dsiems

My Feedback: (1)

I have 1/2" of up ailerons with full flaps (70 degree or so) and no crow with half flaps. I had to add a little more elevator compensation with the crow (from 1/8" to about 3/16") The crow allows the jet to slow even more and you can come in with a little power. This helps if you have to go around, shortens the spool up time of my P70. I Think you will love it. Just try it a 200-300 ft for the first time.

Dean

racer8297

My Feedback: (13)

Ok, thank you dsiems. I will set it up tonight.

Jim

dsiems

My Feedback: (1)

Racer8297, let me know how it works out for you.

[email protected]

Dean

DavKhy

My Feedback: (2)

I have a question about the Reaction 54 kit. What is the going price for an undisturbed kit with retract gear set up? I might have a line on one and want to know what they are worth in this state.

flyinfool1

My Feedback: (2)

http://www.btemodels.com/prices.html

racer8297

My Feedback: (13)

Made 2 flights yesterday. I took 2 ounces out of the nose which seems to have solved the nosing down when turning issue. It also makes landing even slower of you can believe that.

We had a crosswind of better than 20mph. The Reaction handled it just fine. I was almost able to hover it down like my Hangar 9 Cap 27%.

Here are some pics. The power lines and house are about 1/2 mile away.

[img][/img]

dsiems

My Feedback: (1)

Racer8297,
Did you try crow on your R54?

racer8297

My Feedback: (13)

Hi dsiems,

No, I haven''t yet. I have to move a couple of channels around to get the crow going. I won''t get to it until next week. But I am looking forward to giving it a try!

Jim

speedbrake

Dean,
Our messages were deleted by........? Don't think we embarrassed, insulted anyone.

Good to talk with you. Will see you and your R54 later on this summer. Hopefully we'll have a bunch of Reactions to play with in July. Get the word out in your area.

Keith

racer8297

My Feedback: (13)

Ok guys. I want to upgrade the landing gear on my Reaction to something a little more sturdy. I was looking at installing Robostruts 660 since they would bolt right in to the existing units. It seems like I have to cut them shorter than they are meant to be cut in order for me not to have to modify the wheel wheel positions.

Any thoughts on how to approach this?

BTW, had 3 more flawless flights on Friday, bringing me up to 10 flights now.

Thanks,
Jim

ww2birds

My Feedback: (14)

Hi Racer,

Yes, you will need to shorten the 660s .. bit it's easy to do .. just careful work with a dremel cutoff tool and dressing up on the grinding wheel. On my set, I had to very carefully file/grind down the outside diameter to fit into the trunnions .. maybe .010 or .020" .. but pretty easy. You will also need to cut the springs down since the struts are shortened so dramatically .. again no big deal.

I replaced the nosegear with the small trailing link dreamworks nosegear. This worked out really well. I used the stock nosegear, cut it off as close as possible to the coil, but did have to machine an aluminum sleeve to adapt the Dreamworks gear to the wire strut, since the Dreamworks gear is designed for a larger strut wire (maybe 1/4" vs. 3/16" if I recall correctly). Could also have made a new wire/brass assembly (like on the original) with the right size wire vs. making a sleeve to adapt the original .. either way would work.

I have seen the other trailing link struts that Digitech is selling for the K-cats, and they look really nice too .. I was wondering if they would work with the R54, bet they would...

Let me know if you need any more detail or any pics.

You'll see several references to gear upgrades on Bruce's index of this thread.

Dave

racer8297

My Feedback: (13)

Hi Dave,

Thanks for the info. It looks like I have to cut off 3" from the top of the strut. It feels like there is something inside the strut at about 2.5". I don't want to cut through something that needs to be there. I assume that is the spring stop??? What is holding it? How do I get it out? I assume if I take off the linkage that the sping assy and that piece will fall out?

Also, what wheels did you use to replace the Dubro's? The Dubro's are to thick (wide) to properly fit the axle that comes with the 660's.

Sorry for so many questions and thanks for the help.

Jim

cjshaker

How long did it take you to build your Reaction 54s? If you worked on it full time, how many weeks
would it take you to build it?

Thank you,
Chris Shaker
[email protected]

Ron Stahl

My Feedback: (12)

I build faster than most. I built mine in 9 days from start to finish about 6 hours a day.

ww2birds

My Feedback: (14)

Jim,

Yes, that's the spring stopper. And yes, you'll cut off about 3" .. I just went and measured the scrap part I had cut off .. it's 3" on the nose. You will be cutting just below the original spring stopper, it will stay with the scrap, does not interfere with the cut. With the Robart struts they give you new spring stoppers that you put in the new bottom of the tube, presumably to keep it from crushing from the pinch screw on the trunnion. I elected not to use them, essentially using the pocket in the trunnion as a spring stopper, since I did not want to give up another 3/4" of spring length with the strut so short ... but that's just a preference.

I used Trim wheels and brakes on the mains (3", as I recall .. whatever it was, it was the same as the "stock" wheels), I got them from Great Northern Models. I used a BVM nosewheel that fit the Dreamworks strut, got them both from Todd at Dreamworks. Using the UP6 brake valve which is very very nice.

Dave

ps .. Ron makes me feel SLOOOOW .. I took about a month and a half to build my R54 up to the point of being ready to cover (then it sat for almost a year before covering .. other projects...)

cjshaker

Thank you both for the build time answers...
Chris

racer8297

My Feedback: (13)

Dave,

I'll start in on this project later this week.

Thanks for all your help,
Jim

racer8297

My Feedback: (13)

ww2birds,

I've got the mains all set, thanks for all the help. Another question though. If I use a 660 offset strut in the front or the Dreamworks nose gear you used, what secures it the the front retract? Is there a set screw? Or did you JB Weld the whole thing together?

