after playing with my router for a while and trying different stuffs ive decided to have a go at making a MDF mold and pulling a part directly from there

it worked pretty well

http://www.rcgroups.com/forums/showthread.php?t=1823592

next was trying to make some carbon propellers as the plastic ones are too flimsy and the carbon ones are very $$$

this is what i would like to make http://www.rctigermotor.com/show.php?contentid=183

anyways here we go

the plan was to rough cut the mdf to shape and then vacuum bag the mold to draw the epoxy into the mold, then coat with a tooling coat of epoxy

so i layed the mdf onto a sheet of plastic to create a barrier for when i had to vacuum the epoxy .... unfortunately i machined thru this :S so the barrier was broken and i could only get around .2-.3 vacuum ... oh well so we learn

the next mistake was machining a finish cut on the same height.. i should have lifted the cut .2 mm , the mdf swells once it draws the epoxy in , thats why the molds look so blotchy

the bottom half of the mold was cut on .3 steps and the router marks are clearly visable
the top half was cut on .1 steps and im very happy with the finish ! it looks great but takes quite some time to cut

oh and a big thanks to http://www.rcgroups.com/forums/member.php?u=183875 Nhadrian for the drawing

That is actually pretty awesome! Any photos of the finished props?

You rock dude you're my Hero Can't wait for you to cut my DLG

DLG ? pfffft once you got a quad on FPV you aint gonna touch fixed wing for a while

finished props pics coming soon

Have an update on these moulded props?

been so busy with other stuffs ...

anyways here a few pics

next time .. i will pre cut all the tow to the exact size ...

i think ill also take the hole nipple piece out as it makes the layup a pain, and rather just have a little dimple where to drill

sanded to shape

i cant remember the weight, but it was just over 6 grams each ... they still needed balancing

i did fly just the two on my quad, but i think my quad is a little big heavy for this size prop

Gotta cut all the fabric to the right size before you close the moulds. You will get a thinner seam line this way. If you havnt removed it already keep the center pin. You dont have to do the whole blade from one peice of cloth. Instead use two peices but bring them as close to the center pin as possible. Usually the prop nut tightened down on the hub will stop the hub twisting so its not necessary to run the cloth right though the hub.

Looking good!

I would ditch the pin and drill a hole in the mold and insert a drill guide. Insert a plug into the drill guide during the layup. Once cured, pull the plug, drill the hole in the prop through the guide, then demold the prop. At least this is how I would do it.

Originally Posted by wyowindworks

Looking good!

I would ditch the pin and drill a hole in the mold and insert a drill guide. Insert a plug into the drill guide during the layup. Once cured, pull the plug, drill the hole in the prop through the guide, then demold the prop. At least this is how I would do it.

I like your idea Adam if you have a much beefier hub but I'd be concerned with drilling through the continuous fibers on a small prop hub like this. Having the pin already in the tool gives you something to wrap the uni carbon around and if you cut your cloth right (like slowbarless mentions) then you have a pretty easy lay up. You really only need the +/-45 cloth for blade torsion so it can stop short of the center pin. The square corners can get some epoxy/cabosil/milled fibers to minimize trapped air in the corners and prevent voids in the hub.

that makes sense, Troy