Dear DAVID Community,

In 2016, DAVID and this forum have been integrated into HP Inc.
This forum has been read-only since then, and will be switched off by the end of 2019.

To everyone who has contributed here, we thank you for all your work and for the constructive, helpful and friendly atmosphere you have created!
Please continue to discuss on the HP Support Forums.

Nema 17/23 ready Gearboxes

Which camera works? Where can you buy an adequate laser? And more...

Re: Ready Gearboxes

Postby WalterMo » Fri Aug 13, 2010 2:15 pm

To avoid the backlash I have equipped my both planetary gear motors with a spool and a streched rubber band.
Additionally the zero position should be overrun a few degrees during the return run of the laser. Then stopped, changed the direction and slowly approached to the zero position. In so doing any backlash should be avoided.

I have attached planeless scans of both motors, David and Goliath. URPP was set to true.

Walter

P.S. I think meanwhile I have to renew the calibration sheets. :(
Attachments
BeidePlanetenMotore.jpg
David and Goliath
3D gr PlanetenMotor.jpg
Planeless scan with Goliath
3D kl PlanetenMotor.jpg
Planeless scan with David
User avatar
WalterMo
Moderator
 
Posts: 2363
Joined: Mon Apr 02, 2007 6:52 pm
Location: Braunschweig, Germany

Re: Nema 17/23 ready Gearboxes

Postby Khalid Khattak » Sat Aug 14, 2010 4:10 pm

Hi Walter,
Very nice design and compact size of the motor gearbox and laser mount..
Regards
PC: Dell Inspiron i3, 2.27GHz,4GB RAM,64 bit windows 7
CAMERA:
David CCD Mono USB
LASER:
David 5mW Green line laser
PROJECTOR:
3D LED Mini Projector 250lumens, Native 1024x600
[b]http://free3dscans.blogspot.com/
Khalid Khattak
 
Posts: 942
Joined: Thu Apr 23, 2009 1:30 pm
Location: Pakistan

Re: Nema 17/23 ready Gearboxes

Postby milz » Mon Aug 16, 2010 2:26 pm

hi

the "David" box is nice. Selfmade ? eg did you have a shop url ? -)

mfg milz
Xeon x5650@4ghz
Cam : USB2 CCD 1024x768 / USB3 1280x900
Laser : LC532-5-3-F(16x65) Focusable Green
Projector Acer X110P / Acer K132
dControl one David control box + Turntable + automatic texture lights
mooooom bathroom!!!!!!
User avatar
milz
 
Posts: 520
Joined: Wed Jul 15, 2009 12:24 pm
Location: Germany Cologne

Re: Nema 17/23 ready Gearboxes

Postby WalterMo » Mon Aug 16, 2010 6:53 pm

Hi,
Yes, selfmade. It is a part of a 1m long aluminium square tube from a DIY market. Nearly all of my mechanic items are from there.
Additionally I have a small lathe in the basement. :)

Walter
User avatar
WalterMo
Moderator
 
Posts: 2363
Joined: Mon Apr 02, 2007 6:52 pm
Location: Braunschweig, Germany

Re: Nema 17/23 ready Gearboxes

Postby rich0550 » Fri Apr 08, 2011 9:47 pm

man this gearbox thing is a tough find. I have been calling around for 4 hours in the US everything is around $500
rich0550
 
Posts: 70
Joined: Thu Nov 25, 2010 5:23 am

Re: Nema 17/23 ready Gearboxes

Postby bartjuan » Sun Apr 10, 2011 6:59 pm

did you check out phidgets?

you can get the motor and gearbox for about $60 (US)

http://www.phidgets.com/products.php?category=23&product_id=3313

bart
logitech pro 9000
ARDU3 based rig Using Katyb softrware
<5mw <300mA green(532nm) Apinex-#LC532-5-3F
Apinex <5mw focusable red

Minneapolis, Minnesota USA
bartjuan
 
Posts: 45
Joined: Tue Jun 16, 2009 10:54 pm
Location: Minneapolis, Minnesota USA

Re: Nema 17/23 ready Gearboxes

Postby rich0550 » Tue Apr 12, 2011 6:07 am

shoot that is exactly what I am looking for, how is the backlash on this? small backlash?

I was advised on getting a motor with a step angle of .9 degree for large scans will this step of 1.9 be too much??
also I was advised to go with 250:1 gearbox will this one be a bit fast for large scans it says 99.5:1

thank you!
rich0550
 
Posts: 70
Joined: Thu Nov 25, 2010 5:23 am

Re: Nema 17/23 ready Gearboxes

Postby WalterMo » Tue Apr 12, 2011 10:31 am

An alternative is this motor&gear combo which Mike_A is using:
http://stepmotors.org/products/item.php ... 42&cID=138

And here are his first results:
viewtopic.php?f=6&t=2421&start=150

And JBD is also using and even selling it with a complete scanner successfully:
http://www.jbdstudio.com/?p=140

By the way, it's a very informative site. Hats off! Well done!
User avatar
WalterMo
Moderator
 
Posts: 2363
Joined: Mon Apr 02, 2007 6:52 pm
Location: Braunschweig, Germany

Re: Nema 17/23 ready Gearboxes

Postby milz » Tue Apr 12, 2011 11:51 am

hi

Thats allways a con for cheap gearboxes : the backslash
you can avoid this by using a rubber band at the laserholder

greetings
milz
Xeon x5650@4ghz
Cam : USB2 CCD 1024x768 / USB3 1280x900
Laser : LC532-5-3-F(16x65) Focusable Green
Projector Acer X110P / Acer K132
dControl one David control box + Turntable + automatic texture lights
mooooom bathroom!!!!!!
User avatar
milz
 
Posts: 520
Joined: Wed Jul 15, 2009 12:24 pm
Location: Germany Cologne

Re: Nema 17/23 ready Gearboxes

Postby Hordes » Mon Jul 04, 2011 7:26 am

Hi Walter,

The setup with gearbox and motor looks fantastic, but I'm wondering where you got the widget that couples the gearbox to the laser. Did you make that yourself? I can't find anything couples a gearbox (or motor for that matter) to an object that sits at right angles to the motor/gearbox shaft.

