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 DIY zoom - powered via eMotimo TB3 
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Post DIY zoom - powered via eMotimo TB3
Added a zoom axis to Canon 24-105 lens, powered by eMotimo TB3 third output. Setup will work with Dragonframe software, powered via an Arduino and Big Easy Driver.
Quick test:



Attachments:
TB3_Zoom_Main_MG_5652.jpg
TB3_Zoom_Main_MG_5652.jpg [ 200.31 KiB | Viewed 14933 times ]
TB3_Zoom_4images_MG_5652.jpg
TB3_Zoom_4images_MG_5652.jpg [ 197.29 KiB | Viewed 14933 times ]

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Wed Sep 19, 2012 2:45 am
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Post Re: DIY zoom - powered via eMotimo TB3
Awesome! I love seeing DIY projects! Looks like some smooth action too!

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Wed Sep 19, 2012 6:18 am
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Post Re: DIY zoom - powered via eMotimo TB3
Jack Ripper wrote:
Awesome! I love seeing DIY projects! Looks like some smooth action too!


Hi, thanks for the comments. A zoom only test here:

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Wed Sep 19, 2012 6:43 am
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Post Re: DIY zoom - powered via eMotimo TB3
This looks great! I've been toying with adding a third axis to my TB3. Where did you purchase the gear? I took a look at the 99:1 stepper that you are using. Do you find that you need that fine resolution and torque? The 99:1 has a super fine resolution of 0.02° step angle which is awesome. I was looking at another motor that has a 0.9° step angle but by using a smaller gear, I should be able to maintain some pretty fine resolution. Is there a reason you chose a 100 tooth gear. What do you think of this motor? - http://www.phidgets.com/products.php?category=23&product_id=3302_0

Great work, thanks for posting.


Fri Oct 12, 2012 9:43 pm
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Post Re: DIY zoom - powered via eMotimo TB3
franbot wrote:
This looks great! I've been toying with adding a third axis to my TB3. Where did you purchase the gear? I took a look at the 99:1 stepper that you are using. Do you find that you need that fine resolution and torque? The 99:1 has a super fine resolution of 0.02° step angle which is awesome. I was looking at another motor that has a 0.9° step angle but by using a smaller gear, I should be able to maintain some pretty fine resolution. Is there a reason you chose a 100 tooth gear. What do you think of this motor? - http://www.phidgets.com/products.php?category=23&product_id=3302_0

Great work, thanks for posting.


Hi, Sorry for the delay, the topic notification is not working for me, I used the components because they were to hand, I have since moved to another set up that I am just about to post below.

Gear from http://www.ondrives.com
ZG0.8-100 DELRIN GEAR BOSSED 0.8 MOD 100 T - it needs to be tapped for locking screw. I tapped my own for M3 screw.

I am about to try this motor for Zoom: http://www.phidgets.com/products.php?ca ... _id=3300_0 with a 10T, 15T or 20 T.

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Sat Oct 20, 2012 9:36 am
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Post Re: DIY zoom - powered via eMotimo TB3
Focus control setup using a Nema 8 stepper motor with a Mod 0.8 10T gear and a Jag35 100T gear assy.


Attachments:
02_Nema8_MG_5697.jpg
02_Nema8_MG_5697.jpg [ 197.38 KiB | Viewed 14712 times ]
03_Nema8_MG_5695.jpg
03_Nema8_MG_5695.jpg [ 197.27 KiB | Viewed 14712 times ]
04_Nema11_MG_5697.jpg
04_Nema11_MG_5697.jpg [ 200.45 KiB | Viewed 14712 times ]

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Sat Oct 20, 2012 10:08 am
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Post Re: DIY zoom - powered via eMotimo TB3
NICE! I like the idea of the Nema 8 stepper with the small gear. Hopefully the small gear should compensate for the relatively course step angle of the motor. I'd be interested to see how this works out for you. I'm in the middle of working out a setup myself. I'll post some pictures when I have something to share.


Sun Oct 21, 2012 12:40 pm
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Post Re: DIY zoom - powered via eMotimo TB3
Thanks for the pictures of your rig Mike. Nice job of using what you already had to simplify the build. That positioning rack lets it adjust to fit different lenses or shift from focus to zoom to aperture without the usual 15mm rail system. Its a bit more compact without the rail system too. You almost have to let the motor hang forward of the lens to get close enough to use that little gear. Its a good deal though. It gives you a lot of gear reduction going to the lens gear without an additional gearbox. You'd need a really wide lens before it gets in the way. The eMotimo and stage zero make an economical "off the shelf" solution for the other axes. Its an awesome rig in terms of what it can do and it didn't cost a lot to make either.

