Home |
Search |
Today's Posts |
|
Metalworking (rec.crafts.metalworking) Discuss various aspects of working with metal, such as machining, welding, metal joining, screwing, casting, hardening/tempering, blacksmithing/forging, spinning and hammer work, sheet metal work. |
Reply |
|
|
LinkBack | Thread Tools | Display Modes |
#41
Posted to rec.crafts.metalworking
|
|||
|
|||
Hey Iggy - stepper motors ?
David Billington prodded the keyboard
On 29/01/15 14:46, Baron wrote: Terry Coombs prodded the keyboard Got any stepper motors for cheep? I think nema 34's will work , I want to power the X axis and maybe the Y on my benchtop mill . I have (or have components to build) controllers and power supplies , can fabricate mounts and the rest in house . I actually had an 18v HF drill motor all but mounted , using a PWM controller and a 13.5 volt supply . At the speeds I need it didn't have enough torque - though I may revisit that setup now that I can cut gears . And speaking of cutting gears , how about cutting pulleys for cogged belts , anybody got experience doing that that they'd like to share ? -- Snag As if I didn't have enough in the works ... but a powered X on the mill will make some of that a LOT easier! Have you considered car wiper motors ? See my build log :- http://www.homemodelenginemachinist.com/showthread.php?t=23130 You will need to register to see the pictures. One issue with typical wiper motors is they're only intended to rotate in one direction and in my experience don't run as well in the reverse direction. The few I have taken apart only have thrust provision for the intended direction. I have used them to run in both direction and it worked OK. Window winder motors are bidirectional and have thrust pads at both end of the shaft on the ones I've dismantled. Yes that's true ! Which is one reason that I used a tumbler gear mechanism to reverse the table direction. Limit switches take care of running into the ends of the table. As far as servoing is concerned, isn't that what the DRO is for. Set zero and run to value "X" then stop. -- Best Regards: Baron. |
#42
Posted to rec.crafts.metalworking
|
|||
|
|||
Hey Iggy - stepper motors ?
Baron fired this volley in news:magspv$c8r$1@dont-
email.me: isn't that what the DRO is for. Yup. The term "feedback" covers a lot of ground. Lloyd |
#43
Posted to rec.crafts.metalworking
|
|||
|
|||
Hey Iggy - stepper motors ?
On Fri, 30 Jan 2015 08:07:40 -0600, Ignoramus8636
wrote: On 2015-01-30, Lloyd E. Sponenburgh lloydspinsidemindspring.com wrote: Um... I didn't say they were. They can be made INTO servos quite easily, and if you have an application that won't mind the inherent backlash in the geartrain, they're quite powerful and quite inexpensive for the torque they'll put out. My own thinking is, if you are smart enought to make a servo out of a wiper motor and adapt it to a milling machine, you should be able to make enough money in less time to simply buy proper equipment. i +2 on that. Decent low cost steppers af reasonable power are readily available at reasonable cost, and stepper drivers are likewize easily available. When you are done you have something that works properly and looks like it will. To put a decent decoder on a wiper motor takes some hacking. Do you put the encoder on the motor shaft, or on the output gear? On the motor shaft gives much higher resolution, but requires a lot more hacking (physically) to get to the motor shaft. - and then it is all exposed unless you build a housing for it. Or are you talking about a circuit to determine the revolutions by reading the waveform from commutation? If so, even the big manufacturers can't seem to make THAT work reliably.. |
#44
Posted to rec.crafts.metalworking
|
|||
|
|||
Hey Iggy - stepper motors ?
On Fri, 30 Jan 2015 11:43:57 -0600, "Lloyd E. Sponenburgh"
lloydspinsidemindspring.com wrote: Ed Huntress fired this volley in : Those of us who take the "recreational" part seriously should have an easy answer: if you find it pleasurable to do so, then make it. If it's a chore and if the option to buy is reasonable, then buy it. Yeah, I'll go along with that. Lloyd I've often made something and ended up replacing it with something purchased , even though what I made "worked". Generally I'd have been farther ahead buying the right parts in the first place. Buying "parts" does not preclude building the machine. |
#45
Posted to rec.crafts.metalworking
|
|||
|
|||
Hey Iggy - stepper motors ?
On Fri, 30 Jan 2015 15:37:54 -0600, "Lloyd E. Sponenburgh"
lloydspinsidemindspring.com wrote: Baron fired this volley in news:magspv$c8r$1@dont- email.me: isn't that what the DRO is for. Yup. The term "feedback" covers a lot of ground. Lloyd If you are using it for "full stroke" milling I guess a wiper motor is useable. Certainly not if you are going to try to set it up as CNC - which is more what I was thinking of when you mentioned power driving the feed. |
#46
Posted to rec.crafts.metalworking
|
|||
|
|||
Hey Iggy - stepper motors ?
|
#47
Posted to rec.crafts.metalworking
|
|||
|
|||
Hey Iggy - stepper motors ?
|
#48
Posted to rec.crafts.metalworking
|
|||
|
|||
Hey Iggy - stepper motors ?
|
#49
Posted to rec.crafts.metalworking
|
|||
|
|||
Hey Iggy - stepper motors ?
