Richard Harris Posted February 14, 2013 Author Share Posted February 14, 2013 Yes a brass tube works well, but I did leave it off the finished model as I had a thought that some builders may well still be using 35mhz and metal to metal joints can cause interference. I have been pondering the lower battery position over the last few days and think it may well lower the CG positoin, this may upset the stated set up. I am not 100% sure of this and will have to test the set up myself, my gut instinct tells me that the pitch may become sensitive. What we have to remember is that the downthrust of the motor is set to 6 degrees for a reason and that is so that the thrustline passes above the CG position to keep the nose down. Alter this position and may well have an effect. I did however extend the blade length by 20mm to that of the prototype to compensate and give a little more tolerance. I will get back on this one, need to get my model back as those Ashers have it still!! Rich Edited By Richard Harris on 14/02/2013 22:18:10 Quote Link to comment Share on other sites More sharing options...
Stephen F Posted February 14, 2013 Share Posted February 14, 2013 Malcolm . I see what you mean alot simpler and easier to cut more accuate, I've already made mine but will remember if I build another. RActive. The head bearing unit can be any shape you fancy, Heres a photo of one I made earlier for a twin rotor gyro based on a Focke Achgelis FA61 1930s German helicopter ( should of done a build blog) The Bearings are model car wheel bearings from LMS or from Model Fixings .co.uk for this unit they are 5mm id: 11mm od: 4mm d. The prop adapter was 4mm but tapped out to 5mm to fit the 5mm threaded shaft the grub screws add belt and braces. Hope this is useful if you want a drawing let me know. Regards Stephen Edited By Stephen F on 14/02/2013 22:29:06 Edited By Stephen F on 14/02/2013 22:33:08 Quote Link to comment Share on other sites More sharing options...
Stephen F Posted February 15, 2013 Share Posted February 15, 2013 Richard, on the plan the motor thrust line is 22mm below the indicated CG position not above as stated in your last post, I am a bit confused.If lowering the battery lowers the CG position the all you need to do is decrease the motor down thrust.Is this correct. Regards Stephen Quote Link to comment Share on other sites More sharing options...
Richard Harris Posted February 15, 2013 Author Share Posted February 15, 2013 Stephen, The mark shown on the plan is infact it's balance point horizontally and not its true 3 dimensional CG , this true CG position can alter from one model to another depending on a lot of things. This was taken into consideration when designing and the reason for the 'built in' down thrust. Your thinking is correct regarding reducing the down thrust to compensate but lowering the CG can, in some circumstances bring the vertical thrustline of the rotor a bit too close for comfort when it is tilted rearwards. I have tested the Panther really hard over 12 months or so, different blade configurations, power plants, props, thrustlines, electrics etc....the one thing I haven't tested and didn't even think about was lowering the CG by moving the battery downwards. It will most probably be absolutely fine and I am more than likely worrying about nothing! I would just like to know for certain before anyone commits to flight. Rich Quote Link to comment Share on other sites More sharing options...
Stephen F Posted February 15, 2013 Share Posted February 15, 2013 Richard, thanks for the information all is now clear. There is a big yellow thing in the sky today so I am putting down the tools and heading for the flying field. Cheers Stephen Quote Link to comment Share on other sites More sharing options...
Big T Posted February 15, 2013 Share Posted February 15, 2013 Posted by Richard Harris on 13/02/2013 15:55:25: BigT, Mixing opposite roll with rudder is something I wouldn't recommend for someone who is starting out. Take for instance...the model is on it's take off run and starts turning to the left, instinct is to apply right rudder. With the mix suggested this would add left roll and would almost certainly roll the model over, more so if the rotors weren't up to auto rotational speed. It is just better I think to have a model that is trimmed true rather than compensating with mix functions. Yes Rich I agree it could cause a problem, I have my mix switchable so I can have it on when in the air and off when taking off or landing. It's just something I used to do on big prop warbirds and scale airobats like the CAP. Now I use a heading hold gyro on the rudder. Cheating really! I agree with Rich E though, Gyro's do make you a better pilot. Quote Link to comment Share on other sites More sharing options...
Andy Nash Posted February 15, 2013 Share Posted February 15, 2013 I don't have a Lipo battery, only a 2-stroke engine up front. This must have changed the dynamics. But the long tail must have taken the problem away. she flies just great. Andy Quote Link to comment Share on other sites More sharing options...
Robert Foreman Posted February 15, 2013 Share Posted February 15, 2013 I found this in my spares box. It's a main shaft from a Thunder Tiger Mini-Titan heli. I am going to use this as the rotor spindle. It's 5mm diameter and even has a hole for the locating peg, I just need to cut it to length. I've also found on Ebay a supplier for flange bearings Quote Link to comment Share on other sites More sharing options...
Richard Harris Posted February 16, 2013 Author Share Posted February 16, 2013 Robert, Nice find should work well For those that are interested the Minature Flanged bearings I have ordered are 6mm ID x 13mm OD x 5mm thickness and there ID number is F686 ZZ. These match up to those shown on the Genesis PDF. Rich Quote Link to comment Share on other sites More sharing options...
Richard Elliot Posted February 16, 2013 Share Posted February 16, 2013 Well the sun appeared this afternoon so it had to be time for a bit of Panther Play!! Just a note for anyone thinking of going down the (proper) suck-squeeze-bang-blow route......depending upon the weight of your lump you may have to add a hatch to the underside just behind F4 to put your receiver and battery behind the mast for correct weight distribution. I also made F7 full fuz depth to complete this compartment. Cheers Rich Quote Link to comment Share on other sites More sharing options...
