Ive been in the machining industry for about 9 years now, was thrust into a position of running/programing/setting up a myano le with live tooling when i was first hired at a shop about that long ago. since then i have learned how to use fanuc/mitsubishi/seimens/ge before fanuc and now fagor. I dabble in electronics and am slowly learning how to devise my own boards to use as an interface for steppers. Ive dreamed of building my very own cnc mill and lathe but money and time I have a lacking of. the steppers I have couldn't toss a coin in the air, well okay they could but they are mainly out of things Ive managed to scavange like printers and such. to date, all ive been able to do is move a nut up and down a stick of all-thread connected to one of the steppers i have using both EMC and masters5 for windows. I have also used some of the other basic interfaces to provide step outputs to driver boards. So I really dont have anything to show of use, I did manage to get some free chips about 4 months ago for driving steppers that Ive already built one temporary testing board out of, rather nice, in microstep mode and the others, very proactive chip. so I dont have much experience in the pre manufactured stuff. I have picked up enough to know somethings about them and that they are much cheaper then a home built unit. the addage is you cant buy just one resistor. I have 2 oscillascopes and 2 timer packs for the older hp 180 units my tube on the 180 had lived its life out. my computer experience is sorta extensive, I can do and solve most problems with linux sometimes its a quick fix other times its a bit longer. I go by the nick gezr because im a rigrious problem slover and that tends to take time, Its not geezer because that nick name was already registered on dalnet 4 years ago, and it doesnt feel right anymore.
Im currently working on rebuilding a 1947 sb 9" lathe. I recently purchased an atlas 10" and the atlas mill to go with it. both are in need of tender love and care. but not the resurection the sb is being treated to.
I like to ramble on about some things, others I dont feel right about posting to.
I will be helping my friend retro fit a hurco mill with whatever he choses to go with, and it may not be something that isnt comercial, its up to him.
I have come across a lot of different types of machining in the manual and cnc range. any questions are welcome.
phil
who I am or at least one flavor
Moderator: Harold_V
Re: who I am or at least one flavor
Hey Phil,
Are those chips the Allegro controllers? I got a pack of samples a few months ago for a small foam cutting mill I'm itching to get at...
I have a couple of projects ahead in line, but the parts are slowly coming in... Yesterday I nabbed 6 reasonable steppers from a scrap blood analyzer from one of the hospitals I work at as a tech...
Once I get the 3 Axis mill in trim I'll definately post some basic questions as I'm just "hobby" at this stuff.
Frank
http://www.theworkshop.ca
Are those chips the Allegro controllers? I got a pack of samples a few months ago for a small foam cutting mill I'm itching to get at...
I have a couple of projects ahead in line, but the parts are slowly coming in... Yesterday I nabbed 6 reasonable steppers from a scrap blood analyzer from one of the hospitals I work at as a tech...
Once I get the 3 Axis mill in trim I'll definately post some basic questions as I'm just "hobby" at this stuff.
Frank
http://www.theworkshop.ca
hehe
Frank,
Yep the alegro UNC5804b is what I got in.they seem to be a nice chip. Im going to try to change up the way they are used so that i can drive a larger amp load with them. I havent tinkered with them in about 3 months. I do like your lathe project very cool [img]/ubb/images/graemlins/smile.gif"%20alt="[/img]. Ill see if I can get on that this comming week and get you a schematic, this weekend is already packed full.
phil
Yep the alegro UNC5804b is what I got in.they seem to be a nice chip. Im going to try to change up the way they are used so that i can drive a larger amp load with them. I havent tinkered with them in about 3 months. I do like your lathe project very cool [img]/ubb/images/graemlins/smile.gif"%20alt="[/img]. Ill see if I can get on that this comming week and get you a schematic, this weekend is already packed full.
phil
Re: Allegro Schematic
Phil,
the 5804 is the same ones I have! I do have a simple schematic and PCB layout, though as you say it needs an output driver for heavier loads...
I've heard that you can just put high current MOSFets on the output with the chip's output driving the gate, to bump-up the current for heavier applications... though I haven't seen a schematic yet.
If you're looking anyway I'd appreciate a copy, but I won't be doing much for a month or two myself...
Frank
http://www.theworkshop.ca
the 5804 is the same ones I have! I do have a simple schematic and PCB layout, though as you say it needs an output driver for heavier loads...
I've heard that you can just put high current MOSFets on the output with the chip's output driving the gate, to bump-up the current for heavier applications... though I haven't seen a schematic yet.
If you're looking anyway I'd appreciate a copy, but I won't be doing much for a month or two myself...
Frank
http://www.theworkshop.ca
Re: Allegro Schematic
I'll have to get a datasheet and look. If you can run lowside N-channels, International rectifier makes some serious FETs for not much cash... Gee I was just looking at stepper motor controllers the other day...
