FLYPUCK

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Hey Gang,
I pick up a Don Lien Hellcat kit from Bob Holman about 3 years ago and am finally starting on it.
Haven't found any build threads on one of these so I figured I'd give it a go.
If there's anyone who's done one of these kits, feel free to chime in with any tips or pointers you may have. In fact, please chime in. Doing the glass fuse with the foam wings will be a first for me and I could use some help.
Here's what the kit consist of:

hellcat56

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I built this plane and loved it
I now have a Zirolli hellcat
If you want to do a -3 I have a canopy for it
Dont think Bob has any -3 canopy

FLYPUCK

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Thanks Lawrence. I have admired your Cat for some time now. I've seen many pics of it. In fact, your cat is what prompted me to purchase this kit.
PM inbound on the canopy.

=Doug=

FLYPUCK

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What tail wheel did you use?

FLYPUCK

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Making templates for the bulkheads using See-Temp. This is great stuff. Just lay it on the plans and score it with an x-acto knife then bend it on the score line a few times to break it. Makes a nice clean edge for laying out on the ply.

FLYPUCK

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I cut out the rear most bulkhead from 1/4 inch ply and marked its position on the fuse.
Since I don't have Gorilla arms. I stuck the bulkhead to a dowel with double sticky foam.
One thing I'm finding is that the drawing isn't really accurate with the inside shape of the fuse. Any ideas on filling in the gaps on the sides other than cutting a new bulkhead oversized and trial fitting it?

bps

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You might consider polyurethane glue. It expands to fill gaps and will adhere to almost any surface. You would need to clean the expoxy surface well before using it.

FLYPUCK

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Thanks Jeb. I think I will install the formers with Hysol and then go back after it cures and hit the gaps with Gorilla Glue as long as they won't attack each other. The down side would be the added weight as I'm trying to keep the tail as light as possible.

FLYPUCK

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Got all the bulkheads cut and fitted. Here's the firewall. I couldn't find a piece of 1/2" aircraft ply at the hobby shop so I glued two pieces of 1/4" together using Titebond.

FLYPUCK

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Cowl prep

rrudytoo

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FLYPUCK,

A trick I learned some years back that worked well for installing bulkheads into a glass fuselage is to use epoxy with fiberglass cloth on one side of the bulkhead then use Shoe Goo on the other. It fills any gaps that may be present, sticks like crazy and checks some of the vibration present with fiberglass fuselages. As it remains somewhat pliable, you won't have to worry about it cracking with age. Of course, you will need to insure that your fuse is epoxyglass and not polyester glass before using epoxy and to scuff up the area with coarse sandpaper followed by a cleaning with either acetone or alcohol before bonding.

Have fun with your build and I look forward to following your progress.

Al

FLYPUCK

My Feedback: (8)

Thanks for the tip Al. Sound like a good plan with the Shoe Goo. I've never used the stuff and will give it a try. Looks like Tower sells it and I need to order some other things anyway.
It's definately epoxy glass. No smell when it's cut.

=Doug=

FLYPUCK

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I cut small pieces of ply and hot melt glued them to the fuse sides to use as locating blocks to hold the cowl in place while making the cowl mounting brackets. The hot melt works well for this as it has plenty of holding power to keep the cowl in place and will break free of the gel coat cleanly later.

FLYPUCK

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Cowl mounting brackets glued in place. I will install a couple of screws in each one after the epoxy has cured completely just to be sure.

FLYPUCK

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Ok experienced glass fuselage builders. I could use some advise on glueing the firewall in (shown in post 9).
Do I: smear epoxy on the front of the firewall and just clamp it on?
lay it in there dry and put a bead of epoxy and glass or CF cloth around it?

Need some ideas please.

Thanks

FLYPUCK

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Lawrence..I have sent several emails and PMs on this. Please let me know the asking price via email or PM.
Thanks

FLYPUCK

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I've been spending the last few days rigging up a carb adaptor for the 46cc Poulan I'm going to use.
These engines come with this goofy rubber boot for an intake manifold. I'm sure this works well in a saw but for r/c..not so much.
I cut out a U shaped bracket and attached it to one of the fins to hold the carb secure. Down side to doing it this way is that I have to use bellcranks for the throttle and choke.

hellcat56

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I sent you a PM
sorry it has taken so long
Lawrence

hellcat56

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couple of follow ups
I made my own tailwheel using the drawing on the plans
As for attach the firewall
I put epoxy on the front of the firewall
then cloth around the edges
dont worry about the weight you will need it in the nose
On your choice of motors
I would certainly put it on a spare plane and run it a lot befor you install it in you scale hellcat
bad engines on scale planes usually me no more scale planes
lawrence

FLYPUCK

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Thanks for the input Lawrence. I appreciated any help I can get.
Here's one for you. Did you install ply doublers on the wing saddles? I've been thinking about putting them in but I'm not sure if they are necessary.
On the engine. It has flown in a couple of planes without missing a beat. I just decided to redo the carb mounting to stiffen it up. It was a little loose before but nice and secure now.

Thanks,
Doug

hellcat56

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It has been a while since I built it
I did it just like th plans called for.

LDM

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I dont know if its still available but I love this stuffGreat planes was selling milled fiberglass in a small pointed container , I added it to all my high stess needs when glueiing and it works perfactly for adding strength and filler to expozy .
Its cheap , you simply stir your expozy , shake the desired fibers in place and mix again .
It does shorten the cure time of your glue and it will thicken up more then just glue , hope this helps with your gaps .

FLYPUCK

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I got the firewall glued in using both Hellcat56 and LDM's suggestions. I mixed up some 30 min epoxy with microballoons, smeared some on the front, put it in place and poured the rest around the perimeter. Seems to have worked well.
I was going to try my hand at making an access hatch tonight but realized I didn't have any glass heavier than 3/4 oz so, I'll have to wait until I can get by the hobby shop.
In the mean time, I decided to modify the retracts. I picked up a set of Robarts from Hogrider that were made for a Ziroli Hellcat. These turned out to be 1-1/2" too long per the plans so I shorted them by first removing the scissors, then cutting 1-1/2 inches off of the rotating tube. Robart tells me that when you do this you need to also shorten the spring by an equal emount. There was a wooden plug in the upper strut so, I just removed 1-1/2" from that. Then re-assembled them and they are the perfect length now.

FLYPUCK

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Tonight I made my fist attempt at making a tail gear door. I covered the area with cling wrap and layed down some 30 min epoxy, put down some 2 oz glass, carbon fiber and 3/4 oz glass. It appears it is going to come out lumpy from the CF so, I'll probably need to make another try at it.

FLYPUCK

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I'm planning on trying another tail wheel door tonight. I'll go with 2 layers of heavy cloth and 1 layer of 3/4 oz cloth. Question: should I go with the 30 min. epoxy I used before or some finishing resin? Regular viscosity or thinned?
Thanks for the help!