Zoom Finally Flies with Belt Conversion

[rob_jones]

After much cussing and gnashing of teeth, I have finally flown my Zoom 400 with the belt drive conversion for the tail rotor. It has some other issues not related to the belt drive that need to be sorted out, but it's promising so far.

It was a bit more work than I was expecting and required a lot of "engineering" on my part to get the thing put back together. There is also quite a bit of added weight to contend with.

I've only hovered it so far (more test flying expected this afternoon), but it is very smooth and a lot quieter. And a weird side effect is that now the stock foam blades track perfectly when they never would before.

The biggest problem I had is that the conversion raises the top of the frames by about 1/4". This messes up the geometry on the control linkages and the two pitch rods had to be significantly shortened. I actually made them so short that the end of the rods poked through the ball link. This created a lot of binding and made the copter unflyable. I have since fixed the links (I hope) and the head has very little binding or friction in it now.

Also on the docket for this evening's test flight is a pair of Like90 wood blades. I've had them in my possesion since IRCHA, but I crashed the Zoom the first day I was there and have just now gotten it flying again. I'm very curious to see how they perform compared to the stock blades and the MAH carbons.

Stay tuned...

[WillJames]

Cool Rob. Sounds like you got it going on dude!! You getting burned out on the Zoom yet? :)

Funny thing about these micro birds is they take as much or more work than the big birds to fly them. Makes my Extreme seem sooooo simple.

[rob_jones]

They are definately not any less expensive or any less work than any nitro bird I've ever had. But they are a lot of fun, so I guess it's worth it.

You getting burned out on the Zoom yet?

Not yet. Why? You wanna buy it? :) Actually, I have been keeping a very close eye on a couple of T-Rex 450 threads on RC Groups. I may have to start sucking up to Santa...

[Hotshot Charlie]

Hey guys,

I am just about burned out with my Shogun..... not quite..... but almost ! This thing has required twice the money (I expected to spend) and 5 times the time to get her flying. I was just about ready to "stomp" her a couple of days ago, but relaxed and ordered some parts and will give it another shot.

It has been a royal pain in the a$$, but I have learned a lot about mechanics. heheheee

Hang-In there Rob, it sounds like you have had your fill of the little beast also !!!

[rob_jones]

Good news and Bad news.

The good news is that the belt actually works and I got a whole flight without anything breaking! Tail authority seems about the same, but it's much smoother and quieter. Overall, my impression of the conversion is very good, but it's not for the faint of heart. Dave has been very helpful whenever I emailed a question to him and really cares about helping out fellow modellers. But if the thought of sawing your Zoom's frames in half makes you nervous, you had better just stock up on tail gears. I also hear that there will be a factory upgrade that includes better gears (bevel gears, I think).

The Good:Smooth and quiet, likely to be much more durable than the stock gears. Very complete kit and good instructions. Excellent support from the developer.

The Bad:Expensive, not a simple installation. Requires lots of modifications to install.

The Verdict:A very worthwhile upgrade if you're tired of replacing tail gears and are not squeemish about cutting your helicopter apart. Considering that it's not an "official" product, but rather offered as a courtesy by its developer, it's very complete and effective. It would be great to see it developed a little further.


Now for the not so good news. I finally tried the Like90 wood blades and they are a disappointment. The were pretty badly warped right out of the package. I thought about reshrinking the covering to try straightening them out. But just decided to try them as they were and see how they do. I may still try reshrinking them and fly them again. But they really weren't any better than the stock blades. They are smooth and quick, but they still won't track. I could see them going in and out of track while flying around. They got worse at higher head speeds. Maybe they'll get better if I reshrink them...

The Good: Very well balanced with no vibes, quick cyclic response, cheaper than the stock blades.

The Bad: Badly warped, don't track any better than stock blades, likely to not survive even a minor crash

The Verdict: What I would consider a "lateral upgrade"; maybe better than stock, maybe not. But different, at least.

[Hotshot Charlie]

Thanks Rob for the report. Think I will try these new gears I have coming and hope they will do the job. I know the belt is the best way to go, but it sounds as if that is an expensive upgrade with a lot of work.

[Pipefish]

How much for the belt drive modification?

Cheers

[rob_jones]

Follow up

I took a heat gun and tried to take some of the warp out of the Like90 blades (they are some kind of light wood -bass?- with heat shrink covering). I got them pretty straight, but they didn't track any better. The heli didn't have any vibration and seemed to fly ok, but the blades were about 1cm out of track the entire time.


How much for the belt drive modification?

It's $75 +shipping. You can PM hubdave and he will hook you up. I'm 99% sure he is on HeliFreak. If not, you can find him on RCGroups.com.

[Mckoi]

Heliup belt drive units due to hit the streets next week

[NolanManley]

I have the belt drive on mine. Dr Tim and I flew it, I for a few min and he, till the pinion slid up the shaft and took out half my MAIN gears teeth! :shock: Can you say RED locktight???

Belt conversion went pretty smooth. Those DAMN lock collars that go on the main shaft SUCK. I'm having a machinists make me some more here at work today. I'll drill and tap them at home for metric set screws. ;)