vibe 90 and dx7 swash leveling problem

[trillian]

I truly understand that, but you have done all this typing and realistically he is no further forward, after all this time, I have set up probably over time,with crashes and new builds 50 heads, never had any problems like that........

I think he's bound to have it sorted by now. I've setup so many helis myself as well, I could do it blindfolded in combat conditions But what seems obvious, even intuitive after some years of doing it, may still seem elusive to someone that hasn't yet lived with these creatures quite as long.

There are still things that baffle me sometimes, like programmable mixes in the DX7.

[whittm]

Ok. ..hadn't had a chance to look at it till tonight. Got the swash so that it was perfectly level mid stick, top and bottom. Adjusted the links so that they were as per manual. Adjusted pitch on blades so that they are both zero at mid stick.

Checked the pitch top and bottom and they are 1 degree out. ..13 degrees top and 11 degrees bottom. Would I be correct just to adjust the travels equally bottom and top on the pitch, aileron and elevator to get it 12 degrees top and bottom?

Yes, you are bang on wavey davey, I want to know what's going on! In fact, I played around with the travel settings until the amount of throw mid stick, top and bottom is within 0.4 degrees top middle and bottom and within 0.2 degrees mid stick at all locations on the swash around the swash. I want it to fly sweet!

[waveydavey]

It will fly sweet and you wouldn't notice if it was a degree out, you would just trim for the wind in any case. It's different with a flybarred system and they're affected more by the wind. I would shorten the links from servo to swash if it's a standard swash up for +ve collective and lengthen them if -ve for collective until I'd in effect lost a degree and gained one and then redo the head. Or, just adjust the pitch curve but you may want more negative if you're going to 3D

[whittm]

Yep. ..don't want to go crazy with this one....but I would like to get it inverted and don't want to feel cack handed when it is...Thanks.

[whittm]

Ok. ..head is now done! And it's spot on, within 0.3 degrees at mid low and high stick in all 360 degrees of the head rotation. Also 12 degrees
+/-0.3 degrees in high and low. The aileron and elevator are not perfectly equal, but within a degree or so, so I'm quite happy the links to the servos were not set to the exact correct length, perhaps I can revisit it in the future...Thanks trillian and wavey davey!

Now I'm just reading the engine manual. ..Whilst I was doing so, I looked at the helicopter manual to see how the motor and clutch were fitted.

Found something and glad I checked actually! I noticed that the clutch parts weren't engaged and level together as in the drawings. So, I dug deeper and found that the engine mounting has been fitted upside down! So that has to be swapped around now.

I wonder what you guys reckon? Whilst it's out, would I be better having a go at bench running it, to get used to starting it etc. ..?

[waveydavey]

No bench running unless you can load it with prop or something. Depending on how long it's not been run for I would stick new bearings on the crank, particularly the rear and replace the O rings in the carb.

[whittm]

The engine has never been run and was stored in a dry heated workshop for 8-10 years. Never had fuel in the lines either. There's no rust on any bolt head even! Ok, I'll read the manual in my spare time in work today and swap the mount around later and have a go at setting up the throttle servo some time this week.

[whittm]

I'll also check the o ring

[whittm]

Hi there guys, another question or two! I've setup my pitch curves and throttle curves according to freddy can fly on youtube... I liked his explanations better than the other options, would like to ask, what is an ideal position percentage wise for the throttle curve at mid stick for the os 91 engine that i'm running, in idle up 1 and 2?

Also, I wanted to ask what your opinions are on running dual rates and expo on the cyclics?

[waveydavey]

I wouldn't drop the mid point in the curve below 65% ish. If you use a governor which I recommend then ignore the mid point it makes no difference unless it comes off the governor for some reason.

Rates and expo to suit your feel, nobody can tell you what works or give you a guideline as it's down to personal taste. I don't run rates or expo, apart from a little on the rudder. It's just not something I've ever felt the need to do.

[whittm]

A governor, would be a magnetic pickup sensing the main rotor rpm, yes? Not going to be able to buy one any time soon... I've got 90% on Idle 1 and 2, a bit high? Also, just run D/R at %100 with no expo then?

[waveydavey]

Yep for a V curve too high, drop it to around 65% and see how the engine performs. A governor is a couple of quid in relation to what you're about to put in the air so grab one, it'll save so much fiddling. Again the rates and expo are a feel thing, if it rolls and flips too fast for you you're going to want to dumb it down a bit. If it's twitchy at centre stick then you might want to add a bit of expo. Everyones different and what suits some doesn't others. Duncan uses loads of expo and he flies like this

[whittm]

What is the best/cheapest governor? What is the best way to attach them? I watched the install of an align governor online. Trouble is, I can't see how the magnets would attach to my fan? Would I Need a new fan a well as a governor and sensor?

[waveydavey]

I don't know your model but you could use the backplate sensor from horizon etc and I believe the Align governor works well with this.

Align governor with spektrum backplate sensor - Page 1

[whittm]

Been looking around, would this work? My only concern is whether this receiver will work with my dx7.

Spektrum AR7100R Receiver, Satellite Receiver with RPM sensor and accessories | eBay