Slow Low

Over the course of the last month I've been spending my spare time on some of the areas on the underside of the wing plug that need special attention with respect to draft/release considerations. It's one thing to decide to mould wheel and flap bay details, but it's quite another thing to maintain a level of calm persistence as you spend hour after hour after hour holding a little tiny sanding block as your fingers lock up and eventually refuse to hold the darn thing forcing you to stop until the next day.
At first I spent a great deal of time building up draft in the wheel and flap servo recesses with glazing putty. It was boring, but my 4" wheels fit the bays like they should, and release shouldn't be a problem. It's taking some time, no question about it, but every day it moves closer. One of the things that consumes time is the method that I'm using to build up fillet radii in the the tight spots.
In order blend everything in the flap bays, I'm brushing on a light coat of thinned finishing epoxy. I leave it for 8 hours and then sand, prime, and repeat. The thinned epoxy flows very nicely into the corners and has a self-leveling characteristic that just can't be beat. You spend an inhumane amount of time sanding - but what you don't want is a beautiful wing plug sitting in the corner trapped inside a fibreglass sarcophagus

RTK

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Beautiful work!

sunnybreeze-inactive

Slowlow,
The plug is sweet looking. What are you thinning the epoxy with to get it to level out so well? Let's get to panel lines ASAP.

Slow Low

Many thanks to all of you for the kind words, it seems I missed a couple of your posts, though not intentionally.

sir crashallot - good to hear from you and thanks for the encouragement

sunnybreeze - The first one out of the mould is always 2 layers of something around 6OZ cloth. This will give me a part to section for internal templates and also provides objective empirical input as to where support may be needed. (or more importantly where support may NOT be required) It's a good thing to start with the simplest approach and then go from there. Sometimes you get lucky. (I also chose the scale wrt the material properties - so as to help reduce required internals, but don't tell anyone)

RTK - Thank you - I'll try to keep it getting better for you as time goes along.


I'm thinning the finishing resin at 33-1/3% by weight. (1/3 resin, 1/3 hardener, 1/3 methyl hydrate)

As for panel lines - Patience is a virtue! LOL

SCALECRAFT

My Feedback: (13)

Slow

I know the plugs are a drag, but your not going to want to say " I shoulda" when that part comes out of the mold. Your gonna say WOW I just made a model in a few hours. And I can make another and another,..................another

The model you make here now is in a sense immortal. For people who can mold, no model is obsolete.

My buddy and I have made around 15 airframes in all composite along with spinners, props, and anything we can get the material for.

i don't remember if i mentioned this before but on the wings, I use the scale panel lines and wheel pants shape/details to place spars and ribs.

Our wings have 3 ribs per panel, 2 to support the LG plate, and one at the tip/wing joint. The spar sets the locations of all the ribs. The ribs set the location of the spar. All with 1/2 slots in the ribs and spars. Self alignment in a kinda. If you plan well you can have the ribs also set the aileron support caps for the hinges, dowel supports and wing bolt plate.

Nice work. Hang in there. Its ok to walk away from it sometimes, as long as you come back to finish.


Steve

Slow Low

Good to hear from you Steve. Thanks for the encouragement; it's what keeps me going when the going gets tough.

You made a very valid point for anyone else who might be interested in taking on a similar project.
We're only human and everyone who works on something for an extended period of time is likely to feel the urge to make compromises for the sake of expediting completion. In fact, we're all trained from the first day of school to this end and then it carries over into the work/marketplace. We even create fancy abstractions like "the point of diminishing returns" in order to justify compromise. THIS IS WHERE THE LESSON LIES; and it extends far beyond model airplanes.

Yes, I do look forward to the pride of ownership and accomplishment that I will feel as I land the first prototype. In fact, I may have to find a place to fly her away from the field because I may just need a moment to myself. lol
BUT, all of it is just one compromise away from the eternal "I wish I had've spent that extra hour/day/week/month to...", because EVERY single part that comes out of the mould is going to remind you of how you only cheated yourself, EVERY time you look at one.

