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Mumford track and dolly
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Author:  Mumford [ Mon Aug 11, 2008 3:07 pm ]
Post subject:  Mumford track and dolly

No one told me these discussions were going on! Anyway, for those of you who have one of my rotary tables, I have been developing a low cost do-it-yourself track and dolly system for it. I don't really have time to make these for sale, but you can build your own for under $75. Take a look at:

http://www.bmumford.com/photo/dolly

The 5 amp hour battery shown runs the rotary table for about 10 hours with a time lapse motion every six seconds. That's over 4,000 exposures. It would last longer with less frequent motion.

Author:  timescapes [ Mon Aug 11, 2008 9:44 pm ]
Post subject:  Re: Mumford track and dolly

Bryan, it's great to see you here! Thanks for dropping by.

I emailed you about the dolly.

tom

Author:  Matthew David Sleep [ Tue Aug 12, 2008 4:11 am ]
Post subject:  Re: Mumford track and dolly

that dolly looks really cool. I am going to be snagging one of your enhanced rotary tables here soon, Bryan.
Can you sync 2 motors to one time machine? I guess one for controlling the dolly and one for conventional panning?
I honestly didnt know it was within reason (and budget) to do tracking shots.

tom, awesome forum. i had no idea until yesterday that it existed.

Author:  timescapes [ Sat Aug 16, 2008 10:10 pm ]
Post subject:  Re: Mumford track and dolly

Welcome, Matthew.

The answer to syncing two rotary motors is yes. You would simply split the shutter signal from the Time Machine and send it to two different rotary controllers, so they could move at different speeds (one slowly for pan, the other fast for dolly, for example).

Author:  Mumford [ Fri Aug 29, 2008 11:37 am ]
Post subject:  Re: Mumford track and dolly

Matthew David Sleep wrote:
that dolly looks really cool. I am going to be snagging one of your enhanced rotary tables here soon, Bryan.
Can you sync 2 motors to one time machine? I guess one for controlling the dolly and one for conventional panning?
I honestly didnt know it was within reason (and budget) to do tracking shots.



It's possible to split the cable from one Time Machine to drive two rotary tables with the same motor commands. But if you wanted to drive one table with a ramped pan and the other with a different ramp, or no ramp, that won't work. If you want one to ramp and the other NOT to ramp, I have a plan on how to tackle that with one Time Machine. If you want both tables to ramp at different rates, you would need two Time Machines.

Author:  Antz [ Fri Aug 29, 2008 1:41 pm ]
Post subject:  Re: Mumford track and dolly

I like the simple design for the cart.
It would quite easily make one that would fit an existing ladder for something more rigid.

When I get off the Ice in a couple of months I'll definitely be building a few new tracking systems once I have access to my workshop (and a hardware store) again.

One thing I was thinking of trying was a straight wire mechanism that could be anchored between two trees (or other suitably heavy objects) and tightened with a hand winch. Maybe even use a pair of winch cables in parallel as the runners, one above the other, the top wire supporting the weight, the bottom holding it steady.

Author:  Murray Fredericks [ Wed Sep 10, 2008 7:00 pm ]
Post subject:  Re: Mumford track and dolly

Hi Bryan,

Murray Fredericks here - back from the SALT...Thanks for your quick assistance BTW!

I like the look of the track and dolly. Can it be timed in with a 2nd motion controller and panning table to pan the head also while the camera moves along the track??

Cheers

Murray

Author:  Matthew David Sleep [ Tue Sep 23, 2008 10:36 pm ]
Post subject:  Re: Mumford track and dolly

I got my mumford enhanced table and time machine, etc today. Haven't even unboxed it yet, but I have to say Bryan was a pleasure to deal with.
I will post pics of my setup once I get the second table and dolly together in the next couple of weeks.

Author:  Mumford [ Thu Oct 02, 2008 3:00 pm ]
Post subject:  Re: Mumford track and dolly

Murray Fredericks wrote:
I like the look of the track and dolly. Can it be timed in with a 2nd motion controller and panning table to pan the head also while the camera moves along the track??


Murray-

Yes, I have done it as an experiment to confirm results.
http://www.bmumford.com/photo/dolly/wide.mov

The first motion is the track, the second is a ramped vertical pan from the dolly.

Author:  timescapes [ Fri Oct 03, 2008 2:48 pm ]
Post subject:  Re: Mumford track and dolly

Bryan, that is awesome. Can you show us a picture of what the dolly rig looks like with the second head?

Author:  unozig [ Wed Apr 29, 2009 7:23 pm ]
Post subject:  Re: Mumford track and dolly

Antz wrote:
I like the simple design for the cart.
It would quite easily make one that would fit an existing ladder for something more rigid.

When I get off the Ice in a couple of months I'll definitely be building a few new tracking systems once I have access to my workshop (and a hardware store) again.

