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Aug 27, 2019, 07:45 PM
Scale Builder
PS - I did some scale wheel hubs for the Don Smith Hs-129 which I think are the same, or very similar, to those on the 88. Also did a tail wheel which is similar to those found on many Luftwaffe birds but may or may not be correct for the 88. Obviously the strut is not the same but the tail wheel itself might be. Let me know if you're interested.
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Aug 27, 2019, 09:11 PM
Registered User
I really like the Turnigy G110 motors on 8s with the 16x12 graupner props. Have them in an ESM BF110. Too bad they don't make them anymore. The e-flite version is 2x more expensive.
Aug 27, 2019, 11:22 PM
When cows fly!
Aug 28, 2019, 06:15 AM
EB-66C Team Member
J Morgan's Avatar
Thread OP
Thanks Chad,
I've been working on gathering things for the gear. I have a set of the large Springair for the mains that I will be using. And for a guy that doesn't like retracts, I have enough wheels to start a wheel store. Yet, none that I can use for this build. Same as with props( I have them but on other planes and don't want to steal them). I swear, when I quit building I am going to open a Wheel and Prop store. But getting back to the wheels, I got some from HK in but they weighed 8 oz each. That's a pound just for the mains! Finally ordered some Dubro light weight that are 5 oz each. They also are 5" diameter. Scale dia is 6" but I am not running a rotating retract and want this wheel to fit in the wing, hence the slightly smaller wheel. I already had a pair of Robart struts for them.
The tailwheel is from HK, it is an electric assembly so that should all be straightforward. Again, smaller than scale at 2" ( scale one is 3"). But I would have to change or alter the strut to accept a larger tailwheel so will leave it as is and live to fight other battles in the build. But I will certainly keep those 3D wheels in mind as we progress.
And already thinking about how I want to finish focusing on keeping it all light. I had thought I would forego the balsa skinning and just finish the foam to keep it lighter. But I find that getting a fine finish starting with sanded foam is more difficult and time consuming than a balsa skin. And I think this size will handle the extra weight. So probably skin the plane too. Yes, considering your rivets. Man, it would be a bunch. We'll talk about that later.

I have decided to make the fuse a two piece affair for ease of transporting. That will add a bit of extra weight but I plan to make up for it by making my own tube & sockets( lite) and placing the elevator and rudder servos at the junction of the break in the fuse. That will move them out of the tail and much closer to the CG to help with balance.
I believe my three part system for finishing will be helpful in handling the weight ( glass/epoxy, rubbed in spackle, sanded, single coat of poly, wet sanded and primered) and give a nice light finish.
Sitting around and not building gives me too much time to think. I much rather enjoy the speed and spur of the moment decisions while building.

Irb,
I believe I have a G110 or two around here in a plane, just can't remember which one(s). I've had very good luck with SK3 motors and would recommend them to anyone.

David,
Welcome

At some point in the next to weeks I'm sure anxiety will get the best of me and I will start the tedious job of tracing and cutting parts for the fuse.

J
Aug 28, 2019, 06:58 AM
Registered User
I covered the outer wing panels on my big Vulcan with brown paper/wbpu that saves significant weight over foam/balsa/glass and looks good under flat paint. I prefer paper/wbpu to just glass over foam. Weight and dent resistance are similar but because the paper shrinks a bit, I feel I get a stiffer wing.

I assume you'll use that foam ribs and skin with MPF style of wing.

Batteries in the nacelles? Fuselage? Both?
Aug 28, 2019, 11:06 AM
EB-66C Team Member
J Morgan's Avatar
Thread OP
Quote:
Originally Posted by pmullen503
I covered the outer wing panels on my big Vulcan with brown paper/wbpu that saves significant weight over foam/balsa/glass and looks good under flat paint. I prefer paper/wbpu to just glass over foam. Weight and dent resistance are similar but because the paper shrinks a bit, I feel I get a stiffer wing.

I assume you'll use that foam ribs and skin with MPF style of wing.

Batteries in the nacelles? Fuselage? Both?
Yes, on the wing box type of construction.
All good info and questions Pat. Just got the plans out and was looking at batt placement. But the first thing that hit me was that these plans are for an A-4 model, not A-1. My bad, just forgot I guess. But I need to do some research because I thought the A-4 had dual MG-81 guns out the back of the canopy but the molded canopy has a place for a single only. But then I am not pretending to be a JU-88 expert.
It looks like the fuse will BARELY fit on the workbench, it's 82" long. If I make the wing breaks just outside the nacelles that will make the middle section about 42+" wide. I guess that's acceptable. Outer wing panels will be about 3' long.
One pic shows that two 4s-5000 batts MIGHT fit in the underside gondola. IF, and that's a big IF, I can keep the tail light enough to balance with them there it would be nice and still leave plenty of room for a full cockpit. I think you need a detailed cockpit because you can see EVERYTHING in there with all that glass.
Checking out the gear I see a problem with length but I'll get into that later.
The nacelle is 30" long! Stab is 43" but I'm planning on removable sections for it. Looks like the root rib is about 21" long. It's a BIG plane with 11.7 sq ft of WA.
So after looking it all over I'm still on the fence with how I plan to finish it, balsa skin or not? Even thinking about silkspan on the rear section where the fuse separates and then balsa forward. All over the map with this but whatever I decide, I need to keep the tail as light as possible. I may need to cut some 2mm skins for the tail surfaces.
Probably a good thing that I can't really sart yet, gives me plenty of time to think about it.

