new lumia position

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08-31-2013, 17:51
polishedball

new lumia position

Added a 7th lumia position to the beam rail, I like it but still have some tweaking to do.

http://youtu.be/1P2NAV8z6Y8
08-31-2013, 17:58
polishedball

And the previous positions

http://youtu.be/WOfJQ7u0A34
08-31-2013, 18:03
absolom7691

I love the yellow that you're getting in the first video.
09-01-2013, 04:24
Galvonaut

Beautiful.
I love the speed of the motor. How many RPM are you using?
09-01-2013, 07:08
polishedball

Quote:

Originally Posted by Galvonaut

Beautiful.
I love the speed of the motor. How many RPM are you using?

Not exactly sure it is the 2RPM motors I posted about in the eBay thread with a cheap homemade speed control
09-02-2013, 06:51
Jem

Generally the slower the better. You can buy 1/4 RPM motors and I would say these are pretty ideal as long as they move very smoothly, or buy a 1 RPM and slow it down. I'm quickly coming to the conclusion that a 1RPM motor and a geared belt drive is a good thing ;)

One of the problems is that the speed of these motors is measured at the shaft. Once you've stuck a 70 or 80mm bit of circular glass on the shaft the outside of the glass is moving faster. For various reasons it's not always practical to get your beam close to the centre.

Take a look here:

http://www.ebay.co.uk/itm/1710202155...84.m1423.l2649

http://www.ebay.co.uk/itm/1905374762...ht_1489wt_1402
09-02-2013, 07:12
Galvonaut

Yes Jem, I'd like to try that. Swamidog was showing me some pictures and video of his belt driven setup and the lumia looks wonderful at that speed.
09-02-2013, 07:16
polishedball

I'm just too cheap, 2 for $15( http://www.ebay.com/itm/Hankscraft-3...item43be66dddf ) then about a buck to build speed control, .25 for a 1/8 collar or shaft extension and done. I am able to get them to a too slow position also as the motor does run down to about a half volt.
09-02-2013, 08:15
Jem

Quote:

Originally Posted by polishedball

I'm just too cheap, 2 for $15( http://www.ebay.com/itm/Hankscraft-3...item43be66dddf ) then about a buck to build speed control, .25 for a 1/8 collar or shaft extension and done. I am able to get them to a too slow position also as the motor does run down to about a half volt.

Lol... Have you seen the cost of shipping ;)

I have a couple of those motors and some PWM speed controllers. The problem is that you have to give 'em a fair bit of voltage to start them moving then reduce the voltage to get the desired speed, this is faffy. Also, using a PWM controller doesn't really help as it affects the smoothness of the motor. I still figure it's better to either buy a geared motor such as those I linked to OR use a belt drive to adjust gearing to the desired speed. Very very slow is better for lumia ;)
09-02-2013, 08:35
polishedball

ouch just saw the $42 to ship to UK. It is only $6 in the USA

Maybe I have been lucky, these for me restart without having to increase the voltage even when set to less than .5 rpm. I am just using a simple transistor, diode, pot control. The supply I use though is good for 3 amps maybe that stiffness helps.

No doubt a motor geared for it is better not arguing that. Just putting out my experience (I am sure now that I have touted it, it will fail :) )

Quote:

Originally Posted by Jem

Lol... Have you seen the cost of shipping ;)

I have a couple of those motors and some PWM speed controllers. The problem is that you have to give 'em a fair bit of voltage to start them moving then reduce the voltage to get the desired speed, this is faffy. Also, using a PWM controller doesn't really help as it affects the smoothness of the motor. I still figure it's better to either buy a geared motor such as those I linked to OR use a belt drive to adjust gearing to the desired speed. Very very slow is better for lumia ;)
09-02-2013, 08:46
Jem

Quote:

Originally Posted by polishedball

... it will fail :) )

Lol, yes. That's what usually happens to me whenever I mess with elecktrickery... I am soooo unlucky with electrical stuff, give me good old mechanics any day :D
09-02-2013, 10:43
BradleyJay

Wow, I like where you are going with that, keep it up... totally enjoyed your lumia at SELEM. I want one of those glass pieces... Have you tried using a continuous DC Servo with arduino controller to get a slow <1 RPM rotation? I'm thinking of picking up one but not sure if it would step smoothly enough...
09-02-2013, 10:57
polishedball

I didn't make selem this year. Guessing it was displaser or platinum rigs you saw.

I can get the rotation below .5 rpm as it is. I have programmed steppers using audrino for scan through wheels but never for just wheel control.

Quote:

Originally Posted by BradleyJay

Wow, I like where you are going with that, keep it up... totally enjoyed your lumia at SELEM. I want one of those glass pieces... Have you tried using a continuous DC Servo with arduino controller to get a slow <1 RPM rotation? I'm thinking of picking up one but not sure if it would step smoothly enough...
09-02-2013, 11:14
absolom7691

I posted in the ebay thread about these little guys. http://www.ebay.com/itm/171020215599...84.m1423.l2649 I am going to be using them with a DMX "dimmer" to use as a PWM speed control to try and get them to about 0.3 RPM.
09-02-2013, 11:19
BradleyJay

Oh, right that was platinum's setup... my bad... I was just checking out this motor: http://www.servocity.com/html/0_5_rpm_gear_motor.html
09-02-2013, 12:02
Displaser

Quote:

Originally Posted by BradleyJay

Oh, right that was platinum's setup... my bad... I was just checking out this motor: http://www.servocity.com/html/0_5_rpm_gear_motor.html

I've been using the servocity.com 12VDC 1 RPM motors for several years now, just at 5V or so. They only started carrying the .5 RPM motors about a year back - these should be perfect for lumia.

Greg
09-02-2013, 16:11
Robin

I got a few 1/3 RPM motors from surplusshed.com:

http://www.surplusshed.com/pages/item/m2001p.html

They're cheap and they work really well for lumia.