The GAUI R5 - An old school look at a new school RC helicopter

[RGorham]

Here's a couple other mods I did to the front of the R5 to get a little air flow over the ESC and motor.

It's not mandatory but it is a personal preference for me to keep my ESC in the 150 degree range especially on those hot summer days.

[john2kx]

Robert,

Thanks for the details on landing gear training wheels. I had thought about using the white x5 version but I'm sure the x7 is stronger.

Motor/ESC Cooling: great ideas and thanks for sharing!! Where did you find the forward mounted NACA ducts? I have been averaging 150-167F on my Mezon ESCs mounted in high performance glider use without issue. Jeti recommends <100C/212F and I have never approached that even when running 220 amps through the ESC.

I may consider putting some holes in rear fuse of R5 to allow hot air to escape but will only do so after a few test flights and checking my numbers.

All my electronics arrived today and I have about 2 hours of wrenching on mechanics complete. No issues so far and it appears to be a high quality machine.

John

[RGorham]

John,

I plan on doing some exit holes too but I'm making one change at a time and keeping an eye on my ESC temperatures.

Here's a link on where I got the NACA ducts.
I just scuffed the back side and shot them with some black paint and super glued them in place.

Simple and easy.

http://www.hobbyking.com/hobbyking/s..._Duct_Set.html

[john2kx]

$3. What a find!! I'm on it and will have several left for some other projects.

Found a pic of a couple of old schoolers yesterday. 1989 Nats, Pasco, Wa

[RGorham]

OMG!

I can barely recognize me (lol) but who is that next to me?

I remember him but I don't remember his name. Is that you John?

[john2kx]

Tis me Robert. John Thomas. Kind of between disco and Miami Vice era. Funny to look at those pics now. I flew in intermediate and started flying for GMP after that event. We both have changed : ) Lots of grey on this head too.

So glad to see you flying the Gaui line and that you have a R5. I always respected your views back in the day and that has not changed. Your experience has always proved invaluable and I can't express how glad I am that you are sharing your views with this machine.

John

[RGorham]

My goodness John, I knew I recognized you but I just couldn't put a finger on it. It's been a while my friend. How have you been?

Jc Zankl from Empire got me into GAUI. The first time I met Jc he was 3 years old. His dad was one of our customers. I have an X7 Formula that flies fantastic and now the R5. I have several other brands too including a couple old vintage machines...a Cricket and a Legend but I don't fly them much.

We should do a phone call sometime instead of this keyboard chatter which isn't bad but isn't the same. Thank you for your kind words, I appreciate it!

*If you come up with some cool mod ideas for the R5 please post away. It's a good heli however I slightly modify everything just for fun.

Heading out to fly the R5 now, talk to you later!

[john2kx]

Robert

I agree, we should do a phone call. Will PM my number.

Will definitely implement your rear canopy attachment mod. This gent had a issue at 100 mph. See results of damage at 5:00.

Gaui R5 (6 min 10 sec)

[RGorham]

John,

This occurred last night. The bottom of the 4 mm blade bolt lock nut scraped the top of the front fuselage even with my security hardware. I was pulling some high speed fairly tight loops at the time.

I think what I am going to do is use 4 mm (regular nuts) for additional clearance with Loctite. I wish the factory would lengthen the main shaft by 5 mm. It wouldn't affect the flight performance and would give us some leeway for stunts.

Note: keep an eye on your main blade bolts. When I removed my blades last night I noticed my blade bolts were slightly bent and I'm only running 2700 + HS. The stock bolt that came with my kit has an 8mm shoulder whereas a 18 - 20 mm shouldered bolt would be much better thus giving more strength to the bolt.

[john2kx]

Sorry about scratches to canopy Robert. I'm at the point of installing main gear in mine. I believe I can stack all the washers on bottom of main gear bearing block to push main shaft as high as possible. This should gain another mm or so of clearance.

