High Sierra,

I measured the stock downthrust of 3-3/4 degrees with the horizontal stab set @ 0 degrees. I reset the downthrust in my RB to 2 degrees.

Rich

[quote]For those who have changed the down thrust... do you remember what it was stock?[/quote]

OraCover (Ultra-Cote) White (not Transparent White but regulr White) seems to match mine perfectly. I know this because I have re-covered a 6" x 10" area under each wing after my main gear ripped out on first landing as well as the entire left horizontal stabilizer after it ripped off (not completely, enough to allow the plastic hinges to fall loose and the elevator flutter enough to strip the servo gears - luckily my local instructore ACE was handy to land the plane with throttle and rudder alone inthe grass, slick!). In any case, the white matches both in the house and in the sunlight, seems to be an exact match...

JFetter

DT,

I found the best gear block repair is to cut 1/8" ply to fit between the 2 wing ribs that support most of the gear blocks. These ply pieces should also run from top to bottom sheeting, in effect making a bulkhead on each side of the gear block. If you then cut a 1/2" x 1/2" of square balsa stick to fit under the end of the gear block, running from spar to leading edge and add another piece of ply to box this part in, you'll end up with what I have discovered is bullet proof (enough to bend the gear back each hard landing without fear of ripping them out - and I mean HARD bending). Of course I CA'd all these pieces in and then used a syringe to run a bead of epoxy around each piece of ply and around the perimeter of both ribs. To cap it off, thick CA on all gluing surfaces for the new skin and bam, solid as a rock (without the weight, 5.5 oz. total added)...

JFetter

Rbeav533,

Thanks for the info. I keep seeing these Spring Air struts mentioned and have seached the web with no results. Can someone direct me where I can find these? Tower, Horrizon, etc........ I have checked both and do not find any matches.

Or, are these supra struts still made. Again, I searched both TOwer and Horrizon and could find any mechanical's heavier than 5/32. I really don't want to get into the whole air thing just now.

Here's the URL to the 100 Series Retracts on Spring Air's website.

http://www.retracts.com/100.htm

For an air based system the Spring Air retracts are as easy as they come. It's a air up and spring down system, in other words if you spring a leak and loose air pressure the gear will extend on it's own. The other nice things about this configuration is the simplicity, just a single air connection for each retract. Other pluses are a smal and simple spool valve and a small airtank. The downsides are filling the system at the field, Robart Pump, small electric pump, etc. and how to transport the wings with the gear extended (there's a way to handle this).

About the Supra retracts. I believe the old style metal retracts are no longer in production. You might want to check araound at yourr local hobby shops. Sometimes you find these NIB sitting on a shelf. They don't have 3/16" wires, these retracts have 5/32" wires. What makes them desirable is they are ALL METAL construction which translates to very robust. The 5/32" wires will work but be kind of wobbly, so the solution is 3/8" Robostruts and you have a very nice functional mechanical gear setup.

Here's a link to a very informative piece on mechanical retract installation.

http://www.probuild-uk.co.uk/factsheets/retracts.php

HTH

Rich



[link=http://www.retracts.com/100.htm]Spring Air 100 Series Retracts[/link]

Here's some additional info regarding Spring Air. I didn't look at them, but Spring Air happens to produce an ALL METAL drop in replacement for the cheap plastic retracts. You'll find them listed as the 1000 Series on the Spring Air website. They produce the gear setup for wire and another version drilled for 3/8" oleos.

If you don't want to deal directly with Spring Air, then you'll need to order them through a retailer that handles Spring Air. Check the adds in RCM.

Rich

Rich,

Thanks again for the info. The retract that I thought of using are 5/32 and have plastic. I got them at a swap meet so I don't know what they are. Here are some pics, anyone know what they are? Mechanically they work real well, much better than the mechanical rotating retracts in my Kyosho 40 size corsair.

I was looking at the Spring AiR sight and from what I see we are talking well over $100 bucks to get into this system.

Anyone know of a brand of mechanicals that will carry the RB (10-12lbs)?

...Fitted two sets of Supras now , the 40 sie ones on a EZ P51 Mustang and now the 60 size Supras on the RB ...cant fault them at all..supra in fact.....

The trouble with some retracts ....like the ones in the photo's above... is that they have bolt/ screwheads that stand proud on thier side faces..these faces should idealy be flat & a snug fit down inbetween the bearers, Supras are v.high quality glass reinforced mouldings, designed, i believe by Hanno Prettner, double coils at the top and real slick in opperation. you can get them o.k. but you may have to dig around ...readilly available here in the u.k.

If you feel they are not quite siff enough , you can slide a carbon tube over thier ( quite long , in the RB's case ) length ...then top that off with half of a Robart plastic strut cover for a better scale look...

Carefull retract selection and radio ( servo ) placement helped significantly in keeping the RB under 10 lb..

Lord Lucan,

BTW, I have read this thread up to about page 20, in which you hadn't yet reported your RB with the OS 91. I assume that you have flown it by now? How does it perform with the 91? How much weight did you have to add to balance?

I picked up a 91 just for this plane, but also happen to have an OS 160 sitting around. After reading this thread I would be very reluctant to use the 91 and am leaning towards the 160. Any thoughts????