On Sat, 31 Jan 2015 11:23:40 +0000, Baron
wrote: prodded the keyboard On Fri, 30 Jan 2015 15:37:54 -0600, "Lloyd E. Sponenburgh" lloydspinsidemindspring.com wrote: Baron fired this volley in news:magspv$c8r$1@dont- email.me: isn't that what the DRO is for. Yup. The term "feedback" covers a lot of ground. Lloyd If you are using it for "full stroke" milling I guess a wiper motor is useable. Certainly not if you are going to try to set it up as CNC - which is more what I was thinking of when you mentioned power driving the feed. I wouldn't say CNC. Certainly the wiper motor stops dead when the power is removed, well maybe not the armature, but the table does. I can cut a slot within a tenth of a given distance. A caveat is to take the backlash out before cutting or you end up cutting short. Cutting short isn't as bad as cutting long!! You know the old saw - "I cut it again and it's STILL too short" |
#50
Posted to rec.crafts.metalworking
|
|||
|
|||
Hey Iggy - stepper motors ?
On Sat, 31 Jan 2015 11:27:52 +0000, Baron
wrote: prodded the keyboard On Fri, 30 Jan 2015 08:07:40 -0600, Ignoramus8636 wrote: On 2015-01-30, Lloyd E. Sponenburgh lloydspinsidemindspring.com wrote: Um... I didn't say they were. They can be made INTO servos quite easily, and if you have an application that won't mind the inherent backlash in the geartrain, they're quite powerful and quite inexpensive for the torque they'll put out. My own thinking is, if you are smart enought to make a servo out of a wiper motor and adapt it to a milling machine, you should be able to make enough money in less time to simply buy proper equipment. i +2 on that. Decent low cost steppers af reasonable power are readily available at reasonable cost, and stepper drivers are likewize easily available. When you are done you have something that works properly and looks like it will. To put a decent decoder on a wiper motor takes some hacking. Do you put the encoder on the motor shaft, or on the output gear? On the motor shaft gives much higher resolution, but requires a lot more hacking (physically) to get to the motor shaft. No just take the output from the DRO scale. I'd rather just punch in a number - from this point go 100,231 counts, knowing 10 counts is 1 thou, or whatever, and the control does the rest. And you can program the feed speed by adding a delay loop between steps on the stepper. Just using a PWM the motor slows dwn under load so you could get a variable speed feed, which could affect the look of the finish. |
#52
Posted to rec.crafts.metalworking
|
|||
|
|||
Hey Iggy - stepper motors ?
On 1 Feb 2015 03:31:17 GMT, "DoN. Nichols"
wrote: On 2015-01-31, wrote: On Sat, 31 Jan 2015 11:27:52 +0000, Baron wrote: prodded the keyboard [ ... ] To put a decent decoder on a wiper motor takes some hacking. Do you put the encoder on the motor shaft, or on the output gear? On the motor shaft gives much higher resolution, but requires a lot more hacking (physically) to get to the motor shaft. No just take the output from the DRO scale. I'd rather just punch in a number - from this point go 100,231 counts, knowing 10 counts is 1 thou, or whatever, and the control does the rest. And you can program the feed speed by adding a delay loop between steps on the stepper. Just using a PWM the motor slows dwn under load so you could get a variable speed feed, which could affect the look of the finish. Depends. If you make it a *real* servo, there should be some form of speed feedback, so the PWM is automatically adjusted to maintain the desired speed. A *real* servo motor has a tach generator on the shaft as well, so this is easy to do. If you've just got an encoder, you need to integrate the pulse rate from the encoder to derive a speed value, and tuning it is a bit trickier. Standard modern found that out, in spades, on their NC lathes. They attempted to use integrators to control the "servos" for the X and Y axis, and repeatability was terrible. After Standard Modern gave up on the lathe I spent hours on it getting it useable (sort of, anyway)- we changed grounds and sheilding, and put the PC on a dual conversion UPS (separately derived power source) and got the failure rate down from over 30% to less than 3% on production runs of 600 parts. It was the most useless damned piece of equipment I ever had the msfortune of running across, My buddy Steve lost his shirt on it - this was back at the time that Standard Modern failed and before LeBlond took it over. Enjoy, DoN. |
#53
Posted to rec.crafts.metalworking
|
|||
|
|||
Hey Iggy - stepper motors ?