I appreciate the fun of making your own stuff. My hobby seems to have become a lot more building and less shooting as well. If you don't mind a blatant commercial, I steal the fun of building stuff from anyone who wants to just pay me to build them a lensmotor. The TB-3 can run four axes using the aux jack to send step and direction signals to an external driver. I also make an enclosed driver using a big easydriver from Sparkfun in a case with a fan. It plugs right into the TB-3 and usually runs the dolly. The extra current from the big easydriver works best for the bigger motor on the dolly while the TB-3 drives the lensmotor with its third axis driver. I'll try to post some pictures of how the big driver case goes together. They might be helpful if you decide to enclose your driver.


Mon Oct 22, 2012 7:26 am
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Post Re: DIY zoom - powered via eMotimo TB3
sciencelookers wrote:
Thanks for the pictures of your rig Mike. Nice job of using what you already had to simplify the build. That positioning rack lets it adjust to fit different lenses or shift from focus to zoom to aperture without the usual 15mm rail system. Its a bit more compact without the rail system too. You almost have to let the motor hang forward of the lens to get close enough to use that little gear. Its a good deal though. It gives you a lot of gear reduction going to the lens gear without an additional gearbox. You'd need a really wide lens before it gets in the way. The eMotimo and stage zero make an economical "off the shelf" solution for the other axes. Its an awesome rig in terms of what it can do and it didn't cost a lot to make either.

I appreciate the fun of making your own stuff. My hobby seems to have become a lot more building and less shooting as well. If you don't mind a blatant commercial, I steal the fun of building stuff from anyone who wants to just pay me to build them a lensmotor. The TB-3 can run four axes using the aux jack to send step and direction signals to an external driver. I also make an enclosed driver using a big easydriver from Sparkfun in a case with a fan. It plugs right into the TB-3 and usually runs the dolly. The extra current from the big easydriver works best for the bigger motor on the dolly while the TB-3 drives the lensmotor with its third axis driver. I'll try to post some pictures of how the big driver case goes together. They might be helpful if you decide to enclose your driver.


Hi, James thanks for the comments, yes it is good when a home made project works out ok. Next will be the zoom control, I will use the Nema 11 for that as the 24-105 lens is fine when horizontal with the 8 but struggles when tilted. I have a gear but it is 8mm bore and the shaft is 5mm :( I will use a home turned bush for now to experiment with, workshop down for a Winter "spring clean" for the next day....week :-)
I would appreciate seeing some images of your enclosure, mine will need to be quite large, fed up with "skinny" plugs / sockets and will be going for some XLRs and 5-10Metre cable runs.
Keep on "stealing", I'll keep on building ;) ;)

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Tue Oct 23, 2012 10:57 am
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Post Re: DIY zoom - powered via eMotimo TB3
I've been working on a similar setup. I also am using the BigEasy drive and a hand full of stepper sizes. I find that the motors get extremely hot. I adjust the potentiometer but no matter what I do they get really REALLY hot. Do you experience this? It just seems like a lot of wasted energy.


Thu Oct 25, 2012 3:31 am
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Post Re: DIY zoom - powered via eMotimo TB3
Zigmo wrote:
I've been working on a similar setup. I also am using the BigEasy drive and a hand full of stepper sizes. I find that the motors get extremely hot. I adjust the potentiometer but no matter what I do they get really REALLY hot. Do you experience this? It just seems like a lot of wasted energy.


Hi, I find the BED usually runs quite cool (finger test) but the Nema8 seems to run quite hot. The Nema 11 seems quite cool but not enough testing yet and Nema 17 geared Phidgets I could use to cool the beer ;)

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Thu Oct 25, 2012 10:45 am
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Post Re: DIY zoom - powered via eMotimo TB3
Next iteration of Focus / Zoom stepper set-up, a mixture of new and "scrap bin" parts. The 15mm rail camera mount is a cheap China special
costing slightly more than the Jag lens gears. A few odds and ends need tidying up before it is complete.

Edit: 21-Mar-2013
This set up is driven via an external Ardunio not via third output of TB3 and controlled via Dragonframe ARC.