Thanks,
Jim

ww2birds

My Feedback: (14)

Jim,

I used the small nosegear strut from Dreamworks. I think you can find posts using Robostruts on the nose too ... check Bruce's index on www.btemodels.com

To mount the Dreamworks nosegear, I used a Dremel cutoff wheel to cut the stock strut as close to the coil as I could, leaving a straight piece of wire "stub" sticking out of the nosegear. I made an aluminum tube just the right size to slide over the strut wire, and fit into the hole in the Dreamworks strut.

I am down at TG not home, so I can't measure, but I think it's 1/4" and 3/16" for the OD and ID and about 1" long .. I drilled a hole at 90 degrees to the axis of the tube to allow the screw on the Dreamworks gear (a grub screw, as the Brits call it) bite directly into the wire strut.

I can't send a pic right now, but I think you should be able to "picture" it from the text above...

Dave

racer8297

My Feedback: (13)

Thanks Dave, that's what I thought. You didn't JB Weld it? Just the grub screw holding the strut on?

Good luck at Top Gun!

Jim

ww2birds

My Feedback: (14)

Hi Jim,

Nope, no JB Weld .. just the grub screw (on this nosegear this screw does double duty in holding one end of the spring).

thanks for the good wishes!

BTW, the PST crew flew the composite R54 derivative "after hours" today .. looked great!

Dave

flyinfool1

My Feedback: (2)

OK, here is a question for you guys.

On my R54 I have a P70 with Kero start.
I am in the process of replumbing it, since when I got it there was only one fuel shutoff valve and it was on the kerostart line.
I am planning to move the fuel shutoff valve up to the front and locate it between the bubble trap and the pump so that the one valve will shut off all fuel sources to the engine.
The way it was plumbed may have had a lot to do with always get a good flame out the back at startup.

Since I will now have no need to get into the rear hatch for normal field operations I plan to get rid of the rubber bands and screw the hatch down.
That hatch has blown open on almost every flight so far where I have pulled hard positive G's.
I believe that this is due to the bottom of the fuse in the front being slopped upwards and the big hole for the nose gear facing into the wind causing the fuse to be pressurized whenever the jet is at a high angle of attack and going fast. This pressure is blowing off the rear hatch. Yes I tried stronger rubber bands.
I am also thinking of cutting some openings to let the pressurized air in the fuse out in the boat tail area to help feed the turbine.

I had thought about adding a front gear door, but with the often long grass at our field I have seen to many jets getting doors ripped off by the grass.

Does anyone see anything wrong with my plan?

bobparks2

My Feedback: (1)

It could well be air pressure. To significantly reduce the pressure, you would need outlets at least as big as the inlets, which is not practical. I have not finished my R54 yet, but my plan is to not have that hatch at all. A cutout in the structure like that does make the back end a lot weaker than if the structure was continuous. This is not to say that there is a problem, just that no hatch is stronger than any hatch, even one screwed in place.

First, it would not make much difference in feeding the turbine. The turbine needs a LOT of air.. the flow speed at the compressor face is probably 300+ mph at full throttle (I never looked at it for a P70). If you dont have the engine cowled, the normal boat tail can provide plenty of air.

What the cutouts WOULD do is significantly increase the risk of a tank rupture and fire in a crash. One nice thing about the R54 is that there is this large "crush zone" between the engine and tank, and that is by far the best way to minimize the chance of the engine hitting the tank hard enough to rupture it. It is pretty well proven that the fireball crashes happen when you get at tank rupture and dump raw fuel into a still running (i.e. not flamed out ) engine. Fuel on the outside of the engine will not do it, and fuel into the inlet even a second after flame out will not do it.. you just get smoke and a cooler engine.

And even a kevlar tank will not stand up to getting hit by the engine in a moderate speed crash. Yes, its better than plasma bags, but at some crash speed, its still going to break.

The boat tail on the R54 is a great crush zone to either reduce the energy with which the engine can hit the tank, or it could just cause the engine to flip to one side and never hit the tank at all.

ANY holes in the boat tail structure will significantly weaken it for this kind of load. Even notching the boat tail to clear the starter and to allow the engine to move a bit farther forward is a big reduction (half? more than half?).

I dont know of any R54's that have been in high speed crashes, but the chances of one fireballing are among the lowest of ANY jet designs out there. The long wooden nose is also a pretty good crush zone.. much better than the typical composite "egg shell" fuselage.

I fly in California, and for half the year, the best description of the whole state is "burns to easily to even make good kindling", so the whole fire prevention thing is a big deal for me.

Bob

rcguy!

My Feedback: (69)

Put a "floor" (roof?) between the nose gear bulkhead and the next one. This should help block alot of the airflow thru the nose wheel opening.

I have pics posted from my install way back in kit was first released.

Dave Rigotti

maxvertical

Hey Jeff, Love that P-70? It's great in this airframe isn't it.. I used a BVM latch on my rear hatch, very solid, no slop, and works awesome for me. Has the pin and plate on the front, with the latch and latch plate aft. Never had an issue with this yet, and you know when it's closed.
Personally I think it's a combined effort between ram pressure from the nose area, but maybe more of that hatch being located at a low pressure area on the fues. Can't imagin that much air getting by the main tank to blow the hatch open, besides having the open fues at the tail for elevator, doesn't seem likely to be an overpressure, but more a result from low pressure helping lift the hatch. The only openings going aft are for rudder and elevator pushrods, and the opening at the tail is substantial. Just another thought.