converting RAF2000 to the superior Sport Copter rotor system

Kolibri

FW and Gyros
Joined
Oct 17, 2014
Messages
1,636
Location
Wyoming
Aircraft
Cessna 152, 172, 172RG, 177, 206 -- Piper 180 -- RV-7A -- Calidus -- RAF2000 -- Sport Copter II and
Total Flight Time
1000+
Howdy all,

I've received my Sport Copter RAF2000 upgrade of upper mast plates, rotorhead, hub bar, blades, and 4-way air trim. I've not spun it up yet, nor installed the trim, but the rest has been installed. Here are my comments so far. I welcome comments from those who already have the SC upgrade on their own RAF.

crating: For the reasonable $100 crating fee, the custom wooden freight packaging was excellent. Everything was secured inside, and all arrived without damage.

parts quality: Just superb. The difference between RAF and SC is like putting a Yugo next to a Mercedes-Benz. I'll post a photo of the two hub bars side-by-side. The blades are not bare aluminum, but white coated and if waxed should be easy to keep clean.

installation instructions: A bit sparse, IMO. I'd asked for any instructional material in digital format to be sent to me while my order was being fabricated, to give me a heads up on the installation. I received a few pages, but wasn't informed of the below video until the order had shipped.

Before you begin to assemble the blades, you must watch SC's video "Tracking". Since it was so entitled, I thought that it dealt only with tracking, and didn't know that it included some vital assembly instructions. I recommend that the title be changed to "Assembling and tracking your new Sport Copter blades". I also recommend that some illustrated printed material be included on the tracking procedure, vs. only a video.

I prefer to actually download YT videos vs. rewatch them from an Internet connection. Here is a free program to install:

http://www.youtubedownloader.com/

The "Tracking" video can then be saved to a handy tablet. Mine contains all RAF Product Notices and Construction Manual (in PDF and videos), certain RWF posts, photos, maintenance logbook entries, etc. Whenever I work on my gyro, the tablet is nearby in case I need some info or video. (Just to clarify, the DVD was enclosed with the parts, however, my point was that I'd wanted to read/view anything available regarding installation before my order arrived, so that I could use the waiting period to get the most "heads up" on my project. I downloaded their YT video to my tablet for in-shop convenience, not because their DVD was missing from the order.)


assembly:
The rotorhead came assembled and mounted to the mast plates, along with the 4-way air trim. That was a relief. (The EXPERIMENTAL decals I'd ordered locally fit perfectly, and look smart. More below on them.) The assembly easily bolts onto the lower mast. I torqued the bushing bolt to 30 ft/lbs, and the lower bolt to 50 ft/lbs.

Next, I connected the upper control tubes to the steel gimbal activation arm, taking care to readjust the rod end heights to give the arm its 2° left as RAF requires. To my surprise, the gimbal arm rod ends are sensitive to their standoff location within the ears, else they will (on my RAF, at least) bind up on full aft stick. (NOTE: high misalignment rod ends are needed, such as Aurora CM-6.)

The rotors are marked "A" and "B" (though this is not very obvious), and must be installed in their respective sides. It's a bit of a chore to line up the blade within 2 plates and 2 straps, but take your time and do not hammer in the bolts.

The hub bar/rotors drop easily into the teeter towers.

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stuff you'll have to take care of yourself:

EXPERIMENTAL decals for SC's upper mast plates. Instead of crudely sticking on individual letters, go to a signage shop and order two black decals, 2.4"x27". I chose the font DIN-Black for its good symmetry of letters - specify letter height of 2" with color of choice. For just $25, the result is very professional, and your SC upgrade deserves it.

RAF rotor brake cable linkage: The SC rotorhead comes with its own shoe brake, but you'll have to adapt the RAF linkage to it. This was unexpected.

RAF rotor RPM sensor: No SC bracket or instructions were included for this, which also was unexpected and caused delay.

RAF prerotator drive cable: just slightly too large for SC's Bendix drive socket, and a bit of material must be removed. See below remarks.

