Panther Trainer Autogyro

[Keith Edis]

Many thanks to the organisers and flyers at the 2014 Winterton Autogyro meet! Particular thanks to Ian for his help and support over the last few months, resulting in him successfully test flying my Panther on Saturday.

Also thanks to Richard ('The Fireman' for his help and comments on the day.

I'm looking forward to flying the Panther out for myself now!

-Keith

[Richard Harris]

Noticed this on Ebay, absolute bargain?

PANTHER

[Grant Webb]

Hi guys.

I've been hiding out and lurking for the past several months, following various 'gyro builds with growing interest, to the point that I just had to give it a go myself.

Thought I'd share a few photos of my endeavours - it has flown, albeit very briefly. During a test taxi it got airborne by mistake and got to approximately 10 mtrs high before I safely got it back down.

Very next taxi one of the rotor pushrods came loose and the model veered offline after gaining about a mtr altitude before settling back in on it's nose - broke one blade.

I hadn't made a spare so I deemed it better to make a new full set, this time with a spare.

As yet it's still to have a proper flight in anger.

Cheers,

Grant.

Tauranga, New Zealand.

[George Elliott]

Hi Rich,

Better late than never!

I enjoy flying the Atom so much I had to try the Panther and I haven't been disappointed. As you hopefully will see from the video made by my flying buddy, the rotors spin up very easily and the take-off is very gentle. Flying is just as good but landing with my present trimming and experience is far from the finished article.

This was my third flight, the first two being short trials, after which I added more weight to the nose, as the Panther seemed to drop its tail and wallow as speed was reduced for landing. This is obviously not the whole story, even given my lack of experience, since the third landing was the worst of the lot. I have now reduced the back disc angle at neutral elevator stick slightly. I had to remove a little of the material at the core of the mast at the top to allow more downward pitch of the head.

I'm hoping this will make landing more straight forward, and more like the Atom.

I can only repeat what others have said : that the Panther is another great design.

PS I am about to start work on a RPG.

https://www.youtube.com/watch?v=ZPvIH5NB2uU

[Richard Harris]

George (or shall we call you Gyro George),

Nice flying and well edited video, what's the ground handling like on the hard surface?

You video gives the perfect example on how to get rotors up to speed, I may well borrow it in the future

You will like the RPG, just stick to the write up and all will be fine. It is quite an old design now and the Panther blades will probably work just as well on it (if not better) with the same plate and shim set up.

Here is your video:

https://www.youtube.com/watch?v=ZPvIH5NB2uU

Rich

[Richard Harris]

Mods,

For some reason the video won't display when copy and pasting the embed code, any ideas?

 

Thanks

 

Rich

Edited By Richard Harris on 22/01/2016 17:15:26

[George Elliott]

Hi Rich,

Thanks for your kind compliments.

I have put a tail wheel on the Panther instead of a skid. I did this as a result of my experience with the Atom on our rough tarmac surface, since the skid tended to allow the Atom to vere off course due, I think, to the lack of ground purchase at the tail.

You are very welcome to use the footage in any way to further the cause!

George

[Richard Harris]

Gents,

I have been building a 4th Panther for a friend which is just about ready for covering, I know that a few of you have added steerable tail wheels, is there any chance you could pop a few photos up of your installations please?

Also, I seem to recollect that a few installed the rudder servo into the tail end, have there been any detrimental effects to the CG in doing this (this would save me a trip up to the model shop to purchase a snake)?

On a last note DB Sport and Scale seem to have stopped dural strips for U/C's, any links or guidance to a supplier please? I recollect Nogin end metals at the shows but dural was a bit thin on the ground with them. I could make up a piano wire version as a last resort of course but much prefer aluminium.

Thank you

Rich

[Steve Jones 2]

Hi Rich, away on hols til Friday when I will take pics and post to you

Steve

[Steve Jones 2]

Hi Rich, away on hols til Friday when I will take pics and post to you

Steve

[Big T]

I get all of my alloy sheet and strip from http://www.mallardmetals.co.uk. He is a very friendly man, if you ring him and have a chat he will send you exactly the dimension you need. As far as a steerable tail wheel, in my opinion it's not needed, I just put in a skid. The rudder is plenty big enough to swing the tail and in any case you will need a more forward cg at first but that depends on the size of lipo, or are you going glow? BTW rumour has it that coolwinds have a limited supply of ready made blades in stock.

[Richard Harris]

Tim,

Thanks for that I will give them a bell, they are in Birmingham so not that far away, what grade alloy have you used?

This version will be electric and has a slightly longer nose as per the original.

Rich

[Richard Harris]

'fat fingers' = double post!

Edited By Richard Harris on 02/06/2016 09:52:15

[Big T]

HE 30 now called 6082.

[Richard Harris]

Had a ride over to Mallard metals this afternoon and it is a very nice and helpful gent working from his garage! He had me sorted with the 1/8" x 3/4" x 1metre long length of 6082 aluminium, with minimal overheads it cost me a mere £3.50! I explained the needs of us modellers and he is quite happy to help any requests, I will certainly be using him again.

