Thread: lunger cyinder stroke?

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what do you guys think is a good size stroke cylinder for a lunger prop. im going to make a quick prop out of an old static hanging ghoul i got last year. the mech will be a regular lunger mech but i want to make it out of pvc. i know how to do that already. what size stroke cyllinder do you think is good for a lunger prop. the hanging prop is over 4 feet tall but that does not mean i need a 4 foot tal cylinder haha. any help?I believe there is an equation out there for this...

thanks!

Chris,

You can just use the same concept as the clown waist pivot. Just have the prop hanging from a long pipe in the same position as the clown's upper backbone and neck. That way the prop will swing out and down at the TOT. You can use the same geometry that the clown has. The length of the throw of the cylinder can be short or long. If the prop is very light then you can use a shorter throw and mount it closer to the pivot. With this prop I would use a double acting cylinder though. That way you won't fight the return issue. You can power the prop forward and back.

thanks tom,

heres a pic of the mech:

http://www.frightprops.com/small-lunger-mech-0760.html

i want the ghoul to be laying down and then pop up at or above the tots. do you think a 6 inch cylinder stroke is good?

6 inch should be fine. It is all about the framework you build for it. You want a greater increase in distance so it is all about placement of the cylinder. Once you figure out all the pivot points and linkage then you can put the cylinder to the best use at suits your needs.

okay il go with 6 inches. is there a tutorial for measurments of each piece of this mech. otherwie im going according to a picture and id rather not do that hhaa

I built mechanism pretty similar to that one. 6 inches should b enough. I used either 6 or 8 don't recall. I also used mine to push the pvc frame not pull. Not sure witch is better, but that worked for me.

do you have pics or a video?

It would easier to have the cylinder extended then pull the part that starts the extention. This is not a hard build if you use PVC. It's not a hard build if using metal either.

Eyeball it. If your cylinder is 6 inch build the longest section first then attach the cylinder to the base and have one pivot point. The other bar is just support from the first. Once you get the movement you want then fortify it with the second piece.

Remember Bolt, washer,pvc pipe, washer, lock nut not tightened all the way for the pivot point. Go long bolts if going through 2 pieces of metal or PVC.

Don't go to crazy if you use PVC , I wouldn't go above 30-40PSI. Maybe a flow control on the downward motion, which technically is the cylinder extending. I would use a double acting cylinder just for this reason.

Chris,

That is a 4 bar. Totally different than the clown of course. I think I saw a 4 bar measuring tool somewhere. You say you want the prop lying down and then standing over the tots? Maybe the prop could be sitting? I will look for the measurement guide for you.

If you want to mess with it here it is. Takes some time to learn it but it works great.

http://www.boopack.com/software.html