Attachments:
Complete_MG_6834.jpg
Complete_MG_6834.jpg [ 201.21 KiB | Viewed 13787 times ]
parts_MG_6831.jpg
parts_MG_6831.jpg [ 199.72 KiB | Viewed 13787 times ]

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Sun Mar 03, 2013 9:25 am
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Post Re: DIY zoom - powered via eMotimo TB3
MikeA wrote:
Added a zoom axis to Canon 24-105 lens, powered by eMotimo TB3 third output. Setup will work with Dragonframe software, powered via an Arduino and Big Easy Driver.
Quick test:



Looks great for timelapse. Could the focus be controlled with the TB3 instead of Dragonframe with this setup? It would be nice to have a compact, pan/tilt/focus or pan/tilt/zoom setup that didn't require a laptop.

Alternatively, I believe you could buy a "TB3 Black upgrade kit" from eMotimo and add it to your orange (ADD, not replace) to control six axes with Dragonframe without having to wire Big Easy's for each additional motor.


Sun Mar 24, 2013 12:25 pm
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Post Re: DIY zoom - powered via eMotimo TB3
ardpub wrote:
MikeA wrote:
Added a zoom axis to Canon 24-105 lens, powered by eMotimo TB3 third output. Setup will work with Dragonframe software, powered via an Arduino and Big Easy Driver.
Quick test:
/quote]

Looks great for timelapse. Could the focus be controlled with the TB3 instead of Dragonframe with this setup? It would be nice to have a compact, pan/tilt/focus or pan/tilt/zoom setup that didn't require a laptop.

Alternatively, I believe you could buy a "TB3 Black upgrade kit" from eMotimo and add it to your orange (ADD, not replace) to control six axes with Dragonframe without having to wire Big Easy's for each additional motor.


Hi, thanks for the comment, there is no reason why the motor driving the zoom in the original image could drive the focus ring via the third output or use the latest set up and swap out the motor connection to zoom or focus as required.
I have the TB3 Black upgrade kit on its way across the "Pond" somewhere hope to look at the possibility of using it in the way you have outlined.
MikeA

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Sun Mar 24, 2013 2:28 pm
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Post Re: DIY zoom - powered via eMotimo TB3
Thanks--I will experiment with controlling focus directly with the TB3 and its third port when it arrives.

I notice you are using very small gears to get your desired ratios. I don't think I can go that small on my rig without the motor housing hitting the lens.
Have you found a sweet spot in the gear ratio for focus/zoom with a Nema 11? Looks like I will need at least a 40 tooth drive gear for it to have the diameter to clear. My lens gears are around 113 teeth. I was thinking of shooting for somewhere between 10:1 and 30:1, which would require either enlarging the lens gear, or using a gear train or geared stepper, probably the latter for simplicity sake. On the other hand, by enlarging the lens gear I may also be able to use a smaller drive gear.

Thanks again--love this forum!


Mon Mar 25, 2013 10:56 am
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Post Re: DIY zoom - powered via eMotimo TB3
ardpub wrote:
Thanks--I will experiment with controlling focus directly with the TB3 and its third port when it arrives.

I notice you are using very small gears to get your desired ratios. I don't think I can go that small on my rig without the motor housing hitting the lens.
Have you found a sweet spot in the gear ratio for focus/zoom with a Nema 11? Looks like I will need at least a 40 tooth drive gear for it to have the diameter to clear. My lens gears are around 113 teeth. I was thinking of shooting for somewhere between 10:1 and 30:1, which would require either enlarging the lens gear, or using a gear train or geared stepper, probably the latter for simplicity sake. On the other hand, by enlarging the lens gear I may also be able to use a smaller drive gear.

Thanks again--love this forum!


I am using 100 and 25 tooth gears, there is very little room between bracket and lens barrel, maybe 1/8 to 3/16 inch. When shooting I am using 1/16 micro stepping with power always on, neither the power transistor or motor get warm.

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Mon Mar 25, 2013 11:44 am
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Post Re: DIY zoom - powered via eMotimo TB3
MikeA wrote:
I am using 100 and 25 tooth gears, there is very little room between bracket and lens barrel, maybe 1/8 to 3/16 inch. When shooting I am using 1/16 micro stepping with power always on, neither the power transistor or motor get warm.