Malcolm - coolwind.co.uk Posted February 16, 2013 Share Posted February 16, 2013 I'm making the cowl now, not done this before so its all guesswork! I made a dummy ply ring and used this as a target help position the balsa blocks. I think the David plane and permagrit are going to be working overtime tonight I covered the back of the dummy ply ring polythene just in case any glue decided to wander. In the week I managed a bit of balsa bending as well which worked a treat soaked in warm water for about 6 hrs (I forgot about it) then dried around a wine bottle for a day or so. The soft 3mm balsa could be amost folded in half when soaked, but dried out to hold a the perfect curve for the decking Malcolm Quote Link to comment Share on other sites More sharing options...
BILL PETTIT Posted February 16, 2013 Share Posted February 16, 2013 Well I see we are all getting an education on this forum , great idea Malcom is that bottle full or empty ? Also nice bit of flying Richard, looked like a great day to get a flight or 2 under your belt. Wating for the return of Spring here. Bill Quote Link to comment Share on other sites More sharing options...
Malcolm - coolwind.co.uk Posted February 16, 2013 Share Posted February 16, 2013 Bill, The bottles are full when you start and empty by the time you've finished. 3 is a good number! Malcolm Quote Link to comment Share on other sites More sharing options...
Richard Harris Posted February 16, 2013 Author Share Posted February 16, 2013 Nice flying Rich Malcolm, I do like the bottle idea, simple but clever I will be trying that next time. Rich Quote Link to comment Share on other sites More sharing options...
Myron Beaumont Posted February 16, 2013 Share Posted February 16, 2013 How many bottles did you have to empty before deciding on the one fit for the job ? (could save me time/money /enjoyment) Our new mod could probably advise --A wine bottle no doubt . Edited By Myron Beaumont on 16/02/2013 19:59:54 Quote Link to comment Share on other sites More sharing options...
Pete B Posted February 16, 2013 Share Posted February 16, 2013 Well, having just enjoyed a bottle of Jurancon with some ricotta and cinnamon pancakes, I would recommend one of those Thanks for posting that, Malcolm. I haven't had the pleasure of forming 3mm balsa before, so I shall use that method when I reach the decking - still at the tail end this evening! Pete Quote Link to comment Share on other sites More sharing options...
Malcolm - coolwind.co.uk Posted February 16, 2013 Share Posted February 16, 2013 Pete, I havent got a photo of how I did the rear decking, but as you know this changes curature from the mast to the rear. The bottle of wine is fine for near the mast, I then put 2" cardboard postal tube over the neck of the bottle for the narrower section and banded the balsa around this as well, the unsupported bit between the bottle and the tube just needed a wrap of masking tape to stop it bowing out. Note that the kitchen paper towel against the bottle is important, otherwise the balsa just doesnt dry where it contacts the glass, needs the towel to wick the water away to evaporate Not sure i've explained that well, Malcolm Quote Link to comment Share on other sites More sharing options...
Pete B Posted February 16, 2013 Share Posted February 16, 2013 No, that's quite clear, Malcolm, thanks. On the decking between F4 and F9 I was planning to do it it 2 pieces, as RH suggests, but I'd make a card template to gauge the narrowing and possibly kerf the underside of the sheeting if the radius is tight. I'll give your method a try....... Pete Quote Link to comment Share on other sites More sharing options...
Terry Whiting 1 Posted February 17, 2013 Share Posted February 17, 2013 Rich, I noticed in balance your model had one blade directly pointing to the fin, is this the normal procedure? Terry Quote Link to comment Share on other sites More sharing options...
Richard Harris Posted February 17, 2013 Author Share Posted February 17, 2013 Pete, When doing my decking I applied one side and overlapped the top centre line by 10mm or so, then using a straight edge and a new blade in the trusty scaple cut along the centre and broke away the remaining over hang. The second piece was then applied but only glued along its bottom face to start with so that it could be moved about, its top was wrapped over the first peice and marked and cut to suit it. Then just a simple task of gluing it into its final resting place. On my second model I made a mistake and left the second piece too short, no hardship as it was easy to over come with an infill piece in the gap. Hi Terry, As long as the blades are fitted and spread roughly 120 degrees apart, this should be fine. Regarding the CG location, one idea that has been sent to me is to glue a couple of servo brass eyelets in the correct position. A piece of string or wire can then be used to suspend it, leaving your hands to move things about inside if need be. Rich Quote Link to comment Share on other sites More sharing options...
Bernie Posted February 17, 2013 Share Posted February 17, 2013 This looks a nice build .You guys seem to do things so fast and make it look so easy .I am tempted to have ago .i would like to see it fly .Have you got a vid yet? Quote Link to comment Share on other sites More sharing options...
Bernie Posted February 17, 2013 Share Posted February 17, 2013 The vid was great .I think i would go for the ic power .Although i hasten to add there is nothing wrong with electric .I just prefer ic.. Yes! thanks for that. Quote Link to comment Share on other sites More sharing options...
Richard Harris Posted February 17, 2013 Author Share Posted February 17, 2013 Bernie, Here is the prototype flying on one of it's first outings, electric powered. Seems quite a while back now! Go on, have a go Rich Quote Link to comment Share on other sites More sharing options...
Pete B Posted February 17, 2013 Share Posted February 17, 2013 Thanks Richard, I spent today nailing down the curved 6mm strip on the tail strake........ A bit of decking tomorrow..... Pete Quote Link to comment Share on other sites More sharing options...
Bernie Posted February 18, 2013 Share Posted February 18, 2013 Definitely going to build one .Really like the over all design very smart! Thanks for the vid Richard. Edited By Bernie on 18/02/2013 10:27:19 Quote Link to comment Share on other sites More sharing options...
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