Cheers,

M
Hordes
 
Posts: 9
Joined: Thu Jun 30, 2011 3:39 am

Re: Nema 17/23 ready Gearboxes

Postby WalterMo » Mon Jul 04, 2011 8:21 am

Hi M...,
Yes, all my laser holders are self made.
I am lucky to have a small lathe in the basement. :)

Most of the parts are from a DIY market, cutted and glued with an epoxy adhesive. E.g. the sleeve around the laser is a part of a copper water pipe. Inner diameter = 16mm. Suitable for the green laser.
For the thinner red lasers (diam. 14) is an additional slotted sleeve necessary. It was cutted from a plastic tube originally used for a stable protection guide for electric cables in basements and workshops etc.


W
User avatar
WalterMo
Moderator
 
Posts: 2363
Joined: Mon Apr 02, 2007 6:52 pm
Location: Braunschweig, Germany

Re: Nema 17/23 ready Gearboxes

Postby XJoutsider » Tue Jul 26, 2011 5:50 pm

Is any one using this Stepper / Planetary gear combo From Phidgets with the EasyDriver 4.3 board

42BYGHW811-AG99.5 NEMA-17 Bipolar 99.5:1 Planetary Gearbox Stepper
XJoutsider
 
Posts: 1
Joined: Tue Jul 26, 2011 3:24 pm

Re: Nema 17/23 ready Gearboxes

Postby Hordes » Wed Jul 27, 2011 1:07 am

XJoutsider wrote:Is any one using this Stepper / Planetary gear combo From Phidgets with the EasyDriver 4.3 board

42BYGHW811-AG99.5 NEMA-17 Bipolar 99.5:1 Planetary Gearbox Stepper


Yes, I am trying to.

I have had trouble getting it to work but have had some recent success with a very simple circuit and sketch. The only problem is that it seems to be very temperamental. In that one has to get the right combination of current on the easy driver and delay on the rising edge (1000milliseconds and about 2/3 max current seemed to work for me) for it to turn smoothly. If you don't hit the sweet spot then it doesn't turn or behaves very erratically. And even then, in the sweet spot, with a little bit of load on the motor it can swap direction or start missing steps.

Clearly the swapping direction is an issue, but so would be the missing steps, as I understand it, for planeless scanning.

Walter suggested that the pololu driver might work better - have not tried this. It can supply a higher current to the coils (the easy driver is limited to 750mA). I am guessing (as I am really no expert) that because the phidgets motor is rated at 2.5Amps it really needs more than 750 mA for the motor to turn smoothly. But I really wouldn't know.

Khalid also had this motor (if you search the forums you'll find the thread) but it wasn't clear he got it working.

I'll keep trying though.
Hordes
 
Posts: 9
Joined: Thu Jun 30, 2011 3:39 am

Re: Nema 17/23 ready Gearboxes

Postby WalterMo » Thu Jul 28, 2011 5:45 pm

Unfortunately the producer of the Nema-17 motor from Phidgets has built a motor with a very low coil resistance of only 1.25 Ohms:
http://www.phidgets.com/products.php?product_id=3313

That means the limited space inside the motor is filled by a rather thick copper wire with a low number of coil windings.

In general: The power for a motor or a relay is constituted by the product of current and the number of turns of the coil winding. Therefore to achieve the necessary power to drive something, the current must be relative high.

The rated motor current of 2.5A per coil is the maximum current which is only necessary if the motor is heavily loaded. The attached planetary gear shouldn't be a heavy load. So I would say a current of 1.2A per coil should be sufficient. And for this duty the Pololu driver should work fine. It can drive max. 2A per coil and the supply voltage range is specified from 8V to 25V.
To avoid unnecessary heating up of the IC on board I suggest not to use a supply voltage higher than 9V for the 1.25 Ohms stepping motor.

In general it is better to use (if possible) motors with a coil resistance of about 5Ohms or more.

It would be interesting to know what motor current, kind of driver and voltage other user of this motor are using.

Walter
User avatar
WalterMo
Moderator
 
Posts: 2363
Joined: Mon Apr 02, 2007 6:52 pm
Location: Braunschweig, Germany

Re: Nema 17/23 ready Gearboxes

Postby Hordes » Fri Jul 29, 2011 5:27 am

Thanks Walter. That is, again, all very useful information.

Haven't got the pololu driver yet, but will soon I hope.

I am wondering whether its possible to disassemble the motor/gearbox to add another motor. Not sure whether it would be easy to reassemble though!
Hordes
 
Posts: 9
Joined: Thu Jun 30, 2011 3:39 am

PreviousNext

Return to Laser and Camera Hardware

Who is online

Users browsing this forum: No registered users and 1 guest

cron