Great--with a 40 tooth gear, I'm at about 2.8:1. I can probably either fit a slightly smaller gear on the motor or up the size of of the lens gear a tad to get in the 4:1 range without bringing in more gears--Thanks!


Mon Mar 25, 2013 1:12 pm
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Post Re: DIY zoom - powered via eMotimo TB3
ardpub wrote:
MikeA wrote:
I am using 100 and 25 tooth gears, there is very little room between bracket and lens barrel, maybe 1/8 to 3/16 inch. When shooting I am using 1/16 micro stepping with power always on, neither the power transistor or motor get warm.


Great--with a 40 tooth gear, I'm at about 2.8:1. I can probably either fit a slightly smaller gear on the motor or up the size of of the lens gear a tad to get in the 4:1 range without bringing in more gears--Thanks!


I have just received a couple of these boards today that have 1/32 step available, will be trying them out in the next day so I hope: http://www.skpang.co.uk/catalog/drv8825-stepper-motor-driver-carrier-high-current-p-1146.html

Regards MikeA.

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Wed Mar 27, 2013 11:38 am
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Post Re: DIY zoom - powered via eMotimo TB3
Mike that looks awesome, now I want to build one!
I'm a complete noob almost - quick question...

How do you connect the gears to the stepper motor?!
Also what gears did you use...

I'm planning on using this motor from phidgets, but it has a round shaft and I have realized I don't know how to connect it to a gear at all...

Stepper motor?
http://www.phidgets.com/products.php?ca ... _id=3302_0

Gear?
http://www.ebay.com/itm/Fotga-DP500II-S ... 3ccde2bc08


Thank you!


Wed Apr 03, 2013 3:01 pm
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Post Re: DIY zoom - powered via eMotimo TB3
scotchtape wrote:
How do you connect the gears to the stepper motor?!
Also what gears did you use...


The easiest thing to do is to get a gear with a set screw hub. Most lens gears have 0.08 pitch but selecting a gear depends on the size of your stepper's shaft and what ratio you want to achieve. I got mine from Sdp-Si: https://sdp-si.com/eStore/Direct.asp?GroupID=338


Thu Apr 04, 2013 6:53 am
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Post Re: DIY zoom - powered via eMotimo TB3
Thanks.

I did more research and ordered some stuff online.

I ordered a 32 pitch (0.8) mod gear with set screw.
http://www.ebay.com/itm/400407078725?ss ... 1439.l2649
I think this might be too small to fit between the motor and the lens :(
Oh well, I'll try it anyways.

I also ordered a 32 pitch spur gear that I'll try to use with a universal mount hub
http://www.ebay.com/itm/350741357782?ss ... 1439.l2649
https://www.sparkfun.com/products/10006

If this fails I guess I'll have to get a smaller motor than this one I'm planning on using
http://www.phidgets.com/products.php?ca ... _id=3302_0

Is that over kill? Should I use a smaller motor? I don't really know anything about this stuff!

For the stepper controller, should I just get something like this?
http://www.ebay.com/itm/CNC-Stepper-Mot ... 3ccdc67cb8


Thu Apr 04, 2013 8:34 am
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Post Re: DIY zoom - powered via eMotimo TB3
scotchtape wrote:
I think this might be too small to fit between the motor and the lens :(
Oh well, I'll try it anyways.


Is that over kill? Should I use a smaller motor? I don't really know anything about this stuff!



On my rig, I figured out that I need at least a 40 tooth gear for the motor to clear the lens but I'm using a much smaller Nema 11 stepper from Phidgets. I also bought a Nema 17 gearmotor for use on my slider but haven't implemented yet. I think it will be much too heavy for mounting on the eMotimo to control focus.


I have my lens motor assembled and now am just waiting on my eMotimo, which should arrive tomorrow. The motor is held on with zip ties temporarily so I can do some testing because I'm having trouble finding the tiny metric screws for the Nema 11 locally. I will also replace the foam spacer with an aluminum one that won't melt if the stepper gets hot.


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Thu Apr 04, 2013 9:08 am
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Post Re: DIY zoom - powered via eMotimo TB3
scotchtape wrote:
Mike that looks awesome, now I want to build one!
I'm a complete noob almost - quick question...

How do you connect the gears to the stepper motor?!
Also what gears did you use...

I'm planning on using this motor from phidgets, but it has a round shaft and I have realized I don't know how to connect it to a gear at all...