Thanks for the link Tim

Rich

[Erfolg]

I am not familiar with 6082, although i understand that it does not work harden. Yet it can be heat treated, to make a strong UC ?

I understand that 6061 can be precipitation hardened. I believe that 7005 can be hardened by heating and cooling in air.

Yet the reality seems to be that where i live, getting my hands on any quality aluminium will not happen. Even though just a few miles away is a BAE aircraft site.

In fact I gave the scrap man a sheet of silicon aluminium, as it is useless for modelling. May be the most affordable aluminium for making electric/control cabinets, yet is a waste of space for UC legs.

I am so envious.

[Richard Harris]

Carl,

The material is the same as on my original Panther and that has been flying for a good few years now, despite a few heavy landings I have only needed to straighten it once.

No need to be envious,they have a mail order service, what the postage cost are I have no idea but there is an online enquiry form, or just ring them and get a quotation.

Rich

[don cardy]

Having just built a Panther and completing a maiden flight I thought it would be worthwhile recording some of my experiences. My Panther uses all the electrics from a crashed ARF autogyro from which I was trying to gain easy experience before launching out on a large Cierva C30A project! I'm glad I've changed. The plan and the laser-cut parts arrived in good time and I started construction. The plans were very clear and I made rapid progress but soon realised that they said nothing about the initial settings of the direct control head. This detail was probably set out in the RCME articles of March and April 2013 and I had neither of these editions. The "modelflying" website list reprints but a click on the lead only came up with "page not found". Physical copies of these editions are no longer available so having considered the digital archive I took the easy way out and found copies of back numbers on ebay. At last I could get things set up and ensure that the neutral positions of the gymbal and its travel were correct. It was at this point that I noticed that the motor needed side-thrust (not noted on the plan) so this required some corrective work to the motor mounting and the cowling. Then there was the issue of the undercarriage. Nothing ready made could be found so like others I was into sourcing a suitable.supply of alloy bar. I found a helpful local supplier of non-ferrous metals and bought some 1" x 1/8" 6082 T6 bar. This was immensely tough but I managed to bend it well enough making sure I got it right first time using a cardboard template. I found that the fixing hole centres given on the plan at 2x35mm = 70mm apart were wrong and needed to be 60mm if captive nuts on the floor of the fuselage were to be used (ought the plan to be corrected?). When making the blades my previous experience with Morley helicopters back in the 1970s proved to be invaluable. There were quite wide differences in the weights of the three blades according to our kitchen scales and I corrected this with quite large panel pins which I buried in the underside of the balsa part of the blades secured with epoxy in positions along the blades which ensured that the balance point of all the blades was identical. The rotor ran very smoothly on a little motor driven test rig which I have and did so in flight too. The use of shims to give negative blade incidence turned out to be problematic if the blades moved in the lead-lag direction because the amount of contact with the rotor's triangular plate was minimal and they would pop out at its edge. Originally the rotor would not spin up well on my initial take-off hop tests and so I increased the negative incidence. After a successful hop I measured the negative incidence of the flat underside of the blades relative to the triangular plate at 2 degrees and then added an extra bit of ply to thicken the reinforcement plates on the underside of the blades before sanding these to give the required relative negative incidence. The blades now move very smoothly in the lead-lag direction and there are no shims to pop out. All in all I think the design of Panther is brilliant. However, perhaps after three plus years the publishers of the plan could arrange for an issue 2 with corrections and with notes about side-thrust and the gymbal set-up?

Don

[Richard Harris]

Hi Don,

As you are aware the Panther was covered over two issues and soon became sold out, I believe that RCM&E don't reprint but certainly offered a digital issues soon after. It was re printed in the Model flying .co.uk workshop special which included all of the write up of the first two original issues about 12-18 months later but I think that this is now sold out.

Failing all of that the Panther has been covered in great detail on this very thread by myself and some very experienced builders who have all added some great ideas along the way.

There are many gyronuts out there who, like me, are more than willing to give our help and advice, the only daft question is the one that is never asked and we have all been there

As it happens I am just finishing my 4th Panther for a friend, I can pop up a few photos up if you think this would helps in any way?

Thanks for the complements on the Panther, always good to hear as a designer , has your flown yet? Any photos?

I do keep thinking of drawing up a slightly larger version for a 60, though not right now. Interest in this would certainly light the Panther fuse again?

Rich

[don cardy]

Hi Rich,

Thanks for your comments. Yes, it has flown. It's maiden flight was yesterday and it landed in one piece despite this pilot having had no previous experience of autogyros. It was here that I found your videos particularly valuable in the run-up to the maiden flight. Although I do a bit of fixed wing flying much of my time had been spend in model helicopter development where gentle realistic flying is my interest, not aerobatics. Over the last two years I've perfected a NOTAR model using an EDF to power the tail boom. The April 2015 edition of Model Helicopter World in "Scale by Scale" had my article on the early "proof of concept" experiments. Sadly with the cessation of MHW I haven't been able to do a part 2 update, but an article is with a Traplet stablemate and I'm hoping will see the light of day soon.

