# Animated Skelly Swing



## J-Man (Feb 1, 2011)

This thread is on my design of the Swinging Skelly. I didn't come up with the basic idea for this prop, I give credit to others here for that, but I did come up with this design which I believe is a very simple approach to building the mechanism. 






MATERIAL LIST
1x6x18 oak base
(2) 2x4x9.5" uprights
2x6x24 seat
6' - 1/2" pvc
(3) 1/2" pvc tee
(2) 1/2" pvc 45 degree elbow
(2) 3/4" pvc female adapter
pvc glue
wood glue
(4) 3" deck screws
20' - 3/8" rope
3/4 x 2" wood dowel
2" - 3/4"ID vinyl or rubber hose
1/4 x 3" bolt 
(4) 1/4" lock nut
(2) 1/4" nylon washer (1" diameter)
(2) 1/4 x 1-1/4" carriage bolt
Wiper motor
90 degree bracket for motor
PWM speed control

FIND A SPOT FOR THE PROP
Before beginning this project, it's important to make sure you have a tree with a fairly level horizontal limb about 11 or 12' off the ground. The limb should be at least 2" diameter. I used heavy duty industrial zip ties to secure the mechanism to the limb but you can use U-bolts or screws if you're not worried about harming the tree. 

BUILD IT
Start with the 1x6x18 oak base. You can use 3/4" plywood if you don't have oak. I wouldn't suggest pine for the base, it's too soft. Make sure the base is cut with perfectly square ends. Cut the two uprights from a 2x4, 9.5" each.* Use a miter saw or some method to be sure the cuts are perfectly square. Use a drill press and a 1-1/4" hole saw to drill the holes for the pvc adapters. Center each hole in the uprights 1-1/4" from the top. A drill press is very important in this step so the holes are straight. The 3/4" female adapters I used are Charlotte and the "slip fit" end fits very snugly into a 1-1/4" hole. Use a block of wood and a hammer to install the adapters. The threaded end of the adapters face outward when you assemble the uprights to the base. Mark 2 holes at each end of the base for the 3" deck screws to fasten the uprights. Pre-drill the base for screws and use wood glue to assemble the uprights. Make sure they are square with the ends of the base. Follow the labeled picture for cutting and assembling the pvc. Use pvc cement and make sure you push each joint fully together. I highly suggest using glue instead of screws, screws may weaken the pvc and eventually cause a fracture. Be sure the outer vertical legs on each side are aligned when gluing and also leave a little end play so the assembly isn't tight between the uprights. The center leg of the pvc should be slightly angled in the direction of the outer legs, not straight down. I ended up using a 16" length of 3/4" aluminum channel to stiffen the pvc assembly between the uprights. That part of the pvc was flexing each time the roller pushed the swing. Probably not a problem but I wasn't happy with it. I used two hose clamps to secure the channel to the pvc. The roller for the wiper motor is made from a 2" piece of 3/4" hardwood dowel. Use a drill press to drill a 1/4" hole in the center. Cut a 2" length of 3/4" ID vinyl or rubber hose and insert the dowel. Use the 3" bolt, washers, and two lock nuts to secure the roller to the motor arm. I used the arm that comes with the FrightProps motor, it is 1-1/2" hole to hole. Be sure to leave a little play so the roller moves freely. I made a 90 degree bracket for the motor, FrightProps has them but a bit pricey at $20. Use the two 1-1/4" carriage bolts and lock nuts to secure the bracket to the base. You want the the roller to contact the center leg of the pvc when the outer pvc legs are straight down and the motor arm is at 7 o'clock (when facing the motor shaft). The motor rotation needs to be CCW when facing the motor shaft. When the motor is rotating CCW it will contact the center pvc leg close to the bottom and then roll up while pushing the pvc assembly outward and slightly up. The ropes on my swing are cut to 10' lengths with my base at 11' off the ground. The ropes are threaded thru the pvc and secured with a knot at the top. You may need to adjust the rope length to suit your situation.
I secured the skelly to the seat with drywall screws thru the pelvis and legs. The PWM control is essential to this setup, without it you won't be able to adjust the motor rpm to match the swing cycle. I used the low speed wiring on the motor and powered the PWM with 12V. For my setup, 21 rpms was optimal for the swing cycle. Optimal setting has the motor roller contacting the center leg when the swing is ALMOST fully rearward. Slight adjustments of the PWM control make a difference, go a little at time until you get the best swing. 
One last thing to consider is a way to keep rain from ruining the motor and speed control. I made a "roof" from sheet metal and gave it a quick camo paint job to match the oak tree it will be installed in.

