getoutside3274
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- Joined
- Dec 8, 2005
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As a member of CATO, it's becoming the "in thing" to have a Viper IV so I figured I would join in on the drag racing fun!.
Didn't alter the kit too much, mainly changing the shock cord mount, adding motor retention and using 2 - 1 1/2" launch lugs rather then 1 - 6" lug.
Here's the shock cord anchor. 3/16" eyebolt with 2 nuts lock tited on (see the red) and tightened against each other. The nice part about these 3/16" nuts is that they don't rotate in the cluster of 4 - 24mm tubes. Stuffed a piece of wadding into the hole and filled it with epoxy and inserted the eyebolt:
For the motor retenion, a 1/4-20 coupler nut again fit into the cluster of MMT's and didn't rotate. Packed the wadding into the MMT gap and some into the bottom of the coupler nut to keep out the epoxy. Sanded the nut with coarse sandpaper to create ridges for the epoxy to bit into and stuck it in. Took a couple of tries to be able to get the nut in flush with the MMT without the epoxy over flowing:
Had a bit of a scare with the fins. I was ready to bevel the fins and attaching them to the MMT and had a thought. Why don't I use the mower blade sharpener attachment on my dremal to bevel the fins!! At least the rough sanding, then I could touch them up after by hand. Well, got it all set to go, grabbed a fin and started grinding away...only to discover I was sanding the ROOT edge of the fin. AAAHHHHH. Dropped it in panic, thinking I will now have to trim all the fins to match...UNTIL I remembered that you have to bevel the root of the fins to fit in between the tubes. Duh.
Getting ready to bevel the fins:
Now the tricky part. How to hold a 4 motor cluster onto a base designed for one motor. The cylinder to the left is what is supposed to fit in the center hole in the fin jig. The eyebolt with the washers and nuts is what I inserted (from underneath) to screw into the motor retention nut to hold the motor tubes centered and straight. This photo was taken after they were epoxied in:
All clamped up and curing. The 2X4's under the base plate are needed because of the eyebolt:
Applying the fillets:
Ultralight weight shock cord mount on the NC. Cut 2 slots for the nylon strap to fit through:
The drying booth:
The build is almost complete. I've epoxied the MMT to the body tube and should have finishing photos by the end of the week.
Didn't alter the kit too much, mainly changing the shock cord mount, adding motor retention and using 2 - 1 1/2" launch lugs rather then 1 - 6" lug.
Here's the shock cord anchor. 3/16" eyebolt with 2 nuts lock tited on (see the red) and tightened against each other. The nice part about these 3/16" nuts is that they don't rotate in the cluster of 4 - 24mm tubes. Stuffed a piece of wadding into the hole and filled it with epoxy and inserted the eyebolt:
For the motor retenion, a 1/4-20 coupler nut again fit into the cluster of MMT's and didn't rotate. Packed the wadding into the MMT gap and some into the bottom of the coupler nut to keep out the epoxy. Sanded the nut with coarse sandpaper to create ridges for the epoxy to bit into and stuck it in. Took a couple of tries to be able to get the nut in flush with the MMT without the epoxy over flowing:
Had a bit of a scare with the fins. I was ready to bevel the fins and attaching them to the MMT and had a thought. Why don't I use the mower blade sharpener attachment on my dremal to bevel the fins!! At least the rough sanding, then I could touch them up after by hand. Well, got it all set to go, grabbed a fin and started grinding away...only to discover I was sanding the ROOT edge of the fin. AAAHHHHH. Dropped it in panic, thinking I will now have to trim all the fins to match...UNTIL I remembered that you have to bevel the root of the fins to fit in between the tubes. Duh.
Getting ready to bevel the fins:
Now the tricky part. How to hold a 4 motor cluster onto a base designed for one motor. The cylinder to the left is what is supposed to fit in the center hole in the fin jig. The eyebolt with the washers and nuts is what I inserted (from underneath) to screw into the motor retention nut to hold the motor tubes centered and straight. This photo was taken after they were epoxied in:
All clamped up and curing. The 2X4's under the base plate are needed because of the eyebolt:
Applying the fillets:
Ultralight weight shock cord mount on the NC. Cut 2 slots for the nylon strap to fit through:
The drying booth:
The build is almost complete. I've epoxied the MMT to the body tube and should have finishing photos by the end of the week.