Edgeflyer Posted October 8, 2022 Share Posted October 8, 2022 Does anyone recognise this elderly gull winged slope soarer? I've refurbished it and put separate aileron servos. All moving tailplane. Thinking of setting up elevons as well as the tailplane. Quote Link to comment Share on other sites More sharing options...
Trevor Posted October 8, 2022 Share Posted October 8, 2022 That is a modified version of my Black Diamond. Details here: https://www.bartonhewsons.uk/home/modelflying/soarers/dreview.htm plans are still available via the X List 😇 Trevor Quote Link to comment Share on other sites More sharing options...
Edgeflyer Posted October 8, 2022 Author Share Posted October 8, 2022 Thanks Trevor. Pretty surprising to get a response from the designer! I really like this unusual model and hope it will fly as well as it looks. It came to me in a job lot and was in a bit of a sorry state. It sat in the workshop for 2years and every time I looked at it Ok thought "Hmm must get round to getting you flying again ". I wonder how many of these got built and is the modification of the fin and moving tail common? Where do you think the cg should be? I have had other flying wings for slope soaring such as Alan Head's designs and tended to dispense with fins or wing tip stabilisers with no adverse effects. Quote Link to comment Share on other sites More sharing options...
Trevor Posted October 8, 2022 Share Posted October 8, 2022 Hello Phil. I don’t imagine too many Black Diamonds were built, but who knows? I’ve never seen that tail mod before and would be interested to hear the reasoning behind it. My prototype has just changed hands for the second time and I believe is now undergoing a substantial refurb so isn’t available to check the cg. I’d suggest using one of the online cg calculators but, if you’re stuck, I could venture into the archives and try to dig out the plan. Unless, of course, anyone else has a plan to hand😇 https://www.sarikhobbies.com/product/rc1661-black-diamond/ Quote Link to comment Share on other sites More sharing options...
Stephen Jones Posted October 8, 2022 Share Posted October 8, 2022 What are the chances of that. And it flies a treat too. This Lidl build was inspired by the Black Diamond. Steve Quote Link to comment Share on other sites More sharing options...
Trevor Posted October 9, 2022 Share Posted October 9, 2022 I'm astonished, amused, delighted and flattered!! Maybe seeing that version flying so well might encourage Phil to restore the original diamond tail configuration 😇 1 Quote Link to comment Share on other sites More sharing options...
Stephen Jones Posted October 9, 2022 Share Posted October 9, 2022 1 hour ago, Trevor said: I'm astonished, amused, delighted and flattered!! Maybe seeing that version flying so well might encourage Phil to restore the original diamond tail configuration 😇 Well TBH I am also amazed how well it flies it only weigh's 215g yet it can cope with strong winds and picks up speed very well. Although it can lose that speed if turned too quickly also it does not like flying upside down. It does loops very well, and can do tight tuns it also recovers very well I am also only using elevons for control. But then again this does not share the same wing lay out as your Black Diamond. How well does the Black Diamond compare.? Steve. Quote Link to comment Share on other sites More sharing options...
Stephen Jones Posted October 9, 2022 Share Posted October 9, 2022 21 hours ago, Phil B said: Does anyone recognise this elderly gull winged slope soarer? I've refurbished it and put separate aileron servos. All moving tailplane. Thinking of setting up elevons as well as the tailplane. Looks Great would love to see or hear how well it flies. Steve. Quote Link to comment Share on other sites More sharing options...
Trevor Posted October 10, 2022 Share Posted October 10, 2022 Steve, The Black Diamond performs very similarly to your Lidl adaptation (or should that be the other way round?!). I'm interested that elevon-only control works so well. One of the reasons for the tailplane shape on the prototype was to try to increase the tail moment and hence the elevator authority (Chas Gardiner achieved this with his Obelix by extending the chord of the wing's centre section). Based on your experience, I suspect the tail could probably be dispensed with entirely - but it wouldn't be diamond shaped anymore then! 1 Quote Link to comment Share on other sites More sharing options...
Stephen Jones Posted October 11, 2022 Share Posted October 11, 2022 On 10/10/2022 at 07:53, Trevor said: Steve, The Black Diamond performs very similarly to your Lidl adaptation (or should that be the other way round?!). I'm interested that elevon-only control works so well. One of the reasons for the tailplane shape on the prototype was to try to increase the tail moment and hence the elevator authority (Chas Gardiner achieved this with his Obelix by extending the chord of the wing's centre section). Based on your experience, I suspect the tail could probably be dispensed with entirely - but it wouldn't be diamond shaped anymore then! Hi Trevor, I think i would like to do some redesign work on this model as I do like the look of it, but would prefer it to fly faster and also fly well inverted. That would then be a nice all-rounder good looks and a performance to match. it would also be easy for me to remove the tail-plane and see how it flies as a pure gull wing model as I still have my prototype foam build. Steve 1 Quote Link to comment Share on other sites More sharing options...
MattyB Posted October 12, 2022 Share Posted October 12, 2022 (edited) 13 hours ago, Stephen Jones said: Hi Trevor, I think i would like to do some redesign work on this model as I do like the look of it, but would prefer it to fly faster and also fly well inverted. That would then be a nice all-rounder good looks and a performance to match. it would also be easy for me to remove the tail-plane and see how it flies as a pure gull wing model as I still have my prototype foam build. Steve If you want to remove the tail and improve the performance you are essentially going to need an entirely new model since you've effectively created a plank flying wing! If you do go that route do some research into the PW (Peter Wick) aerofoils - they have been optimised and extensively tested in slope planks and are difficult to beat in terms of the balance of outright speed and turn performance. https://www.rcgroups.com/forums/showthread.php?387891-PW-airfoils Edited October 12, 2022 by MattyB 1 Quote Link to comment Share on other sites More sharing options...
Stephen Jones Posted October 12, 2022 Share Posted October 12, 2022 I have a few ideas to play with, the aerofoil was going to be the 1st change from the start. Thanks MattyB for the link. I will have a look at those. 👍 Steve. Quote Link to comment Share on other sites More sharing options...
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