3/4 Panther build

[Erfolg]

Using simple geometry, I have concluded that the total movement of the rotor head required, is 21 degrees.

Again by simple proportion/geometry, if the servo movement is normally approx 45 degrees, then if the servo arm/attachment, is approx 1/2 the head arn length, I should get approx 22 degrees movement.

There is just one fly in the ointment and that the head does not move equally, that is 11 degrees each way. It is required to move by 7 degrees one way and 14 degrees the other. This seems to suggest a radical offset of the servo arm, to get the differential by a massive amount. which seems to indicate 45 degrees from the normal 90 degrees to the axis of the push rod.

Now all this is by doodling, with numbers. What I really, really, could do with, is feed back from others.

I can see that the Panther head, is easier to set up than the HK head, as each servo does one thing, the HK arrangement is interactive. This requires the movement of two servos to move the head on a single axis. Being a fan of KISS, the Panther design has a lot going for it.

The roll axis movement being a bit less will have to be done via the Tx, aileron setting, end point.

I could do with others thoughts and experience, particularly with the HK head.

Edited By Erfolg on 30/03/2013 16:15:20

Edited By Erfolg on 30/03/2013 16:18:07

[Erfolg]

This project has become mired by the supply chain and my lack of confidence to make a set of blades.

The supply chain side stems from my activating the HK please inform option, for C30 rotor blades. I have now noted that the blades no longer appear as spares in the C30 spares.

I have no confidence that I have the necessary knowledge or skills to manufacture a set my self.

At present I am very undecided how to positively advance the project, in the sense that the risks can be minimised.

For the moment I will complete the links to the head, the servos being in place. Yet again i have lost the sketches I made to provide the differential movements required, to achieve the head angles and lineality throughout the range. I guess if I can do it once, I should be able to figure out how to do it twice.

[ken anderson.]

well done ...... looks good erfolg....have a look at TW'S blog and RH'S ... they both describe how to make a set of blades......i was a bit reluctant at first--but once you get you head around it and have a go...you'll be churning them out....

ken anderson....ne..1 .blade dept.

[Koen Smits]

Erfolg, I don't know how good you are in reading the german language, but in the link below there is a clear description how to make and balance a set of blades

**LINK**

Koen Smits

[Erfolg]

Keon

I have read the post now. It seems everything is easier in the USA, can you really buy blades so easily?

Anyway, making the sanding jig and making a decent sanding block to match the jig cam/contours seems to be the issue.

For the moment I will hang on and hope, against hope, that HK buy another batch.

I really do now regret delaying my purchase by one day, where the stock went from 11 sets to 0, overnight.

[Malcolm - coolwind.co.uk]

Have you decided yet how big your rotors are going to be?

I guess to some extent it will depend on your finished weight.

malcolm

 

Edited By Malcolm on 01/05/2013 00:43:26

[Erfolg]

Malcolm

The 3/4 size was chosen so that the standard HK, C30 head set and rotor blades could be used.

I will have to take note of the C30 kit details to get the rotor diameter again, as I have forgotten and am pretty sure I have not noted it on my reduced size drawing/sketch. Just in case I am forced to try and make my own set.

[Malcolm - coolwind.co.uk]

Erfolg,

The C30 blades are 442mm long, 39mm chord and 4.5mm max thickness with the mounting hole 5mm in from the blade end.

Malcolm

[Erfolg]

The 3/4 Panther has been on hold for some time now.

The main reason has been my reluctance to make some blades. This reluctance has two parts, the first is my ability to produce 3 near enough identical blades. The second is having sufficient knowledge as to what makes a good blade, such details as the profile, the LE contour, the transverse position of pivot point.

There is a second complicating issue relative to the head control. I particularly like the RH mounting concept, for the servos. Which I have duly copied. I also wanted to remove another variable, in the head construction, purchasing a C20 head set to achieve this objective. Unfortunately, this set up leads to some unusual servo arm positions to achieve the head movements. Having worked out these positions and relationships, on paper, I then allowed the paper to become lost. Now I have not got a clue as to what is required. To recover the position, I will need to both look at the panther dwg and the Panther build thread, as the info is somewhere there.

The first issue of the blades has been resolved by the generosity of TH and guidance of RH and a order from HK for a few items. This interaction is a good enough reason to go to Greeacres, in itself.

Although i have just placed an order with HK (UK) I now realise I should have also ordered some clevises, as this is one of the reasons I did not make the head connectors. My only excuse is that unfamiliarity of Autogyros does not lead me to an automatic generation of a check list of bits required. Poor excuse though, as I should always carry metal clevis as a stock item.

Anyway, the project is slowly stirring into life again.

[Richard Harris]

Carl,

Nice to finally meet you the weekend , here is a link to the blades you had donated 'BLADES'

Another link is HERE to a set of 3 LA Rotor shape blades and HERE to a pair of longer LA500 blades (these would need the tip weights removing for 3 blades)

Rich

[Erfolg]

It seems it may be that it will be never in receiving my ordered Durafly blades.

