Amadeus
#1
Thread Starter
Amadeus
Time for a new F3a model. Electric this time. Working name is Amadeus. The fuselage will be molded and the wings balsa on foam. I will cover the molding process, which is something not seen here much.
#3
Thread Starter
I will go through the process I use to make a composite fuselage. I'm up to about 10 now, the last 2 were 40% IMAC so this one is relatively small.
I dimension the drawing at 100mm stations and transfer it to 6mm MDF. The off cut will be the splitter plate, more on that later.
I dimension the drawing at 100mm stations and transfer it to 6mm MDF. The off cut will be the splitter plate, more on that later.
#5
Thread Starter
From this point I will use different methods to build the fuselage shape. My first plan was to cut 100mm long cross sections derived from the Solidworks model. However I wasn't entirely happy with the shaping in solidworks so I am going to do the shaping free hand using profile gauges to get symmetry. I did use the CNC foam cutter to do the top view though.
#6
Thread Starter
Vacuum bagged the other side on. Am using PU glue as it is fairly fast gap filling and works well in the vacuum bag. I have 2 vacuum pumps. This one is for white foam as is a diaphragm pump and is happy running at reduced pressure (5psi here) so it doesn't collapse the foam. The other pump is an oil filled vane pump for composites in molds and is best run at full vacuum or the oil drains out.
#7
Thread Starter
Trimmed of the outline with a hand held hot wire. Powersupply is a transformer on a light dimmer.
Started roughing out the shape with a bread knife.
Started roughing out the shape with a bread knife.
Last edited by RodneyFord; 06-28-2015 at 03:10 PM.
#9
Thread Starter
The fin is built up for accuracy. I use Profilli pro for my airfoil work. The airfoil is SD 8020 with the trailing edge thickened to a blunt 6mm and the root high point moved back to blend into the fuselage. The solidworks model helped to visualise the fit. Once the design was sorted out I printed out the ribs and used a glue stick to attach the printouts to the balsa. Lots of ribs for stiffness. Also made some leading edge templates for accuracy.
Last edited by RodneyFord; 06-28-2015 at 10:24 PM.
#12
Thread Starter
Used the canopy base to set the nose angle at 1/2 degree. There will be no right thrust as the model will have a contra drive or use throttle to rudder mixing if only one prop.
#16
Thread Starter
Talking about the 3D printer, I will use it to make some parts. I am thinking of inserts to go into the mold for air exhausts. Spat and leg patterns. Am experimenting with nylon filament with a view to doing the 95mm spinner.
#17
Thread Starter
Did some rough shaping on the lower nose area. Actually nothing complex here, just want it fairly low drag and smooth here to get the air moving down the fuselage easily. Not worried about taking off too much foam as it is easy to build up later with bondo after it gets glassed. Much harder to take glass away and redo it.
Last edited by RodneyFord; 07-19-2015 at 01:14 AM.
#21
Thread Starter
The interesting bits for me are the things that are done differently or in a new way.
These are:
The free form shaping using the profile gauge for symmetry (I got pretty close by eye)
Polyester mold with gel coat sprayed in with popcorn gun (I got a new compressor that will run continuously)
Engineered mold locating and joining system.
1mm Rohacell for the sandwich material in the finished fuselage.
My first decent size electric model. I might do my own contra gearbox, I mean how hard can it be!
#22
My Feedback: (4)
Hi Barrie nice to hear from you.
The interesting bits for me are the things that are done differently or in a new way.
These are:
The free form shaping using the profile gauge for symmetry (I got pretty close by eye)
Polyester mold with gel coat sprayed in with popcorn gun (I got a new compressor that will run continuously)
Engineered mold locating and joining system.
1mm Rohacell for the sandwich material in the finished fuselage.
My first decent size electric model. I might do my own contra gearbox, I mean how hard can it be!
The interesting bits for me are the things that are done differently or in a new way.
These are:
The free form shaping using the profile gauge for symmetry (I got pretty close by eye)
Polyester mold with gel coat sprayed in with popcorn gun (I got a new compressor that will run continuously)
Engineered mold locating and joining system.
1mm Rohacell for the sandwich material in the finished fuselage.
My first decent size electric model. I might do my own contra gearbox, I mean how hard can it be!
Nah, just kidding. Would be well worth having a go. I haven't seen an exploded view of one, but I think there would be a fair bit of work involved. I'm a first class machinist by trade, so would be very interested. Post plenty of photos and give a good description of what you do if you decide to try.
#23
Thread Starter
If it were easy, everyone would be doing it. Lol.
Nah, just kidding. Would be well worth having a go. I haven't seen an exploded view of one, but I think there would be a fair bit of work involved. I'm a first class machinist by trade, so would be very interested. Post plenty of photos and give a good description of what you do if you decide to try.
Nah, just kidding. Would be well worth having a go. I haven't seen an exploded view of one, but I think there would be a fair bit of work involved. I'm a first class machinist by trade, so would be very interested. Post plenty of photos and give a good description of what you do if you decide to try.
#25
Thread Starter
An issue with this type of pattern is the lack of rigidity. At the moment it is a bit of a banana by 4 or 5 mm. I will need to stiffen it up or anything could happen when I glass it. I have put the laser line on it here to see how it is. I think I will inset some spruce strips along the sides and hold it straight while the glue dries.
Last edited by RodneyFord; 06-30-2015 at 06:38 PM.