wjcalhoun

More pics from the build
#8, #9 - at least 45* elevator throw L and R; note difference in rod geometry; servo arms are 1 1/4"
#10 - note that the pull-pull cables change direction on entering the guide tubes. There is a conduit (black) on the port side for the elevator wire; if you use dual cables, there are also holes in the formers on the starboard side to secure the cable for the R elevator servo
#11 - pull pull setup; Aeroworks hardware on all control surfaces
#12 - large fuel tank - note rule
#13 - solder spliced, not plug-in extensions
#14 - AW hardware, 1 1/4" aileron servo arms

taildragger56

Thanks Bill!! will be most helpful.

jet22b

Bill,
I do love your set up!!!
Thank you for sharing!!!!
Sonny
aka
jet22b

wjcalhoun

More pics and thoughts from the build

The firewall is solid, and the carb venturi is only about 7/16" away. On the advice of the small engine gurus, you know who they are!, i drilled the FW at the intersection of the centerlines (where the carb faces) with a 7/8" brad point bit to provide unobstructed carb airflow.

The DLE55RA fits beautifully; cowl requires minimal trimming. The muffler/diverter does not interfere with the engine box at all.

I did find that the ignition does not fit well. Book recommends for it to be on top of the engine box, but if there, it interferes somewhat with the cowl ring as one installs the cowl. There is insufficient clearance to mount it on either of the sides. One option is the bottom outside (or inside) of the engine box, but I chose to mount mine INSIDE the engine box, starboard side (on the port side it would interfere with the throttle linkage). There is plenty of room there (see photo below). I put my ignition battery on top, which does not interfere with the cowl ring.

I am getting down to my punch list for completion.

Pic #15, #16, #17 - Cowl installed over the DLE55RA
#18, 20 - muffler fit; it is close, but one can get to the mounting bolts for the muffler with the engine installed. In #18 see hole in FW
no #19
#21 - Choke linkage; i used the snap on ball link provided. it is a PULL-ON geometry, not a PUSH-ON
#22, #23 - Ignition module installed inside engine box

Spridal

My Feedback: (17)

You might want to take a look at the rudder control arm. The way it is mounted will place undue stress on the arm and will eventually fail.

wjcalhoun

Spridal:
Is your point that the ball link should be under the tiller arm to reduce stress on the servo bearings? if so, point taken. if not, could you clarify?

Another quirk about the DLE55RA, which you can see in Pic 21 above (choke linkage). The standoffs normally install with the flat-sided end against the firewall, and the full flange against the engine. However, the SHCS that hold the two crankcase halves together interfere with the full flange, and one has to install the standoffs backwards, with the flat-sided end of the standoffs against the engine mounting lugs.

Slow and Steady

Seams like you would want the full flange on the firewall for maximum bearing and less chance of crushing the wood. WJ, thanks for all your effort in sharing the build photos. Seams like you were able to get alot of deflection on the elevators.

wjcalhoun

S&S
I hear what you are saying about the direction of the standoffs, but i think the idea is that you can pull them down tight against the FW with a wrench. Actually, i had no problem getting them tight with a rubber gripper and an allen wrench, so i did not need a wrench to snug down my standoffs to the FW.

I would not presume to have everything right, so i am very interested in seeing other builds. For example, Spridal's issue with the plywood support for the stab tubes is something i will address.

On the elevators, yes, there is nice deflection. I'm hoping it will be enough to do harriers / hovering with the R90.

Best
Bill

Slow and Steady

Should do a great flat spin and possibly a knife edge spin. I wonder if the dihedral will effect the knife edge spin?

wjcalhoun

Well, the R70 will knife-edge spin once in a while, when my thumbs work right; now that my CG is where it should be, it flat spins beautifully (better upright than inverted). I don't think the edffective dihedral on the R90 is any more than on the R70. I'll be interested in seeing how the R90 flies, but i will not be able to wring it out for a while. New DLE55RA, so I'll have to take it a bit easy for a gallon or so.

Spridal

My Feedback: (17)

Spridal

My Feedback: (17)

You are correct, the "full flange" should mount to the firewall. The "full flange" provides a little more area for "load spreading" against the wood.

wjcalhoun

OK - i see the point; thanks
The screws actually bite into plywood reinforcement there, but it is something to watch for certain.

Granpooba

My Feedback: (5)

Just purchased a new SUV and have sort of a silly question, but here it is.

What is the exact full length measurement of the 50CC Revolver fuselage, from tail to spinner ?

Presently have two Revolver 70's, one running a Saito .91 and the other a DLE-20.
But before I lay down the $$$$$ for the 50CC, I just want to make sure it will fit in the new SUV.

Thanks guys .........

microdon2

My Feedback: (47)

Granpooba - I have a 2006 Honda CRV and recently picked up a pre-owned 100" Extra 260. This thing is huge. The guy had to take the gear off to fit into my car. To fit it length-wise I had to lay the passengers seat down backwards, after sliding that seat all the way forward. So it's doable. Though if I take my son to the field with me he'll have to sick in the back with the wings. (Haven't flown it yet).

