BT Freestyle setup thread.

[swatson144]

I arrived today in good shape so here we go.

How it was packaged.

Steve

[swatson144]

What's in the box. Just like you see no building commenced.

[swatson144]

more

[swatson144]

First part of the setup (can't really call it a build now can wee?) is to get it standing up and mount all the stuff we have little choice on location.

Note this heli is intended for experienced hobbiest and comes with no instructions other than assembling the head. Since I think this is the 14th every made I doubt that me having to back track and change things around will be an inconvience. Though I know of no other setup/build thread in existence less than 100 pages long.

Thus the orbit 15-18, 9254, and GY-401 stuck in place, with the delrin legs.

[swatson144]

I won't reinvent the wheel. The instructions that can be downloaded from BT www.ballistictechnolgy.com are pretty encompassing. There are a few points I didn't quite like.

Since this is a head assy there is no reason that a customer should have to cut threaded rod. It's too easy to bundle rod and cut it. For the love of Pete, set a fence and use a band saw BT. Roll the ends on the belt sander and let us build indoors. I'm beggin ya!

Step 1 the drag links should face opposite directions. There is a flat that goes towards the ball. This is important, since it calls for gluing the driving drag link. This isn't mentioned and in in a rare moment of actually thinking I figured it out on my own.

Step 13 is to make 2 bent links 2 3/4" long. There is no mention of the length to cut the 2-56 threaded rod. I found that 2.00" was fine after much experimenting. Just cut the rod to 2" and you can make workable linkages.

Step 14 See step 13 above and substitute .5" for 2"

All in all pretty minor stuff. If you don't know how to figure rod lengths it'd be good practice for the linkages stage later. Well I did say that this heli is not intended for the beginner. Still it would be advantageous for the experienced builder to have about 2$ worth of 2-56 all thread on hand (and some 1/2" 4-40 screws in case the dropsies get you).

Stuff I did like.

Nice pictures detailing each step.

In the heli I received the more confusing points were obviated by being pre assembled. Someone had trouble with the head block and seesaw assy so it was done. The same with the mixing arms.

The head allows much adjustment of mixing ratios. I set mine up for medium.

Linkages made of 2-56 are very srong for a 3 pound heli, and replacement shouldn't be a problem. Just cut another from a 1$ stick of 2-56 all thread.

No missing parts. Except a "brain fade" that gave me an extra foot of 4-40 and no 2-56. If I had read this 1st I would have already had extra on hand. :D I had just used up the last replacing a Corona tail push rod.

BT includes several extra ball links in the package.

[swatson144]

servos and adjustments.

The heli is designed for HS-81 servos on the collective, and S9254 on the tail.

I elected to use HS-85MG on collective. There is a slight difference in height above the tabs and it really made my build more interesting than it should have been.

I know exactly what I'm going to do when the weather turns bad. For now I elected to finish the build without using anything more than an experienced hobbyist should have laying around.

The elevator servo drug on the tail belt. There is about .14" more case above the tabs and the "hump" is much longer. Simply drilling out a 3mm std (non self locking nut provided a good shim, and restored the geometry at the same time.

The same issue brought me interference with the tail drive pulley on the ailerons and pitch servos. Since I really liked the geometry the way it was (very near perfect) I elected to install the servos upside down and run longer linkages.

You have to make your own linkages for the servos also, but here it is a boon. Since there are many different servos that can be used on the cyclic having premade linkages would just be a waste as they would only work with HS-81 servos anyway.

Measuring for the links was pretty straight forward and simple. Temporarily mount the servo with the arm centered, set 0 pitch, swash level and measure center to center. the links provided needed the rod shortened .6" for the pair. CL-.6"=threaded rod length

As you can see in the pic above the geometry is about as perfect as one could hope for.

The tail control rod is plenty beefy. I elected to run a longer arm than I normally would to provide clearance under the tail boom support. Since the rod was nearly touching one of the boom support rods I covered the support rod in heat shrink to keep from having the carbon fiber rods from knocking together.

