drac1

My Feedback: (4)

Yeah, weights are finally coming down. Hopefully they will continue with R & D and get the weight down more. It should be possible to get a glow prop down to 80 - 90 grams.

I've only had a couple of flights so far, but it seems pretty similar. It may be a bit better in verticals and I haven't really had enough time to really test how it pulls through radius's into up lines, but it certainly is at least as good but with a weight saving.

I buy direct from APC.

rm

My Feedback: (27)

Central hobbies a lot cheaper.

drac1

My Feedback: (4)

Hmm, correct. In the past APC have been the same price as Central. But when I ordered the Carbon props from APC, Central didn't have them yet.

It's interesting that retailers are selling products cheaper than the manufacturer. RC Japan sell YS stuff cheaper than YS.

MTK

My 21x10.5 N wood/carbon composite weighs 82.5 grams. In process of finishing up the Griffin gas conversion so I'll know soon enough how this one does on the OS33 and in the air.

MTK

Scott,

APC would need a significant tooling change to get a solid prop that light. If they reduced blade thickness at the hub, narrowed the blades a bit more and converted to 100% carbon, 90 grams is doable. Even at 100$ it would be a bargain. Problem is that they would sell only a couple handfulls so tooling cost is possibly a big choke point.

In meantime, I am finally healthy enough to continue my R$D. Now if I can only find my mag balancer ..........fool thing disappeared.

drac1

My Feedback: (4)

Hey Matt,

it will be interesting to see how the new prop goes.

The wood/carbon prop you made for me is 96 grams and performs very similar to the APC 21 X 10PN and PNC. I'm more than happy with it, but keeping it tight on the YS is a problem so I'm not using it at the moment.

Need to come up with a method to stop the wood crushing. Been thinking on it.

Scott

drac1

My Feedback: (4)

Yeah, you are most likely correct in regards to cost being a factor, but there's no harm in hoping. With the imminent demise of Oxai, there may very well be less GP planes available which won't help the cause either. Hopefully someone will take over and continue with GP versions.

Yep, things have a habit of disappearing even when I know where I left them

Glad you're health is returning.

MAVROS

Thanks mate

MTK

Scott,
You might want to cut a pair of sandpaper rings and glue them to the prop hub. When I ran 120 and 140 4 strokes back in the day, this never failed.

rm

My Feedback: (27)

Finally got some decent weather around here.

Haven't been able to get a lot of time on the cadence yet though. The DA's been a nightmare. 1st 3 flights went without a hitch. Was really stoked with the combo. Cadence has a nice presence in the air. It looks big. The DA pulled it with a lot of authority. Since then the engines been hit or miss. It will run or it won't. It'll start but then it won't take throttle. Then it will start and take throttle. Put a flight on it, and next flight it won't take throttle again. I'm thinking the ignitions crap. If I send the motor back it'll prob be a month before I get it back in the air, so I'm thinking of getting a new ignition to try and if that fixes it, I'll just send the original ignition in for warranty. Be about the quickest way I can figure. Hopefully that's the problem.

Pentathlon with the eme35 is running like a swiss watch. Ran the 19x11 3B mejzlik this weekend and it worked well with this combo, turning it at 69-7000. Motor only has 4.5-5 hrs on it so far.

PepsiMike

1) I really like your Cadence, nice job.

2) Perhaps a velocity stack on the carb might help. If you replace the ignition with an RCExcel unit, I believe you will have to adjust the timing. (DA's ignitions are proprietary.)

3) I really like your Cadence.

rm

My Feedback: (27)

Thanks, i found on another site they had a bad batch of ignitions and my serial number falls in the range, so I'll be giving them a call tomorrow.

MTK

RM,

When the flex header goes, do the fiberglass and ultra copper repair. It's much better than Teflon unsintered tape that DA uses. Or you can do it now before the tape leaks all the black gunk through it. You would have to remove the tape and rewrap the flex joint with the treated fabric. I found its easier to place the fabric in an envelope of parchment paper and work the Permatex into the weave with a wallpaper roller. Three wraps around the joint with plastic cling wrap wrapped tightly to hold everything snug, will have you back in business. Allow at least 24 hours of cure

A shame that engine problems seem to persist. You have had more than your share.

I just completed the rebuild on my first GT33. I haven't run it yet but very soon. It's in the newly reworked Griffin which was all electric but now is modified for gas. It should be in the air next weekend.

flyintexan

My Feedback: (1)

Your finished Cadence looks great!

Has anyone tried using Viton as a header to pipe coupler material?

Mark.

maustin

My Feedback: (7)

rm, nice looking plane. I know you only have a few flights on it but how are the flight characteristics compared to the Pentathlon?

rm

My Feedback: (27)

Thanks guys. Talked to DA today. They're sending me out a new ignition today without waiting for the old one to get there (and I didn't even need to ask). That's great service.

If the problem then persists I'll need to return the motor. Hopefully, it won't come to that.

I was thinking of using rescue tape when the header started leaking. Guys seem to like it and claim it lasts, Would be a lot easier. DA has come out with a new solid header for the 35 in 0, 25, and 50mm drops. I got them to add one with my ignition shipment.

Viton, according to mcmasters has a heat rating of 400 deg. The copper goop is rated at 600 and the fabric is 1100 deg. I don't think the viton would stand up. Matt prob knows more about this.

