Crew chairs: Any experience with vacu-forming?

[megoscott]

I keep thinking of how to make crew chairs for bridges and other playsets. I've looked into having them made overseas, but I personally can't see selling 5000 chairs to make it worthwhile.

I'm pondering making the backs of the chair vacuformed, and then make the base of the chair one molded piece, drill a hole in the stem and seat base. and connect the two with a glued in rivet or something. I don't have a lot of experience with these methods. Anyone have any opinions about how feasible this is?



I'm thinking a base like this would be easier to cast than the post with four feet like the Mego stool has.

[livnxxxl]

I personally can't see selling 5000 chairs to make it worthwhile.

That would be a whole boat load of crew members. I like your idea. I have thought about Vforming off and on for a while myself. I hope someone knowledgable responds to your thread.

[shellhead]

Vacuforming would be a great option for the chairs Scott, at the theme park I work as an artist at, we have made tons of stuff that way. The chair back could be tooled (sculpted) in its possitive form exactly the way you want it to appear,then a silicone mold made of it and cast in urethane resin. This casting is then "clayed -up around the edges so only the finish surface of the seat is showing, the clay will taper away from the edges to the tabletop.
A second mold is made over the chair and the clay and a casting is made in a concrete like gypsum material( Ultra-cal 90 is commonly used). The reason for the clay is so when the hot plastic sheet is vacumed down over this stone form, the plastic will not be able to pull under the chair and permanently lock onto the mold.
The stone masters can be reproduced , say, 20 times and attached to a perforated grid, then you can make 20 chairs every time you vacume this "gang mold".
The gang mold can be scaned and ploted for a laser cutting machine to cut the chairs out of the big sheet of formed plastic.
You can use a variety of plastics,styrene,PVC,Kydex, etc., in a vast color range, tho I assume you'll basic black, and this will save you on paint costs.
Hope this helps !

Chris

[megoscott]

Wow, Chris, thanks for that response. You had me at Hello....I'm poking around my area for artists that can do this kind of work. With all the model shops (ILM, etc) around here I might be able to get something going.

[ctc]

Hmmmm....

Vaccumnforming would be perfect! I've been humming and hawing about it for a while. I KNOW it's possible to make a small former, (a friend of mine had one) but I'm not sure how....

Don C.

[Mikey]

The only problem with vaccuforming is each chair would need to be cut out and sanded.
That's a lot of chairs

Unless, you vaccuformed about 4 chairs at a time and sold them (still connected) as a kit... meaning the buyer would cut them out and complete them themselves.

[david_b]

I just kept bringing up this idea on different posts, figuring that if those of us on the Forum had the talent to scupt a face, then a chair shouldn't be much of a stretch. Granted, plastic would be cool, but I was curious what options are out there. As you could imagine, there's be LOTS of interested purchasers.

I like Scott's rendition above, unless someone had Autocad and developed another mold.

Just curious ~

[CrimsonGhost]

Would the chairs be a bit flimsy? I'm sure plastic with different grades of thickness could be used, so maybe that wouldn't be a problem. My only experience with vacuform items are plastic containers that are made for left overs and oven roasted chickens at the grocery store, and they seem to add patterns and recesses for extra strength.

Otherwise, it sounds pretty cool!!

[shellhead]

Would the chairs be a bit flimsy? I'm sure plastic with different grades of thickness could be used, so maybe that wouldn't be a problem. My only experience with vacuform items are plastic containers that are made for left overs and oven roasted chickens at the grocery store, and they seem to add patterns and recesses for extra strength.

Otherwise, it sounds pretty cool!!

At work, we've had three quarters of an inch plexiglass vacced into a globe , so thickness won't be an issue,except for matrial cost. Eighth inch black KYDEX would be stronger than injection molded styrene of the same thickness,and if the molds are scaned and laser cut as described above, there will be no need for sanding as the laser will leave a neat polished edge.

Chris

[AAAAA]

great idea I would use Co-polymer plastic, stronge even thin, does not crack.Low temp heated plastic with great moldablity.

[david_b]

Ah, I love it when great minds start.. percolating..! Greatness awaits us all!

Drive On, McDuffs ~

[captact]

If they ever get to be done and sold by anyone,..im interested in 6 of them for my 8" Hall of Justice!

[ctc]

Hmmmm....

I don't think making the originals would be real tough.... some hard wood scraps, a Dremel and a LOT of patience would do it.

Don C.

[megoscott]

Well, Chris's process sounds great, but it also sounds like a lot of resources (if you don't have a theme park shop, that is...)--a pretty big vacu-former to do do 20 at a time and then laser cutting them out?...then molding the chair base and attaching the two....And after you factor in all that work would it have been that much more expensive to get it injection molded?

[REMOVED]

I've done some vacuum forming..... It's not hard to make a former but the heating becomes the problem. You could do it in your oven but....would you want to eat food out of it then.

You would need a fairly big vacuum bed to pull a form with that depth........ but if you're willing to use your oven, you could do it pretty inexpensively.

It would be a lot less labor, I would think, to cast them with pressure casting...

I've always wanted to make some chairs................ It sounds like a cool thing however you decide to do it..