...and so to all of us who work away while others shake their heads -

#1 - you have my respect on many levels
#2 - the entire world is conspiring against you - DON'T CHEAT YOURSELF

SCALECRAFT

My Feedback: (13)

Slow

Your so right.

I find the word "never" a personal challenge and motivational.

Also, I would look to fly the prototype on a day when no one is around. You don't need the anxiety. Its not a model you assembled, its your model.

Slow, if you don't mind, which models have you flown before. I fly scale warbirds from WWII, 48"spans to 72" and Ducted fans, glow and EDF. And I have a couple of turbines I have yet to put in something.

The 48" span warbirds really are what keep one sharp.


Steve

Slow Low

Oh boy, over the years I've flown more models than I know I can remember. I started with built up freeflights with 1/2A's, then moved to control line everything from 1/2A's to 0.10, 0.15, 0.19, 0.29, 0.35, 0.36 Fox, McCoy, Enya, K&B, stunt, combat etc etc

When I could finally afford a radio in the late 80's I got into R/C, converted most of my old control line engines after hours in the highschool shop and put them into a lot of my own designs because it was always cheaper to throw something together on my own than to buy a kit. Oh boy, when I got my first 60 I thought I was something then! I never really got into turbines or ducted fans because it's just too much dang stress for me these days lol. I do have an old dynajet pulsejet on little lead bellied control line racer somewhere, but I haven't flown it since I could drive a car or drink lol.

I was not a middle class kid, but for some reason my father had every model and full scale airplane magazine there was from the 40's all the way up. He kept them all sorted in boxes and hidden away (I think it was the only thing that he really had that he could call his own.) but by the time I was 7 or 8 I'd studied every one of them 100 times and had enlarged every plan I thought worthy by hand too! The result of all of that, is that I'm a WWII warbird nut! I've built and flown just about everything outside of jets over the years, but a WWII warbird is something deeply special for me - it's just part of who I am. Sounds corny, but I remember being 10 or 11 years old lying in bed studying the lines of almost everything from Corsairs to P-40s to Harvards to Lightnings...all of them until I could draw them by hand. Then I'd compare them to the photos to see how scale they were, and I'd do it all over again until I got each of them to a point where I could draw in the original formers ribs and stringers. While other kids were daydreaming about whatever it was they daydreamed about, I was quite honestly dreaming of the day that I could afford to pull together one of the moulds that I'd built 100 times over and over and over in my head. I remember being in middle school figuring out how I could make a bladder to expand inside of my mould in order to join halves when I couldn't even afford to eat lunch or take the bus home. LMAO NO ONE made model airplanes out of composites in those days.

Well, I'm sure you got more than you bargained for there eh?! Long story short - WWII warbirds only please these days, usually 60 size sometimes 90 - one day 50cc gasser before I die please.

SCALECRAFT

My Feedback: (13)

It appears we may have the same disorder. My wife calls it an obsession.

Either way, it makes one go beyond the average.

Steve

Slow Low

I fear there may be a little Howard Hughes in each of us, but if you can't chase dreams then what's the point. You're a lucky man to find a woman who is accepting enough to call a spade a spade my friend. Well I'm off to wash my hands again! lol lol lol

Slow Low

Since my last post I've done some more work in the flap bays but to be honest, I woke up one morning after having sanded all night in my dreams and was very disheartened to find that it was still the way I'd left it the day before. LOL So I figured that a break from that task was in order, and I moved on to something else that had been aggravating me for some time now.

Overall this kit has been a joy to build, but if there was something that I would improve it would be the wing fillets. The precut ply fillet bases need to be extended further out the wing near the leading edge. There's nothing I can do now with the fuselage complete and it slipped by me or I'd have fixed it. So having stared at this annoyance for months I needed to do something to ease my mind. I decided that with no options for achieving a scale look, I would improve the fit so that when someone noticed the form deficiency they could comment on how I tried to fix the fit instead! lol

There's still some finish work to be done obviously, but it's shaped in for the most part. So now I can go ice fishing this weekend and at least feel like I made a little progress.

sunnybreeze-inactive

Slowlow,
looks sweet to me. Lets get the mold made on move onward so I can see the finished wing! Keep posting and passing on the lessons learned.

