Extreme Flight RC 91" Yak 54 build

[dribar]

OK -- two day countdown to the DA-60 arriving...

In the meantime, I found the lock nuts on the workbench and installed them.


...and got the elevator servos, mpi arms and supplied linkages installed. These savox servos are by far the fastest servos I've ever had. Zander was standing by for expert one-year-old advice.



I extended the throws to 120-130% and they go right to the stops where the elevator hits the stab. Amazing. My MXS is at 88 degrees of deflection -- we're pretty close on this guy too. Instructions said I might need to extend the exit holes for the arms but it wasn't needed. The Savox could actually rotate beyond that the elevator can deflect so I dialed them back. It is at the limit for deflection.



I think that's it until the DA-60 shows up. Might as well go fly the MXS today & tomorrow.

Peace.

 

[Bigroger]

That pull pull wire routing through the secraft turn buckle still doesn't look right.

Are you sure both the inwards and outwards ends of the wire go through the crimp tube?

They both have to go through otherwise it will pull free under flight loads.

 

[dribar]

That pull pull wire routing through the secraft turn buckle still doesn't look right.

Are you sure both the inwards and outwards ends of the wire go through the crimp tube?

They both have to go through otherwise it will pull free under flight loads.

Yes -- I have it as you describe. The pic is deceiving because I had a 1-2 inch tail and didn't want to cut it off yet so I strung it back up through a few times and wrapped it around the pull cable. Once a few flights are complete, I'll trim it and it will look better.

 

[Bigroger]

Sweet.

I did find I had to replace the standard cable after a few flights due to stretching.

I went with the 0.8mm secraft cable and all is good after many, many flights.

 

[dribar]

A quick note on batteries. I have two FromeCo Relion 5200 flat packs for my AR9000 receiver. I've used FromeCo a lot in the past with never an issue. In this case I ordered them with EC3 and regular JR plugs. The EC3 will stay plugged into the receiver and the JR used for charging and also a quick check at the field for status.

Tonight I did a quick test with my Thunder AC-6 charger. Historically I used the FromeCo cube for charging but wanted to try something new this time. the AC-6 did a great job and took the battery right to 8.4 volts. Nice. I plugged the 8ball checker in and it was perfect.

I know you guys all know all of this stuff already, but I wasn't sure how well the AC-6 was going to work... and if it was going to shut off at 8.4 volts correctly.... It did. All is well. DA-60 tomorrow. Yay.

Peace.

 

[dribar]

DA-60 showed up last night. I was hoping to at least get the four bolts in, but investigation revealed a few things:

1) the pic in the manual shows the carb rotated to put the throttle linkage bottom right. This doesn't work with a slimline Pitts muffler because of the orientation of the needle valves. It can only sit one way. It would be better if the carb had 90 degree options but the only way to rotate it is 180 degrees. So the manual and throttle servo placement is all wrong -- actually it's probably more suited for a tuned pipe but not a slimline pitts muffler.

2) Because of the throttle orientation, the throttle linkage is on the top, but the servo is in the floor... crap. Gotta figure that one out.

3) Now I understand the pic in the manual actually shows how much of the firewall they had to remove to make the DA-60 fit. They don't say anything about it, but I will need to carve at least 1/2 to 3/4 in of material in a couple of places to give clearance to the fuel line, throttle linkage and choke linkage. Then fabricate some way to move the throttle higher inline with the linkage. Arghhhh.......

For some reason I thought this was going to be a bolt-it-on thing... time to be a modeler I guess.

Peace.


UPDATE: I called DA and they told me the DA muffler bolts to the side and will not block the needle valves. So the Slimline Pitts is going back and the new DA muffler will show up in a few days. Crisis averted. Note to self -- The slimline Pitts muffler does not allow rotation of the carb.

 

[dribar]

After trimming ~1/4 in of material off the top and bottom of the firewall opening, I got the DA-60 mounted.



Fuel line is connected too. I added a loop so that I could pull the filter out of the motor box for cleaning down the road.



Also manufactured a forward facing choke wire.

 

[dribar]

Installed the linkage for the throttle servo. The carbon pushrod EF supplied was about an inch too long even with the ends twisted all the way on. Surprising.



Attached the ignition and tied up all the wires.



Dropped some thin CA in the motor box hatch holes and will attach that tomorrow.

Muffler and new dremel will show up on Friday so hopefully we'll have some gas running thru this baby this weekend.

 

[dribar]

This should be the last day in the house. We have a rule that once it's started, it never comes back inside.

After mounting the muffler from DA... I spent the afternoon carving out the canopy. I am very happy with this muffler already -- found out it comes with a smoke port. Something to explore later.



I use the hot knife approach so it's not a messy job at all.



...then used a soft dremel tool to clean up the edges. I did a quick balance and it was dead-nuts on. EF doesn't give you a measurement -- just "the wing tube"... Here's how she looks at this point ready for engine start tomorrow:



Gotta go spend some time with the family.... peace.

 

[dribar]

Started the DA-60 for the first time today. No problems except for the ignition battery coming loose. I added another zip tie in the other direction and it all looks good now. No leaks, everything checked out.

[video=youtube_share;DqUhIMFeLb8]http://youtu.be/DqUhIMFeLb8[/video]

In case you're wondering, YES that is my wife and YES I live a blessed life -- way beyond anything I've earned or deserve. Thank God for that

Peace.