Van's Air Force
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RV-3 Fast Back
- Thread starter mmcdonald
- Start date
Larry DeCamp
Well Known Member
Fastback considerations
IF you plan to make a " tipper " AND the sheet metal rollover protection structure, you are almost there anyway. To get a smooth fuse top I made new tabs on the fuse formers so a different skin is all you would need for the fastback.
The canopy frame can be glass instead tubing for good support of the rear cut ( I can send you pics ). The rear canopy skirt is extra work for little gain and the plex back there is heavy, good riddance !
I was a newbie so followed the plans. If I were to repeat the offense ( my wife's perspective) I WOULD DO A FASTBACK
IF you plan to make a " tipper " AND the sheet metal rollover protection structure, you are almost there anyway. To get a smooth fuse top I made new tabs on the fuse formers so a different skin is all you would need for the fastback.
The canopy frame can be glass instead tubing for good support of the rear cut ( I can send you pics ). The rear canopy skirt is extra work for little gain and the plex back there is heavy, good riddance !
I was a newbie so followed the plans. If I were to repeat the offense ( my wife's perspective) I WOULD DO A FASTBACK
Ed_Wischmeyer
Well Known Member
I've seen an RV which simulated the Spitfire rudder profile with paint. Interesting.
Your mileage will vary, but having had an RV-4 tipper and three RVs with sliders, I'm very partial to sliders for hot weather. And I've been jealous of RV-3 canopies that can be opened in flight. Maybe you could have a slider / fastback? (I'm full of great ideas that require other people to do the work.)
Ed
Your mileage will vary, but having had an RV-4 tipper and three RVs with sliders, I'm very partial to sliders for hot weather. And I've been jealous of RV-3 canopies that can be opened in flight. Maybe you could have a slider / fastback? (I'm full of great ideas that require other people to do the work.)
Ed
David Paule
Well Known Member
Tony Spicer
Well Known Member
HFS
Well Known Member
Drawing 22 - Fastback
I have a copy of an original -3 drawing by Van (from 1984) listed as Drawing 22-Fastback. There really isn't much info on it other than the scaled profile of the aft section for the "fastback" configuration.
John Harmon made several "razorback" 3's, way back when,and would probably be a good resource for bulkheads, dimensions, etc. You should be able to reach him at his cafe (Rocket Cafe) at Bakersfield Muni (L45) in Cali.
David Howe
HR II S/N 002
I have a copy of an original -3 drawing by Van (from 1984) listed as Drawing 22-Fastback. There really isn't much info on it other than the scaled profile of the aft section for the "fastback" configuration.
John Harmon made several "razorback" 3's, way back when,and would probably be a good resource for bulkheads, dimensions, etc. You should be able to reach him at his cafe (Rocket Cafe) at Bakersfield Muni (L45) in Cali.
David Howe
HR II S/N 002
smokyray
Well Known Member
Look no further...
The original HR1 began life as an RV3. Only a few were built but Harmon still sells FB parts. Check their site out...
www.harmonrocket.com
V/R
Smokey
Mark,
The original HR1 began life as an RV3. Only a few were built but Harmon still sells FB parts. Check their site out...
www.harmonrocket.com
V/R
Smokey
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smokyray
Well Known Member
To Three or not To Three...
Mark,
Not surprised, glad it worked. (knew it all along
) The RV4 and RV3 aft fuselages are identical from the F407 bulkhead aft, hence why HR2 parts fit the 4 and the 3.
John Harmon built the first HR1 and HR2 from RV3 and RV4 kits he had on hand after drawing a chalk line on the hangar floor for the fuselage dimensions. The rest as they say, is history...
Thanks for the progress pics!
V/R
Smokey
Mark,
Not surprised, glad it worked. (knew it all along
) The RV4 and RV3 aft fuselages are identical from the F407 bulkhead aft, hence why HR2 parts fit the 4 and the 3. John Harmon built the first HR1 and HR2 from RV3 and RV4 kits he had on hand after drawing a chalk line on the hangar floor for the fuselage dimensions. The rest as they say, is history...
Thanks for the progress pics!
V/R
Smokey
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Could you expand a bit more on the process to making everything fit? What skin did yo
The Fastback mod is fairly easy.
After rolling fuselage shinny side up, you need to cut bulkheads F305, F306 and F308 off and leave 2" above 1/8" longeron.
Bulkheads supplied by by Harmon Rocket LLC are notched for the longeron which was extemely helpful and accurate for alignment. Pulled string line along top to check bulkhead alignment.
Width for F306 and F308 was off about 3/8". I had seen this problem in the HR section on VAF. I cut these pieces at the top and added a 3" filler piece at the top to fill 3/8" gap.
Used 1/8" flush rivets to attach HR bulkhead mods. Flush riveting facing fwd on F305, and flush riveting facing aft on F305 and F306.
Installed plywood and bracing to hold everthing in place before skinning, see pic.
In rough cutting the skin from 4 x 8 sheet I added an extra 2" to measurements and I would encourage this. Used wife seamstress tape to pull measurements.
For skinning I pre-drilled the bulkheads first to establish spacing and alignment for rivets. Skin was held in place with ratch straps and I climbed inside to drill skin at bulkheads from inside to out while wife placed clecos on outside.
Holes for longeron were already drilled, used hole finder to set skin on longeron. Released clecos on one side and drilled remaining holes clecoing as each hole was drilled. Reset bulkhead clecos on other side, released clecos on side just drilled on drilled longeron on other side.
F305 bulkhead was drilled last, and I released bracing and sighted the fit before drilling inside to out.
The Fastback mod is fairly easy.
After rolling fuselage shinny side up, you need to cut bulkheads F305, F306 and F308 off and leave 2" above 1/8" longeron.
Bulkheads supplied by by Harmon Rocket LLC are notched for the longeron which was extemely helpful and accurate for alignment. Pulled string line along top to check bulkhead alignment.
Width for F306 and F308 was off about 3/8". I had seen this problem in the HR section on VAF. I cut these pieces at the top and added a 3" filler piece at the top to fill 3/8" gap.
Used 1/8" flush rivets to attach HR bulkhead mods. Flush riveting facing fwd on F305, and flush riveting facing aft on F305 and F306.
Installed plywood and bracing to hold everthing in place before skinning, see pic.
In rough cutting the skin from 4 x 8 sheet I added an extra 2" to measurements and I would encourage this. Used wife seamstress tape to pull measurements.
For skinning I pre-drilled the bulkheads first to establish spacing and alignment for rivets. Skin was held in place with ratch straps and I climbed inside to drill skin at bulkheads from inside to out while wife placed clecos on outside.
Holes for longeron were already drilled, used hole finder to set skin on longeron. Released clecos on one side and drilled remaining holes clecoing as each hole was drilled. Reset bulkhead clecos on other side, released clecos on side just drilled on drilled longeron on other side.
F305 bulkhead was drilled last, and I released bracing and sighted the fit before drilling inside to out.
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smokyray
Well Known Member
Mui Bueno'!
Mark,
Nicely done!
When the time comes I think there is a HR-1 canopy frame drawing somewhere on the Harmon website.
Very cool...thanks for sharing.
V/R
Smokey
Looking forward to seeing the finished product!
Mark,
Nicely done!
When the time comes I think there is a HR-1 canopy frame drawing somewhere on the Harmon website.
Very cool...thanks for sharing.
V/R
Smokey
Looking forward to seeing the finished product!
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