Steve

SCALECRAFT

My Feedback: (13)

Hi Slow

I have a question.

I am no expert on the p-40, but is not the LG fairing shape incorrect. if its unfinished, then know the answer.

Slow Low

You are correct sir - there are still fairings to be moulded separately, which also contain the doors.
This plug shape will provide a cavity in the mould to accept the hardwood blocks and rib inserts, while the fairings containing the gear doors will be put in place during final assembly.

SCALECRAFT

My Feedback: (13)

Nice forward thinking.

A lost art and teaching

Steve

mr_matt

My Feedback: (10)

Love your videos, thanks for posting.

I got to watch an ex hollywood SFX expert make a mold for a scale UAV project and I could watch his techniques for hours. Your work looks similar. Thanks again.

Props4ever

Hey James,

Sorry been away from your thread on here, i got into my Avro Arrow that it took me away form other project of mine. You know the belly lander one!..hehe. Tonight i have come to conclusion "not to leave original major project for another big project!", now that couple more guys are very much interested in getting my composite short kits, i am getting back into it. I am not sure how i can do big one at the same time but will see. You flaps bay and wheel bay are looking so good that i literally don't have words to describe my true feeling about them, they are just GREATLY done!!

Steve,
Man i will catch up on your Tempest thread also as i will be bugging both of ya once again real soon with my moulds for the S Connie.

As for panel line i will follow what you and Bob with 1:8th B-1B did and let see what James will do also, i think this is the best and safest way to do them.

Great Job James, keep it up!!...

Slow Low

I've been delaying this post primarily because it's difficult to demonstrate progress at the rate that I know others enjoy watching. However, I've been asked to put down my sanding block and share; so share I will.
As many of us know any good finishing job goes through an alternating state of ugly, better, ugly, better, ugly, better until you decide at some point that better is just not going to happen again. I tend not to like to share pics of the ugly, but I suppose it does provide some insight into what a blended surface looks like under that final coat of primer, and that is what you're getting tonight.
I've been working away steadily on the mounts for the mains. This is an area which will never been seen after the exterior pods containing the doors have been installed, but none the less it deserves proper attention as it will form deep cavities in the finished mould which will need to release. I've tried to show pics which give an overview of the process, but won't bore you with the repetition that's actually involved. In order to achieve a final blended look, I've now applied thinned finishing resin and then sanded it level three times now. I know it looks ugly, but it's getting pretty close. Hopefully the next series of pics will be nice and shiny!
It's worth noting that over the years I've learned that this is not something that you can power through and get done properly in a week or two. It's tempting to think that with constant effort you could get this sort of thing done in short order but in fact what time has taught me is quite the opposite. It sounds corny I know, but when you want something you can be proud of, you don't build it; it builds itself through you. You have to work in short spurts and then just walk away. Don't worry about walking away, it will call you back and when it does you'll be at your best. You can't force your will on something like this and that's the point. It's not a project to be managed, it's a manifestation of something intangible. I know what it sounds like and twenty years ago I'd have been laughing out loud for sure. Live and learn I guess, live and learn.

sir crashallot

looking good, as they say it always looks worse befoe it begings to look nice or somthing like that. it will be a fine p40 when its done and thats clear from the amout of time and effort you have put into it.

