Thread: prop pivot help!

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so im making a pnuematic clown prop that pivots foward at the waist...
i have pictures here to show and the probelm is that i cemented the tee piece at the wait where the spine and the hips connect because when i started making it i dodnt think about making it pnuematic...

I need advice pn what to do before i do the wrong way and ruin the whole structure can iounmelt the glue or brrak the tack si i can get it to pivot or do i take a sawzall and cut it out at the edges and replace it with another tee?

Help please!
Thanks,
Chris

This is exactly the structure I was thinking of.

I think if you cut the cross brace near the hips it is your best bet. Just leave about a inch of tubing exposed on each side. Then you can use connectors to allow a new cross brace. Do me a favor. Do not cut anything yet. I need the dimension of the distance between the hips. Take the measurement from the middle of the vertical pipe in each leg. I also need the size of the pipe you are using. It looks like 1 ". The key to the pivot is to get a X connector, but a slip over. This will allow you to have a cross pipe that is unbroken. I have a site you can order the parts from. The spine will still glue as you have it now, but the opposite side will have a section that will be what you attach the cylinder too. Once I have the design I will give you a list of parts you will need. I will also need the length of the cylinder. Including the body.

And take a deep breath. You have 10 months to get this done. Haste makes waste. Lets get all the dimensions first then you can cut once the geometry is worked out.

Chris,

Looks like we may need to make the entire cross bar the pivot. So you may need to cut the legs. I presume you have an elbow at the hips. Go to this site and look at what is called a slide on T. We an use the 4 way connector that looks like a T with the 4th connection 90 degrees to the other three. This will make the cylinder mount easier. You can have different mount points to increase or decrease the total movement, plus it will be easier to connect your bungy return cords. You will be adding two three way connectors at the feet to make a cross at the feet and to allow for the triangle structure behind the prop. This will give you a nice sturdy platform.

http://www.creativeshelters.com/Fitt...e&fnSKU=PVC-41

okay spinman lots of goof info!
today i will get you the size of the cylinder body and stroke
-distance between cylinder at hips

i am alittle confused at the mounts i will eventually need a specified diagra to help...
but after you said cut the legs i got confused because i am nsure where the cylinder is being taking place
i will need a parts list i presume after you draw up the diagrean i will hopfully join in everything
Thanks
Chris

The only reason I said you may need to cut the legs is because I can not locate a 4 way connector that will slip over the 1 " pipe. So instead the spine, cross / hip bar, and the 90 degree pivot control bar will all be glued together. You will replace the elbows at the top of the legs with the slip over T's. Your cross / waist bar will need to be long enough to extend past the slip over T's so we can use some pins or screws to hold it from slipping side to side. I prefer to not make items like this permanent, but you could use some cut connectors to make it permanent. I have some ideas as to how you can do that.

So cutting the legs is just to create a means to make the swivel. The pivot will still be at the waist.

gotcha okay so u dont want me to do anytihng until u draw up a diagram and send me a parts list correct

Hey spinman,
I have rough measurments for you..

length of cylinder and stroke combined- abt. 14 in
distance from hip to hip- abt. 15 3/4 in

If we can work of these measurements thats work great so just let me know when you have the diagram and parts list or if you want to give me the parts list ahead of time before diagram lemme know! either pm me or just reply to thread
Thanks man,
Chris

I will be done with the diagram after this weekend. I am trying to use my cad program. I will just guess on the balance of the dimensions. Like the length of the leg etc. You can adjust easily. Re the cylinder. So when the rod is completely retracted, I take it the cylinder is around 10 inches in length. I wonder why the cylinder is so much longer than the throw? Usually not the case. That is likely a special design unit. May even have two pistons.

well i did include the exra 2 inches where the clamp or pivot rod mounting place goes to after the cylinder body where you put a mounting brackert through and what not...
but i thought we might need to add that length from wherever we decide to mount it in... its a bimba cylinder i got off ebay lol
diagram this weekend sounds great im assuming ill get the parts list then too or before whenever you want if i have to get the parts online then getsing the parts list early would help
Thanks,
Chris

I need the actual length of the cylinder. From the mount to the other end of the shaft. Fully extended and fully retracted. Your two by four is going away if you build as I am designing. The whole unit will be PVC. All you will need to do is bolt it to a base that is sturdy enough to hold it. I do not like combining materials. I made a fully collapsible mount for my three reindeer and santa display on the roof. No screws no wood. Fits on the peak of the roof and is 16 ft long. Breaks down to four sections of 4 ft lengths. Store it in a canvas bag. In your prop I am not planning on designing to break down, so it will end up being 16 " wide X 6 Ft. The waist down portion will be a triangle that will extend rearward about 2 ft. The cylinder will mount to a cross brace in the middle of the back portion of the triangle. The pivot is that 4 way connector I told you to look at. The arm will extend out 90 degrees from the spine toward the rear of the prop. You will need to drill holes in the pipe to mount the shaft from the cylinder. If you have limited access to the proper tools, I can make some of the mount parts for you and send them to you. I have a drill press and an X / Y axis vice. The rest will be just cutting pipe and gluing. I might want to help with the pivot part as well. But we can go over that later.