Bell 222 550 size project

[npomeroy]

Originally Posted by Tman49

When you cut the vertical pin, and put the silicone tubing on, what's preventing the pin from coming out of the hole? Sorry if this sounds like a duh.

Good point. I didn't mention... I have tied a loop of braided wire around the assembly to hold it in place. It doesn't look too silly - could represent a brake line or other cable.

[npomeroy]

Originally Posted by Tman49

When you cut the vertical pin, and put the silicone tubing on, what's preventing the pin from coming out of the hole? Sorry if this sounds like a duh.

And another thought... My drawing wasn't correct to scale. It may be practical to not shorten the pin so much (so the set screw can still hold it in place) and use a much shorter bit of spring inside. There needs to be some of the barrel freed up to take the 3mm wire but the length is open to experiment.

[Napoleon_Tanerite]

Well, I finally set aside my Habu 32 project and did some initial mockup work on the B222/430, and it was universally bad news. First is my E-Flite retracts do NOT fit as I expected. The mount plate for the electric retract is about 1/8" too wide. Top that off is my struts are too long to fit in the wheel well, and I will need to cut them off, probably around the halfway mark or so. To fit the retract mechanism I will probably knock the blind nuts out, fill the hole with epoxy, and re-drill it. Should be fairly easy, but certainly is frustrating.

[npomeroy]

I've pretty much got the main retracts working. They are quite sensitive in the lock-down mechanism, i.e. they took a lot of adjustment to lock down without the servo needing to exert constant force. There's still some servo buzz but I'll check the current draw.
The bad news is that although my JR9503 (actually the DSX9II non-American market version) has servo speed reduction only in the planks menu, not in helis. I guess I'll buy a Turnigy servo speed regulator.
Will post some images soon.

[Napoleon_Tanerite]

Today I tapped out the blind nuts and filled the holes with epoxy. My project has been very slow going due to my work schedule.

[npomeroy]

I seem to have the main retract system operating. I did quite a bit of fiddling to get them to lock down without stalling the servo too hard. The servo does buzz, and draws about 150 mA at full up or down. I re-did one of the wire pull rods (that go inside the black cube) to avoid having any exposed thread dragging in the hole. You can see in one of them some brass wire I used to stop the elbow sagging. You can't see it from the outboard side.

Also, I'm thinking to attach the tail servo to the boom directly (using a TRex 600 servo clamp) so that there is no effect on the tail pitch if the boom needs to be adjusted to regulate belt tension.

[npomeroy]

Excuse the fact that this thread contains a lot of "thinking aloud" about pros and cons, as well as direct construction.
- Concerning the tail boom assembly: I think the assembly sequence will be: [boom plus attached push-rod plus front servo arm] will be inserted from the tail end; [tail servo bracket] will be slid over the boom from the front as the boom "arrives" from the rear. Then the servo arm will be attached to the servo (which will require the boom assembly to be rotated about 90 deg). The servo bracket tightens with hex key so should be able to be done inside the fuse. The belt will need to be pulled rearwards through the attached boom, and then the tail pulley will need to be attached.

- I've cut the top cowling in half behind the rotor hole with scissors, and am attaching tabs to overlap under the forward section for tidy attachment (photos soon).

- A decision: Whether to attach (at least the front cowl section) with magnets or screws. The pros and cons are fairly obvious in terms of complexity to create vs convenient removal for access. I really would prefer the lipo(s) to be removable rather than recharging in situ. This is mainly because most of the time the model will be a Shelf Queen rather than in a back shed, and I don't like having lipos in the house for extended periods. I think I'll wait until I'm installing the mechanics to see how easy it is to remove the battery - not made any easier considering it looks like the battery will need to be as far forward as possible PLUS I'm hoping to put in some cockpit detail.

[npomeroy]

I've been playing with colour. This is some very dark blue metallic I had made up, sprayed on a primed 3 inch diam mailing tube, with some gold vinyl stripes. The vinyl is from the printing shop where they can use it to make lettering as well.

[Napoleon_Tanerite]

I'm glad you've had time to work on yours. I haven't touched mine since I filled the holes on the retract slots. Too busy with work and honeydos.

[npomeroy]

Originally Posted by Napoleon_Tanerite

I'm glad you've had time to work on yours. I haven't touched mine since I filled the holes on the retract slots. Too busy with work and honeydos.

I had to Google "honeydos" LOL (sympathy though). I'm in the middle of 2 weeks "holiday" (teacher but there are work jobs to do too...) so am trying to get the fuselage at least primed if not colour coated while I've got some full days to work on it.

