3D Spiral lollipop help

[NeathawkSigns]

Hello Im a first time poster on here!! I started a 3D sign making company and recently made a 3D tooth with a face (butt &all). After I finished and installed the teeth (3),I got a proposition to make 3D spiral lollipop for a candy store. 4 total. The "candy" part is 7 ft tall with the post it being wrapped around is roughly 4.5" wide. I have previously usedPVC to make my signs. I was thinking of using HDU for this project. It is interior and will be on direct sunlight. I was thinking of using 3inch HDU carve the exterior of the pop then turn itover and carve a half circle (where the post sits in it) and do the same on the second side. Paint the pop then glue to pole. Does this sound right to do? We have a 4x8ft shopbot. Is HDU the right material to use? Any and all suggestions appreciated.

[knight_toolworks]

I don't think hdu would be good where people can touch it.

[myxpykalix]

I am confused by your description of the spiral candy? Do you have any pictures or drawings of what you are trying to do? Are you talking about a flat spiral lollipop (the part you lick)
or are you talking about a spiral that wraps around a column similar to this picture?:D

[NeathawkSigns]

Attached is the type of pop we are making 7 ft.

[CNYDWW]

Looks like you'd be hard pressed to mill that on a 3 axis machine without quartering it. Doing two pieces, the sides are going to loose detail. If by chance you have a 4 axis machine and aspire, all you'd need is the 3d model and do it that way. Another option would be milling out a mold from extruded polystyrene insulation board. You can get it in 2" thickness. Biggest issue with that is finding an affordable castable material that will hold up. Not to mention weight issues. Castable resin would be the best bet for durability but it is expensive and heavy. They do however have options to add filler beads and the like. Fillers reduce weight and volume of the expensive resin.

Regards
Randy

[Brady Watson]

You sometimes have to think outside the box for a project like this. You *could* machine a couple of long strips of HDU or even plastic cast them with the rounded profile & wrap them manually onto a dowel or mandrel to get the final look you are going for. You may have to scarf the back to make them flexible enough, but with a little bondo or thickened epoxy, it's pretty straightforward.

-B

[NeathawkSigns]

The reason I was going to use HDU was because it is much lighter and I can get 2" or more thickness if I need too. I was going to epoxy the exterior halves to give it a hard shell per say, and then sand/paint. Then when I was installing glue to steel posts, epoxy the seams lightly sand and touch up paint. Attached is a drawing I did. I may just try out on 2" installation foam first.

[zeykr]

Swim noodles wrapped around a post is what comes to mind.

[myxpykalix]

You don't say, so i will assume you do not have an indexer? If you had one I could make you a spiral toolpath to cut this easily. If you need someone to cut this on an indexer i could possibly do it for you.

If interested I could find the link to a guy who was making things like spiral legs in "halves" and gluing them up which is what I think you are trying to do.

[bleeth]

You can do the spiral by heating PVC and wrapping it around the stick. Machine your half tube first. Go bit by bit with a heat gun (very slow) or a torch (lots quicker) if you have a good touch. For the torch use the yellow cans. That's how to bend Acrylic and or Solid Surface also if you don't have an oven.
Worked in a PVC plant night shift in college. It bends real well with heat.

[CNYDWW]

You can do the spiral by heating PVC and wrapping it around the stick. Machine your half tube first. Go bit by bit with a heat gun (very slow) or a torch (lots quicker) if you have a good touch. For the torch use the yellow cans. That's how to bend Acrylic and or Solid Surface also if you don't have an oven.
Worked in a PVC plant night shift in college. It bends real well with heat.

Nice call Dave! I'm going to be playing with "thermoforming" some pvc signs after they're milled for some different effects. Just didn't think of it for this project.

Regards
Randy

[Brady Watson]

If you cast 60 Shore D Polyurethane you can heat it up in a bathtub full of hot water and twist it around the same way.

-B

[myxpykalix]

If you go the route of heating and bending something I might suggest you build a box similar to my solar hot air heater and put your pipe in there to heat it up if you need to uniformly heat the whole thing up at once. I was getting 200+ degree readings in the box letting it sit in the sun for 30 minutes.

[bleeth]

No prob Randy. Let us know how the finale goes.

[CNYDWW]

No prob Randy. Let us know how the finale goes.

I think i'm going to wait for cooler weather to play with it. Hot enough in here as it is.

[NeathawkSigns]

I haven't played around with it much yet, but will Cut 3d allow us to carve one side, rotate 90 degrees, carve again, repeat until all 4 sides are carved?

[myxpykalix]

The short answer i believe is yes. What i would do is build a jig where you can cut one portion, rotate, cut a second, rotate, ect and keep it all indexed.

I would also make sure i leave enough material on the top and bottom evenly squared so that it will fit into your jig snugly so when you rotate it stays where you want it.

[CNYDWW]

The short answer i believe is yes. What i would do is build a jig where you can cut one portion, rotate, cut a second, rotate, ect and keep it all indexed.

I would also make sure i leave enough material on the top and bottom evenly squared so that it will fit into your jig snugly so when you rotate it stays where you want it.

A little trick to add to jack's advice. Use a thin piece of material or scrap, do an inside profile cut the exact size of the blank you're going to mill with a dogbone fillet at the corners. That way your x,y zero will be perfect when manually indexing.

Best of Luck
Randy

[gc3]

The short answer i believe is yes. What i would do is build a jig where you can cut one portion, rotate, cut a second, rotate, ect and keep it all indexed.

I would also make sure i leave enough material on the top and bottom evenly squared so that it will fit into your jig snugly so when you rotate it stays where you want it.


a sample of indexing...http://www.vectric.com/forum/viewtopic.php?f=38&t=8701&hilit=indexing

[rej]

i like the swim noodle idea with epxoy - or- if you dont have an indexer, find someone with a legacy mill.
seems they could make one of those pretty easy.

[NeathawkSigns]

That is so funny- I thought the swim noodle was a joke... Now that doesn't seem like such a bad idea LOL.