4-way air trim: This was more involved than I expected, and will need about 6 hours of work (i.e., another day). The instructions, however, seem pretty thorough with many color photographs. I'll post how this went when I finish it.

gimbal arm rod ends with 0.406" housing width are too wide for SC arm: See a below post discussing this.​


some recommendations so far:
I've been very satisfied with my Sport Copter order, albeit with a few suggestions.

a thorough website FAQ to anticipate and head off customer concerns and questions. A few times I had to call Jim Vanek (who's been always available, patient, and helpful), when probably half my questions could have been addressed in an FAQ.

a comprehensive ordering checklist for the customer, including everything SC needs to know in advance (e.g., angle of upper mast plates to rigid mast, how many joystick trim controls to include, photos of RAF if necessary, etc.). This would avoid any need for individual emails about such items. (For example, I was early on asked about the "angle of your mast position for the cheek plates" which seemed to regard which mast # setting I was using since each of the 4 cg positions create their own angle. However, what they need are the cheek plates actually measured against the lower mast, which will show an angle of 0-10°. Mine was 4°. We got the misunderstanding sorted out.)

all areas of remaining custom fabrication clearly explained, which is my biggest sticking point. Not all owners have a machine shop, or are very mechanically inclined. Either the entire package drops-in/bolts-on, or what does not is very specifically described so that the customer has no surprises and delays.

getting your rotorhead/mast plates/air-trim before the blades, in order to use that time installing such while your blades are being made. I feel rather "behind the curve" due to sub-assembly surprises for the rotorhead, and would have preferred to hit the ground running with all that completed before the hub bar and blades arrived.

replacing all OEM $2 control rod ends with Heims or Auroras before adding the SC rotor system.

going to Jim Mayfield's idea of 5/16" shanked Aurora rod ends for the pitch authority control rod. The SC rotor upgrade is significantly heavier through the stick, and I really cannot imagine somebody relying upon RAF's OEM ¼" rod ends there.

upgrading to RAF's Product Notice 40 control system parts, which are more robust. I've not done so yet, and I think Sport Copter would be wise to include such in their RAF conversion package. Customers would be wise to pay the bit extra for this added insurance.​

I'm in no hurry to complete the installation, and will take my time. Although it can be tested/flown with the RAF trim, due to the much heavier stick pressure I think I will wait until I've installed SC's air trim.

Regards, Kolibri
 
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Got my Phase 1 operating permission for the 5 hour flyoff; that admin stuff went very smoothly, and the fellow couldn't have been more pleasant and easy to work with. He was impressed with Sport Copter's quality.

Finished the day with the rotor brake cable connected (pretty easy, though with some fab), and the RRPM sensor installed (which required making a custom bracket from the rear of the torque tube).

The SC prerotator Bendix socket caused a snag, due to being out-of-square from heat of the gusset welding. The drive cable just would not insert. So, I dressed out one end of the drive cable to match, but it took my A&P's clever way to gauge the socket from all directions to finally figure out exactly what was needed. I'm not keen on it, and will probably ask for a replacement socket after the holidays.

Am taking a few days off from it all, and next time I will spool up the new blades for tracking. Then, I'll tackle the air trim installation.

Photos below, enjoy!

Kolibri
 

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Heim HM-6M too wide for the SC gimbal arm in my RAF

Heim HM-6M too wide for the SC gimbal arm in my RAF

With full aft stick (the SC rotorhead has a bit more range than the RAF), the gimbal arm ears will bind on my Heim HM-6M rod ends, despite different offsets with combinations of thin/thick 416 washers. (The attached photo shows the SC arm at almost full aft stick.) The Heim housing width of 0.406" is too wide. (My upper mast angle is 4°, but those with less angle may not experience such binding.)

