Hobby King Mini-Stick 580mm "Electric to Cox" Conversion

Well, I got a little time over the last couple of days to finish up on the Hobby King Mini-Stick.  I hope this doesn't count as a thread hijack, but I didn't think we needed to start another thread for the Mini-Stick. Flight gear as follows:

3 Hextronic HXT500 5 gram servos,
300mAh Turnigy Nano-Tech 1S flight battery
Turnigy voltage booster for receiver and servos
Value Hobby DSM2 6-ch receiver
Spektrum DX6i transmitter
Well used TD .020

All up weight RTF is 5.33 ounces.  This thing should scream.  I think I may have to postpone the first flight until I get new glasses.  I'd hate to lose orientation on the first flight and trash it.

So, build notes and impressions.  The first thing that comes to mind is that I wish the Hobby King USA warehouse had the kit instead of the ARF.  The build quality is okay, but needs a lot of tweaking.  Very few angles on the fuselage are straight.  Had to do a lot of sanding to get the stab parallel to the wing.  The cutout for the rudder was okay, but the stab had to be offset about a 1/8 of an inch for the bottom of the fin to fit in the stab cutout and have the rudder/fin 90 degrees to the stab.  And the firewall was crooked, one side being larger than the other, making a slight trapezoid instead of a square.  We'll come back to the firewall.  I'm not sure what kind of adhesive they used for this, but I applied a bead of thick CA along all angles from the firewall back to the former aft of the wing.  Should keep any joints from separating.

Wing:  Nothing to say.  It's built pretty straight and smooth.  I like it.  In fact, it'd be nice if Hobby King sold just the wing.  I'd buy about 10 of them for different projects.  It'd make a good built-up replacement for the Ace foam wings.

Control surfaces:  Since this is an ARF, I didn't have a great deal of choice on hinges as I didn't want to do a lot of extra work.  I'm partial to Monokote hinges, but I don't have any red covering that matches well with the covering Hobby King used on this airframe.  I ended up using the CA hinges, and they worked out okay, but not as free moving as I like.  Cutting back the covering to get good glue joints to wood was a pain.  Even using a new #11 blade and being VERY careful not to cut deep, the wood is so soft that even light pressure cut too deep into the wood.  I had to use more glue than I like gluing the surfaces in place to get the cut line of the stab/fin covered enough that I was sure they were secure.

Servo install: Even for little 5 gram servos, I had to enlarge the cutout in the wing and in the servo tray in the fuse to get the servos to fit.  On my next build I will remove their tray and make my own, I think.  Also, putting the servos in the installed tray, the pushrods were hitting the wing dowel that goes across the fuselage.  The dowel could have gone about about 3/8" higher, and will be on the next build.  I had to cut the dowel and really glue the remaining parts to the fuse sides and the back of the rear former.  For the wing servo, I had to do a little surgery where the pushrods exited the fuse sides.  The elevator pushrod exit slot was placed pretty well, but the rudder slot was way too low.  I realize that the two sides are made identical to save money and time, but the carbon fiber pushrod would have bent up considerably to meet the rudder horn.  I cut a slot directly above the existing rudder slot, and then glued the piece that I had just cut out into the existing slot.  From a few feet away you can't tell that there is a plug there.

Pushrods:  The kit comes with carbon fiber rods with wire z-bends that are attached with heat shrink and CA.  They seem to work okay.  Time will tell on their durability.  You just have to make VERY sure you get the control surfaces and servos exactly neutral before shrinking the heat shrink, applying the CA, and cutting the rod to length.

Landing gear:  Sucks, pure and simple.  There was no cutout for the gear in the bottom of the plane.  They must have filled it with glue when gluing the gear formers to the frame.  And the gear wasn't exactly symmetrical, either.  With the stab/elevator on the bottom rear, you'd think that they'd have at least a skid at the back to protect it, but no.  I got a micro tailwheel to go back there, but it seemed too flimsy.  So, I just dug an old Goldberg wingtip skid out of the junk box and glued it to the bottom of the fuse for a tail skid.