One thing I was thinking of trying was a straight wire mechanism that could be anchored between two trees (or other suitably heavy objects) and tightened with a hand winch. Maybe even use a pair of winch cables in parallel as the runners, one above the other, the top wire supporting the weight, the bottom holding it steady.


How di dyou get on? I started to think about that while doing a timelapse near the Christchurch Gondola ride. Must have a closer look at DOC's flying foxes and the Mt Hutt skifield next month.

Author:  Antz [ Thu Apr 30, 2009 2:49 am ]
Post subject:  Re: Mumford track and dolly

Alas I didn't have nearly enough time off this year, I ended up staying on into the summer to help out a bit longer.
Not nearly enough time off to play before I came back for the winter.
I did come up with another idea I have yet to try out using two telescope trackers at the same time, just have to wait for a calm day to try it out now (it is almost always windy here).

Author:  unozig [ Sun May 17, 2009 1:24 am ]
Post subject:  Re: Mumford track and dolly

Antz wrote:
I like the simple design for the cart.
It would quite easily make one that would fit an existing ladder for something more rigid.

When I get off the Ice in a couple of months I'll definitely be building a few new tracking systems once I have access to my workshop (and a hardware store) again.

One thing I was thinking of trying was a straight wire mechanism that could be anchored between two trees (or other suitably heavy objects) and tightened with a hand winch. Maybe even use a pair of winch cables in parallel as the runners, one above the other, the top wire supporting the weight, the bottom holding it steady.


You mentioned else where that you had a winch on your 4WD. I have come across one of these cheap winches for pulling boats onto trailers. Would that be smooth enough to pull a cart on a track? The cable is 30' long and pulls at 6' per minute without load.

Author:  shutterdrone-old1 [ Sun May 17, 2009 6:30 am ]
Post subject:  Re: Mumford track and dolly

unozig wrote:
You mentioned else where that you had a winch on your 4WD. I have come across one of these cheap winches for pulling boats onto trailers. Would that be smooth enough to pull a cart on a track? The cable is 30' long and pulls at 6' per minute without load.


A winch will not pull in an exactly-straight line. If you notice, the cable wraps around the winch drum from side-to-side, you would need a rigid enough structure for your dolly and track to overcome the movement created as it does this. Also, a winch is not the most efficient, power-wise, and many will consume a lot more power (it's designed to pull more weight than you're trying to move) than, say, mumford's rotary axis.

!c

Author:  Antz [ Sun May 17, 2009 12:19 pm ]
Post subject:  Re: Mumford track and dolly

shutterdrone wrote:
unozig wrote:
You mentioned else where that you had a winch on your 4WD. I have come across one of these cheap winches for pulling boats onto trailers. Would that be smooth enough to pull a cart on a track? The cable is 30' long and pulls at 6' per minute without load.


A winch will not pull in an exactly-straight line. If you notice, the cable wraps around the winch drum from side-to-side, you would need a rigid enough structure for your dolly and track to overcome the movement created as it does this. Also, a winch is not the most efficient, power-wise, and many will consume a lot more power (it's designed to pull more weight than you're trying to move) than, say, mumford's rotary axis.

!c

I'd have to agree. That type of winch would be quite fast and potentially uneven for time-lapse.
Another Idea I sort of toyed with was the possibility of using a modified / very low geared looping capstan winch mechanism on a 4x4, then use the whole 4x4 as a dolly with the camera mounted on it. It would probably be pretty smooth on most flat surfaces, and allow big tracking movements without the need for a actual dolly track.

Author:  unozig [ Sun May 17, 2009 4:30 pm ]
Post subject:  Re: Mumford track and dolly

Many thanks guys, has any one winched a 4WD ? I'm sure it would slow down that 6'/min with out load to ideally 1'/min say?
Power would not be a problem and I don't think the line would wobble to much.

Author:  Antz [ Sun May 17, 2009 10:21 pm ]
Post subject:  Re: Mumford track and dolly

Most off the shelf winches I've used (from memory) move about 6" / sec, which is way too fast for most TL.
You can easily halve this by feeding the winch line out and back via a pulley at the far end.

When on level ground very little power would be required, so a very light-weight motor would do it, but it would probably need to be fed through a gear box to bring the speed right down. You could probably pick up an old gear box for next to nothing from a wrecking yard. It would be a handy way of controlling the speed too.

Author:  shutterdrone-old1 [ Mon May 18, 2009 7:53 pm ]
Post subject:  Re: Mumford track and dolly

Well, my winch will pull my vehicle (oh, say, about 4800lbs give or take 300 lbs) at a rate of about 1'/min - and that's considered a fairly slow speed. If you were to attempt a pulley-setup, it would require multiple, expensive, snatch-blocks (that's a lot of weight to risk your life and investment on cheap home-depot hardware).

