fliegertom

[8D]  schade!

fliegertom

Below you can find a few pics of my progess of the alighting gear.

For more informations click here.

Happy New Year!!!

abufletcher

Looks really professional, Tom!

I think I'm temporarily out of steam for detailing. It's be a LONG couple of months. Interesting. Intense. Satisfying. Sometime surprising and even inspirational. But it's been hard detail after hard detail. So maybe what I need to do is something simply like gluing some balsa together. BTW, have you noticed we seem to work like "tag-team wrestlers." Just when you run out of energy ad/or time, I get going. Then I get tired and you take over!

abufletcher

I'd like to emphasize that there's nothing "hard" about the kit itself. In many way, this kit goes together very easily. It's just that a model like this encourages you to go "all out" and any of the WWI 2-seaters have loads and loads of "interesting" detail. By comparison, the fighters can be almost childishly simple. I've definitely been pushing my building envelop on this one.

fliegertom

Hej Don,

Wir sind schon ein tolles Team.....wie zwei Bergsteiger, die sich gegenseitig beim ausruhen sichern!
Nicht zu lange ausruhen.....! [8D]

Für Dich ein gutes Jahr 2011

Tom

ARUP

Nice build but..... wow- the 'photo busted stuff' is kinda off the hook, man! Chill and enjoy some Welsh Rabbit for the New Year!

abufletcher

Ah, this is the life! New Year's morning at the field for that First Flight! When I first got there, it was snowing lightly. Then the sun came through and it was just crazy wind...enough to blow my hat off. But I was determined to fly and so took off straight into the wind and had a great "wild ride" before my hands started to go numb. The landing was a hoot, more like hovering in than landing. But I nailed it.

Then it was into the "clubhouse" for a cup of instant joe.

86analysis

My Feedback: (-2)

Great build thread!  Enjoying it thouroughly!

abufletcher

Thanks. Once I build up some mental energy, I'll get started again. By the way, the silicone mould does seem to have finally cured after three or four days in my heated office.

I also prefer to wait until RCU has sorted out its "teething problems" (to be generous) on the new servers before I continue to photos of the build. They've already lost a dozen or so pages of photos on this thread. I might get back to building soon but I won't post photos until RCU gets its act together. If they can't get things sorted out, I'll just continue the build elsewhere.

abufletcher

It's been about a week. The silicone finally set. So what now? I think I need to cut some channels. Also do I need to spray the mold with release prior to pouring the casting resin? I plan on taking this slow.

GianFrancesco

at least the chemical has made his work!
The RTV siliconic rubber I know, does not need of any releasing agent as it doesn't stick to any material except than to itself; between the two parts of the mold is sufficient a bit of talcum powder to prevent to stick.

GianFrancesco

Abu I have forgotten to point out:
no channels to allow the air to exit; it is better to open a hole by a sharp cutter in the mold at the base of the cylinder; so it is easier to check the pouring of the epoxy and the air bubbles have a "large" surface for emerge.

abufletcher

What about air out channels? I saw these on several of the molding videos I watched.

Also, so I need to "pre-pour" drops of resin into any of the depressions before closing up the mold and doing the full pour?

GianFrancesco

From my experience the cut showed on the part at right is enough; you can put some drops of epoxy mix by a small wooden stick into the deepest details; at least in the head and/or in the connecting tubes between the cylinders; this even when the mold is closed; be careful to poure the mix solwly and to beat a bit (*) the mold to allow the air bubbles to go up; the shape is quite simply and I think shouldn't be any difficulty.
(*) This from my ancient experience in precast concrete industry; I have used also the plate of my vibrating scroll saw to shake a bit the molds....

abufletcher

These aren't the cleanest castings in the world, but with a little work, they'll do for my model. On the first attempt I didn't stir the resin long enough and some gooey stuff settled out on the bottom. Also, it was obvious that I would need to "pre-fill" some of the holes. But the next six went well. I never did get a completely clean casting of the bottom flange (which doesn't really matter). The original master weighed 21g. Each of these cast cylinders weighs in at about 35g so that's up over 200g for the cylinders. I could probably remove 50-60g of that.

Anyway, I guess this will do for my first attempt at silicone mold making/resin casting. In the end, I spent a lot of money on materials, spent two weeks or more making a master and preparing a mold, ended up with cylinders that I'll still have to clean up a bit and detail, and that weigh a third more than the master. Was it worth it? Yes and No. Yes, in that I've learned a new modeling skill that I'm sure will come in handy in the future. No, in terms of cost/time effectiveness and aesthetic pleasure of having made something by hand. A better solution is a set of laser cut disks. Bear in mind that I'm not a fan of plastic modeling.

[BUT YOU'RE GOING TO HAVE TO WAIT TO SEE PHOTOS BECAUSE RCU IS STILL HAVING PHOTO UPLOAD PROBLEMS[:@]]

GianFrancesco

At the time I asked to myself: Was it worth save some grams on the cylinders and then have to put a pound of lead to balance the plane?

abufletcher

That's sort of what I figure too. Nevertheless, using a Forster's drill bit I was able to get the cylinder weight back down to 21g on my "test cylinder." So at least I can't complain that the castings are heavier. I suppose in the end, it's a matter of preference. Casting definitely has some advantages.

I posted the photos on Tom's CI thread on RC-Network:

http://www.rc-network.de/forum/showt...95#post2150095

GianFrancesco

Looked at the photos: the cylinders looks good; the air bubbles can be avoided as said by "pre-filling" the cavities; can help, in particular with round objects, a slow centrifugation of the mold; I used a small electric motor "Mabuchi" from a plastic tank model to drive a small circular table; for the base flange you can open quite all the hole and this is surely helpful

abufletcher

With the brand I used ("WAVE")would definitely say the release spray (same company) is helpful. I didn't spray the release on the first attempt and I think that's part of why I had some mold damage getting the part out on that first casting. Little bits of the silicone got torn away (in the "cooling" ripples and need the pipe) and so these flaws got replicated in all the subsequent casting, on which I did use the release spray.

I'll go ahead and hollow out the cylinders since if I need weight I'd rather add it lower down (and concentrated further forward). After that, I'll start in on the usual plastic modeling step of repairing and prepping the parts.

abufletcher

Very good suggestion!

abufletcher

OK. I'll give the photo upload another shot.

Yep. Maybe fifth time's the charm.

abufletcher

Here's my little casting station. And a photo of the hollowed out cylinder.

abufletcher

I did one more cylinder with the hole enlarged and that did indeed solve the problem with the base flange. I'm not sure it's worth using any more of my resin though to since the rest of the cylinder isn't any better looking and I don't think the flanges will even be visible. I might even end up cutting off the base of some or all of the cylinders.

GianFrancesco

I understand that perhaps doesn't matter but only as a philosopical dissertation:
How long is the curing time of the resin you are using; my resin had at least 20 min. at 20° C.; if shorter the air bubbles couldn't have enough time to come out; if the flange would be strategical you might fill it with an addensed mix (adding a tixotropic agent) that remains where is put.

abufletcher

The resin is almost as thin as water so bubbles in the resin itself isn't really a problem. But I think I was getting a few air bubbles sticking to the surface of the mold. The resin sets in about 5 minutes and is fully cured in about 10 minutes. Seems like pretty good stuff.

I also through about pouring in a little and swishing it around the inside of the mold before pouring in the rest. The main problem now though is the minor damage to the mold caused during the first casting. Holes from air bubbles are easy enough to fill but fining down rough areas where bits of silicone were torn off is more difficult and time consuming.