Stepper motor?
http://www.phidgets.com/products.php?ca ... _id=3302_0

Gear?
http://www.ebay.com/itm/Fotga-DP500II-S ... 3ccde2bc08

Hi, I am using a 25 Tooth 0.8 mod gear with a 5 mm bore, this give a tight push fit to the Nema 11 stepper motor, no screwws required.

Link: http://www.bearingshopuk.co.uk/08-mod-x-25-tooth-metric-spur-gear-in-moulded-delrin-500-36640-p.asp

NEMA 11: http://www.active-robots.com/motors-wheels/bipolar-stepper-motors/bipolar-32mm-mini-stepper.html

Cheaper NEMA (maybe same motor): http://www.zappautomation.co.uk/en/nema-11-stepper-motors/349-sy28sth32-0674a-high-torque-hybrid-stepper-motors.html

I have one of each and find no difference in performance for the purpose I am using them for.

The lens gears are JAG35 100 Tooth.

Thank you!

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Thu Apr 04, 2013 9:33 am
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Post Re: DIY zoom - powered via eMotimo TB3
Hi guys,

Thank you for that!!!

I will try the Nema 8 motor from Polulu and Nema 11 from phidgets.
Going to write a guide later so noobs like myself can do this :)


Thu Apr 04, 2013 11:20 am
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Post Re: DIY zoom - powered via eMotimo TB3
I admire your enthusiasm Scotchtape. But lets back it up one step. Before you get into browsing CNC drivers let me ask what Software are you planing on using to map out the move and communicate with the Stepper Driver.


Software
Emotimo Head - http://emotimo.com/
Has Pan and Tilt plus a 3rd output that can be used to pull focus

Dragonframe - http://www.dragonframe.com/
Full blown PC/Laptop software to control as many Axis as you will ever need.


Drivers
http://www.pololu.com/catalog/product/1182 - Used in the Emotimo Head
https://www.sparkfun.com/products/10735 - Used in many DIY setups


Thu Apr 04, 2013 11:47 am
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Post Re: DIY zoom - powered via eMotimo TB3
Yes I'm planning on getting the Emotimo head and Dragonframe :)
Planning on using Dragonframe to control it all for some shots.

I just finished building a DP zero rig (my first project!) and I spent way too much money already haha.
I'm still really new at all of this, literally just got into this stuff half a year ago and been doing tons of reading and researching.
Prior to this the only soldering I've done is on my guitar. Haven't really used any other power tools either!

If the emotimo had 4 axis that would be awesome so I wouldn't need DF! DF is freaking amazing, but lugging a netbook around is not.

I thought I would save money by going DIY but as yet I have not :)

You guys keep upping the game for timelapses!

I'm slightly confused about the arduino>driver>motor connections.
I'm assuming you just wire it together and somehow stick it in a case? I did not know that you needed a separate power supply for the motors.
If I just use a 12V blue brick will that be sufficient? My current case for the MX2 DIY is so ugly and... well... at least it sort of covers it.


Thu Apr 04, 2013 12:48 pm
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Post Re: DIY zoom - powered via eMotimo TB3
Power the driver and the driver will power the Steppers. Not familier with the "Blue Brick" how many AH is it rated?


Thu Apr 04, 2013 12:58 pm
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Post Re: DIY zoom - powered via eMotimo TB3
As I understand it, If you're using the eMotimo's 3rd axis to control focus/zoom (or a slider), you don't need to solder anything.

Just connect the 4-wire stepper motor to a 4-wire Molex connector (https://www.sparkfun.com/products/9920)--I used heat shrink connectors. If you're powering a smaller motor like a Nema 8 or 11, you will need to turn down the potentiometer on the existing stepper driver (http://www.pololu.com/catalog/product/2128), or the motor will get hot. Here is some other useful info: http://emotimo.com/index.php?option=com ... icle&id=49

I'm not sure how complicated the modification is to upgrade to 6-axis with Dragonframe but I think most of the work is done for you (http://emotimo.us6.list-manage1.com/tra ... 8b86237908).

Brian also just sent out a newsletter announcing 3-point moves with the latest firmware!


Thu Apr 04, 2013 1:47 pm
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Post Re: DIY zoom - powered via eMotimo TB3
If you search for 9800mah lithium ion rechargeable battery on eBay you'll see them.
People say that apparently there are only around 4000maH but it still works great for my purposes.
Outputs 12V. Used it with audio gear and my dolly and works fine so far...