I can get about 6 minutes of pull w/ the motor idling before voltage drops below 12v, normally keeping it at 3k RPM + to get about 10-15 minutes of pull before the battery voltage drops below 12v. That's because it's electric, you can always go hydraulic, but you're going to need a hydro pump, or use your power steering box to run it.

If you're going that route to save money, you won't. You'd have to buy the winch, a means to mount it, and then you'll always need a tree or sand anchor and a clear path. How much weight are you moving? Dayton makes a 1.5RPM 736 oz/in 12V gearmotor that's just a bit bigger than the palm of my hand. Servocity has them for $40. It costs a lot less, uses less power, and doesn't require thousands of pounds on the other end =) Just use it like Mumford shows in his designs.

!c

Author:  unozig [ Mon May 18, 2009 8:20 pm ]
Post subject:  Re: Mumford track and dolly

Thanks guys! What I was thinking was drive 4WD with a trailer to location. Then set up the rig and get the winch to pull the trailer ( with ballast). As the stated 6'/min without load is as we know to fast for TL. Hence wanted an idea of how much weight I need. The speed of 1'/min is ideal as the winch cable is 30' long. Now will have to do the maths for power requirement using a deep cycle secondary battery.

Author:  Antz [ Mon May 18, 2009 10:19 pm ]
Post subject:  Re: Mumford track and dolly

The power draw of the winch will vary a lot with the load placed on it, and many of them are not designed to run for long periods of time, so personally I would be inclined to build a custom rig myself. The cost would be pretty minimal with a bit of cannibalization of old parts.
With the 12,000lb winch I had on my Landcruiser I typically only had enough power for about 3 major winching / un-bogging sessions per day before the dual battery system lost most of it's capacity.

But it sounds like you have one that will probably do the trick. A car trailer with a good 3rd wheel would probably do well I would imagine, but would need slightly smoother ground overall.
I'd be most interested to hear how you get on.

Author:  A.S.I.G.N_Baz [ Thu Jun 11, 2009 7:17 am ]
Post subject:  Re: Mumford track and dolly

Great bit of kit! Gives me copious amounts of grand ideas.

I would like to know more about the hardware and software used to control this. I have a Canon 400D and an Apurture APTR1C intervalometer.

1. Where do you get the drum, stepper, and other electronics units you have there? What do they cost?
2. What do the other units on the dolly do? How does it all work?
3. Does the Dolly just move between shots, or during them?
4. Can the camera or intervalometer run the movement of the dolly between shots, or do you have to drag your laptop out field with you?

I can make all range of different tracks and custom dollys in my workshop, it's the electronics I am lost on.

Oh, if it's any help, my photography is all time lapse night skies of 30-40 second exposures with about 8 second intervals between them.

Baz.

Author:  milapse [ Thu Jun 11, 2009 8:58 am ]
Post subject:  Re: Mumford track and dolly

A.S.I.G.N_Baz wrote:
1. Where do you get the drum, stepper, and other electronics units you have there? What do they cost?


He sells the entire kit - 'time-machine', rotary table and cable to connect to your particular camera for something like $1300-1600

A.S.I.G.N_Baz wrote:
3. Does the Dolly just move between shots, or during them?


between

A.S.I.G.N_Baz wrote:
4. Can the camera or intervalometer run the movement of the dolly between shots, or do you have to drag your laptop out field with you?


that's what the 'time machine' does. no laptop. but you know this stuff it not 'light'. A laptop is noise to the system.

Author:  A.S.I.G.N_Baz [ Thu Jun 11, 2009 9:34 am ]
Post subject:  Re: Mumford track and dolly

Ahh...Thanks. Sorry about that...I missed all the links up the top.

Cheers.

Baz.

Author:  Jeff Wright [ Sun Nov 22, 2009 4:52 pm ]
Post subject:  Re: Mumford track and dolly

unozig wrote:
Antz wrote:
I like the simple design for the cart.
It would quite easily make one that would fit an existing ladder for something more rigid.

When I get off the Ice in a couple of months I'll definitely be building a few new tracking systems once I have access to my workshop (and a hardware store) again.

One thing I was thinking of trying was a straight wire mechanism that could be anchored between two trees (or other suitably heavy objects) and tightened with a hand winch. Maybe even use a pair of winch cables in parallel as the runners, one above the other, the top wire supporting the weight, the bottom holding it steady.


You mentioned else where that you had a winch on your 4WD. I have come across one of these cheap winches for pulling boats onto trailers. Would that be smooth enough to pull a cart on a track? The cable is 30' long and pulls at 6' per minute without load.


As your cable fills the drum of the winch it will increase the diameter and will exponentially change the speed of the the dolly with every layer.

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