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Or at least as far as Utah - If it "flies" on the track is to be seen.
Some may recall that I added a coda to my "Hatching an Eagle" thread last spring describing the unfortunate practice incident wherein an errant flying doorstop carried the Eagle into the wall at an horrific speed with the resultant loss of 3 of the 4 tailpipes and the drivers head. I subsequently determined the the front axle carrier had been slightly bent causing an intermittent bind.
One of the less endearing characterisitics of polyester resins is their brittle nature. When I examined the remnants to see if rebuilding was possible, it was clear that so much of the exhaust manifold detail had been carried away with the pipes that the shell was , at least for me, a total loss.
A replacement was ordered and arrived in good time. I decided to avoid the possibility of a repeat of the previous experience by re-creating the body in a less frangible material. I will briefly describel a process that I have used for some time will good results.
The shell was cleaned up, a few minor surface imperfections filled and smoothed and a little modification done to increase the space in the rear by about 0.5 mm in each direction. This shell was converted to a pattern by stuffing it with modellling clay and a silicone rubber mold was poured.
With this mold in the rigid carrier in which it was cast I slosh cast a very thin resin shell using a slow curing (20 min pot life) high strength resin. This was allowed to cure for about 48 hours and then,without removing the shell from the mold strategic reinforcment was done by laminating very thin kevlar scrim to the inside of the shell using a low viscosity epoxy resin. After another 48 hours, the resultant body was removed, cleaned up and prepped in the usual fashion.
This body weighed 3 grams compared to the 7.5 gram weight of the bare fibreglass version.
The chassis is mostly unchanged except that I used this opportunity to remedy a defect in the original model. I felt that the first one had a bit of a "nose high" attiitude. I scrapped the front end assembly (providentially held on with 2-56 machine screws) and built a new one, unashamedly copying David Lawson's " full width upper suspension member" practice. This is the result with the original version in the foreground:
![]()
Careful examination will reveal a layer of black material between the assembly and the chassis. This material is, in fact, 0.050" rubber which, combined with the machine screw fixing, allows one to adjust the height of the front end over about a 0.012" range to accomdate different braid or rail height or recess.
Next I turned my attention to the rear and did a bit of judicious filing of the rear axle carrier and skimmed about 0.008" from the periphery of the gear so:
![]()
(Sorry about the focus)
This and the minor mods to the rear of the pattern resulted in much less mayhem perpetrated on the rear of the shell.
And it all went together like this:
![]()
And, particularly for Russell:
![]()
I also changed tires and added about 3 grams of lead under the motor - We shall see
On to the next project!
EM
Some may recall that I added a coda to my "Hatching an Eagle" thread last spring describing the unfortunate practice incident wherein an errant flying doorstop carried the Eagle into the wall at an horrific speed with the resultant loss of 3 of the 4 tailpipes and the drivers head. I subsequently determined the the front axle carrier had been slightly bent causing an intermittent bind.
One of the less endearing characterisitics of polyester resins is their brittle nature. When I examined the remnants to see if rebuilding was possible, it was clear that so much of the exhaust manifold detail had been carried away with the pipes that the shell was , at least for me, a total loss.
A replacement was ordered and arrived in good time. I decided to avoid the possibility of a repeat of the previous experience by re-creating the body in a less frangible material. I will briefly describel a process that I have used for some time will good results.
The shell was cleaned up, a few minor surface imperfections filled and smoothed and a little modification done to increase the space in the rear by about 0.5 mm in each direction. This shell was converted to a pattern by stuffing it with modellling clay and a silicone rubber mold was poured.
With this mold in the rigid carrier in which it was cast I slosh cast a very thin resin shell using a slow curing (20 min pot life) high strength resin. This was allowed to cure for about 48 hours and then,without removing the shell from the mold strategic reinforcment was done by laminating very thin kevlar scrim to the inside of the shell using a low viscosity epoxy resin. After another 48 hours, the resultant body was removed, cleaned up and prepped in the usual fashion.
This body weighed 3 grams compared to the 7.5 gram weight of the bare fibreglass version.
The chassis is mostly unchanged except that I used this opportunity to remedy a defect in the original model. I felt that the first one had a bit of a "nose high" attiitude. I scrapped the front end assembly (providentially held on with 2-56 machine screws) and built a new one, unashamedly copying David Lawson's " full width upper suspension member" practice. This is the result with the original version in the foreground:
Careful examination will reveal a layer of black material between the assembly and the chassis. This material is, in fact, 0.050" rubber which, combined with the machine screw fixing, allows one to adjust the height of the front end over about a 0.012" range to accomdate different braid or rail height or recess.
Next I turned my attention to the rear and did a bit of judicious filing of the rear axle carrier and skimmed about 0.008" from the periphery of the gear so:
(Sorry about the focus)
This and the minor mods to the rear of the pattern resulted in much less mayhem perpetrated on the rear of the shell.
And it all went together like this:
And, particularly for Russell:
I also changed tires and added about 3 grams of lead under the motor - We shall see
On to the next project!
EM
