counterweight for trap door

[rieferman]

I have a few ideas in mind but always like to hear creative ideas... Building a trap door at the top of the barn steps. It's 4 feet wide x 8 feet long... so it's heavy. I have the pulleys etc. for a counterweight system.

So, what would you use for a counterweight?

 

[NUTTSGT]

Maybe a couple of old window weights.

 

[BWS]

Quikcrete in a sheetrock dope bucket,drop an eye hook in......once cured,flip it to empty......or.......go steal some kids dumbell weights,keep adding till you get the weight....or.....Fred Flinstone(think bigazz rock).......or.........springs with articulated arm(think pulldown attic doors).Good luck,BW

 

[larry4406]

Use a length of 4 inch pvc pipe with end caps. Drill one end cap, insert an eye hook, add coupling nuts and more threaded rod. Along the length of the threaded rod, have a nut a large washer and another nut. Repeat the nut/washer/nut a few times. Fill with concrete. The concrete will grip the washers preventing pullout.

Determine how much counter weight you need to counter balance your door, use the density of concrete to find out how much you need, then size the pipe length accordingly.

 

[Tyrol67]

A friend used Larry's idea but also put the PVC weight into another PVC pipe. It was a snug fit so it almost acted like a pneumatic cylinder offering some dampening on open and close. He also hid the weight inside of a wall. The system was used To drop a full stairway from the loft. Worked great. Key is getting the right weight. Those stairs dropped or raised with minimal force and then travelled very smoothly due to the dampening. He may have put a small hole in either end of the outer tube to contol the air release. I am also doing a trap door but I expect it be lighter, so I am going to try some gas springs first.

 

[Buckled]

We had the same set up in our old barn and my Dad used an old cam shaft.

 

[akdiesel]

You could use the springs that are used for tilt trailers, and adjust them for just the right tension.

 

[tcianci]

I did one once and just welded up a couple of arms that bolted to the door and extended beyond the pivot point. I bolted concrete blocks to the arms. It worked out great and the customer liked it because it had no moving parts, cables or links. The building inspector liked it too, which was my biggest concern/

 

[rieferman]

Hey guys,
Thanks for all the ideas. I ended up using weight lifting weights as my temporary solution. I liked this because it allowed me to exactly match both sets of weights, and also easily quantify how much weight I needed. Now that I know the door opens and closes very easily and smoothly, I will go ahead and do something a bit nicer that can be hidden behind a finished wall at a later date.