.... Managed a couple of flights with the Bear, before the bad weather cut us short []...The .91FX "c" spec is superb even though brand new, hence still rich and not yet realising its full potential. No issiues on power here at all .

This will be next summers jewel in the sun ...keep her to a respectable weight and the .91FX is more than plenty....2.8 BHP..in standard form....what more could you want

As you can see some people consider the 1.60FX " Grossly oversized "...Hmmm..Lots of people want this model to go fast. The Full size RB is Fast, 528 mph was it .... but what does this equate to in " Scale like speed " for a model of this wingspan..? I dont know.

With all the shifting of gear / tank & everthig up front i had to add about 1 1/4 oz to balance the RB....this may well come off next year when i get used to her.

Jwortner,

I agree with Lord Lucan about those swap meet retracts you have. The Supras are your best bet in a mechanical retract. You have to remember that although mechanical retracts look inexpensive compared to air systems you must include the cost of a retract servo (Decent ones cost about $35 and go up) and if you're real anal you should use a seperate battery and switch to provide power to the retract servo.

The Spring Air #116 setup I'm using cost about $110 when I bought them a couple of years ago. This is for a full system which includes the fill valve, spool valve, air tank. lines and a couple of T-fittings. Most other retract systems cost more because you must buy all this stuff in addition to the retracts.

Rich

RB Color? Does anyone know what the Gold color is, or if any touch up paint is available yet?
Thanks,
Dudley

Rich,

OK, I give up on the mechanicals. Just talked to Spring Air and they are not making theirs yet. I just ordered the Spring Air 103HD completed setup for about $140. The owner of the complany has a RB too and he used these. Welcome to the word of pneumatic retracts I guess.

Now I just have to decide, OS 91 or OS 160 !?!?!?!?!?!?!?! Ahhh

ys140 - gotta go with the engine that sounds as close to a wright 3350 sound as possible - hahahahaha

jmo

Dudley,

It looks like I'll be trying to figure out what color paint to use for some minor touch up. I haven't flown my RB yet, it's still on the table. However I have found that the paint that TT is using doesn't have any plasticizer in it. I was gently flexing the canopy/cockpit section after installing the framework and canopy hooks which allow it to be removable, ala Ducted Fan style. As I was flexing I heard a crack, I initially thought the liteply framework had broken, no such luck, it was the paint cranking that made the sound. So I'm thinking Duplicolor touch up paint from the autoparts store to match the paint and I'll repair the hairline cracks, with some CA and 3M green spot putty.

I'll post my findings after I perform the repair.

Rich

Rbeav, if you want an exact match on your paint try an autobody supply store. Some have the equipment to analyze a paint specimen then prints out a 'recipe' for the paint formula. This would provide you with and exact match. Color, depth, and metallic size/amount. Specimen should be fairly flat. Cowl may not be a good specimen. Your local bodyshop may be able to point you to a supply store that would be equipped to do this for you. Of course then you may have to buy an applicator if you don't have a spray gun. I know there are reasonably cheap gizmos that enables you to make a pint of paint 'aerosol'. Don't know how much you're prepared to spend. Just thought I'd let you know the solution's available.

Well, well.

Look who has joined the conversation. Welcome aboard, America! (a.k.a. PH) [sm=lol.gif]

That' MISTER PH to you sir. [sm=wink.gif]

OK folks...now that many of these birds have been built, what the hell were they thinking when they listed this plane as a .60 to .90 size? I keep seeing everyone puting over 1.0 engines except a few and still hear about how tail heavy it is!!!!! What kind of wing load are you guys getting after leading down the front end just to get this thing to balance?? I have the Little Toni and added nothing in means of Xtra weight to the nose to have it balance with the Super Tigre G-.90 engine! In your opinions, will this same engine be a fit for the RB? This engine has GOBS of torque and enables you to turn a larger high pitch prop and really get some speed. I use a macs tuned non muffled pipe and love it! Any thoughts would be appreciated.

Jim

Well, time to get to work. Just got my Bear from Santa last night. Hey, have they beeeed up the gear mounts from what you others had (see pic below)?????? This looked pretty meaty to me. Just wondering if I really need to cut into the wing to beef it up or not. I have a pair of Spring Airs with 3/16 wire struts to mount.

....Hmmm have they beefed up the mounts or not [:-].....these pics were taken at the begining of October......Whatever, i employed Vamps mod....no problems.

Looks the same as mine which was purchased a few months ago....looks like you need the beefing up mods

I'll second that...No change on those gear mounts in the pictures.... If the rails that the gear screws to are narrow, You will have issues.... Think of the moment that the gear produces on those narrow rails.....Pretty easy to fold them back.

Guys,

Here is a video I found on another forum of a RB that was converted to electric power. There's a long thread accosiated with this particular RB which includes many good photos and tips about the conversion. The only specific I recall about the power system is that he was turning a 19x11 composite 3 bladed prop. All up weight was over 12 lbs and the plane looks like it flew very well on electric power.

Rich


http://rcgroups.com/gallery/data/500...10_08_04_2.wmv

Very impressive. Looks fast and the run time is pretty good. But a silent Rear Bear is like a mermaid... Only half the fun.

Reminds me of a $2000 park flyer.

Jim