Another RAF owner (N73GK, serial #H2-00-11-478, expired on 10/16/2012) kept his old RAF gimbal arm on the SC conversion, as seen on this Sport Copter website photo:

RAF2.jpg


(However, I personally would not use the old/skinny RAF gimbal arm in this heavier SC conversion, but this was the first conversion and according to Jim they didn't then have a gimbal arm for the RAF. This gyro owner went to a Wayne Hubb arm later.)

Aurora CM-6 rod ends work in my SC arm.
Those with the Wayne Hubb RAF arm may be OK with Heim HM-6Ms.

Sport Copter uses Aurora HXAM-T high misalignment rod ends with a housing width of 0.355". (Theirs are specially made with 0.25" ball I.D., so no ⅜" Orlite bushing is necessary.) Until I procure a pair of Auroras, I will in the brief interim use a pair of locally found FK rod ends which are housing width similar, and I've the bushings already in stock.

Today I'll swap out the Heims, and then spool up the new SC rotors. I may begin to install the air-trim, but will likely delay for a separate full day.

Regards, Kolibri
 

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The local rod ends alleged to be mfg. by FK, are not necessarily so once I queried the supplier. I.e., they could have been made by one of several companies. (The tech couldn't quote any load rating.) Thus, I cannot trust that they are FK rod ends with strength of 5100 lbs, so I will not fly them.

I must order replacements. My choices seem to be:

Aurora CM-6
Aurora CAM-6
Aurora VCAM-6
Aurora CM-6ET
Aurora HXAM-4T (the 6T has 7/16" shank)
FK HJMX6T​

No flying today, but I can at least spool up the blades for the first time.
Everything else (but the air-trim) is complete.
Prerotator lubed with MolyGraph (I found it only at NAPA).
 
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Nice rotor set ! How much more does the sport copter parts weagh over the RAF parts.
Did you adjust the hang balance according to RAF specs. or Sport Copter ?
 
Boots, I'll do the final W&B once the air-trim is installed, as those parts weigh enough to factor in.

I think I'll take a break from the gyro this week. Back after the New Year!
 
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adapting the RAF prerotator cable sheath to the SC Bendix

adapting the RAF prerotator cable sheath to the SC Bendix

My schedule flip-flopped for the day, so I spent today on the gyro. But for the air-trim, I'm nearly there.

Solved a problem with the p/r drive cable. The sheath collar fits in the SC Bendix (see photo at left), but the drive cable inside was about 1" too short. This limited how much the cable ends could engage within their respective square sections.

The easy solution was to trim off one sheath collar at the set screw channel (see photo at right). A die grinder works great for this. Beforehand, goop some grease down in the opening to catch the shavings. Clean up and chamfer the edges. This trimmed collar will now go up in the Bendix. Install the cable and sheath, tighten the Allen set screws to imprint the collar, and then you'll know where to mill some 0.080" deep flats. Don't forget to add a secondary retention, and safety wire all pairs of Allen screws (they've drilled heads).

All that done, my Bendix drive still would not engage the ring gear, and thus needs a slight adjustment. It will be nice to hear that drive Clunk! and then see those handsome white blades turn for the first time.

_________
My pair of Aurora CM-6 rod end bearings for the gimbal arm arrived, which should solve the binding issue during full aft stick. That should conclude the mechanical tinkering required for my SC conversion. So, perhaps I'll fly it tomorrow.

Regards, Kolibri

 

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I think that calling your new rotor system superior is being optomistic, so far there have

been a few parts you have needed at additional costs ,things not fitting exactly right,etc

then theres the cost,for what you have paid it should have been complete,not sorta

complete. And if thats not enough there are couple of things built into the hubbar that

I personally am not sure of,but the overall quality and reliablity have been proven with

time and some of the features are way ahead of the curve. I believe overall its a quality

rotor system,however calling it superior is a subjective thing that has nothing to do with

anything,I just hope that it will make you happy and feel safer.






Best regards,
 
Lock wiring could be tidier\ tighter, long ends with sticky out bits, silicon tube in twists will help stop damage of paint\ anodizing
Hate those ends have the scars to prove it :eek:
Hope the flying is good & comes up to your expectations at the least you know there are no hidden scary bits.
 
