Need help scaling a prop with very little reference

[ssdesigner]

I am trying to build this prop from The Loop and I feel like I am stuck. I've stared at this so many times I feel like a mental block just won't let me progress without a little guidance. If you are reading this, thank you. Please take a moment to chime in with any thoughts you might have. I appreciate it very much!

Ok, the prop. This is a focal piece for one episode. The only things that I feel like I have as a starting point are the removable wrist bracelets at the top and the clear acrylic tube that can be removed. The bracelets need to fit on the wrist of both a small, younger woman and an average build young male. I landed on 2.75" ID on the 1/4" thick bracelets and 1/2" diameter acrylic rod. When I scale that up, the prop seems HUGE. Like way too big. But to shrink it means the bracelets get so small that I wouldn't think that they would fit on an average size male wrist. So, I need some perspective here.

 

[ssdesigner]

Here are a couple of pics of my print so far with measure for scale:

 

[eethan]

Hey,
I think the bracelets are probably not the best reference size as they probably could have used separated props that they resized to the actual actors wrists.
I would say that maybe basing the overall size on something that would feel confortable in your own hand or those of a Woman from your relatives would be a nice start as eventually, I'm guessing the prop is for you to keep.
something interesting that I find in the second ref is that the left hand of the woman seems to be grabbing exactly half of the diameter of the object. You could ask that Woman of your relatives or yourself to try different sized cylinders until this feels close to that ref.
good luck with that project, the loop is a cool different show

 

[ssdesigner]

Thanks for the reply, Eethan!

This was my weird, roundabout way of arriving at the scale for the bracelets. Based on the assumption that the acrylic rod is 1/2" in diameter, the bracelets should be approx. 3/4" tall in the width of the band.

 

[lmgill]

Using the actors hand as reference is likely not the most reliable. Actors are often much smaller than they seem on screen. (We did some costume pieces for the old series Charmed, and I could almost use the bracelets as a thumb ring)
I would scale it around the commercially made items you have to buy /use, this is what the original builder would do. The acrylic rod which you have scaled to 1/2" is a good start. I see three things in the photos that are most likely commercial products, the rod, the screws and the rocker switch. There may be some components on the circuit board you can identify. Or a common dimension of the metal bands.

When I scale pieces, I compare as many of the "off the shelf" items as I can, to see if they share a common scale to the reference photo. Keep in mind also, when people fabricate things, they most often make things to even or common units of measure, unless they have to fit preexisting restraints.
So if the prop was built in the US, then I would trust 1/8" increments over random ones. If Europe, then maybe 5mm increments.
I'll then scale the photo and write a factor number on it. Keep in mind anything that is closer to the camera or farther away, will be a different scale (factor) So try to pick things that are on the same plane in relation to where the camera was.
You need to go back and forth with comparing these off the shelf or common measured things in the picture with each other, until you find the most likely scale. Its easy to settle on something, only to find partway through your build that you now find evidence the scale is different than what you decided. (Which I think is what you are asking here)

Look at the switch. Regardless of what size the actual prop is, if you build a replica, the proportions of the pieces you can get, will be more important when the replica is finished. If this was made in the US. (particularly LA.) then there is a good chance the rocker switch came from McMaster-Carr and they have a rocker switch that looks promising. Here is their page of rocker switches. About halfway down is a switch and below that is the rocker (sold separately) McMaster-Carr has by far the best online catalog I have seen. If you click on the part, it will bring you to a page of that part, and in many cases, a drop down menu of drawing assets, 2d and 3d.

The factor is the number you have to multiply by to translate the measurement on the photo, to the size of the finished prop. If you photo is "actual size" 1:1 then the factor is "1". If the photo is 6 times bigger than your prop, the factor is 0.16666. Now anytime you need a measurement of something in the photo, measure the photo and multiply by the factor for that photo. You of course need to do this for each photo.
To find the factor, find the items that are most likely off the shelf items and divide the size of the actual item by the size from the photo. The biggest item you can do this with will result in the more accurate factor number.

Hope this helps some

 

[ssdesigner]

lmgill - thanks for the detailed write up, I sincerely appreciate it. I do have a couple of quick questions if you don't mind.

The button that I purchased scales out like this:

 

[ssdesigner]

And here is a photo where I am attempting to gauge overall width compared to my wife holding a 9.75" wide (the scale I have if the button bezel is 1.8" tall) object. In this case, my coffee thermos

 

[lmgill]

The switch you have looks spot on. I would not get to caught up in how it looks in someone's hand, as the focal length of the camera lens can affect this a lot. Your photo with the switch scaled to the body is what I would go with.

 

[lmgill]

I use dial calipers all the time, it's the tool I use most consistently. Being able to measure thing to thousands of an inch, may seem like overkill, but it comes in handy more often than you'd think. Error will creep in at every process, so accuracy can not be underrated. I almost always use decimal measurements (instead of fractions)
Being able to measure a photo (or anything) with calipers and do the math from a decimal measurement is proven to be more accurate as well as more convenient.

If you find yourself needing to go from imperial to metric often, digital calipers are very handy. I have one that also gives fractions. (But 69/164th is easier understood and used as .4207")

 

[ssdesigner]

One last comment on the overall scale. There is a scene where the actress first finds the tube and pulls it out of the lake. She puts it in an antique Simonson tackle box:

And they measure 13" wide. So, scaling off the button puts this prop at 9.75" tall. And here it is just before she pulls it back out of the tackle box:

 

[ssdesigner]

Inside the tackle box for broader perspective:

 

[ssdesigner]

I use dial calipers all the time, it's the tool I use most consistently. Being able to measure thing to thousands of an inch, may seem like overkill, but it comes in handy more often than you'd think. Error will creep in at every process, so accuracy can not be underrated. I almost always use decimal measurements (instead of fractions)
Being able to measure a photo (or anything) with calipers and do the math from a decimal measurement is proven to be more accurate as well as more convenient.

If you find yourself needing to go from imperial to metric often, digital calipers are very handy. I have one that also gives fractions. (But 69/164th is easier understood and used as .4207")

I totally agree. The calipers are super helpful. I'm also a fan of scaling inside of Adobe Illustrator. From there I can move things around and quickly adjust up or down.