How did you guys do the measurement for current protection?


Thu Apr 04, 2013 1:58 pm
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Post Re: DIY zoom - powered via eMotimo TB3
As I understand it, If you're using the eMotimo's 3rd axis to control focus/zoom (or a slider), you don't need to solder anything.

Just connect the 4-wire stepper motor to a 4-wire Molex connector (https://www.sparkfun.com/products/9920)--I used heat shrink connectors. If you're powering a smaller motor like a Nema 8 or 11, you will need to turn down the potentiometer on the existing stepper driver (http://www.pololu.com/catalog/product/2128), or the motor will get hot. Here is some other useful info: http://emotimo.com/index.php?option=com ... icle&id=49

I'm not sure how complicated the modification is to upgrade to 6-axis with Dragonframe but I think most of the work is done for you (http://emotimo.us6.list-manage1.com/tra ... 8b86237908).

Brian also just sent out a newsletter announcing 3-point moves with the latest firmware!


Thu Apr 04, 2013 1:59 pm
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Post Re: DIY zoom - powered via eMotimo TB3
I'd already be using the extra aux motor for the dolly, hence the need for DF for focus/zoom control :)


This part about the current limiting confuses the crap out of me:

Current limiting
To achieve high step rates, the motor supply is typically much higher than would be permissible without active current limiting. For instance, a typical stepper motor might have a maximum current rating of 1 A with a 5Ω coil resistance, which would indicate a maximum motor supply of 5 V. Using such a motor with 12 V would allow higher step rates, but the current must actively be limited to under 1 A to prevent damage to the motor.

The A4988 supports such active current limiting, and the trimmer potentiometer on the board can be used to set the current limit. One way to set the current limit is to put the driver into full-step mode and to measure the current running through a single motor coil without clocking the STEP input. The measured current will be 0.7 times the current limit (since both coils are always on and limited to 70% of the current limit setting in full-step mode). Please note that changing the logic voltage, Vdd, to a different value will change the current limit setting since the voltage on the “ref” pin is a function of Vdd.

/// So where exactly do I measure current so I can adjust it?


Thu Apr 04, 2013 2:00 pm
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Joined: Thu Feb 10, 2011 1:35 pm
Posts: 23
Location: New Orleans, Louisiana, USA
Post Re: DIY zoom - powered via eMotimo TB3
scotchtape wrote:
If you search for 9800mah lithium ion rechargeable battery on eBay you'll see them.
People say that apparently there are only around 4000maH but it still works great for my purposes.
Outputs 12V. Used it with audio gear and my dolly and works fine so far...


Wish I had gotten this instead of the 7.5ah lead acid that just arrived at my doorstep.


Thu Apr 04, 2013 2:02 pm
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Joined: Thu Feb 14, 2013 12:24 pm
Posts: 284
Post Re: DIY zoom - powered via eMotimo TB3
Instead of lead acid, you can also look at those motobatts.
They are AGM. Look really good but I only have used them in vehicles...

Another option that someone posted were those li-poly batteries.
They're a lot more finicky when it comes to charging and maintaining though.
High capacity, fast charge, low weight! But sheesh, I can't be bothered to maintain them properly...

Lion batts I can just forget about.


Thu Apr 04, 2013 2:05 pm
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Joined: Thu Feb 10, 2011 1:35 pm
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Location: New Orleans, Louisiana, USA
Post Re: DIY zoom - powered via eMotimo TB3
I finished my focus/zoom motor rig but am disappointed and surprised to discover that it doesn't have enough torque to turn the lens gear on any of my lenses. :cry: I'm surprised because I know Mika A had success with the same lens (24-105/4) and a Nema 8 (I'm using a Nema 11).

I even tested a borrowed a Tamron 24-70 (pictured), which has a very loose and easy-to-turn focus ring but still wouldn't budge.

Any suggestions for the best way to add more torque?

EDIT: After some more testing, I believe the issue is not necessarily one of insufficient torque but a problem related to the potentiometer on the driver not being set properly for this motor, causing 'skipping.' I'm going to open it up and do some tinkering and more testing--will report back on my progress.