[swatson144]

Here are some pics as tested AUW 3 lbs 4 oz (1304g) with uBEC 5V, Castle creations HV45, Plettenberg Orbit 15-18, Berg7, Eagle tree micrologger, 3x HS-85MG on cyclic, GY-401/9254 on tail, 2 2100 mAH 3s in series as 6S. Please excuse the wiring mess as I don't cut wires until I am sure I like the locations of all the components.

I've had a couple of flights with a bad High frequency tail "swimming" back and forth very fast and about 1/2" each way past center. It is not gain related and I have it narrowed down to a critical linkage length on the tail servo. It's pretty rare phenomenon but I have been blessed with running into it once before. The gyro can't seem to put the tail where it wants and over shoots, then over shoots going back. It's much like tail wag from too much gain but very small, fast and violent. The swimming is not gain related and does the same from 5% AVCS to 35% AVCS where "wag" comes in. It only happens in HH mode and shifting to rate calms it down and my amp draw drops 4A when it's not swimming. The fix was simply moving in a hole on the arm. Now the tail holds fine. Naturally I discovered the real solution after moving all the gear around. It was a case of the HS, mechanical linkage ratio, and tail blade length combined to make a very unhappy gyro.

It's an incredible heli. It's responsive and seems to have no mass in the air. I haven't gone beyond some slow forward flight for 2 mins at a pop to land and check everything out. So far it is taking 315W (~14A) to hover and a bit less for SF.

It needs a canopy since I can't keep good orientation on an all black heli. So I have stuck a 7$ canopy from a BP explorer on it until I can do something with the Darth skin it came with.

I got a 5 min hover in before it started raining, then a 6 min flight slow cruising in the side yard between rains. It's pretty amazing so far. Seems pretty weightless. Rocking the ailerons it really wants to flip. I can't wait to try it in a larger area.

[swatson144]

reserved in case

[swatson144]

That should leave me plenty room reserved feel free to comment or question.

Steve

[eddiemoth]

The long wait is OVER! I am very glad you got it before Christmas. Wow, you got it almost done in one day. How thick is the the CF. It looks very strong. :D

[swatson144]

The wait seemed long but 1 week was gone for Thanksgiving. Then there was a unforseen wait for bearings. All in all it was the best experience I have had with custom work.

The thick part is laminated wood and CF (dragon plate?) and is indeed awesome strong but very light. The thin parts are 2mm CF. The swash is a jewell. I've been building the head (I had to take a break to make some money). The fit and finish of this thing is awesome. The pieces just snap into place and it is all aligned and ready for screws.

Alot of it was preassembled (standard) I think he cuts pieces and while he's watching the CNC op he fits the last cuts. I normally don't like much assembled but it sure saves time and it isn't like some minimum wage worker is doing it pressed for production numbers. He loctites everything and frankly I think I'm more likely to screw up than he is.

The build is smooth (I'll detail the few bumps in the sections above) I'm well pleased, and very sure this is the right sized heli for me.

Steve

[Ranger]

Looks very interesting Steve, but a bit over my head at this stage. I'll stick to the Rappies for now
Glen.

[swatson144]

The thing had been a smooth running heli for so very long and then picked up a vibe which started out as only sometimes present. Then worked it's way to always present.

I finally tracked it down to the large bend in the mixer links IAW the instructions. It seems when every thing is newish it's all good but after some use and blade tracking etc and the things loosen up they spin out and the ball links contact the bottom swash which twitches the mixing arms. I have re-done them to just have enough bend to clear the flybar carrier.
http://www.rchelicoptertown.com/forum/photoplog/file.php?n=203&w=o

You can see the slight bend in the red link at the top and it's black opposite on the bottom. I also use these links for blade tracking. Since they are intentionally bent I just bend the red one a little more and if tracking gets worse straighten it a little more.

Steve