SMALL - espritmodel.com SMALL - Telemetry SMALL - Radio
Reply
Thread Tools
Old Dec 24, 2012, 12:35 AM
Registered User
China, Guangdong, Shenzhen
Joined May 2011
24 Posts
Quote:
Originally Posted by helichoper View Post
Yes i have the same problem,i did this to hopefully help some.
I love this Chrismas Red Dress~~~~~
suzanne lee is offline Find More Posts by suzanne lee
Reply With Quote
Sign up now
to remove ads between posts
Old Dec 24, 2012, 12:51 AM
Registered User
helichoper's Avatar
Australia, SA, Adelaide
Joined Nov 2006
538 Posts
Quote:
Originally Posted by suzanne lee View Post
I love this Chrismas Red Dress~~~~~
Thank you Suzanne you have given me a idea to add Santa and presents
helichoper is offline Find More Posts by helichoper
Reply With Quote
Old Dec 24, 2012, 12:55 AM
Sky's not the limit, ground is
skydanz's Avatar
USA, CA, San Jose
Joined Dec 2007
855 Posts
Gentlemen please, if you have one of these Auto-Gs, read all the posts in this thread. It will make your first experience much more successful.

To answer the question, again, yes the directions are confusing. Standing behind the AG, the rotor should tilt right with right aileron stick movement and left with left aileron. The elevator should move up with up elevator stick and rudder move right with right stick.

Don
skydanz is offline Find More Posts by skydanz
Last edited by skydanz; Dec 24, 2012 at 11:36 AM.
Reply With Quote
Old Dec 24, 2012, 06:00 AM
Registered User
Dangerous Dick's Avatar
Cheshire, England
Joined Mar 2001
504 Posts
Flew mine yesterday - in gale force winds (forecaster said 45kmh!). Needless to say, it didn't need a 'run-up', just a steady nerve as it spooled up right in front of me doing a lot of twidling on the sticks to keep it from tipping over .

Got it around in a few circuits and then landed OK - definately an experience, not too sure I'd want to repeat it though. Just hate taking a model to the field and not flying it.

Since I, ahem, ran out of plastic 'Y' pieces and started using ply alternatives I've noticed a bit of a wobble in the head - pronounced on the tail, and even more noticable on the undercarriage. I received my spares from HK on Saturday and fitted the replacement Y thinking that would sort it out - flex and accuracy in drilling holes etc. I know it was windy (understatement of the year!) when I test-flew but the wobble was still there. In fact, the wind dropped significantly later on (just as the sun went down!) and it was still the same.

I've checked the bolt / shaft and it's perfectly straight although there is a fair bit of play in the bearings - too much for my liking and definately a suspect for the bad vibes. Just wondering - how much play have you got in your head assembly? Anyone else getting a wobble / vibration?

Going to go to the bearing shop before it closes for the holidays and try a new pair

Cheers,
Richard.
Dangerous Dick is offline Find More Posts by Dangerous Dick
Reply With Quote
Old Dec 24, 2012, 06:38 AM
Registered User
helichoper's Avatar
Australia, SA, Adelaide
Joined Nov 2006
538 Posts
Hi Richard my motor shaft isn't perfectly straight and i get a small vibration from the prop when under power,my main shaft is straight and i do have sum bearing play but when in a hover with no power applied the copter is running smoothly- just have a check that your prop is running smoothly and your main shaft is straight to rule them out as being the problem.
cheers
Grant
helichoper is offline Find More Posts by helichoper
Reply With Quote
Old Dec 24, 2012, 08:27 AM
Registered User
Taget's Avatar
United States, MI, Marquette
Joined Dec 2010
208 Posts
Well i got to fly my Auto-G yesterday and it was alot of fun. I hand launched with a good run forward and she lifted nice and slow. On my second flight one of the damaged blades let go and it came down pretty hard but repairs are limited to the blades and a motor shaft. The 2 flights took place indoors and the club members were very interested.

The one thing i noticed was that it was very power sensitive. It seemed that i needed to keep the throttle in one very specific spot to keep level flight. Could this be a "CG" issue where i need to adjust my Hang Angle ? it kept ballooning, not sure if there is an auto gyro specific term for this.

thanks and Merry Christmas
Taget is offline Find More Posts by Taget
RCG Plus Member
Latest blog entry: CNC Machine update.
Reply With Quote
Old Dec 24, 2012, 09:17 AM
Registered User
Dangerous Dick's Avatar
Cheshire, England
Joined Mar 2001
504 Posts
I thought about the motor shaft but on breaking the three bladed prop the other day I found I had a folding assembly 11"x8" which (when the threaded portion of the shaft was dremelled off) fit perfectly and on spinning it up it's spot on. Also, taken up high and powered off completely, the auto will 'glide' down with not motor running but still wobble and when I've held it against the wind without any motor running at all I can feel the wobble through the main wooden frame so I'm convinced it's in the head itself.
The blades are balanced and I can't see a bend in the bolt but something has got to be out.

