn...0a_driver.html

Good luck,
Dan

[newguy1985]

thanks alot for the help..its hard to find anyone who is familiar with longs-motors stuff, but i was skeptical at first, but it seems to be some decent components. how do these chinese electronics compare to higher-end components? did you buy the same 1600 oz/in kit that i got dan?

[newguy1985]

another question...i am concerned about dust getting on the lead screws and binding up on the nut...i bought bronze acme nuts because they were cheaper than antibacklash nuts and i wanted to get my table running asap..they seem to be pretty tight as far as backlash goes, but can someone give me some insight on the advantages/disadvantages of bronze nuts or spring loaded anti-backlash nuts

[Dan911]

did you buy the same 1600 oz/in kit that i got dan?

No, I have the 4 axis 878oz.in, I use 2x 48V power supply's.

[jcyonngs76]

i recently bought 3 of these from ebay with 1600 oz motors 24 v power supply and 5 axis bob. im having trouble calibrating them in linuxcnc im getting .089 per .100 test but this is not consistent per test length ie .2 .4 .5 all have different errors. I have tried multiple settings , different computer, 48v p.s unregulated (only one axis) and the same result im thinking it may be the bob but im kinda stuck any help is appreciated thanx