Granpooba

My Feedback: (5)

Maybe your son could sit in the 260.

wjcalhoun

Granpooba
I have been out of town, but can get that measurement on the R90 tonight for you.

Granpooba

My Feedback: (5)

Be greatly appreciated. I think we are looking at about 82 inches total. But I could be wrong.
Thought that I was wrong once before, but I was only mistaken.

wjcalhoun

Gran:
Mine measures 81.5 +/- about 0.3 from the aftmost point (bottom/back edge of rudder) to tip of spinner. There are not many things that build technique will alter in that length aside from rudder hinge gap and the thickness of the spinner back plate, assuming that you use the book value for FW-> thrust washer distance.

wjcalhoun

Well guys, I finished the R90 build; i'll note a few more build items, and then pics of the finished aircraft.

The big spinner looks great, but it is a pain to mount and demount. Drilling the backplate is not too difficult; i used my prop drilling guide; holes drilled to 13/64" which is clearance for a 5mm bolt.

I replaced the little 4-40 phillips screws with 4-40 SHCS, loctited in. Getting the screw immediately behind the prop blade is a real pain (first two pics) with the stock phillips screws; SHCS much easier.

The lower cowl mounting bolts are accessiblt only from the front of the cowl. I had to enlarge the cowl opening behind the muffer to make them accessible. Not too big a deal, but was an unexpected late mod.


My outfitting:
DLE55RA / Xoar 22x10 / stock 'muffler' - exhaust diverter
Hitec HS-7954SH for all control surfaces; HS-5625MG for throttle
RCExl ignition kill switch
Futaba 617 receiver
Dual LiFe 3600 mAh batteries through dual miracle receiver switch (port side); batteries had to be mounted by the gas tank for balance.
2000 mAh 4.8v NiMH ignition battery through miracle switch (starboard side)
Custom vinyl from VinylForRC.
CG is 7 7/8" from LE at fuse - per book.

Still need to put a couple of tanks of gas through it on the ground for break-in, needle setting, etc, so probably will be a week or so before she maidens.

Despite the early static about the 'plain' covering scheme, I think she actually looks pretty good and will present well in the air.

Bill


She built to 19#5oz dry, AUW, which is about 3/4 pound less than I thought she would build, based on the manual.

jet22b

Bill;
She look good!!! Now I would be more than happy to take it off of your hands!!! You did a great job and I can not wait to hear your flight report!! God speed on the maiden flight!!!
BTW: That was a very nice place you took the pictures at!! Was that your club flying field??
Sonny
aka
jet22b

Slow and Steady

Looks like a typical wide open Texas backyard! Along with a clean and professoinal build.

wjcalhoun

S&S
Thanks for the nod; yes, that is my backyard out over the lake. Pontoons on an R90?

microdon2

My Feedback: (47)

With a backyard \ lake situation like THAT who needs a field??? Just get AMA to sanction your yard!

Bill - nice job on the Rev 90! She's real pretty. Can't wait to hear your maiden report. btw - I'm new to giant-scale planes. Can you describe the advantage of using two LiFe batteries (I assume it's redundancy...) and exactly how you wire them? Are the receiver \ servos pulling from both at all times, or some receivers pulling from one battery, etc? And when you charge them, do you charge them separately through individual ports in the Miracle Receiver switch?

Mike

wjcalhoun

Hi Mike
The dual batteries are for redundancy. I use a single receiver Futaba setup, and my single receiver has 7 channels, all in use (2 ailerons, 2 elevators, 1 rudder, 1 throttle, 1 kill), so i power the receiver via Y harnesses. I use channel 1 and 6 (L Aileron and R Aileron in my setup) because i need an extension to connect to the aileron anyway, and power input is nearly at opposite ends of the receiver bus. Each battery lead goes to a separate switch; the switch output goes to the Y-harness plugged into the receiver; the miracle switches I use have two independent switches for two totally independent circuits. The receiver then pulls from both batteries via the Y harness. Some might say it is better to use a power share to prevent one battery from draining the other if one fails, but i have not personally taken reduncancy and contingency protection that far.

You COULD charge through those ports, but I don't. LiFes shold be balance charged, so i have to have the canopy off anyway to get the balance lead connected. I use the Deans connector to charge, and charge them at 1-1.3C independently (these 3600 mAh batteries I will charge at 5 amps initial); it is generally less than 25 min to recharge each battery after flying. I do charge my ignition battery through the port because 1) it requires no balanciing, and 2) it would be a pain to pull the cowl.

My charger quantifies the amount of energy (mAh) put back on the charge, so I do watch to be sure the amount put back in for each battery is about the same. Mine are usually within 10%, and one battery is commonly consistently higher - that is if the "A" battery gets 10% more input this time, it will probably take 10% more the next time also.

Hope Santa brings you an R90.