Good luck and happy swinging!


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## DaveintheGrave (Feb 12, 2004)

Great design, J-Man! Big improvement over my two-piece one.

Nice!


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## J-Man (Feb 1, 2011)

DaveintheGrave said:


> Great design, J-Man! Big improvement over my two-piece one.
> 
> Nice!


Thanks DaveintheGrave! Yours is pretty awesome too!


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## ghostlland820 (Jan 11, 2014)

Simple, elegant, inspiring design. Thanks!


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## J-Man (Feb 1, 2011)

ghostlland820 said:


> Simple, elegant, inspiring design. Thanks!


Thanks ghostlland!


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## thehoghunter (Jul 24, 2007)

Wow J-Man, great design. Will have to try this.

Question on the skelly you used - I noticed the feet are connected. Would free movement from the knee down cause problems with the swinging? It would seem more natural if the bottom portion of the legs were moving...just wondering if you had tried this or not.


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## J-Man (Feb 1, 2011)

thehoghunter said:


> Wow J-Man, great design. Will have to try this.
> 
> Question on the skelly you used - I noticed the feet are connected. Would free movement from the knee down cause problems with the swinging? It would seem more natural if the bottom portion of the legs were moving...just wondering if you had tried this or not.


Hey thanks! I used a Pose-N-Stay which doesn't have free joint movement unless it's modified. The feet aren't tied together, it's just the natural way the legs wanna go when he's sitting. I don't think free movement at the knees would affect the swing, it should be fine.


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## mharnish (Apr 27, 2017)

Thanks for the awesome tutorial. I just finished building mine and it turned out great. I haven't added the ropes/swing/skelly but the mechanism is running well. I'll post some pics once I put it out this year. One thing that would be helpful is listing the PVC length for the main top tube. I fudged it and got it fitted pretty well but it is the one measurement missing from your diagram.

Where did you get the sheet metal you used for the cover? I would like to do something similar but wasn't sure where to get it. Does Lowes or Home Depot sell something like that?

Thanks again!!


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## J-Man (Feb 1, 2011)

mharnish said:


> Thanks for the awesome tutorial. I just finished building mine and it turned out great. I haven't added the ropes/swing/skelly but the mechanism is running well. I'll post some pics once I put it out this year. One thing that would be helpful is listing the PVC length for the main top tube. I fudged it and got it fitted pretty well but it is the one measurement missing from your diagram.
> 
> Where did you get the sheet metal you used for the cover? I would like to do something similar but wasn't sure where to get it. Does Lowes or Home Depot sell something like that?
> 
> Thanks again!!


I was a Union Sheet Metal Worker for 37 years so I have a few pieces laying around. You might check with a local Heating/Cooling company and see if they'll sell you a piece of 26 gauge. Scrap yards might be an option too.


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## stick (Apr 2, 2009)

You should be able to find sheet metal at Lowe's or Home Depot the size you need. It is located around door parts and mailboxes I thank. You may need to ask a store person.

J-Man thanks for this how to.I like to make one one day.


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## J-Man (Feb 1, 2011)

stick said:


> You should be able to find sheet metal at Lowe's or Home Depot the size you need. It is located around door parts and mailboxes I thank. You may need to ask a store person.
> 
> J-Man thanks for this how to.I like to make one one day.


You're quite welcome!