Back to work on these 100 year old pocket doors ����

Edit: don't have the r5 with me but thought of a couple of more possible ways to increase head bolt clearance.
1. Flip blade bolts upside down. Thinking bolt head is thinner that nut
2. Adding a 1mm or so plate between lower mechanics and fuse. Double edit. After thinking about this more, I believe this will cause issues with the mounting bolts used to secure fuse to mechanics.

[RGorham]

Pushing it real hard last night. A very efficient helicopter.

[john2kx]

Looks like a very well matched system Robert.

After looking at some of my earlier ideas now with the r5 in hand, I really don't care for any of them. A longer main shaft sounds like the way to go, along with full shouldered blade bolt.

I don't think I will put mine in the air until I have a custom shaft made or gaui puts one out.

As with any new machine, there are issues that need attention and I'm sure Gaui will take the nessasary steps to address the issues found by those who have invested in their product.

John

[RGorham]

My findings are being relayed to the factory John. Changed my blade bolts to 18mm shoulder and changed the 4mm lock nuts to a much lower profile one, 3.5 mm clearance now. Test tomorrow.

[john2kx]

Good luck with the changes. I'll be interested in how the blade bolts hold up since I see 14S in my future.

[RGorham]

John,

I flew the R5 hard today at 2800 HS with the new 22T pinion and using the longer shouldered blade bolts (12.9 steel grade) combined with the lower profile lock nuts with 3mm clearance between fuse and nut.......all is good.


The new cradle is nice too.

[RGorham]

John,

[john2kx]

Sweet!!!! Got a hit from youtube about a hour ago that you posted a new vid while I was at the flying field. Made me pack up my stuff and head to the house to start wrenching on mine again.

Best vid I have seen of the R5 Robert, and I think I have seen them all. Looks/sounds like the 22T pinion makes it go faster. Tried to order one from Empire today but had no luck. Did find the storage stand though.

John

[john2kx]

Originally Posted by RGorham

My findings are being relayed to the factory John. Changed my blade bolts to 18mm shoulder and changed the 4mm lock nuts to a much lower profile one, 3.5 mm clearance now. Test tomorrow.

Robert,

I did manage to come up with these 4x25MM, 18MM shouldered bolts today and thought I had arrived. These are the same bolts the x5 guys are using to solve similar issue with bottom blade grip hole (stock bolt elongates blade grip).

The 18mm shoulder that I have actually tapers right before the threaded section and just so happens to be where the bottom hole of blade grip starts, making the bolt have a loose fit. If I install the bolt from the bottom of blade grip, it is loose at top of blade grip. I installed a blade and retention nut and can feel play in the system just like the stock x5 has.

Per my measurements, there is room to add another 2mm of shoulder, making 20mm shoulder the correct fit. I will continue searching for the right bolt.

John

[john2kx]

Robert/Joel/All,

I have slowly assembled my R5 to the point of having the mechanics assembled, motor and servo mounted. It has been a pleasant build with only a few issues. A couple of questions:

Retract mechanism/gear/part that rotates 90 degrees from fuselage: there was a shim that came in the same bag. Where is this installed? Between the body and rotatable section. Seems like the obvious place to install it as it would provide some clearance without allowing gear to scrub fuse. Some might think it fits between aluminum bellcrank and top bearing.

Supplied Retract servo: mine failed about 2 minutes after plugging it in to rx to check throws. Was using 4 cell nicad at 5.02 volts w/o supplied regulator connected. Servo was not attached to anything at this point. Servo is locked in one position and will not move.

I went thru some spares and ended up at my LHS for a replacement. The only servo I could find to fit was a Hitek HS 5065MG. Torque is 25 oz @ 4.8 volts and 30 oz at 6 volts. Is this a adequate servo for this application?

I would really like to have a HV servo with plenty of torque to handle the loads while landing and eliminate the supplied regulator if possible.

At this point, I have lost confidence in the supplied servo, even if I had a replacement. My concerns are with a failure while landing and the servo not working.

John

[john2kx]

Lg