Re: OT: stepper motors, etc
Actually (and I am replying to the OP, not my own message) you might be better off with a grunty servomotor. Some R/C servos are capable of very high torque and rapid and accurate positioning. In fact, since a servo is often used to give a 180 degree output range it might suit this project better to gear the output down (because such a large range is not required) and thereby increase the torque. That would keep the cost down too, and you wouldn't have to write your own PID controller for positioning. A
Re: OT: stepper motors, etc
On Tue, June 2, 2009 12:37, Craig Falconer wrote: > Vik Olliver wrote, On 02/06/09 15:02: > >> You probably want to drive the tensioner through a worm gear, which >> automatically ratchets. > > How do you slack off the tension later, if there's some kind of one-way > ratchet in there? With a manual release? You don't. You just run the worm the other way (it is, after all, a worm that turns). Ratchet is probably a poor choice of word. Fundamentally the worm gear prevents any load on the output being passed back to the input. http://en.wikipedia.org/wiki/Worm_drive A
Re: Desktop suddenly insists on showing all contents of $HOME
i solved that one by using gksudo nautilus which logs you in as root, then moving the folder back to the filesysten where it belongs. Cheers chris T On Mon, 2009-06-01 at 17:28 +1200, Andrew Packer wrote: > On Mon, 2009-06-01 at 15:56 +1200, chris wrote: > > I have had this happen > > You have to add that line SHMConfig to the options section of xorg.conf > > then reboot. > > > > I am asuming that the mouse pad works perfectly for other users? > > I confess I didn't think of trying the touchpad while logged in as > another user. No one else uses the touchpad. (I use it only rarely - > ordinarily have a trackball plugged in.) > > I've added the line Option "SHMConfig" "true" to /etc/X11/xorg.conf, and > the touchpad config program now works. At least, it runs. > > I've still got my entire home folder on my desktop, which is the main > problem. > > =Andrew > > >
Re: OT: stepper motors, etc
Vik Olliver wrote, On 02/06/09 15:02: You probably want to drive the tensioner through a worm gear, which automatically ratchets. How do you slack off the tension later, if there's some kind of one-way ratchet in there? With a manual release? -- Craig Falconer
Re: OT: stepper motors, etc
On Tue, 2009-06-02 at 15:02 +1200, Vik Olliver wrote: > If you do find a supplier of nice stepper motors, please let me know. I > can only find fairly feeble ones from Jaycar that asplode if left > connected to their rated operating voltage. > > Vik :v) You probably need washing machine motors for your needs, Vic (: -- Steve Holdoway http://www.greengecko.co.nz
Re: OT: stepper motors, etc
On 02/06/09 Wesley Parish wrote: Sorry to be so off-topic, but are there any stepper motor suppliers in Christchurch? I'm wondering if there are any small enough to fit in a cramped location, yet powerful enough to change tension on a wire already under considerable tension? And electrically robust enough to handle regular on-off switching, while using as minimal an amount of current at as low a voltage as possible? You probably want to drive the tensioner through a worm gear, which automatically ratchets. If you do find a supplier of nice stepper motors, please let me know. I can only find fairly feeble ones from Jaycar that asplode if left connected to their rated operating voltage. Vik :v)
Re: Stepper motors.
A source of "potentially robust" stepper motors is from cars with climate control air-conditioning - they are also used to pulling cables. (Not Alfa 164s though because their stepper motors are a weak point) 2009/6/2 Christopher Sawtell : > I have a few loose and various stepper motors, also a couple of old printers > which will have some in as components. > > Molten media have a nearly continuous supply out of scanners, printers, old > disks, etc etc. > If mine are no good, I'd suggest you try there. > > -- > Sincerely etc. > Christopher Sawtell >
Stepper motors.
I have a few loose and various stepper motors, also a couple of old printers which will have some in as components. Molten media have a nearly continuous supply out of scanners, printers, old disks, etc etc. If mine are no good, I'd suggest you try there. -- Sincerely etc. Christopher Sawtell
Re: OT: stepper motors, etc
Wesley Parish wrote, On 02/06/09 13:11: Sorry to be so off-topic, but are there any stepper motor suppliers in Christchurch? I'm wondering if there are any small enough to fit in a cramped location, yet powerful enough to change tension on a wire already under considerable tension? And electrically robust enough to handle regular on-off switching, while using as minimal an amount of current at as low a voltage as possible? This is for my Pedal Steel Guitar The Next Generation ;) You want to make it self-tuning or something ? Possibly need some kind of reduction gear instead of making the stepper do it all. And it would have to lock still under no-power, else the string would pull back to slack. Probably need some other controlled clamp to hold the string once its been tensioned. -- Craig Falconer
OT: stepper motors, etc
Hi, folks Sorry to be so off-topic, but are there any stepper motor suppliers in Christchurch? I'm wondering if there are any small enough to fit in a cramped location, yet powerful enough to change tension on a wire already under considerable tension? And electrically robust enough to handle regular on-off switching, while using as minimal an amount of current at as low a voltage as possible? This is for my Pedal Steel Guitar The Next Generation ;) Thanks Wesley Parish "Sharpened hands are happy hands. "Brim the tinfall with mirthful bands" - A Deepness in the Sky, Vernor Vinge "I me. Shape middled me. I would come out into hot!" I from the spicy that day was overcasked mockingly - it's a symbol of the other horizon. - emacs : meta x dissociated-press
Re: Tonight
linux-users@it.canterbury.ac.nz writes: >Checking in to confirm we're farewelling Chris from 6:30pm tonight at >the Twisted Hop. I can't make it, but I'd be obliged if you could tell him "thanks and good luck" from me. Leif
Re: Tonight
YES! 2009/6/2 Roy Britten > Checking in to confirm we're farewelling Chris from 6:30pm tonight at > the Twisted Hop. > > See you there. > Roy. > -- Sincerely etc. Christopher Sawtell
Tonight
Checking in to confirm we're farewelling Chris from 6:30pm tonight at the Twisted Hop. See you there. Roy.
Re: Desktop suddenly insists on showing all contents of $HOME
On Tue, 2009-06-02 at 07:40 +1200, Nick Rout wrote: > what does ls -l ~/Desktop tell you? IIRC, when I ran ls -l ~/Desktop early on in the investigation, the output showed the same files that I saw by opening a Nautilus window via Places > Desktop. When I booted up this morning the problem was gone. The desktop is now showing the contents of ~/Desktop. Running ls -l ~/Desktop and comparing with the GUI version (with "View Hidden Files" ticked), the outputs are equivalent. Between when I sent the request for help and this morning, I had powered down and rebooted the laptop at least twice (it doesn't get left running because electrical energy is limited here, and suspend-to-RAM crashes more often than not). I'm very happy to have my desktop back, but puzzled. =Andrew
Re: Desktop suddenly insists on showing all contents of $HOME
On Mon, Jun 1, 2009 at 5:28 PM, Andrew Packer wrote: > On Mon, 2009-06-01 at 15:56 +1200, chris wrote: >> I have had this happen >> You have to add that line SHMConfig to the options section of xorg.conf >> then reboot. >> >> I am asuming that the mouse pad works perfectly for other users? > > I confess I didn't think of trying the touchpad while logged in as > another user. No one else uses the touchpad. (I use it only rarely - > ordinarily have a trackball plugged in.) > > I've added the line Option "SHMConfig" "true" to /etc/X11/xorg.conf, and > the touchpad config program now works. At least, it runs. > > I've still got my entire home folder on my desktop, which is the main > problem. > > =Andrew > > what does ls -l ~/Desktop tell you?
