# Annoyed with my Coffin Erector.



## scream1973 (Dec 23, 2007)

I have built the coffin erector from the Dc props book.. and without load it works awesome.. However when i put the prop i wanted to erect which is a foam latex zombie torso which i mounted to a piece of pvc pipe that slides down onto the the steel bar even at 100 psi its not moving.

The action is a pull vs a push with the cylinder.. So to swing it up the cylinder is pulling the piston inwards..

Any ideas on how i can fine tune this or get it to work or will i need a larger bore cylinder currently i have a 1.125" bore cylinder with a 3 inch stroke.
The only thing i can see is that the torso just weighs to much when its on the end of the pvc creating to much leverage..


Ideas?


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## eanderso13 (Apr 10, 2008)

I did something like this with my Nosferatu erector...I ended up putting some springs attached to help start the pulling motion. You got any pics of the mechanism with ans without the prop attached?


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## scream1973 (Dec 23, 2007)

I can take one tomorrow ..


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## kprimm (Mar 14, 2009)

Yes I was going to suggest possibly springs or a bigger cylinder. How heavy is the prop?


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## scream1973 (Dec 23, 2007)

I forgot to take a picture.. got caught up in smoking a turkey and working on finishing touchs for other pieces.

The prop is only about 10-15 lbs but i think from a leverage standpoint its tall ( around 3 ft ) on the end of a piece of pvc so the leverage makes it alot heavier .. I ended up changing the mount point of the pivot and that got it to pop up but flipped over and then when i bolted it down to a coffin it wouldnt pop it again and ended up jamming and bending a section of threaded rod.. so i have to change that out.

probably gonna end up needing a bigger bore cylinder.


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## Thisaintmayberry (Aug 23, 2010)

This might be a stupid question, but are you using a dual acting cylinder and at least a three way solenoid? If not, that could be the problem.


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## craigsrobotics (Oct 12, 2009)

*yes*

spring-assist on bringing the prop up. Make sure you have enough volume going to the valva/cylinder. Some basic questions, tho - 1) What size bore cylinder are you using? 2) What type of valve 3) What type of compressor CFM and pressure are you pumping?:googly:


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## craigsrobotics (Oct 12, 2009)

oops, meant VALVE....that could have been messy if I messed up another letter...LOL


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## scream1973 (Dec 23, 2007)

To answer those questions.. Its a double acting 1 1/16 bore 3" stroke bimba cylinder with a 5 way MAC solenoid valve. Compressor does 4.3 CFM @90psi and have tried all pressures from 0-100 psi.


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## scream1973 (Dec 23, 2007)

Heres some pics of the mech with the cylinder detached as i bent the threaded rod..

They are in my album under misc in case they dont show for some reason

http://hauntforum.com/album.php?albumid=26&pictureid=8520

http://hauntforum.com/album.php?albumid=26&pictureid=8519


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## eanderso13 (Apr 10, 2008)

Yeah, it looks like a really harsh angle for that cylinder to pull at. Almost pulling directly backward. I would say try starting the thing at a slight incline or/and use some springs to help start it's movement. My Nosferatu is over 5 feet tall and I raise it with about 25psi using the right angle and a couple springs.


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## debbie5 (Mar 2, 2007)

craigsrobotics said:


> oops, meant VALVE....that could have been messy if I messed up another letter...LOL


Hahhahahahha!


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## scream1973 (Dec 23, 2007)

Maybe if i rebend the "arms" and make it higher so the cylinder is at an angle vs flat.


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## eanderso13 (Apr 10, 2008)

Also, really make sure your pivot point is not binding! I used pillow-block mounted bearings:
















Not a requirement, but it really did make the movement smooth and I have not had any problems with the joint locking up.


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## scream1973 (Dec 23, 2007)

My pivot is just washers and its pretty loose so i don't think thats the issue.. Its probably more like you are saying that the angle is just to much to overcome.


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## mickkell (Jan 16, 2009)

I'm no expert but I would agree that the angle is to severe.


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