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1  Using Arduino / Project Guidance / Re: Clothesline pulley on: July 24, 2013, 04:40:46 am
Ok, thanks robin and Peter.
I will try to use a dc motor and make some experiments.

As robin said, the clothesline will be a closed loop between a pulley at each end of the scene.
My cable should be as tight as possible to avoid the sagging.
I hope it won't increase the motor effort to much

the good idea is the friction wheel to make the cable stuck to the pulley.
Should I also pick some pulley with an inner rubber material to help the cable follow the rotation?
2  Using Arduino / Project Guidance / Re: Clothesline pulley on: July 23, 2013, 05:55:03 am
Budget?
How durable does this need to be? Super temporary...or like, every night for a few months?

Hello Chicago Dave.
It can't exceed 300$-350$.
The mechanism should be kept for ten shows this fall maybe more next year.  So it is not supposed to be super temporary. We will only ajust its length to the stages we will visit in the future


What's the diameter of the pulley? Pi * d will give you the amount of linear movement for one revolution of the pulley, assuming no slippage. From that you can work out how fast the cable will move (RPM * Pi * d).
Speed of a walking man = 3 to 4MPH..say 3.5MPH. 3.5 * 5280 /3600 =  ~5.1 feet per second.
Assuming a 4" diameter pulley and taking Pi as 3 for ease of calculation, one revolution of your pulley will move the cable ~1 foot. You need ~5 ft per second for walking speed, so 5 revs/second = 300 RPM. You'll have to experiment with the RPM to match the walking speed of your actors. 300 RPM seems a bit fast. I'd start with 150 RPM and increase it, if it's too slow.
Torque will depend more on the amount of friction in the system and the weight of the moving parts than the speed.

Thanks for your explanations.
3 light coat hangers will be moved, their overall weight won't exceed 1kg.
Pulleys will be machined in aluminum by a friend and bearings will decrease friction as much as possible.
Until now I have only used cheap steppers with small stall torque and low speed.
So, I wish I could find a strong stepper, even with specs beyond my needs, and not to worry about its capabilities.
would you have an idea of the stepper I could pick to use with the big easy driver?
Do you think 3 Nm cnc machine steppers will do the job?

Thanks again

3  Using Arduino / Project Guidance / Clothesline pulley on: July 22, 2013, 06:17:17 pm
Hello,
For a stage design project, I will have to build an arduino based clothesline pulley.
The project is to motorize the pulley thanks to a stepper and I would need your help to study its feasibility.
The clothesline would be 8 meters long (25 ft) and will have to move a few coat hangers at the speed of a walking men
I have already used steppers with an arduino and an Easy driver.
But my questions here are dealing with the choice of the stepper and the mechanical design of the pulley.
Which torque will I need if I want to make the coat hangers move quite fast (with 10cm wide pulleys for instance.)
What kind of cable and what pulley material would you choose to prevent slippage?
Thank you!
4  International / Français / Re: Max MSP et plusieur Xbee.. on: February 14, 2011, 07:48:41 pm

Peux tu m'en dire un peu plus sur le rôle de la télécommande?  est ce une telecommande tout simple avec des boutons à presser par les acteurs? 
si c'est le cas je ne pense pas qu'arduino soit utile, à moins que des capteurs particuliers y soient associés...
j'attends de tes précisions smiley
5  International / Français / Re: contrôler des solenoids on: February 01, 2011, 01:59:08 pm
 je crois que ceux que j'ai ont une section de 0,5 mm . (meme taille que ceux trouvés dans les starter kit par exemple)
6  International / Français / Re: contrôler des solenoids on: February 01, 2011, 12:54:16 pm
oui je voyais les cartes prépercées et cuivrées mais je ne savais pas qu'il en existait de telles avec des connections en bandes...
je vais essayer de trouver ça alors, merci!

question annexe.
si j'utilise des solenoids de 24v. est ce qu'il faut une section de fil plus epaisse que la normale?
7  International / Français / Re: contrôler des solenoids on: February 01, 2011, 11:41:22 am
Merci J-françois.
Ce circuit vierge fonctionne comme une breadboard ? avec des connections dans le sens de la longueur?
8  International / Français / Re: contrôler des solenoids on: January 31, 2011, 12:32:08 pm
aucun problème taddot.
je veux controler le remplissage de recipients a l'aide de valves/solenoids....
9  International / Français / Re: contrôler des solenoids on: January 31, 2011, 10:49:41 am
Bonjour, merci pour vos réponses.
j'avais trouvé ça de mon côté : http://www.arduino.cc/playground/uploads/Learning/solenoid_driver.pdf ou la diode n'est effectivement pas à la même place?
par contre je crois que je suis largué pour comprendre ton post fdufnews.
je vais surement avoir des solenoids de 24 V.
En fait ce qui me fait peur c'est que je vais devoir balader ce montage. et j'aurais bien aimé un truc solide en fait.
car j'aimerais avoir une bonne dizaine de solenoids
Le côté carte relai était envisagé pour la facilité. Idéalement, j'aurais bien aimé trouver un circuit à monter/souder moi même à la rigueur et qui soit tune alternative à la breadboard.
merci!
10  International / Français / contrôler des solenoids on: January 30, 2011, 08:42:16 am
Bonjour.
pour un petit projet, je cherche a pouvoir contrôler plusieurs solenoids.
apres quelques tests depuis mon arduino et un petit montage transistor et diode, je voudrais trouver quelque chose comme une carte controleur (plus solide que mes petits montages ) et qui me permette d'en controller facilement plusieurs à la fois.
pensez vous que ce genre de choses soit de qualité?
Relay Development Board je pourrai contrôler les solenoids en sortie de relay...
merci de me faire partager vos expériences précieuses à ce sujet.
Bonne journée!
11  Forum 2005-2010 (read only) / Interfacing / Re: Using Arduino with Max/MSP - Jitter on: February 14, 2010, 03:49:35 pm
I'm under max 5, never tried 4.6 withe arduino...
hope your monitor will work...
12  Forum 2005-2010 (read only) / Interfacing / Re: Using Arduino with Max/MSP - Jitter on: February 14, 2010, 02:00:19 pm
did you manage to make it work?
13  Forum 2005-2010 (read only) / Interfacing / Re: Using Arduino with Max/MSP - Jitter on: February 13, 2010, 08:39:34 am
Hi Jcontrols
If you're confortable with max, there is no reason to leave it!
for my projects i also use maxmsp jitter with arduino.
I've loaded firmata on my arduino shield (firmata examples are provided  in arduino 18 app)
http://www.arduino.cc/playground/Interfacing/Firmata
and parse signals with the maxuino patch:
http://digitalcoleman.blogspot.com/2009/03/maxuino-005-released-arduino-firmata-v2.html
there is also the Arduino2Max exemple available here:
http://www.arduino.cc/playground/Interfacing/MaxMSP#arduino2max but you'll have to program the arduino board up to your needs...
bye


14  Forum 2005-2010 (read only) / Français / Re: servo moteurs on: February 22, 2010, 04:16:45 am
Ok, je me lance dans ta solution.
Merci beaucoup en tout cas.
15  Forum 2005-2010 (read only) / Français / Re: servo moteurs on: February 22, 2010, 01:23:54 am
Super merci...
sinon pour une tension fixe, Les alim type téléphone mobile en 5v sont trop légères  (700 mA) ?
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