Firewall/Motor Mount:  Since this was designed for electric, it had a big ole hole in the middle of the firewall.  So, I cut a piece of 1/16" ply roughly to shape and glued it to the firewall with thick CA.  Then I used an emery board and sanded it to shape.  As I said before, the firewall wasn't exactly a square.  You don't notice it from a couple of feet away, though.  But, after getting it to shape and holding it out at arm's length, something didn't look right.  As assembled, the firewall actually had left and up thrust.  So, I took a piece of 3/32" ply and sanded it to a wedge.  Then I traced the back of the .020 on it and cut it to shape.  Rotated it until I got a couple of degrees down/right thrust and glued it in place.

Final assembly/balancing.  The wing is held on with rubber bands, which I like personally.  I had to put the receiver/battery/voltage booster right behind the firewall to get the balance right.  I may put the receiver beneath the wing leading edge and use a 750 mAh 1S battery for the flight pack behind the firewall to balance it out.  The 750 mAh pack is only 10 grams more.  The instructions say to balance it at 100mm from the leading edge.  If I did that, it'd balance just in front of the aileron hinge line.  So, I made marks on the bottom of the wing at 25% and 33% and balanced it between those points.

I think that's about it.  So is it worth the $29.00?  Yeah, it's okay.  I wouldn't want to pay more, and I'd really prefer the $16 laser cut kit, but I'm not sorry that I bought it.  I'd have to say that my biggest complaint is that THE FIN IS RED!!!  A Stick should ALWAYS have a white fin.  I just didn't have any white covering on hand, and wasn't going to spend over half the kit cost to buy a roll of covering for that little piece of balsa.

And now for the pictures. I'll do it in a couple of posts to keep this manageable:









More to come,
The Exhilarated Mark

More completion pics:













That's All.  Hope you enjoyed the pics/comments.

The Exhausted Mark

congrats!

Almost Ready to Fly is a bit of a stretch isn't it. If you want it to fly right anyway.It looks good after you fixed all the critical angles though. I hope to read a good flight report of its maiden. I wonder how they do such a bad job of pre-assembly. Up and left thrust? A misaligned stab? Too far aft CG? Anyone who doesn't understand the basics of how a plane flies would be in for an adrenalin packed 30 seconds for their maiden flight.

Thanks for posting about it, Mach II.

That's awesome... you beat me to it LOL.  It's all good... I've been working on my Jeep.

How's the CG?

Hi there. I am really interested in the radio set up that you put together for the Hobby King Mini-Stick:

3 Hextronic HXT500 5 gram servos,
300mAh Turnigy Nano-Tech 1S flight battery
Turnigy voltage booster for receiver and servos

It seems like a super light option. I checked the Hobby King site.

How did it work out for you?

Did you have good flight times with this set up?

Does the voltage booster plug right into the Lipo battery, or did you need to make a connector/adaptor, etc? I can't seem to figure out what connectors the battery and voltage booster uses.

Would this set up work with the 2 gm Orange micro receiver?

Thanks a lot for your help.

George

I'd go with an OrangeRX. I plan for my 020 to be throttled also

I'm really interested in Mark's radio set-up with the single cell Lipo and the voltage booster. It's seems like a super light way to power a 1/2A model without heavier NiMh batteries.

Has anyone had success with this set-up? Did it work for you, Mark? Do you need a special charger for a such a small Lipo?

Thanks,
George

Not sure how this panned out George.
I spent a year and a half trying to perfect a similar model, first with 010 power then PeeWee 020
power.
Although I only had Rudder+Elevator I went for simplicity and a 120mah 4 cell nimh which weighed 15 grams, this was enough for 4 or 5 flights and being a nimh was much easier to charge imo.

Also imo Cox engines don't lend themselves very well to being RC throttled and with a plane this small
it's probably best to forget the throttle.
 

Serceflyer wrote:I'm really interested in Mark's radio set-up with the single cell Lipo and the voltage booster.  It's seems like a super light way to power a 1/2A model without heavier NiMh batteries.

Has anyone had success with this set-up?  Did it work for you, Mark?  Do you need a special charger for a such a small Lipo?

Thanks,
George

I still haven't flown the Mini-Stick.  I need new glasses that would let me see better before I try and fly it.  I know if I try and fly it now, I'll lose orientation and stuff it.  I'll just use the charger that I have for all my LiPo's to charge the receiver battery.  It goes down low enough on charging current that I won't overcharge the battery. But, if I didn't, I also have a E-Flight charger for on of my indoor helicopters designed for 350mAH batteries, so I could use that to charge the battery.

The Blind Mark

Reminds me I must get the TD hooked up over Christmas.