I've managed to get a couple of new bearings so I'll get them fitted later and see if I can take the slack out of the head section.

Taget, these things - mainly due to the lack of elevator control on the head - are very power sensitive to keep from balooning. The trick is to fly nice and slow and use the throttle as a height control rather than speed control. Very difficult to get the CofG out when using a 1300mAh battery as there's no room for pushing anything heavy outward from the central mast in any direction.
Dangerous Dick is offline Find More Posts by Dangerous Dick
Reply With Quote
Old Dec 24, 2012, 11:18 AM
Registered User
Taget's Avatar
United States, MI, Marquette
Joined Dec 2010
208 Posts
thanks DD, i had figured that it was mainly speed dependent as halfway through the first flight i gave up on the ailerons and elevator and just flew with the throttle and rudder, which was very effective. I think i will set up a throttle curve to make a larger sweet spot for cruising. Now i need to find a new motor to fit in this, I am hoping the spare park 480 i have will be able to move it along.

Any recommended methods for balancing the blade assembly ? i had set mine up on a center point and balanced them so they were level but i am wondering what others do to balance there blades.
Taget is offline Find More Posts by Taget
RCG Plus Member
Latest blog entry: CNC Machine update.
Reply With Quote
Old Dec 24, 2012, 11:41 AM
The 1st Sofaman
Sofaman NJ's Avatar
United States, NJ, Hawthorne
Joined Mar 2012
494 Posts
Maybe they were trying to from the front?

From the rear....right aileron....it should lean to the right and vise versa.

Dave
Sofaman NJ is offline Find More Posts by Sofaman NJ
Reply With Quote
Old Dec 24, 2012, 12:25 PM
Keep it simple
alfoot's Avatar
Salisbury,England
Joined Jan 2005
974 Posts
Hi DD,

It might be worth looking at whether the 3 blades are exactly 120 degrees to each other. If one of the blades has struck the ground it is possible that one of the inner blade bolt holes may have elongated, and that blade will have been knocked slightly backwards. A small amount is all that would be needed to give some vibration.

Most folks remove the inner bolt and have sacrificial cocktail sticks in its place. Have you done this? Alternatively have a look at all of the inner blade bolt holes for any evidence of "blade strike" damage.

Hope this helps.

Al

Quote:
Originally Posted by Dangerous Dick View Post
I thought about the motor shaft but on breaking the three bladed prop the other day I found I had a folding assembly 11"x8" which (when the threaded portion of the shaft was dremelled off) fit perfectly and on spinning it up it's spot on. Also, taken up high and powered off completely, the auto will 'glide' down with not motor running but still wobble and when I've held it against the wind without any motor running at all I can feel the wobble through the main wooden frame so I'm convinced it's in the head itself.
The blades are balanced and I can't see a bend in the bolt but something has got to be out.

I've managed to get a couple of new bearings so I'll get them fitted later and see if I can take the slack out of the head section.
alfoot is offline Find More Posts by alfoot
Reply With Quote
Old Dec 24, 2012, 01:07 PM
Sky's not the limit, ground is
skydanz's Avatar
USA, CA, San Jose
Joined Dec 2007
855 Posts
Richard, are you using two bolts per rotor or one with a tooth pick in the inner hole? In any case, as a test, try using just one bolt in the outer hole and make it snug but not overly tight. Allow the rotor to spin up to speed and see if the wobble stops. I've found one thing that causes wobble, even more than blade balance, is when one blade is out of alignment or not 120 degrees. You may have a bolt hole in a blade that has opened up.

I have flown three of these gyros and they all have a degree of looseness in the rotor bearing. They all smooth out as the rotor gets up to speed.

