David Oatham Posted August 14, 2020 Share Posted August 14, 2020 Hi Andy, you will enjoy building your Panther I'm sure. This thread is VERY long as you will have discovered, but from my experience it's worthwhile wading through it. There are (or at least were) a few minor errors on the plan, but that is no criticism of Richards design. Regarding the top spindle, I did as was suggested and placed a 'Wanted' ad on the BMFA Classifieds and picked up one for £10. My Panther is still awaiting its' maiden flight which may take place this Sunday, weather permitting Enjoy the build !! Quote Link to comment Share on other sites More sharing options...
Bob Cotsford Posted August 14, 2020 Share Posted August 14, 2020 I was curious whether the height of the blades above the tilt pivot was critical as I was thinking an old pancake can motor from a dead Pheonix glider might be repurposed as a bearing unit with the windings and magnets removed. Quote Link to comment Share on other sites More sharing options...
Richard Harris Posted August 14, 2020 Author Share Posted August 14, 2020 Andy, I have put an add on this forum for gearboxes in the past with fruitful results, Astro or Irvine units are the cream if you can get one. If you have no luck I can machine a spindle up for you but would have to get the materials needed first? Bob, Your right in your thinking, the further the blades are from the head pivot the more load is exerted on to the control mechanisms. An old brushless motor works fine as I have tried it on smaller models, with the Panther I would say you would need one with at least a 5mm shaft if using a standard prop driver. I say that as I once had a 4mm shaft shear in flight, probably down to an poor balanced set of blades Rich Quote Link to comment Share on other sites More sharing options...
Bob Cotsford Posted August 14, 2020 Share Posted August 14, 2020 Cheers Rich, that's another project lined up then. Quote Link to comment Share on other sites More sharing options...
Andy J Posted August 15, 2020 Share Posted August 15, 2020 Posted by Richard Harris on 14/08/2020 22:19:20: Andy, I have put an add on this forum for gearboxes in the past with fruitful results, Astro or Irvine units are the cream if you can get one. If you have no luck I can machine a spindle up for you but would have to get the materials needed first? Bob, Your right in your thinking, the further the blades are from the head pivot the more load is exerted on to the control mechanisms. An old brushless motor works fine as I have tried it on smaller models, with the Panther I would say you would need one with at least a 5mm shaft if using a standard prop driver. I say that as I once had a 4mm shaft shear in flight, probably down to an poor balanced set of blades Rich Richard Thanks very much for the offer. Need to look first through my old motor box to see what could salvaged to make a head. Think I have an old dc motor with a gearbox, so its just a matter of locating it. Quote Link to comment Share on other sites More sharing options...
Big T Posted August 15, 2020 Share Posted August 15, 2020 Posted by Bob Cotsford on 14/08/2020 18:56:46: I was curious whether the height of the blades above the tilt pivot was critical as I was thinking an old pancake can motor from a dead Pheonix glider might be repurposed as a bearing unit with the windings and magnets removed. I have done the same. As long as the blades clear the tail fin when the rotor is tilted back to the max for spin up it will be OK. Quote Link to comment Share on other sites More sharing options...
Andy J Posted August 17, 2020 Share Posted August 17, 2020 Found an old gearbox in my motor spares box which has a 3.8mm shaft. Am I correct in assuming this is not suitable for a panther? Quote Link to comment Share on other sites More sharing options...
Richard Harris Posted August 17, 2020 Author Share Posted August 17, 2020 Andy, I had a similar gearbox fitted to one of my first autogyros, it flew well for a few weeks but always had a wobbly UC. This was caused because of an inbalance in the rotor disc that I was going to get round to fix. One day the 4mm shaft fractured, as you can guess the fuselage was like a lawn dart and the blades floated to a soft touch down. The model was repaired with an Astro box fitted, the blades were balanced properly and I had many safe flights there after. Ever since then I have been meticulous in the balancing of all my blades as I'm 99% this was the cause of the failure and any model around this size uses at least a 5-6mm spindle. I have found the photos I took at the time, the model before it happened, the shaft failure and front end damage. In a nut shell, if it were me I wouldnt use it on the Panther. Of course I could have had a substandard shaft but I will never know. Rich Edited By Richard Harris on 17/08/2020 23:08:23 Quote Link to comment Share on other sites More sharing options...
Andy J Posted August 18, 2020 Share Posted August 18, 2020 Having read the thread I did suspect that this would be the answer Richard. Will return it to the scrap box as I can see there would be insufficient metal to drill it out to let in a 10mm flanged bearing. Now thinking a combination of your solid ply base design with a fixed 5mm shaft extracted say from a 450 or 500 helicopter, topped off with a Coolwind Models C30 Razer, 5mm bearing assembly is the way to go. Whilst contemplating, will dig out my old Atom which I never got flying, but think there will be damage to be repaired first before any attempt at flying can be done. Just got halfway through the Atom thread to see what I did wrong. One thing I do like from your pictures above is the elastic band preventing the undercarriage legs from deforming too far under crash or heavy landings. Quote Link to comment Share on other sites More sharing options...