I think that calling your new rotor system superior is being optomistic, so far there have been a few parts you have needed at additional costs ,things not fitting exactly right,etc then theres the cost,for what you have paid it should have been complete,not sorta complete.
eddie, since it is a conversion from a different mfg., I am willing to take a few snags in stride, especially since Jim Vanek has explicitly reassured me that I am free to phone him regarding any questions. In fact, he prefers to personally counsel RAF conversion customers, given variances in machines and owner mechanical ability.

I do, however, still believe that some of my issues could have been anticipated if not avoided completely (especially the high misalignment rod ends -- just throw in a couple of $8 Aurora CM-6s in the kit to make sure). The sticking Bendix drive probably could have been noticed before shipment, as they assembled the entire rotorhead there.

I merely report my experience as it unfolds; SC may consider as they will any suggestions.



And if thats not enough there are couple of things built into the hubbar that I personally am not sure of
Hmmm, I've really no idea what you could mean there. The bar is one-piece, with all bolts correctly worked in shear. What aren't you sure of?


however calling it superior is a subjective thing that has nothing to do with anything
I disagree. Between RAF and SC rotor systems, the qualitative disparity in design/materials/workmanship is hardly optimistic or subjective, having compared them side-by-side. Performance is reported to also be improved, with a 10mph higher cruise speed for the same engine RPM. Once installed, I've never heard of anyone going back to their RAF rotor system.

______________
Lock wiring could be tidier\ tighter, long ends with sticky out bits, silicon tube in twists will help stop damage of paint\ anodizing
500e, thanks for that tip, good one.

______________
Aurora CM-6 rod ends now installed and adjusted. As you can see, they are washered towards the front for proper clearance.

Use MolyGraph grease for the prerotator cable. (Probably a good idea for other gyros besides RAF.)

The sticking Bendix drive I'll sort out this week, then begin to fly it.

I recommend that bar and blades are installed at the very last. It is much easier to replace/adjust the gimbal arm rod ends or test the prerotator with a bare rotorhead. (We dropped in the blades because on Day 1 we had enough hands to do so, but not reliably later.)

Also, this is a perfect time to replace the pair of mast AN8-35A bolts and AN365C820 nuts ($16 total). While replacing these bolts, I backed them up with some large AN970-8 washers, to increase torsional rigidity of the plates.

Regards, Kolibri
 

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Bendix sort out.

Bendix sort out.

No adjustment needed, turns out that it'd been just a bit overlubed. Jim and I resolved to this conclusion in parallel about the same time, so I backed out the two cap screws holding the Bendix drive inside its housing (very slick SC design for easy access) to pull out the "guts".

The helix gear wouldn't even slide on the shaft when pointed down, so I many times worked the parts to push out and mop up the excess lube, along with some TriLube to thin it out. Pretty quickly it all freed up, and even a cordless drill chucked to the PTO cable side began to produce some engagement. Turned 45° downward, the drive will spiral down on its own, which is a good sign. The day got late, so I'll spool up tomorrow. I'm confident that engine powered prerotator will engage now.

______
air trim: I think I'll mount the compressor upside down (no problem, apparently) underneath the battery shelf, and the air tank to the left diagonal landing gear tube. This will keep all the air hoses outside, and at minimal lengths. I've heard of these components mounted inside behind the seat, so that's also an option. The stick 4-way trim control will require some custom installation, as the wire loom hasn't a natural exit on the RAF tube (without drilling a hole and weakening the tube). I think I've a least-worst solution to that.

_______
Related news: my senior A&P had a stroke last week, didn't regain brain activity, and passed away over the weekend. His elder son (the only other A&P here) naturally has much on his plate now, but one wouldn't know it with how helpful to my project he's still remained to be through it all. I'll be glad to finish up, and clear up his shop space and head space.

God bless our local A&Ps!

