Gantry design question

[D.C.]

I was considering it for a 4x8 build.

I'm not sure you would lose that much strength, plenty of people make torsion boxes using only glue for joining for example. The vacuum process is really to squeeze the different layers of cloth together around a complex shape, when you are dealing with a ready made flat sheet you can achieve the squeezing the old fashioned way with weight or clamps. If you were to try to make the gantry in one piece then yeah you would need a vacuum to ensure good contact in all areas.

[martin54]

I was considering it for a 4x8 build.

I'm not sure you would lose that much strength, plenty of people make torsion boxes using only glue for joining for example. The vacuum process is really to squeeze the different layers of cloth together around a complex shape, when you are dealing with a ready made flat sheet you can achieve the squeezing the old fashioned way with weight or clamps. If you were to try to make the gantry in one piece then yeah you would need a vacuum to ensure good contact in all areas.

Sorry but that's not true at all, I could quite easily manufacture a complex shape without the use of a vacuum just by using the right weight cloth and simply laying the cloth around a mould or covering the part if I was just skinning it. The carbon fibre part that I made would look just the same as a part made using a resin infusion system but that's where the similarities end. The part produced by resin infusion would be far lighter & stronger than the part I made, what the vacuum actually does is remove all the excess resin which cant be removed from a traditional type wet lay up. The strength comes from the layers of cloth being closely bonded together, the less resin that is present the stronger the bond.