Larry Jaques wrote:
On Wed, 28 Jan 2015 22:58:41 -0600, "Terry Coombs" wrote: Got any stepper motors for cheep? I think nema 34's will work , I want to From $12.99 w/ f/s on eBay http://tinyurl.com/of8584m How much torque do you need? Those cheaper ones are all nema 17's , I already have 2 of those . I have the power supply here now that I intended to power those with , I'll be looking at some reduction for torque increase . I can get either 9:1 or 16:1 in a fairly small package using 20dp gears . I never expected the responses this thread generated ... I just wanted a uniform speed for the X , and if I can work it out the Z . -- Snag |
#54
Posted to rec.crafts.metalworking
|
|||
|
|||
Hey Iggy - stepper motors ?
On Sat, 31 Jan 2015 23:51:59 -0600, "Terry Coombs"
wrote: Larry Jaques wrote: On Wed, 28 Jan 2015 22:58:41 -0600, "Terry Coombs" wrote: Got any stepper motors for cheep? I think nema 34's will work , I want to From $12.99 w/ f/s on eBay http://tinyurl.com/of8584m How much torque do you need? Those cheaper ones are all nema 17's , I already have 2 of those . I have the power supply here now that I intended to power those with , I'll be looking at some reduction for torque increase . I can get either 9:1 or 16:1 in a fairly small package using 20dp gears . I never expected the responses this thread generated ... I just wanted a uniform speed for the X , and if I can work it out the Z . With steppers on x and y you can program for angle cuts too. |
#55
Posted to rec.crafts.metalworking
|
|||
|
|||
Hey Iggy - stepper motors ?
On Sun, 01 Feb 2015 01:08:48 -0500, wrote:
On Sat, 31 Jan 2015 23:51:59 -0600, "Terry Coombs" wrote: Larry Jaques wrote: On Wed, 28 Jan 2015 22:58:41 -0600, "Terry Coombs" wrote: Got any stepper motors for cheep? I think nema 34's will work , I want to From $12.99 w/ f/s on eBay http://tinyurl.com/of8584m How much torque do you need? Those cheaper ones are all nema 17's , I already have 2 of those . I have the power supply here now that I intended to power those with , I'll be looking at some reduction for torque increase . I can get either 9:1 or 16:1 in a fairly small package using 20dp gears . I never expected the responses this thread generated ... I just wanted a uniform speed for the X , and if I can work it out the Z . With steppers on x and y you can program for angle cuts too. The price of servos has fallen and they are readily available in the used market. Why not simply use servos rather than jitterbugs? Gunner "At the core of liberalism is the spoiled child, miserable, as all spoiled children are, unsatisfied, demanding, ill-disciplined, despotic and useless. Liberalism is a philosophy of sniveling brats." PJ O'Rourke |
#56
Posted to rec.crafts.metalworking
|
|||
|
|||
Hey Iggy - stepper motors ?
On Sat, 31 Jan 2015 23:51:59 -0600, "Terry Coombs"
wrote: Larry Jaques wrote: On Wed, 28 Jan 2015 22:58:41 -0600, "Terry Coombs" wrote: Got any stepper motors for cheep? I think nema 34's will work , I want to From $12.99 w/ f/s on eBay http://tinyurl.com/of8584m How much torque do you need? Those cheaper ones are all nema 17's , I already have 2 of those . I have I noticed that a minute after sending the URL. Vendors put "NEMA 17 23 34" in the titles and it screws up searches. I saw one listing for a boresnake which stated that it worked on bores from .17 to 12ga. the power supply here now that I intended to power those with , I'll be looking at some reduction for torque increase . I can get either 9:1 or 16:1 in a fairly small package using 20dp gears . I never expected the responses this thread generated ... I just wanted a uniform speed for the X , and if I can work it out the Z . Also, don't forget Burden Surplus www.surpluscenter.com for all sorts of gearhead drives at different RPMs for cheap prices. -- Self-development is a higher duty than self-sacrifice. -- Elizabeth Cady Stanton |
#57
Posted to rec.crafts.metalworking
|
|||
|
|||
Hey Iggy - stepper motors ?