I've long been interested in the history of helicopter development and was aware of the significance of the autogiro development in the 1920/30s. Your history article in the February 2013 RCME (also bought over ebay) covers it very well. It's for this reason I decided to have a go, as a new project, at a stand-off scale Cierva C30A from scratch with a 6 ft rotor. I have much background material from when I used to do talks and demos locally on the subject. This includes stuff relating to Hafner's work as well as Cierva's. Maybe we'll even get round to jumping take-off?

I hope this explains why, when I decided to order a Panther plan, I had no awareness of the background material you refer too. I was busy doing other things. And I guess this will apply more and more as time passes and other modellers decide to have a go at something new. The club members who witnessed my flight yesterday were "tickled pink" with the "swooshing" noise Panther made and perhaps now someone else in the club will have a go?

The only pics I have were taken indoors but when I've some taken outdoors and mastered how to attach them to a reply I'll send you something. My Facebook page has a couple of pics.

Don

 

Edited By don cardy on 06/01/2017 20:10:20

[don cardy]

Hi Rich,

At last some pictures taken outside. This first one now includes a pre-rotation system based on one obtained from the far-east which I had fitted to my ARF model before its early demise and which then provided the mechanical parts for Panther. Thus this Panther uses the main motor (a prop adapter was needed), the servos and push-rods, the wheels, the gymbal control arms (as axles for the under-carriage), and the LiPo from the crash site. It was after my Panther's maiden flight that I decided to fit the pre-rotation system. My club's take-off and landing area is virtually square and works well for fixed wing and helicopter model but in calm weather the available length of take-off run seemed very marginal on my Panther's maiden flight. My pre-rotation system has been re-engineered to use the bearings, main shaft (cut-down), main gear and one-way bearing from a mini-Titan helicopter. The bearing block is made from four pieces of MDF glued together rather like your head-set system, and then turned on a small lathe to tidy it up and house the ball races. A long 2mm pin (instead of bolt) acts to link the one-way bearing sleeve with the main shaft and with the triangular rotor plate. The design is quite compact with the rotor plate being only about 5mm higher than on the original head-set with plain bearings.

Don

[don cardy]

To additional pictures.

The first is a close-up of the Panther's pre-rotation system; the second has my NOTAR helicopter in the background. This project has occupied me for the last two years and has fully working Coanda-slots in the EDF powered tailboom. Panther and what follows are expected to provide new challenges.

Don

[BILL PETTIT]

Oh baby Don I am so looking forward to seeing a short video of the rotor in action, I have been struggling with my version. Your panther looks AWSOME! Bill

[Richard Harris]

I will second that , it's a Sterling job Don

Your spindle and pre-rotator look to be well thought out, do you know the ratio between the gears and the KV of the motor?

Though not my thing the helicopter looks like it has raised some interesting engineering challenges, interestingly I have found that the majority of gyronuts have a fixed wing background.

It would be interesting to know your thoughts on how flying your Panther compares to your helicopters?

It does need someone in the office mind

Rich

[don cardy]

Rich,

The motor for the pre-rotator is 820KV, the pinion is 12T and the main gear 150T. The motor is really only for 2 or 3 cells and I'm running the Panther on 4 cells so have to keep the power to the pre-rotator turned down a bit. I ran the pre-rotator up with Panther sitting on the bed in our spare bedroom a couple of days ago and at half throttle on the TX slider control it was running smoothly at 500 rpm according to my tachometer. This seemed quite good to me as one of the contributors to this thread had, I think, measured about 700 rpm using a data logger in flight. Clearly a bit more throttle on the TX would probably have got to 700 rpm, but not indoors!

Now I hadn't done the calculation before but if we say that half throttle is equivalent to 2 cells then the formula, ignoring any efficiency factors, gives 2 cells x 3.7 v x 820 KV x 12 T / 150T = 485 rpm. Wow, what a surprise when theory works out as close as that!

I took Panther out this morning. There was hardly any wind. I first flew my small Stearman biplane and its take off run on our grass strip, muddy with worm casts, was at least 10 metres. I then switched to Panther and ran the rotor up using the prerotator, probably to a bit beyond 500 rpm. Leaving the rotor at its neutral pitch position (+ 6 degrees), I shut down the pre-rotator and at the same time gently opened up the main motor. The take off run was less than for the Stearman , I'd say 6 or 7 metres. and Panther climbed gently away. I completed several LH circuits and then noticed at the end of an up-wind leg that the aileron control was getting sluggish. I decided it was time to land but half-way down the down wind leg couldn't prevent Panther spiraling in. Damage wasn't that bad, one broken rotor blade; the pre-rotator had a very slightly bent shaft which I have since straightened (helicopter experience) so it's prefect again; and the main motor, firewall and cowling ripped out of the fuselage. Nothing else. I shall now repair the front with a longer bay for the battery etc, and a shorter motor compartment. I'm also swapping the servos for new ones whose spec I know and replacing the ESC / BEC too.

Reminds me of my early days with Morley helicopters when I had to teach myself to fly and had to put the tail boom back together nearly every week. I also had to make rotor blades too!

Will keep you posted about how it compares with helicopters.

Don