Kolibri
 
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Sorry to hear regarding Your AP a good one is hard to find.
My condolences to his son
 
progress update

progress update

500e, thanks for that. The funeral is next week, and I'll try to get my gyro out of their shop ASAP.


___________
Am nearly done with my SC conversion. Here are some notes along the way.

___
stick grip: Ray Allen Company G205 Stick Grip (www.rayallencompany.com)

Ray Allen Co. instructions were very thorough, with many diagrams.

If you're not asked, then tell SC in advance if you need one or two control grips. I was sent two, which were pre-wired at SC to be used independently (as in "Wiring Style 2", but the two Ray Allen REL-1 Relay Decks were not included because the servos have internal relays). DO NOT REWIRE THE GRIPS! SUCH IS NOT NECESSARY. DO NOT USE THE RAY ALLEN DIAGRAMS, AS SC'S METHOD IS DIFFERENT.

There are 7 wires from the grip control: 4 grounds from the 4 switches, 1 common ground (this will likely have an overhand knot tied at end), and the shielded pair for the PTT switch. (They are 26 gauge, all white, bummer.) No positive wiring to the stick, so that nothing can get fried.

The four switches' Common terminals (for Ground) were wired at SC, and these will be crimped into the included wiring harness for the servos.

The fifth wire comes from #4 switch Normally Open, for the trim's ground.

The SC tech wired the PTT switch for their own sub-loom (a shielded pair) -- easy to splice into the existing PTT cockpit wires.

The length of the 5 wires was a foot too short at 55" to reach to the rear cabin wall (although the PTT pair was ample at 72"). Insist on 72' so you won't have to add any length at the last moment.

__
grip installation This was rather tricky since the RAF stick collar bolts to the control bar in such a way that the wiring loom has no exit. (You don't want to drill another hole in that bar, weakening it there.) So, an exit hole must be drilled somewhere on the control stick. I put this new stress riser up about as high as possible (just under the prerotator lever bracket), to reduce its arm and lessen the chance of the stick bending there under normal use.

Feeding the seven wires through a ¼" hole seemed a challenge, so I had the idea of using 18" of the supplied air hose as a guide (which will protect against chafing). The hole initially drilled, I hogged out it out in line with the stick to reduce the loom bend angle. The piece of air hose fed in easily enough.

When feeding in the wires, save the heat-shrunk PTT pair for last, as it is stiffer than the individual 5 thin wires and can be pushed through last when it's tight in there.

The 5 wires are all white (Ray Allen really should have used a colored wire for at least the lone ground), and if you push them through all at once you won't know which was soldered where without a VM to test. The only wire of the five you need to separately identify is the ground wire. (It'll probably have a knot at the end.) Untie the knot, push it through the air hose guide, then retie the knot. The other four all go to the four servos' ground, and you can easily swap plugs later to correspond stick buttons to their correct servo (and side).

I.e., it's not really necessary to mark these four wires with their grip switches (as I did). But, if you want to, here's how:

1) snip off all wire ties around the 5-wire loom, so that you can handle each wire individually.

2) disassemble the grip and orient the cap per the instruction diagram, so the Switch #1 is north, #2 east, etc.

3) have a black Sharpie and some Scotch tape handy. You're going to tick mark each wire according to its # of switch. (I was going to first mark up all wires before pushing them through, but realized that the ink would smear off. So, push through each wire separately, and mark at the other end.)

Select the #1 switch wire, push it through, apply 1 tick mark at the end, then seal the ink with a bit of Scotch tape. Then, swtich #2, push through, apply 2 tick marks, etc. Switches #3-4, then the NO terminal of switch #4 (assuming #4 was the switch having an Normally Open terminal wire), and finally the PTT pair. (My piece of air hose was almost too long, and I barely got the PTT pair through, so use no more than 12" to reduce the total friction.)

4) gently pull the air hose down to snug the cap onto the stick. Then secure the cap to the stick with some electrical tape.

5) cable-tie the air hose loom to the control stick, angling the bottom toward the cockpit center. Once you install the loom under the seat (or underneath the fuel tank) to the servos behind, remember to leave enough extra length for inflight stick movement.