Don

Edit: Al explained very well just after I typed this so I thought I'd add it anyway.
skydanz is offline Find More Posts by skydanz
Reply With Quote
Old Dec 24, 2012, 04:20 PM
I'm slow but I'm expensive
Ken Lilja's Avatar
United States, GA, Snellville
Joined Nov 2003
574 Posts
Blade balance, rotor head

For blade balance just get some 3mm drill rod stock from an industrial supply house (McMaster-Carr, MSC, Grainger). I use the DuBro balancer as it allows for large diameter props and rotors. Place 1 blade straight up. Add weight to the right or left blade tip until that blade will stay vertical. Do the same for each blade. It will have interaction, so you may need to make several runs at it. What you want to have happen is the rotor can be set at any point of rotation and stay put. 3 blade props are the same.
On the rotor head I found that one bearing was a very light press fit and at the other end it was a clearance fit. That won't do, at least not for long. Anything that can move will, and it only gets looser with time. And the looser it gets, the faster it will wear or fail. My solution is to Loctite the bearings into the head. There is a Loctite that is specifically for plastic - plastic and plastic - metal applications. It does not hurt plastic. It is a version of CA.
Bearings: The stock bearings are extremely loose fit to the shaft. I ordered some bearings from VXB and some 3mm drill rod to make a custom shaft. To my surprise, the original shaft - bolt was a good fit to the new bearings. I had figured that the bolt was some or all of the problem. I also eliminated the vertical play in the rotor shaft.
I tested (on purpose) the head and blade holder with acetone. It did dissolve the plastic. These parts are some type of normal plastic, not a reinforced nylon type. That doesn't matter if they do the job.
I will make up a blade holder out of .032" G10 or .062" HDPE. If I go with the HDPE I will cut it with a hot wire so not to leave any nicks. I have no idea how much flex or stiffness is required.
Ken
Ken Lilja is offline Find More Posts by Ken Lilja
RCG Plus Member
Reply With Quote
Old Dec 24, 2012, 09:46 PM
Registered User
United States, GA, Newnan
Joined Aug 2010
1,107 Posts
Ok fellas I've been lurking, but dang...these look like fun (I'm 3D heli for the past few years)!!!

Looking at that motor, man it sure looks like the powerhouse that HK put in that awesome lil sttiP bipe...me and a buddy each had one; and we upgraded the juice to 4S/1300 in those suckers (had to upgrade esc to 30A)

I just remember that motor being a good one, for sure...anybody got a sttiP? Same motor in the Auto-G?
poiyt is offline Find More Posts by poiyt
Reply With Quote
Old Dec 25, 2012, 01:17 AM
"Aircraftus Fragmentum"
kydawg1's Avatar
Motor City USA
Joined Mar 2007
3,593 Posts
......finally my parts and extra Auto-G kit have been shipped.
kydawg1 is offline Find More Posts by kydawg1
Reply With Quote
Old Dec 26, 2012, 01:56 PM
Registered User
Germany, BY, Schongau
Joined Aug 2012
18 Posts
Assembly and Head modification

Greetings, fellow Auto-G owners...

after having my Auto-G delivered some days ago I did the assembly on the craft.

The pushrod for the rudder was a little long, but the recommissioning of the service hatch allowed a shortened z-bend on the pushrod and a recentering of the servo arms, which where both a notch off.

I glued a small magnet to the hatch and will have to attach a small metal patch inside the fuselage as a counterpart, but after that access to the servos will be easy.

Adjusting the pushrods for the head was much simpler, but the horrible vertical slop in the head and the wobble in the axis bothered me a lot, so I did a small modification.

It turned out that the axis (probalby a 3x45mm machine screw) is a little short on diameter and the bearings are a little to big....

I had some high quality shouldered bearrings from an old heli (Ikarus Piccolo) and some nice little thrust washers from strongrcmotors.com. After reassembling the unit slop is almost completly gone.

The only problem is that the shouldered bearings used up more of the length of the axis than the stock ones did. After putting the rotor on with the double nuts there are only 2-3 threads left, which is not enough for the rotor button. Ah well, a visit to a local screw merchant for a longer screw will do the trick.

Now the head spins wihout any wobble or slop and turns almost forever. As advised I use toothpicks for the inner screw hole.
Still on the to do list before maiden is balancing the main blades and the prop.
Weather here (southern Germany) is a little on the gusty (up to 60 kmh) and wet side at the moment. I guess, this will leave me with time enough to do the balancing and re-read the thread.
Attached are some pictures showing the mods.

Ralph
racs is offline Find More Posts by racs
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Help! Slow-g slow stick auto gyro PilotDragonfly Auto Gyros 4 May 23, 2012 08:14 PM
Sold Zenoah G-23 w/muffler and FEMA auto start LotusTRBO Aircraft - Fuel - Engines and Accessories (FS/W) 1 Jul 05, 2006 11:27 PM
Discussion Xero G Auto. epc2 Electric Heli Talk 2 Apr 01, 2006 07:08 PM
Video Xero G Auto. epc2 Electric Heli Talk 0 Apr 01, 2006 02:35 PM