Austin, can't really say at this time. I've got a lot of time on my pentathlon. My initial thoughts when I flew the cadence on the first day and the motor was running perfect was wow. It looks a lot bigger and felt lighter on the sticks. Was running the 20x10 turning around 7000. Wing was set to +.75, cg was about 3/4 back of leading edge of wingtube. Upline 4 pt were effortless and the plane held its line really nice and the DA could have went forever. Downlines looked to need barely a touch of throttle/elev mix. Knife edge coupling was present. Rolls looked nice. My thoughts are I want to get this plane in the air and working on as quickly as I can.

drac1

My Feedback: (4)

Your DA symptoms do sound like ignition. Hope the new ignition fixes it.

The plane looks good.

MTK

Mark, Viton is pretty good material for many apps but exhaust coupling of a gas engine or a YS is not one of them. Temperature is too high. Teflon tubing is better standing up to heat just fine, but it requires clunky clamps to seal.....too stiff and it eventually leaks.

Turbo hose is pretty good. It's thick walled and heavier than desired but it does the job.

My solution was a thin walled, very flexible ceramic fabric impregnated with Permatex ultra copper. It has turned out to last 1000 runs and still going and only needs plastic tie wraps to hold. It doesn't get stiff with time and has not burned through yet, for good reason. Works as well on the YS too. One neat feature of this method is you can custom mold whatever shape you like. Curves, bends, bulbs, dissimilar diameters, whatever, are all straight forward.

MTK

RM, I am leary of solid DA steel headers. I had one on my 55 and it broke in four or five flights at the flange. Their flex steel headers are heavier but are a better solution.

Let me throw this out....I've made aluminum adapters before to couple dissimilar exhaust shapes. I used hand tools which was tough, but if you have access to a machine shop, it's elementary.

flyintexan

My Feedback: (1)

RM,

I have been flying the prototype a good bit lately and wanted to simply share where I'm at with the setup and changes that I plan to make to tweak the design a bit more later this Summer.

PROTOTYPE CADENCE – MARK HUNT
DATE: 04/20/16
MODS/ADDITIONS: Wingtip Fences, Vertical Fin Leading Edge strake, Reduced belly pan fin height (1-1/2” height), top fin added (1-1/4” height)
Weight: 4860g flying w/ 1300g motor pack (3560g w/50g rx pack, no motor pack)
CG: 1/8” in front of rear edge of wing tube
Motor right thrust: 2.50° right (stock)
Motor down thrust: 0.25° down (stock – 0°)
Wing Incidence: 1.05° positive
Equipment:
Motor: Scorpion F3A
ESC: Castle HV80
Prop: 21.0 x 13.5 Falcon
Radio: Futaba
Low Rates:
Aileron: 10° up, 12° down
Elevator: 12° up, 13° down
Rudder: left, right 28° (*note: only using 15% expo on rudder)
Snap Rates:
Aileron: 20° up, down
Elevator: 9° up, down
Rudder: left, right 18°
Radio Mixes:
Down elevator with idle: 2%
Throttle to rudder: 1% left rudder at idle, 2% right rudder at full throttle
Rudder to Aileron: 3% right aileron with full right rudder, 5% left aileron with full left rudder
Rudder to Elevator: 2% down elev w/ full left rudder, 5% down elev w/ full right rudder

Planned changes to the kit for later this Summer include: Slightly higher wing location, small addition of dihedral, small increase in wing area, slight change to vertical fin, smaller belly fin, show optional small top fin on plans, show optional sleeker nose profile which can be done easily by the builder, simple laser cut parts canopy attachment method...I think that's it....

The above setup is in my opinion slightly nose heavy but I prefer that. This setup snaps extremely well and with 7 snaps in the "F" pattern I will likely work with this setup for a little longer. Adding the wing tip fences made positive spin entry very predictable and improved wing tip stability in the wind...less wing tip wiggle in high wind. I flew it in the last contest with favorable results despite some high crosswinds directly toward the pilot. For what its worth, I'm flying it similar in speed to a glow setup and it really grooves nicely. It can be slowed down but I'm counting on windy conditions at every contest...especially the Nats.



Best Regards,
Mark

rm

My Feedback: (27)

Mark, thanks for sharing your setup. Hope your stayin dry down there. I'm hoping my ignition gets here by Friday, so i can get it out this weekend.

The wing panels u sent me were 36" and i left the tips square. I look forward to seeing your canopy attachment method. That's one thing I wish i had changed to a slanted front end.

MTK

Mark, sounds like the PT pitches slightly to canopy on both sides. Also sounds like it has slight adverse roll couple.

Is the stab incidence zero? About 0.1degree positive might help the pitching without trimming the CG location.

raising the wing and increasing dihedral should eliminate the roll couple. Although your PT may need only one or the other since you are so close. How much dihedral angle is the PT carrying? And how far below the thrust line is the wing located? On my designs I've settled on 3 degrees dihedral for a wing location of 12-13mm below the thrust vector datum. The last two models have been built that way with zero roll couple. But actually, it's wing location only. I've opted to build in the dihedral as the panels are flat on the bench upside down. It's so much easier to install accurate wing sockets this way. For the thickness I play with, dihedral is precisely 3 degrees.

interesting finding re wing tip fences. I'll have do some testing to see if mine can benefit. Since developing the higher taper ratio wings 15 or16 years ago, my wings have handled xwind well. But if fences help certain maneuvers, it's worth pursuing.

lofl

Congratulations Mark on that 1st place win. Impressive!!

... Still working on my Cadence, just on the final steps before paint.

L8tr.
Reg

lofl

Here are a few shots of my build as I progress in my build.

rm

My Feedback: (27)

Looking good. u gonna glass everything?