____
electrical servos: They must be kept dry, thus best inside the cockpit. (Now, instead of running 5 air hoses through a cockpit hole, one could build a watertight servo box outside. This was tempting at first, but I chose inside the rear cabin wall, and it required <2' extra hose length -- plenty of air hose is supplied.)

_____
compressor: Viair 92 Compressor Kit (#00092), www.viaircorp.com

This pump has a 100 psi 9% duty cycle per hour (5 min. on / 55 min. off), with a max pressure of 120 psi. The air tank will cycle off the pump at 105 psi. It's wired to a 15A breaker (not included).

Although the Viair user manual specifies "flat, upright, and secure" location, Jim has seen no issue with mounting the pump upside down beneath the battery shelf. Neat idea. There is plenty of room, and the RAF shelf is strong enough. My A&P countersunk the four 10-32 screws, securing the pump with nyloc nuts. (They will be added to my pre-flight checklist.)

air tank: a pair of 1" and a pair of 1½" DG clamps (rubber lined) and the tank can be conveniently mounted to the left landing strut just forward of the pump. The drain valve is closed when extended.

I think I'll have the air-trim system fully installed over my next work day there.


________________
FIRST TAXI TEST:
Bendix now engages at once during prerotation, so I spooled up the SC rotors for the first time. I immediately noticed how much quieter and smoother the system was compared to RAF. Gaining RRPM took ~20% longer because of the heavier blades, but nothing objectionable. On the ramp, I spun up to 150RRPM, then released the p/r lever. (The rotors seemed to need no adjustment in tracking.)

Having done a very thorough preflight beforehand, I decided to taxi-test. Taxiing to the hold-short line, I let the rotors wind down on their own (without brake). The head is so smooth that I still had some 85RRPM when I arrived; they just didn't seem to want to stop. And that was without much stick warbling at the lower RRPMs from RAF blades. Very impressed so far.

Now, Jim alerted me to expect very strong stick pressure while still temporarily using the RAF trim, and he was quite right. Beginning my quasi-takeoff roll after 150RRPM (intending only to taxi), once the rotors hit 200RRPM from full aft stick it was very difficult to push stick forward. So, I reduced power to idle and came to a slow stop. I cranked in max nose down trim on the wheel, and tried again. This was somewhat improved, but not sufficiently to try a takeoff roll, so I called it a day for the taxi test. It was all a very different sensation than what I'd gotten used to after 103 hours in a stock RAF, but I look forward to flying these new SC blades which feel very much more "alive".

I hope that I don't have to change the mast bolt setting from #3.

Roll was pretty neutral during these two taxis, so I must have adjusted the gimbal arm rod ends correctly with a 2° left tilt per RAF specs.

_____
I welcome any comments or PMs from those who have installed SC rotors on their RAF. What was it like for you to retrim?

Thanks, Kolibri
 

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SC trim pump and tank installed

SC trim pump and tank installed

Only a half-day work here, as the viewing is later this afternoon (funeral tomorrow).

The pump and air tank installed tidily (photo below).
The 1A and 15A circuit breakers are now in the dash panel.

Air hoses and wiring are all that remain. I've decided to run the servos' air hoses through the cabin wall, behind the seat. Although I don't like boring a hole in the cabin, an outside waterproof box just wasn't feasible.

Weather has been uncooperative so far for flight testing; winds today constantly 20+ knots. So, it may be into next week before I fly.

Regards, Kolibri
 

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Your doing good things it seems with that RAF of yours. Hey Kolibri . Keep up the good work.