I'm dealing with HP (Agilent) HCTL-1100s pulled from a PnP machine along with the servos and servo amplifiers. I'm starting to write code to deal with the ISA card the controllers are on...
I'm dealing with HP (Agilent) HCTL-1100s pulled from a PnP machine along with the servos and servo amplifiers. I'm starting to write code to deal with the ISA card the controllers are on...
Don't take life seriously, it's not permenant
Ive been playing with the Allegro chip
But im not there just yet, still having some mental blocks I need to overcome but I think Im close to really having a nice cheap controler.
on the schematic, pins 2 does not touch 1 and 3 but via the 2 clamp diodes, same for pin 7 I missread the internals of the darn schematic so once I put this new info to use, I should be able to up them to 5amp capicity.
phil
on the schematic, pins 2 does not touch 1 and 3 but via the 2 clamp diodes, same for pin 7 I missread the internals of the darn schematic so once I put this new info to use, I should be able to up them to 5amp capicity.
phil
Re: Ive been playing with the Allegro chip
Alright here's a quick drawing of possible FET solutions. NOTE: There are no protection diodes on this sketch. Also I don't know steppers, I deal with servos so I don't know if you'll have a problem with grounding the commons and driving the phase.
The N-channel needs to be a logic level FET in this set up because the hex inverter won't put out enough voltage to saturate the gate. The P-channel needs to have it's gate limited to not more than 12 volts lower than the source. do it with a resistor inline to the gate and a 12 volt zener between the gate and drive voltage.
For FETs look at www.digikey.com International Rectifier IRF5210 for the P and IRL540N or IRL2910 for the N.
Well feel free to comment or kick me in the ... teeth or whatever.
The N-channel needs to be a logic level FET in this set up because the hex inverter won't put out enough voltage to saturate the gate. The P-channel needs to have it's gate limited to not more than 12 volts lower than the source. do it with a resistor inline to the gate and a 12 volt zener between the gate and drive voltage.
For FETs look at www.digikey.com International Rectifier IRF5210 for the P and IRL540N or IRL2910 for the N.
Well feel free to comment or kick me in the ... teeth or whatever.
Don't take life seriously, it's not permenant
Re: Ive been playing with the Allegro chip
I have one less chip now [img]/ubb/images/graemlins/smile.gif"%20alt="[/img]
was trying some expermitation before the link below. I just wish it would have let me see or at least smell the smoke. you know you can only let it out once.
phil
was trying some expermitation before the link below. I just wish it would have let me see or at least smell the smoke. you know you can only let it out once.
phil
Re: Ive been playing with the Allegro chip
Well, get a syringe and a bottle of liquid smoke and squeeze some back in.... [img]/ubb/images/graemlins/grin.gif"%20alt="[/img]
(It's also handy to have a tube of tolerance for those out of tol parts)
You need to have a friend around to use as a fuse (that's what friends are for) If they're really dumb you can use them as a circuit breaker.
Miswire or too much current? Those chips really don't run much current. What is the draw on the steppers? Just the solenoid for tripping the sear in a paintball gun draws 3-4 amps, Even the tiny pneumatic valves draw .5 amps. I'd think you'd need a fair amount for moving leadscrews.
The part that is a pain comming off that Allegro is they are active low outputs so you have to invert them to drive N-channel FETs. I think Maxim makes some that the outputs are FET drivers. I'll go look.
(It's also handy to have a tube of tolerance for those out of tol parts)
You need to have a friend around to use as a fuse (that's what friends are for) If they're really dumb you can use them as a circuit breaker.
Miswire or too much current? Those chips really don't run much current. What is the draw on the steppers? Just the solenoid for tripping the sear in a paintball gun draws 3-4 amps, Even the tiny pneumatic valves draw .5 amps. I'd think you'd need a fair amount for moving leadscrews.
The part that is a pain comming off that Allegro is they are active low outputs so you have to invert them to drive N-channel FETs. I think Maxim makes some that the outputs are FET drivers. I'll go look.
Don't take life seriously, it's not permenant
Re: Ive been playing with the Allegro chip
The Scematic looks great! Not too painful at all...
I once tried to design a DC motor controller w/regenerative braking... It was an education and a half in P& N-Ch Fets and Back-EMF spike suppression... Ultimately the Controller worked upto 170Amps Peak, but the Regen Braking was dropped after I filled a coffe-cup with burnt parts over a 4 week period...
Thanks
Frank
http://www.theworkshop.ca
I once tried to design a DC motor controller w/regenerative braking... It was an education and a half in P& N-Ch Fets and Back-EMF spike suppression... Ultimately the Controller worked upto 170Amps Peak, but the Regen Braking was dropped after I filled a coffe-cup with burnt parts over a 4 week period...
Thanks
Frank
http://www.theworkshop.ca