Slow Low

I'd originally moved away from work on the flap bays because I was beginning to have dreams about it. This is usually a good sign that a break is in order, so the gear mounts got some attention. Well I made enough progress on the mounts that today my eyes moved back to the flap bays and I quickly remembered what it was that I found discouraging enough at the time put me off.
There's a lesson here. As you spend more and more time on something you naturally get more and more emotionally involved with it. This is what a little time and perspective helps to diminish. After glassing and then finishing every corner of those flap bays, the last thing I wanted to do was apply some more epoxy and do it all again. I knew it needed doing, but instead I sat there for a couple of days with the wing in the corner just looking at it dreading the thought. Meanwhile nothing was happening except that I was reinforcing the notion of my dread. I decided to move onto something else. Today it happened - it started calling my name. It never ceases to amaze me how the biggest obstacles seem to be self-realized and if you can find a way of moving on, time will often erode them.
After taking a good hard objective look at the situation with fresh eyes I can see that most of the corners that I worked so hard to get clean are not conducive to the moulding process. I knew this - I've locked things in fibreglass before - but I sure didn't want to come to terms with it because I'd just spent all that time getting them "darn near perfect" lol
The pictures should speak for themselves. What they won't tell you is that there's eight hours cure time until they can be blended before flipping the wing and repeating. It may take two applications to get things good and uniform, so that's likely three or four days of patient waiting, and I suspect that that may also have had something to do with the hurdle. All in all, it's a "better safe than sorry" situation!

Slow Low

...just some quick pics today of the ongoing saga in the flap bays
I need to do something else for a while again, so I'm headed into finishing the flap servo bays before coming back to finish this area.
2 weeks - 6 coats of epoxy - one side and then the other - much sanding

Upside:
1 - ease of mould design/construction (might have had to split mould down centre of each rib)
2 - ease of part release
3 - ease of mould prep (waxing)
4 - improved rigidity of wing structure through form in a high stress area of the wing

Downside:
SANITY ;-)

SCALECRAFT

My Feedback: (13)

Slow

With all due respect.

I could be wrong and I hate laying up composites; so it could be me.

But, the details in the wing plug are going to create an overtime labor issue in the layup. The square servo bay, the flap bay ribs a lot of hard angles.. I would cut out a hatch and build a wood box for the servo and maybe for the flap ribs, use a vacuum form insert. Just a thought.

Still nice plug work.

steve

Slow Low

Hi Steve - Hey man, when you're a veteran of this sort of thing, you don't have to worry about offending me, I'm glad to have your input. I hear what you're saying and I've given it much thought over the last year or so.

We ended up at the same place for the flap servo bays. I'll be building ply box inserts with aileron pushrod guides on the front edge to use during the joining process. I'm not going to close in the bottoms of those recesses when I do the layup. They will just give me a nice riser to self align the ply boxes, a nice pre-finished edge on the exterior to cast covers from, and a natural bonding face for the boxes. You're right in that I don't necessarily need to make them "more than functional", but there's this demon that lives inside of me that requires me to step up. I know, I know, it's not rational but I also know that leaving them looking all asymmetrical or not closing them in when I layup the mould will bother me to no end every time I look at it later. It's just easier to spend the few hours it will take to ease my mind in the future. I can always cut the bottoms out of the mould if I need an access hatch later. The plan doesn't require an access point there, but it's an option for unseen contingencies I suppose.

I also considered the vacuum formed rib details in the flap bays. It's a good idea, and it's certainly how I see most of them done. The pros would include perfect symmetry of each rib because they would all be copies of a master, easier mould prep, easier layup, reduced weight if your not careful etc. On the other hand, I'll be splitting the mould down the centre line of the trailing edge. This will leave a very thin cross section on each side of the part. Any tendency to buckle, and the first place to give is gonna be the seam. I just don't want it to open up or even move enough to jam the flaps on approach. I'm also trying to avoid as much finishing work as possible. I took a similar approach on the fuselage when I moulded the exhaust stacks integral to the fuselage. There are approaches that are cheaper, easier, and more scale in appearance, but it's pretty nice just to pull it out of the mould and not worry about it any further. (and oh ya - I haven't seen it done before either - that's a big challenge not to consider weighing the risks)

Respect back at ya sir, and keep the ideas coming any time you see fit.

Slow Low

The dearest woman in the world stands behind me as I type this morning. She would like you all to know that if any of you ever find yourselves doing anything like what you see in these pics, alone before breakfast on a Sunday morning, you should re-evaluate your priorities. [:@]

SCALECRAFT

My Feedback: (13)

I see your point, and more so, the point of the dearest woman.





Recovered plugaholic/mold maker. Well, almost recovered.

Steve