Sincerely SWilliams
 
Missed seeing you at the funeral, but then there was a very large crowd and maybe you did not come down stairs for the lunch. Most of my friends I did not recognize due to being dressed up, even did not recognize Larry from the Southern Hills, because he was not wearing a cap and had a suit an tie on because he was a pall bearer. plus I have never seen you without shorts on. I did get to see a lot of old friends that I have not seen in years, after they came up to me and called me by name and I recognized the voice, including Jerry's wife, who I haven't seen in 40 years. All in all a very nice funeral, although hard to let a good mechanic go. Jerry did a lot of conversions for me over the past 40 years, including my first, putting a 0360 in my Cessna 170B in 1974, after he received his A&P. They showed pictures of a bunch of us at Oshkosh in 1974 or 5. I am the one in the cowboy hat to the right of Jerry. We made many trips together in the 70's, including the National Air Races in Reno. After I moved away in the late 70's, I would still have him do my annuals until about 1990 or so. It is a shame that a person has to die and then be recognized by all his friends for his willingness to always get you back in the air, even if you were several years out of annual. Rest in Peace Jerry, God made you a great mechanic so you could keep the rest of us alive.
 
swilliams, thanks for that.
I'm very close to flying it, and will certainly enjoy its new wings.

______
feedpro, sorry to have missed you, too; I didn't go the lunch afterward. Yes, Jerry was a born A&P and a very kind man, unfailingly helpful to any pilot in need. We all lost a good friend, personally and for GA. He really was a local legend.
 
26 ga. wires are tedious to work with; most wire strippers go down only to 22 ga., thus one must very carefully do them by hand. (My A&P had a fantastic wire stripper, usable down to 30 ga.)

Fired up the pump; a vigorous little unit. Have a bit of cabin wiring yet to do. Mounting the elec. servos now, and then the hoses. May finish today, and the winds are so far calm.
 
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air hoses and electrical servos installed

air hoses and electrical servos installed

Made some good progress today. Here are some notes.

securing old RAF cable trim:
In the upper landing gear strut is a nylon bracket, which has a handly hole to zip-tie the dangling trim cable eye. (Use two, because: why not?)​


cutting air hoses
These must be cut cleanly and squarely. Don't snip them with wire cutters; at least use a razor-blade push knife. Cut the hoses just a bit long per application, which will keep end pressure inside the fittings. SC provides plenty of hose.​


air hose from tank to inside cabin:
Just follow the wiring from outside at the keel/mast junction, which will emerge behind the seat tank. Cable tie the hose out of contact with the lower control yoke and control tube. (The air tank valve is left extended; pushing up opens it to drain any water.)​


drilling cabin hole for the four air hoses:
Four air hoses will need to fit within a rubber grommet, and .75" I.D. is just right. The fiberglass shell is .165" thick, so make sure the grommet will splay out wide enough. For location, I chose just right of center, and up high. With a hole saw, drill from inside out, with light pressure at the last to avoid chipping the paint too much.​


electrical servos inside cabin:
I used steel ⅛" pop rivets (⅜" long), with washers at each end. Choose a location low enough to clear the rear seat lip. Drill from cabin side out. You'll need to unbolt the lower control tube from the scissors to allow room for the rivet gun. I'm very happy with the tidiness of this secure mounting. Notate with a Sharpie P(itch) and R(oll) on the respective servos.​


air hoses from cylinders to servos:
Per SC's photos, the bottom of each cylinder goes to the left hose mount on the servo. Snake a length from outside, connect to the servo, and then snake all air hose through the prerotator mast bracket (there's a handy rectangular hole. Cut each hose long enough for a S-bend near the mast, which will help to keep the hoses intact at their connections. Cable-tie the hoses together every several inches. Goop in some black silicone to seal inside the grommet.​


12V+ wire from air tank to dash panel:
Same procedure as above to snake the wire through. Use 12 ga. wire, and about 5' of it to reach all the way to the power bus under the dash panel. Once it emerges from behind the seat tank, cut a 3' piece of air hose to act as a guide to snake the wire through on the right side of the frame under the seat tank.