Attachments:
photo.JPG
photo.JPG [ 114.78 KiB | Viewed 13284 times ]
File comment: Nema 11 w/40 tooth gear.
photo2.JPG
photo2.JPG [ 221.07 KiB | Viewed 13284 times ]
Sun Apr 07, 2013 8:32 am
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Location: UK
Post Re: DIY zoom - powered via eMotimo TB3
ardpub wrote:

EDIT: After some more testing, I believe the issue is not necessarily one of insufficient torque but a problem related to the potentiometer on the driver not being set properly for this motor, causing 'skipping.' I'm going to open it up and do some tinkering and more testing--will report back on my progress.


Hi, don't despair, have had same problem, I just tweaked the driver pot and away to go :D

Note: I use a separate Ardunio board + BigED's for my Zoom and Focus motors not the third output on the TB3 for the NEMA 11's.

Neat looking job you have made. I have just modified mine using lighter 1/2 x 1/8 inch aluminium strips. They have a bit of spring and hold the gears in mesh better.

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Sun Apr 07, 2013 11:29 am
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Joined: Thu Feb 10, 2011 1:35 pm
Posts: 23
Location: New Orleans, Louisiana, USA
Post Re: DIY zoom - powered via eMotimo TB3
Thanks--I eventually plan to go that route as well but for the gig I bought it for, which starts Thursday, It probably won't be practical to tote a macbook around with me (I assume you are using Dragonframe w/the second arduino).

I haven't been able to open up the TB3 yet because the screws appear to be an odd size--3.5mm hex. I'm going to the hardware store today and hopefully I will find the right size wrench to make it work.

On a side note, I figured out a way to mount my one piece of rail to the macro plate separately, so I don't have to use the baseplate from my camera rig. Its still a little heavier than I'd like it but much more stable because it reduces the overall height and minimizes the gap between the camera and TB3.


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Mon Apr 08, 2013 7:23 am
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Location: UK
Post Re: DIY zoom - powered via eMotimo TB3
ardpub wrote:
Thanks--I eventually plan to go that route as well but for the gig I bought it for, which starts Thursday, It probably won't be practical to tote a macbook around with me (I assume you are using Dragonframe w/the second arduino).

I haven't been able to open up the TB3 yet because the screws appear to be an odd size--3.5mm hex. I'm going to the hardware store today and hopefully I will find the right size wrench to make it work.

On a side note, I figured out a way to mount my one piece of rail to the macro plate separately, so I don't have to use the baseplate from my camera rig. Its still a little heavier than I'd like it but much more stable because it reduces the overall height and minimizes the gap between the camera and TB3.


Hi, you should have been supplied with a set of Hex wrenches when you purchased the TB3 ?? Yes I do control the second Arduino via Dragonframe. Good luck with the gig, hope to see some footage on here.

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Mon Apr 08, 2013 9:26 am
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Joined: Thu Feb 10, 2011 1:35 pm
Posts: 23
Location: New Orleans, Louisiana, USA
Post Re: DIY zoom - powered via eMotimo TB3
MikeA wrote:

Hi, you should have been supplied with a set of Hex wrenches when you purchased the TB3 ?? Yes I do control the second Arduino via Dragonframe. Good luck with the gig, hope to see some footage on here.


Doh! They were tucked in the inside pocket of the bag--didn't even notice.

I opened it up and did some tests at different settings but am still unable to get satisfactory results. It seems to need more torque and as a result, the motor is skipping (though, now it runs fine off the rig, when not engaged with the lens gear). After I set start and end points and the other settings it tries to go back to the starting position but only makes it a small part of the way.


Mon Apr 08, 2013 6:39 pm
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Joined: Thu Feb 10, 2011 1:35 pm
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Location: New Orleans, Louisiana, USA
Post Re: DIY zoom - powered via eMotimo TB3


On further testing, I managed to get some decent results with some consistency for two of my lenses with focus/zoom rings that are easy to turn. I definitely still need to up the gear ratio to get more torque for my other lenses and even more importantly, better accuracy. Even the two lenses I've gotten to work will stall when pointed upright (:29 seconds).

Setting focus marks with the TB3 controller's side-to-side movement is tricky (better gear ratio will help with that) but I'm also quickly discovering that the benefits of Dragonframe may outweigh the inconvenience of having to have a laptop .

(note: the first shot is only 2-axis)


Tue Apr 09, 2013 7:22 pm
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Joined: Thu Feb 14, 2013 12:24 pm
Posts: 284
Post Re: DIY zoom - powered via eMotimo TB3
What motor are you using?
Do you have a link / torque specs?


Wed Apr 10, 2013 6:07 am
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