J
Aug 28, 2019, 11:43 AM
EB-66C Team Member
J Morgan's Avatar
Thread OP
Here's the problem with the gear. The Springairs are the same size as in my big Helldiver( 28 lbs) so I know they will handle the weight.
Length is a problem but with these Robart struts I think I can lengthen them w/o much problem. If they don't rotate they need to be mounted higher up in the nacelle than the plan shows in order to get as much of the wheel up in there as possible. It still will stick out some. But I am adamant on no gear doors so there will be an opening anyway. If they don't rotate but go straight up then there will be a smaller opening.
Robart has rotating retracts ( refurbished, used?, crashed and fixed?) for about $150 each, Horizon has them on sale for $315/pair. New are about $400/pair.
That's all moot I guess as I'm not doing gear doors so................ I'll just lengthen the struts and go with them. Wheels in the pics are 5" but not the ones I will be using.

J
Aug 28, 2019, 12:50 PM
Big gov never Works
St. Martin's Avatar
Hi Cob now I know where to find you, to see what your up to.

Fuzz
Aug 28, 2019, 02:57 PM
Registered User
Quote:
Originally Posted by J Morgan
..........One pic shows that two 4s-5000 batts MIGHT fit in the underside gondola. ..........
J
Got room in the cowls to put the batteries along side the motor? Nice area behind the cowls for a hatch.
Aug 28, 2019, 03:16 PM
EB-66C Team Member
J Morgan's Avatar
Thread OP
Quote:
Originally Posted by pmullen503
Got room in the cowls to put the batteries along side the motor? Nice area behind the cowls for a hatch.
Pat,
There is plenty of room right behind the motors in the nacelle for batteries. In fact I could use the FG nacelle top as a hatch. It all comes down to balance and how light the tail is. Being a twin with the motors sufficiently in front of the CG, maybe it will work. If I wind up putting the batts in the nose, I'll need the escs up there too so the wire runs aren't too long. I could put them with the motors but that would require caps and I'd rather not have to use caps as I think it's more of a bandaid than a solution. I know they work, I've used them before but still..... Long motor wire runs I never worry about.
But with these WW II prop warbirds it seems the batts always have to go in the very front.

J
Aug 28, 2019, 05:07 PM
Registered User
p901P901's Avatar
You could always just use the air actuator for custom retracts. Will need to make a trunion and a bearing mount to the structure. I will use Robart #620108A https://robart.com/products/620108a-...inder-assembly air cylinder for my project.
Aug 28, 2019, 07:16 PM
Registered User
tspeer's Avatar
Quote:
Originally Posted by J Morgan
...But getting back to the wheels, I got some from HK in but they weighed 8 oz each. That's a pound just for the mains! Finally ordered some Dubro light weight that are 5 oz each. They also are 5" diameter. Scale dia is 6" but I am not running a rotating retract and want this wheel to fit in the wing, hence the slightly smaller wheel. I already had a pair of Robart struts for them....
I recently created my own wheels using 3D printing. The hubs were PLA and the tires were TPU. They worked out really well, and I ended up printing another set for a fellow club member.

The first tires I printed had 4 layer walls and infill, and were way too hard. Then I went to 4 layer walls and no infill - still too stiff. Two layer walls and no infill were just the ticket. The tires were glued to the hubs with 3M 77, and I don't think I'll ever have to worry about them coming loose. I was surprised at how well the TPU printed. I had no problems or failures at all. I did, however, make sure I coated the platform with glue stick because I've read that TPU can stick to the platform so strongly that it can ruin the platform when you try to get it off.

With 3D printed wheels you could put in scale detail and make them just the right size for your struts. You may never have to buy wheels again!
Aug 28, 2019, 08:12 PM
EB-66C Team Member
J Morgan's Avatar
Thread OP
Quote:
Originally Posted by p901P901
You could always just use the air actuator for custom retracts. Will need to make a trunion and a bearing mount to the structure. I will use Robart #620108A https://robart.com/products/620108a-...inder-assembly air cylinder for my project.
Phil
I really like how you approach the mechanics of your designs. Me, I have zero metal working skills other than a set of files. Your idea would be great but I'm keeping this as simple as I can and light as possible.The Springairs are pretty light, wheels are 5 oz each( just got them in), the Robart strut being the heaviest item and it still needs extended. The wheels will stick out a little when retracted but given the room and the geometry of the 90 degree units, it can't be helped. I can live with it though. Scale will suffer in this build but I don't want to be married to scale and gain weight. It will still look enough like a JU-88 for me.

tspeer,
I envy you guys with 3D skills. There is no getting around it, 3D printing is the wave of the future. And it's just getting started! But at my age I would rather cut foam and balsa than sit down to learn the skills necessary. But that's just me. Have to admit, I do enjoy watching all the new things that modelers are coming up with using 3D printers. I'll bet your wheels are nice.
I do have an outlet for printed MG81 guns for the 88 and will get them ordered soon. I'll post a link to that site when I do.


Have been thinking about the surface of the 88 and maybe go with balsa skinned fuse (little extra strength since it will be two sections) with silkspan covered horizontal and vertical. That will help the weight in the tail. Wing I'm still mulling over.

J
Aug 29, 2019, 02:36 AM
71% of the world is runway . .
Bart83's Avatar
2 pages already . . . looking forward to this build.

Have fun,

Bart
Aug 29, 2019, 06:13 AM
EB-66C Team Member
J Morgan's Avatar
Thread OP
Thanks Bart,
Hope we will all have fun.

Another modeling friend of mine from Germany sent me this video this morning. We just think we build large airplanes. This beautiful model has a 10M wingspan!!! And the pilot flies it like he stole it. An amazing aircraft but you know the first thing I noticed about it? NO GEAR DOORS!!!!!!
So I guess there are people out there that feel like I do.
Anyway, enjoy the video.
GIGANTIC 10 METER LARGE RC CONCORDE - MAIDEN FLIGHT (10 min 8 sec)


J


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