On Sun, 01 Feb 2015 00:01:33 -0800, Gunner Asch
wrote: On Sun, 01 Feb 2015 01:08:48 -0500, wrote: On Sat, 31 Jan 2015 23:51:59 -0600, "Terry Coombs" wrote: Larry Jaques wrote: On Wed, 28 Jan 2015 22:58:41 -0600, "Terry Coombs" wrote: Got any stepper motors for cheep? I think nema 34's will work , I want to From $12.99 w/ f/s on eBay http://tinyurl.com/of8584m How much torque do you need? Those cheaper ones are all nema 17's , I already have 2 of those . I have the power supply here now that I intended to power those with , I'll be looking at some reduction for torque increase . I can get either 9:1 or 16:1 in a fairly small package using 20dp gears . I never expected the responses this thread generated ... I just wanted a uniform speed for the X , and if I can work it out the Z . With steppers on x and y you can program for angle cuts too. The price of servos has fallen and they are readily available in the used market. Why not simply use servos rather than jitterbugs? It's my impression that for the DIYer, stepper controls are easier and cheaper to source - but if good surplus servo controls are available at reasonable price, of coarse use them. I've got several rather large and clunky servos around, but no drive circuitry. Definitely too big to put on my Myford lathe - - - - . Then there are the servoed motors out of inkjet computers - too small for the job. Steppers out of old LaserJets are a dime a dozen and about the right size..... Gunner "At the core of liberalism is the spoiled child, miserable, as all spoiled children are, unsatisfied, demanding, ill-disciplined, despotic and useless. Liberalism is a philosophy of sniveling brats." PJ O'Rourke |
#58
Posted to rec.crafts.metalworking
|
|||
|
|||
Hey Iggy - stepper motors ?
On Sun, 01 Feb 2015 05:59:21 -0800, Larry Jaques
wrote: On Sat, 31 Jan 2015 23:51:59 -0600, "Terry Coombs" wrote: Larry Jaques wrote: On Wed, 28 Jan 2015 22:58:41 -0600, "Terry Coombs" wrote: Got any stepper motors for cheep? I think nema 34's will work , I want to From $12.99 w/ f/s on eBay http://tinyurl.com/of8584m How much torque do you need? Those cheaper ones are all nema 17's , I already have 2 of those . I have I noticed that a minute after sending the URL. Vendors put "NEMA 17 23 34" in the titles and it screws up searches. I saw one listing for a boresnake which stated that it worked on bores from .17 to 12ga. the power supply here now that I intended to power those with , I'll be looking at some reduction for torque increase . I can get either 9:1 or 16:1 in a fairly small package using 20dp gears . I never expected the responses this thread generated ... I just wanted a uniform speed for the X , and if I can work it out the Z . Also, don't forget Burden Surplus www.surpluscenter.com for all sorts of gearhead drives at different RPMs for cheap prices. I've got a couple Nema 23s I have considered putting on the Myford. |
#59
Posted to rec.crafts.metalworking
|
|||
|
|||
Hey Iggy - stepper motors ?
On 2/1/2015 3:25 PM, wrote:
On Sun, 01 Feb 2015 00:01:33 -0800, Gunner Asch wrote: On Sun, 01 Feb 2015 01:08:48 -0500, wrote: On Sat, 31 Jan 2015 23:51:59 -0600, "Terry Coombs" wrote: Larry Jaques wrote: On Wed, 28 Jan 2015 22:58:41 -0600, "Terry Coombs" wrote: Got any stepper motors for cheep? I think nema 34's will work , I want to From $12.99 w/ f/s on eBay http://tinyurl.com/of8584m How much torque do you need? Those cheaper ones are all nema 17's , I already have 2 of those . I have the power supply here now that I intended to power those with , I'll be looking at some reduction for torque increase . I can get either 9:1 or 16:1 in a fairly small package using 20dp gears . I never expected the responses this thread generated ... I just wanted a uniform speed for the X , and if I can work it out the Z . With steppers on x and y you can program for angle cuts too. The price of servos has fallen and they are readily available in the used market. Why not simply use servos rather than jitterbugs? It's my impression that for the DIYer, stepper controls are easier and cheaper to source - but if good surplus servo controls are available at reasonable price, of coarse use them. I've got several rather large and clunky servos around, but no drive circuitry. Definitely too big to put on my Myford lathe - - - - . Then there are the servoed motors out of inkjet computers - too small for the job. Steppers out of old LaserJets are a dime a dozen and about the right size..... Gunner "At the core of liberalism is the spoiled child, miserable, as all spoiled children are, unsatisfied, demanding, ill-disciplined, despotic and useless. Liberalism is a philosophy of sniveling brats." PJ O'Rourke Coffee can (2 pound) sized servo's are used on CNC CAD/CAM plasma tables. Might find one for sell and have two X/Y nice ones with internal glass. Mine does - and has a third smaller one for Z. So I can cut wavy sheet metal following he metal up and down while cutting. Martin |
Reply |
|
Thread Tools | Search this Thread |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Forum | |||
Question about stepper motors | Electronics Repair | |||
Testing stepper motors | Electronics Repair | |||
Hobby and Stepper Motors | Electronics Repair | |||
Hobby and Stepper Motors | Electronics Repair | |||
Stepper motors and Servo motors for CNC | Metalworking |