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## htmagic (Apr 5, 2017)

In Home Depot, look next to the angle iron and unistrut material. They sell 24 in sq sheets of sheet metal, expanded metal, and also diamond plate which is heavier and chrome plated. Tractor Supply Company (TSC) also carries this type off stuff. 

If you have a salvage yard near you, these places have scraps of various metals including sheet metal. They sell it by the pound and there is often great savings if you don't mind doing a bit of cutting yourself. Also, if someone is throwing out a hot water heater, freezer or refrigerator you can score on some sheet metal.


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## Barbie K (Jul 1, 2015)

I want this!


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## Diabolical (Sep 16, 2017)

Now that is cool and awesome. lol


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## katiebugbows (Jan 27, 2018)

I just have a few questions about the swing prop. I understand that the rope is threaded through pvc, but where exactly is it knotted? 
Is the "3/4" aluminum channel " square shaped or is it rounded -like the pvc. You mentioned that you attached it to the middle pvc arm with hose clamps, but in the picture, the hose clamps are up top on the horizontal pvc. I know that it's been a while since you built this, but this is the best design I've seen and I could really use your help!! Thank you so much!!!!


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## J-Man (Feb 1, 2011)

katiebugbows said:


> I just have a few questions about the swing prop. I understand that the rope is threaded through pvc, but where exactly is it knotted?
> Is the "3/4" aluminum channel " square shaped or is it rounded -like the pvc. You mentioned that you attached it to the middle pvc arm with hose clamps, but in the picture, the hose clamps are up top on the horizontal pvc. I know that it's been a while since you built this, but this is the best design I've seen and I could really use your help!! Thank you so much!!!!


The aluminum channel is 3 sided square and is hose clamped to the horizontal pvc between the uprights. 
The ropes get theaded thru the pvc arms and simply knot them at the top so they can't pull thru. 
Good luck with your swing!


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## draxula16 (Apr 7, 2017)

Hey J-Man, thank you again for this post. Quick question, is there a specific name for the roller? I looked it up on Home Depot's site and only see paint rollers (unless that's what it is  ) .


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## J-Man (Feb 1, 2011)

draxula16 said:


> Hey J-Man, thank you again for this post. Quick question, is there a specific name for the roller? I looked it up on Home Depot's site and only see paint rollers (unless that's what it is  ) .


Look back at the first post with the material list and instructions, it's just a 2" length of 3/4" dowel with a 1/4" hole drilled thru it and a piece of 3/4" ID vinyl tubing over it. The 1/4"x 3 bolt goes thru the dowel to make the roller. Happy Haunting!


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## draxula16 (Apr 7, 2017)

J-Man said:


> draxula16 said:
> 
> 
> > Hey J-Man, thank you again for this post. Quick question, is there a specific name for the roller? I looked it up on Home Depot's site and only see paint rollers (unless that's what it is <img src="http://www.halloweenforum.com/images/smilies/biggrin.gif" border="0" alt="" title="Big Grin" class="inlineimg" /> ) .
> ...


Apologies! You too!


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## ghostlland820 (Jan 11, 2014)

I'm thinking of doing a circus theme this year and am trying to imagine how your skelly swing could be transformed into a skelly trapeze. Due to lack of trees in convenient locations, I'd probably have to plant poles in the yard. It would be easier if I could keep the motor on the ground and maybe use a cord to pull the arm on the cross piece. Hmmmmmm.....


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## J-Man (Feb 1, 2011)

ghostlland820 said:


> I'm thinking of doing a circus theme this year and am trying to imagine how your skelly swing could be transformed into a skelly trapeze. Due to lack of trees in convenient locations, I'd probably have to plant poles in the yard. It would be easier if I could keep the motor on the ground and maybe use a cord to pull the arm on the cross piece. Hmmmmmm.....


While just about anything is possible, I'd try to keep the motor up top. That being said, not sure you'll get enough swing out of this for a trapeze.


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## ghostlland820 (Jan 11, 2014)

Can you recommend a reliable brand/model of PWM controller? Thanks.


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