5X12X4 Gantry router for foam milling

[Rogge]

I've been meaning to post to this forum for a while now. About two years back I spent a lot of time on these pages, and I learned tons from all the wonderful people who have posted about their experiences. Here is a brief description and a few pictures of what a group of engineering students from UIowa were able to accomplish with the help of all the people who post to these pages.

The machine that we built is a foam-cutting gantry router for milling plugs for fiberglass mold making. The dimensions are large - 5' X 12' X 4'. The plugs that we make are used to make molds for fiberglass fairings for recumbent, solar-powered bicycles (check out www.iowasolarbike.org). The frame is 2" angle iron, and the gantry is 2" aluminum square tube. The linear bearings for the X axis were custom - a piece of 2" steel square tubing set at 45 degrees (diamond shape) with v-groove wheels that run along the top and bottom of the tube. The bearings for Y and Z were standard 20mm rail and blocks from VBX bearings. Drive for X is a chain drive, Y and Z got ACME leadscrews. Interestingly, the chain drive (which we thought would be a weak link) turned out to be the smoothest drive of all (whipping from the lead screws limits us to 80 ipm travels in Y and Z). We easily get 500 ipm on the X axis.
We write our code (and develop the CAD models) in Pro E - and I'll make a little plug here - Pro E may be a little tricky to learn (esp the CAM) but once you learn it, it is fantastic.
The machine holds .010 tolerances, repeatability is considerably better that than. For what we do, .100 is plenty.
All in all we spent around $2500-3000 on the project. It was ALMOST more fun that riding the bikes at 50 mph...

[ZOB]

That is awesome, well done.

[eloid]

Originally Posted by Rogge I've been meaning to post to this forum for a while now. About two years back I spent a lot of time on these pages, and I learned tons from all the wonderful people who have posted about their experiences. Here is a brief description and a few pictures of what a group of engineering students from UIowa were able to accomplish with the help of all the people who post to these pages. The machine that we built is a foam-cutting gantry router for milling plugs for fiberglass mold making. The dimensions are large - 5' X 12' X 4'. The plugs that we make are used to make molds for fiberglass fairings for recumbent, solar-powered bicycles (check out www.iowasolarbike.org). The frame is 2" angle iron, and the gantry is 2" aluminum square tube. The linear bearings for the X axis were custom - a piece of 2" steel square tubing set at 45 degrees (diamond shape) with v-groove wheels that run along the top and bottom of the tube. The bearings for Y and Z were standard 20mm rail and blocks from VBX bearings. Drive for X is a chain drive, Y and Z got ACME leadscrews. Interestingly, the chain drive (which we thought would be a weak link) turned out to be the smoothest drive of all (whipping from the lead screws limits us to 80 ipm travels in Y and Z). We easily get 500 ipm on the X axis. We write our code (and develop the CAD models) in Pro E - and I'll make a little plug here - Pro E may be a little tricky to learn (esp the CAM) but once you learn it, it is fantastic. The machine holds .010 tolerances, repeatability is considerably better that than. For what we do, .100 is plenty. All in all we spent around $2500-3000 on the project. It was ALMOST more fun that riding the bikes at 50 mph...

what glue did you use the glue up the 2" foam sheet to gethere? also interested what you used to protect the foam as a barrier / coating, fiberglas resin eat up foam on contact?

[Telly]

Sir, I need a longer upcut spiral bit....please

Very nice work!

[CarveOne]

Originally Posted by eloid what glue did you use the glue up the 2" foam sheet to gethere? also interested what you used to protect the foam as a barrier / coating, fiberglas resin eat up foam on contact?

West System slow cure epoxy does not melt pink, blue, or white foam. In my own work I use #105 resin and #206 hardener with fiberglass cloth as a barrier. Use the same epoxy for gluing the foam layers. Just squeege on a thin layer and apply weights to keep it firmly pressed together until cured.

CarveOne

[Rogge]

We used epoxy (System Three Silvertip - a little nicer to work with than West System) to stack the foam up. Then we did a skin coat of epoxy/microballoon filler on the foam plug followed by a coat of DP90 epoxy primer before gelcoat to keep the foam and gelcoat from interacting. A better method would be to use faom that has no problem with polyester resins (gelcoat). I can't remember the name of the foam, but it is the stuff you find on the inside of the foil-faced foam panels. Cyano-something-or-other.

[advt001]

Rogge in pic#4 (showing the tool cutting the foam)where did you get the long tool?

[Rogge]

Originally Posted by advt001 Rogge in pic#4 (showing the tool cutting the foam)where did you get the long tool?

We made that tool by pressing a 1/2" ball nose endmill onto a chromoly shaft. It was pretty well balanced - we did a little straightening and then threw it in the router. The spindle bearings seemed to hold up ok (we've only run this machine for maybe 50 hours total).

[z321]

I am just curious as to what design you followed in the build for your machine.

Originally Posted by Rogge I've been meaning to post to this forum for a while now. About two years back I spent a lot of time on these pages, and I learned tons from all the wonderful people who have posted about their experiences. Here is a brief description and a few pictures of what a group of engineering students from UIowa were able to accomplish with the help of all the people who post to these pages. The machine that we built is a foam-cutting gantry router for milling plugs for fiberglass mold making. The dimensions are large - 5' X 12' X 4'. The plugs that we make are used to make molds for fiberglass fairings for recumbent, solar-powered bicycles (check out Web Template). The frame is 2" angle iron, and the gantry is 2" aluminum square tube. The linear bearings for the X axis were custom - a piece of 2" steel square tubing set at 45 degrees (diamond shape) with v-groove wheels that run along the top and bottom of the tube. The bearings for Y and Z were standard 20mm rail and blocks from VBX bearings. Drive for X is a chain drive, Y and Z got ACME leadscrews. Interestingly, the chain drive (which we thought would be a weak link) turned out to be the smoothest drive of all (whipping from the lead screws limits us to 80 ipm travels in Y and Z). We easily get 500 ipm on the X axis. We write our code (and develop the CAD models) in Pro E - and I'll make a little plug here - Pro E may be a little tricky to learn (esp the CAM) but once you learn it, it is fantastic. The machine holds .010 tolerances, repeatability is considerably better that than. For what we do, .100 is plenty. All in all we spent around $2500-3000 on the project. It was ALMOST more fun that riding the bikes at 50 mph...