Andy J Posted September 4, 2020 Share Posted September 4, 2020 Fiberglass sheet arrived from the far-east today but a quick measurement shows it to be 1.7mm against the 1.5mm specified. Is this going to matter for the blade plate? Decent gearbox has also been sourced for the rotor head, so just waiting now for the laser cut parts to arrive from Sarik before I can start building. Quote Link to comment Share on other sites More sharing options...
Andy J Posted September 24, 2020 Share Posted September 24, 2020 Made a start on constructing the mast and head now that the parts have arrived from Sarik. Well impressed with the quality of the cut parts. Concerned that my 20mm plastic hinges I have available for use on the lateral head tilt don't appear to be very strong so wondered if anybody replaced these with a dolls house style metal hinge. Quote Link to comment Share on other sites More sharing options...
Michael Pirie Posted October 1, 2020 Share Posted October 1, 2020 Good idea to use metal hinges. I've replaced my plastic ones at least three times! Quote Link to comment Share on other sites More sharing options...
Andy J Posted October 1, 2020 Share Posted October 1, 2020 Well unfortunately could not find a suitable metal hinge Michael, so lashed out on some rather expensive Du-Bro heavy duty hinges. Given these are rather thin, packed out the gap with two shims of 0.4mm epoxy sheet. Also ran some 0.4mm epoxy sheet on the inside of the mast head bearing plates given the ply as supplied by Sarik was a tadge under size to the mast doublers. So the head now sits in a low friction sleeve rather than ply to ply. Anyway the mast build has progressed very quickly, but can't complete the fuselage as don't currently have any 3mm sheet for the sides, so that will be another trip to my local hobby store. Will go armed with my micro scales to also purchase the wood for the blades. Assuming most people split a 4 inch sheet to form 2 blades rather than purchasing 3 sheets of 3inch. Quote Link to comment Share on other sites More sharing options...
Richard Harris Posted October 2, 2020 Author Share Posted October 2, 2020 I've used the plastic hinges for many years as it creates a break point in an 'event' which generally means less damage to the mast and fuselage. The tricky bit is trying to dig the hinges out but it is quite doable. Rich Quote Link to comment Share on other sites More sharing options...
Andy J Posted October 10, 2020 Share Posted October 10, 2020 Looking for a suitable source of metal for the undercarriage. Any recommendations? Also is anyone selling an engine cowl and canopy for the Panther. Fuselage is now 50% complete having got to the point of installing the turtle decking 3mm balsa which is currently sitting wrapped around a wine bottle overnight having been first soaked in ammonia. Sure water would have also worked but ammonia softens the balsa far better. Quote Link to comment Share on other sites More sharing options...
David Oatham Posted October 10, 2020 Share Posted October 10, 2020 Hi Andy, the only place I found for the dual u/c when I got to your stage of the Panther build was DB SPORT AND SCALE. They were very helpful. Best of luck with your Panther, one day I'll get around to flying mine, but it always seems too windy lol. Dave Quote Link to comment Share on other sites More sharing options...
Trevor Posted October 10, 2020 Share Posted October 10, 2020 I used a commercial wire undercarriage, possibly this one: **LINK** Trevor Quote Link to comment Share on other sites More sharing options...
Trevor Posted October 10, 2020 Share Posted October 10, 2020 I used a commercial wire undercarriage, possibly this one: **LINK** Trevor Quote Link to comment Share on other sites More sharing options...
Carlos Rodrigues Posted October 17, 2020 Share Posted October 17, 2020 Hi, Where can i find the Panther plans? I am building a Revolver II from Richard and would like to build this cool Panther. Carlos Quote Link to comment Share on other sites More sharing options...
Andy J Posted October 17, 2020 Share Posted October 17, 2020 I acquired a plan on ebay by searching for the RCM&E magazine dated March 2013. Cost was just short of £5. Believe Sarik also still do the plan but at a far higher price. Cut parts from Sarik are very good quality and well worth the money. Quote Link to comment Share on other sites More sharing options...
Michael Pirie Posted October 17, 2020 Share Posted October 17, 2020 Plan from Sarik Hobbies, cost £16.50 Quote Link to comment Share on other sites More sharing options...
Carlos Rodrigues Posted October 17, 2020 Share Posted October 17, 2020 The main problem is that I live in brazil and postages are too high. I was trying to buy a downloadable version. Quote Link to comment Share on other sites More sharing options...
Richard Harris Posted October 18, 2020 Author Share Posted October 18, 2020 Carlos, I have just searched ebay and have found THIS, worth sending them a message to see if they would post to Brazil? Failing that its SARIK as they own the rights to RCM&E plans I believe, I very much doubt they would send digital plans though as its their bread and butter. You could also put a wanted add on this site, its free to do so. Rich Quote Link to comment Share on other sites More sharing options...
Bob Bertram Posted October 19, 2020 Share Posted October 19, 2020 Hi Carlos, PM me with your address, I may have a spare in my store. Bob Quote Link to comment Share on other sites More sharing options...
Bob Bertram Posted October 19, 2020 Share Posted October 19, 2020 Hi Carlos, check your in box. Bob Quote Link to comment Share on other sites More sharing options...
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