F-20 TigerShark 144th Lee MMX PMC

[Micromeister]

OH this one is gonna be a challange. We are right on the cusp of the model being too small for conversion.
The F-20 is a neat looking aircraft I am hoping I can make it fly without altering the overall look to much. Luckly it is a single motor jet, trouble is at 144th scale there isn't much room inside the model for anything beyond a 1" MMX-II motor and perhaps we are hoping anyway the required amount of #9 lead shot to get her stable.

Here are of few of the beginning photos in the process. BoxArt & kit instructions.

First Tape Dryfit with a bare MMX-II motor casing shows we Can to something...just not sure what yet

OK lets do the 2-view cardboard cutouts to see what we'll need to make this thing stable. Humm....Looks like this is going to have to be a rear ejection motor kick pod type recovery. Maybe we'll have space for a tiny drag out streamer? Need to check the clay mass to get the #9 shot count and look at where it can be stowed.
Can I possibly increase the aft opening to take a T2++ (.316") slider tube?
more to come..

[kruland]

John,

I lost count a little while ago, but it seems you have started a dozen or more PMC build threads. I have been wanting to try this for quite some time and your detailed instructions are very helpful. I have acquired 3 plastic models (which you have already completed) on which to try it myself.

Thank you for sharing all this with us.

Kevin

[Micromeister]

John,

I lost count a little while ago, but it seems you have started a dozen or more PMC build threads. I have been wanting to try this for quite some time and your detailed instructions are very helpful. I have acquired 3 plastic models (which you have already completed) on which to try it myself.

Thank you for sharing all this with us.

Kevin

My Pleasure Kevin! thank you for the kudo's.

I tend to build Mod-roc types in batches. seems it's PMC's time as I've been collecting kits for several years... Gotta build em or sell em I'm out of room LOL!!! So we'll build a few.
Great to hear your taking the plung, any help i can be with your builds, please don't hesitate to ask.

[dlazarus6660]

You beat me to it! I have a F-20 of my own design(read copied) started a few months ago

[Micromeister]

You beat me to it! I have a F-20 of my own design(read copied) started a few months ago

Pretty Nifty
Is that a T3 or T4 size model. and do you intend it to be some sort of ejectable pod powered so it glides for recovery?

I'll be starting the real in-depth conversion of my F-20 hopefully this week. I'll be attempting to enlarge the aft opening enough to allow a rear ejectable T2+ motor pod possibly with a drag-out teflon streamer. should be a very tight fit. I'm concerned I won't have enough room with the Motor pod & streamer to balance the thing with nose weight. We'll see...I think it's going to be close.

[dlazarus6660]

BT-55 with Bullpup N/C and Boattail. BT is 12.75 inches long

[Micromeister]

We've completed most of the conversion on the F-20. Do to it's very small size there isn't a good place to split it to create a nose section. After doing the early Dremel routing out of the aft end and removing a good bit from the inside fuselage it was determined with a Piece of T2+ (micro minimum diameter body tube) placed all the way to the cockpit tub their just was not enough room for all the inner stuff for a normal break apart flying model.

This one is going to have to be Rear ejection. UGH! that means I had to remove even more plastic and round out the fuselage enough to pass a T2++ (.316" OD) tube as a pod slide tube. T2++ telescopes over our normal T2+ Micro motor tubing. Cutting a 1" T2+ motor tube I added a double length 3/8" T2 (.246") motor stop extending out the back 3/16". this well house a .020" dia Stainless steel bend double hook shockline & Streamer anchor point. I'm have to show you guys the bent wire and mounting method a bit later when I get the pics out of the camera. After drilling 2 tiny hole 180° apart in the extended coupling the hook prongs are inserted in the cardboard bound by a bit of CA inside and out. the outer area is then ground down flush with the exterior of the T2 tube allowing the unit to slide nearly friction free in and out of the T2++ body tube. Now we'll set the Motor mount & shockcord mount aside while we tackle how and where we will install the 2.8grams of Nose weight needed to make our model stable.

Just no where to put all those tiny #9 lead shot without removing the cockpit tub. it just has to be done. Dremel on...we carefully cut out the entire tub leaving only the exterior edge. a tiny filler piece of .010" styrene is MC'ed in place to close off the area so we can fill the void with shot. We're building this one Wheels up also so a new front wheel well door is fashioned for the styrene sheet as well. After a bit of CA & the tinyest amount of Epoxy applied to fix the T2++ bodytube in the fuselage the two halves of the model are MC joined. now we're ready to load the nose weight and fix it in place with a small amount of CA run thru a scrap of T2 tubing to the top of the lead deep inside the model. I suppose it might have been possible to load both halves before they were joined but I wanted to get the Shockline as far down in the nose as possible surrounded by lead shot and CA/epoxy. I forgot to mention we're using a 70lb Braided Kevlar 42" long shock line triple knotted and buried in the nose weight. the kevlar is run on the outside of the T2 glue deliver tube so only the kevlar in the nose is glue soaked.
After allowing the model to stand on it's nose for a couple hours the CA as set and it's time to inject just a bit of 5 minute epoxy to seal off the end of the T2++ motor tube from the plastic. Using the same T2 tube and a 3/16" hardwood dowel punger, a small mount of epoxy loaded in the forward end of the T2 tube is carefully inserted and squeezed out sealing the T2++. again sit this assemble aside to cure.

While the epoxy is curing we decide which weapons will be added, assemble, and CA to the ends of Bamboo sticks for painting. Stores pylons are added to the under wing and belly. Now the wing and elevators are installed taking care to align them. some of the center seam lines were kinda bad so a little CA is added, cured and sanded smooth, A needle & pin vise and panel scribe tool help re-install the panel lines after sanding. Most of this was done so quickly many of the steps were missed as I was concentrating on the HOW to make this one work...sorry bout that. I did catch myself before I went to far I'll upload the photos take soon.

We're ready for a light primer coat and two greys on the aircraft. while it's drying, the weapons stores are brush painted.

Before adding the stores I wanted to be sure I got the CG correct. added our 1/2" by 12" yellow teflon streamer after tying on the shockline to the stainless anchor mount. slide a MMX-II in the mount, just taped the canopy in place...dang it...shes still a tab bit tail heavy.
only one thing to do...I'll add a few more shot in the canopy tub hole. CA in place and perhaps paint the inside of the canopy dark blue or black? Well see.

After painting the upper body gunship grey over the bottom aggressor grey the shot in under the canopy may not be objectionable.
Hopefully tonight I'll get the stores added and canopy installed.

Hope to unload the camera also if time permits, perhaps photos will upload tomorrow?
Edit: Haven't captioned these pic yet hope they help with the text above.

[Micromeister]

A few more uncaptioned photos during this not to well documented build. When I have a little time I'll caption & replace these photos.
Last two show the F-20 pretty much ready for decals and Matte clear coat...Still trying to decide if I want to paint the inside of the Canopy to hide the extra nose weight. Painted current LOWt is 9.3g with MMX-II motor. Swing test is immediately stable, She should be good to go.
Having family in for the week shortly so modeling will be curtailed while Granddad Plays with the toddler Grandson and Baby Granddaughter

[Micromeister]

F-20 is finished and ready for flight. had hoped to get this and a few others in the air over the weekend but didn't get to the field
flight reports soon.. I hope.

[Micromeister]

Great to hear we have another Micro PMC freak LOL!
What specific models have you laid hand on. I'm still looking at a huge pile of Plastic kits waiting conversion.