Include a 20 ga. length of wire inside the hose, as this wire will go from the air servos power connector to your dash panel's 1A breaker. You could even use a length of hose as loom all the way to the panel (only after you've installed all the working air hoses, to make sure you've enough hose).​


dash panel (1A and 15A breakers)
Breakers were not included (I think they should be, so ask), but my A&P had them. Aircraft Spruce sells them if not available locally. I hadn't room to add these breakers in line with existing ones, but they fit side-by-side nicely nearby. Be patient drilling these two .460" holes, as the dash veneer will chip easily. Start with a 3/16" pilot hole, and use 3-4 successively larger bits.

Use 12 ga. wire, crimp on some eye connectors, and wire from the master switch to the 15A breaker. Bridge to the 1A breaker. Attach the two rear cabin wires on their respective breakers.

While you've the dash out, inspect and clean up any issues. Confirm tightness of all those screws, look for any chafing, etc.​


trim servos' ground wire:
There's no better ground point than where the engine block is bolted to the mast right side. And, it's just 4" away from the cabin hole for the air hoses. Crimp an eye connector to a length of wire, and you're done.​


___________
Weather's turning snowy, so I may enjoy a break for a few days.

Have a great weekend,
Kolibri
 

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liftoff!

liftoff!

I had some business to take care of this afternoon, which cut into my first flight test, but I went up for a half hour and 3 landings. I'll write more once I've some more time in the air, but meanwhile some impressions:

My imagined apprehension was always learning the air-trim quickly enough on the takeoff roll to mostly null out stick pressure. It went about as I thought (she needed nose-down), and once I'd bipped the trim to get me in the ballpark on the roll, she felt about ready to get airborne. Once up, I quickly sorted things out, and by the time I was about to turn crosswind most of the drama was over.

Stayed in the pattern a few times, and then buzzed around a few miles. Returned for 3 landings. Base/final power settings are different, but I'll get used to them. SC rotors noticeably more efficient, with much more float in ground effect. (My impression is that the RAF rotors more abruptly lose their lift before touchdown.) The SC rotor lift dissipates smoothly, however, and all my flares/touchdowns were pretty decent considering what I was getting used to (and after not flying a gyro for nearly 3 months).

The air-trim system is trés chic, and its intensity can be adjusted via the two servos' bleed valves. I began with them backed out 2 turns, per rec. of the tech. This was about right for a first flight. Pressure is dumped more quickly than made, but with practice comes finesse. I really appreciate leaving behind those Flinstones trim wheel cranks. Feels pretty cool to tap a control stick button and hear/see/feel the rotorhead obey.

My previous PTT switch was near the throttle, and now it's on the grip cap.
Feels good to have morphed into 1998 there, heh.

There are adjustable friction blocks on the trim cylinders. I may squinch mine down a bit, as I'm used to a little more trim stability. As they were, I was readjusting trim about 30% more than previously, although it was a bit gusty above 500' AGL. There is rather a lot of adjustability in SC's trim system, to suit any taste. It's really quite a sophisticated adaptation.

Stick pressure during flight was perhaps 15% more than with RAF rotors, about what I'd heard/expected.

I had some increased stick/cabin shake, which I attritube to the mast bushing bolt torque (it's at 25 lbs. -- the lower nut at 45 lbs.). My hunch is that I should loosen it one flat at a time (I don't "see daylight" between the cheek and nylon plates). Perhaps at the same time I need to tighten the bottom nut to a full 50?

The rotors seemed to track very nicely under load, so no adjustment is nec.

I'll edit in a few days some of my prior posts to fine-tune the installation tips; learned a lot along the way. This will significantly help the next guy (and may there be many more). (Quick tip: the RAF p/r sheath is just too long, as the SC Bendix bottom is lower than RAF's. I wonder what length the SC sheath is. My RAF p/r sheath wanted to crash into the control tube during aft/right stick, so I had to anchor it out of the way. I also relocated the roll cylinder bottom mount bracket toward the mast front, allowing p/r sheath clearance.)

In short, it felt really good to be back up after nearly 3 months. In the meantime, I had to fly a 172.
Don't cry for me, Argentina!

Regards, Kolibri
 
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