I decided "screw it" I won't bother with magnets to attach the cowling. So it will take another minute for pre-flight. Attached are images of the tabs I made to attach the front to rear half of the top cowling. In order to make sure the curve was followed I made the tabs from laminations of brown paper. The first was glued on with methyl-acrylic adhesive http://www.toprc.co.nz/webshop/produ...roducts_id=590 - this stuff is perfect for attaching anything to fibreglass or metal. Then the next three laminations were done with epoxy. I used ply blocks and Du-Bro 2 x 1/2 button head screws into the plywood blocks.

I also glued small strips of plywood inside the boom where the elevator attaches, to give more attachment depth.

Today did the more obvious blemish and seam filling and sanded all the outside of the fuselage.

There is a question whether to attach the windshield early (securely masked) so that the join gets nicely painted, or just paint the windshield frame while it is separate and glue it in after the main paint job. I think Ill do the latter to give less chance of blemishing the windshield and to maximise the "open" time for cockpit or other fittings. I have found that using clear silicone sealant to glue in windshields any excess glue can be rubbed away without creating blemishes.

[npomeroy]

Filled blemishes in the fibreglass and gave first primer coat today.

The supplied two small vertical fins are made of some sort of plastic that doesn't look like it will take paint very well, so I re-made them from 1.6 mm plywood. The weight penalty is only about 2 grams. The horizontal stabilisers will be attached to the fuselage with a pair of carbon rods (1.6 mm diam). Pre-attaching the rods to the stabilisers gives something to hold them by while painting. Being rough balsa wood they need a lot of surface preparation.

[fightingmosquitoes]

Pics man! Pics!

[npomeroy]

Originally Posted by fightingmosquitoes

Pics man! Pics!

Sanding and priming pics are a bit boring but here they go...
Note my broom-stick system for holding the fuse for painting.

The black line on the fin indicates the path of the wire internally. It is twisted slightly so the end is glued to the inside surface of the fin.

[fightingmosquitoes]

Nice pics! She's going to look good!

I assume the carbon rods in the horizontal stabilizers are going to get trimmed way back before assembly. How do you intend to keep the stabilizers level and rigid? I'm guessing the boom mechanics are going to run right down the middle, so any kind of solid rod connecting the two stabilizers is out of the question. I think they're going to sag attached to the body shell alone?

[npomeroy]

Originally Posted by fightingmosquitoes

Nice pics! She's going to look good!

I assume the carbon rods in the horizontal stabilizers are going to get trimmed way back before assembly. How do you intend to keep the stabilizers level and rigid? I'm guessing the boom mechanics are going to run right down the middle, so any kind of solid rod connecting the two stabilizers is out of the question. I think they're going to sag attached to the body shell alone?

Yes the carbon rods will be trimmed so they don't intrude on the boom mechanics. I managed to glue some strips of 3mm ply (very roughly the outline of the stabiliser cross section) inside the fuse with liberal amount of "modified acrylic" adhesive. So the holes accepting the rods will be at least 5mm deep, into which the rods will be glued. The holes in the fuse are a loose fit to allow adjusting the exact angle when the stabilisers are finally glued on.

The small bolts through the ply fins are temporary to hold them while painting.

[npomeroy]

I thought I was doing well:
- obvious blemishes filled with epoxy putty
- grey primer
- "pin holes" and smaller blemishes filled with acrylic filler
- sanded, often back to bare fibreglass
- grey primer
- sanded, often back to bare fibreglass
- white primer

Oops, what are all the tiny black dots? I thought they were some artefact of the spray paint not sticking in little dots, but held up to the light they are holes! (image attached). So, at least the white primer shows them up. I will be rubbing fine lightweight filler over all the dots, sand and spray again.

An insight I gained from the book "There are no secrets" by Harry Higley (http://www.harryhigley.com/Books3.htm) is that you can't fill blemishes with paint. The idea is to paint -> sand back to surface -> keep repeating. So the only paint that survives the sanding is the amount that is in the grooves. With ENOUGH coats the grooves will be filled, but filler speeds the process
.

[npomeroy]

Here it is after about 8 coats of colour. It's not quite as dark as the test batch I tried, but it didn't seem to darkening with additional coats so I decided to stop. The earlier coats I buffed with a woollen sock.

[MotorRotor]

Man-o-man that paint job looks great!!

[npomeroy]

Originally Posted by MotorRotor

Man-o-man that paint job looks great!!

Thanks. It looks good in the photo, and overall it is OK. But the wooden parts are showing sanding scratch marks when held to the light, even though I thought I'd got them perfectly smooth. Not sure yet whether to ignore the imperfections or smooth and re-spray.

[Tman49]

It's gonna look SWEEEEEEEEEEEEET, whatever you decide to do!