Hi,
I’ve made a mould for this spoiler
cad animation here:
http://youtu.be/OLzTd7JZ3Ek
Pic of the mould:
My questions are:
what is the best way to infuse this, front to back or left to right?
Also, i dont think the carbon will drape into the ends well without pleating, is there a way to neatly cut some profiled pieces to place in the ends before the rest of the reinforcement goes in so the finished part looks nicer?
hope this makes sense??
HP textiles in Germany sells a dry fabric that has a very light coating of adhesive on it so that when you cut it, it doesn’t fray and you can lay it up like a prepreg and then infuse. Alternatively you can spray bond some very light FG viel to the backside of your visual carbon layer, that’ll help cut down on fraying if you decide to make some relief cuts
You could also figure out where the relief cuts need to be, make a pattern.
then spray tack some FEP or plastic to the carbon, transfer the cut pattern, then lay the first ply in and tack in place. A pain but it can help keep the weave from distorting too much or fraying.
This is where dry layup is a pain. I wish I could just do everything with prepreg.
And how about the infusion direction? Is it better to do a short wide infusion from front to back or long narrow from left to right?
I know absolutely nothing about infusion yet from experience. But just thinking logically, I would say left to right. If you go front to back with such a short cross section wouldn’t it be possible to pull epoxy into the resin catch can before the whole part was infused.
Always draw the resin the shortest distance. So run your spiral along the length of the spoiler.
I would infuse from center to the outsides. From front to back can also work, but such a short way can cause problems.
Shortest distance, like said above. I have many spoiler molds, many that are verge similar to that. I make the molds in two pieces because a one piece mold for a spoiler is usually a hard de molding process.
will MTI hose work ok at just one side of the infusion rather than all the way around?
Yes, at such a part there is no need for using the MTI hose around the perimeter. You can use it on one side or at both Wnds and infuse across or from the center to outside.
Something like this set up?
Yep, that’s pretty much exactly how I do all my infusions with MTI.
I would put resin line in center ( perpendicular to length) then put 1/2 meter of mti hose on each end in a “u” shape. You will half the mti hose and won’t infuse downhill ( unless you rotate mold as you infuse).
cheekybrad, you mean like this!
Yes, fold a piece of infusion mesh around the resin line and make a " flying resin line" to eliminate print thru from resin line.
I would recommend the setup like Hanaldo mentioned of running the infusion lines out the outside, running on the perimeter allowing the resin to run the shortest distance.
The benefit is that when over, the lines are on the excess/cutoff, and there is no print thru of the line in the part.
Running the way that is mentioned in the post above this one, with the line running inside has the negative consequence that the infusion line can become trapped inside the part at the deepest point because resin may begin to pool at that site.
I build wings very similar to the on that you are building, like I mentioned before, I have tried both ways of running the infusion and because of the sharp angle of the top of the wing, and because of the spiral being stuck inside because of resin pooling in the tightest portion of the wing, I can only recommend the first setup as the best setup for a type of wing like this.
Both ways will work for the infusion, but what I’ve learned is that running it straight through will leave you with a clean part, whereas the other method with the spiral inside may leave you with remnant spiral that is have stuck inside the wing.
The mti hose will only be on your vacuum feed.