I may need another change of plan with respect to the blades.

It only goes to show, that timing is everything in this world, and I certainly have  lost the knack, it would seem

Edited By Erfolg on 25/07/2013 22:02:04

[Tom Wright 2]

Keep a look out on the Crane Fly threads Erf ,suitable blades are due to me manufactured in the UK.

Tom.

[Erfolg]

Although the project has been on the back burner, it does continue to make a little progress.

So this is how it stands.

Although I have previously made a sketch of the head control rods, servo arm settings, I stupidly have lost it. So it seems i will have to read back to find the tilt angle required for the head, and the angles it needs to move through. Using the HK head has made the setting up less than straight forward with the side by side servo mounting used.

My other issue is making/procuring a new head/delta plate to replace the HK unit and to incorporate single fixing hinging.

Apart from the previous issues, I seem to have a potential CG issue, that of it being to far forward.

Apart from these minor issues, everything is going, really well.

[Malcolm - coolwind.co.uk]

Posted by Erfolg on 18/09/2013 22:49:17:

My other issue is making/procuring a new head/delta plate to replace the HK unit and to incorporate single fixing hinging.

Erfolg,

I think a standard 4" Delta with the C30 mounting is what you require, they are available readymade in my shop

Malcolm

Coolwind

[Tom Wright 2]

Looking good Erf . Those blades turn anticlockwise so looking from the rear a little left trim is a start point , the pitch trim will depend on the model's AUW as will the ability of those blades to fly the model within the trainer category . The blades are designed for an AUW of 22 - 23 ozs.

Tom.

[Erfolg]

Just outside the weight specified @ 24 oz with all sevos, Rx, motor. Minus propeller or ballast if needed.

[Tom Wright 2]

The rotor back trim at your suggested AUW would be the mast angle plus the the back trim value ,I guess the total needed would be 10 - 12 degrees as this is the value my Auto - G requires with the HK blades and neutral elevator.

You did not mention if the lipo was included in your weight prediction if this is needs to be added then I would be quite happy to ballast my model and check how the blades respond to the extra weight .

[Al - AJ Blades Ltd]

Erfolg,

more suitable blades can be found at **LINK**.They are far more durable and will carry more weight.Just look for the Crane Fly type

Alan

Edited By Just Al on 20/09/2013 22:44:43

[Erfolg]

Al

I think there will be a CG issue, using a 2200, 3s. To overcome this issue i will ballast the model, to obtain an acceptable CG, then select a Lipo based on this mass. Doing this should reduce the AUW, solve the CG issue, with the downside of duration.

It could be that the motor selected could be too heavy and powerful. Experience will hopefully point the way to improving the arrangement. It could be that the nose is too long for electric work, in that their could be wasted space where the Lipo and ESC are located, which could be improved.

It could be......................................................................

I assume that your blade observation is based on AUW?

Time will tell with all.

[Erfolg]

OMG Tom, my eyesight must be going, I have just spotted your post.

Yes the weight, does include the Lipo. The 2200 mentioned above.

I have just started to draw out the linkage requirements as I thought they have been stipulated (I think/thought) by RH. Having now completed the drawing, and taking measurements as indicated by RH, I have come to the conclusion that this gives a head movement of 16 degrees. Which is not in a different ball park, but I guess the way to go is to set up to 10 degrees, but leave 5 degrees on the travel volume of the servos, if needed.

I have just found an issue with the side by side servo arrangement using the HK head. It appears that I will introduce some roll movement when tilting the head back and forward using the servos. I was tempted to reposition the servos to eliminate the issue. For the moment I have decided to try the set up as it is, and see if it is real, rather than in my mind.

[Tom Wright 2]

The AUW prediction sounds very reasonable and I would not worry about using a smaller lipo as 2 or 3 minutes is more than enough stress on the pilot when learning to fly autogyros .

From the data you have provided the power requirement and trims should be the same as the Auto - G. 180 to 200 Watts as indicated on a wattmeter should do nicely.

Tom.

[Koen Smits]

Hi Erfolg,

I think you should rotate the HK head 90 deg. left or right and arrange 1 servo at the leftside and 1 servo at the rightside of the mast.. Mixing the servo control as V tail or Delta.

Succes.

Koen

[Erfolg]

Keon

It certainly would make setting a lot easier.

For the moment I will leave it as it is. However I suspect that I will be forced to change the arrangement to the one you suggest.

There are two reasons why I am reluctant to change, one is the work, the second is an increase in weight, the third is the body is a little to narrow to allow full throw 90 degree throw servo moment, whilst achieving the movement required, or over driving the servo travel.

[Al - AJ Blades Ltd]

Hi Erfolg

My post was based purely on your expected AUW.

May I wish you every succes with your project.

Alan