Andy Stephenson Posted July 13 Share Posted July 13 I am shortening the nose on my Dave Smith Models Joker 60 to get the balance right and I have lost the original instructions. I tried to cut a precise amount from the front but I can't be certain how accurate this is. Is there any info on the engine thrust line on this model or the original Matt design. The only data I can find online is for the Joker 25 which has 1.5° downthrust and 2°sidethrust but it also shows 0.5°wing incidence which I believe should be zero on the 60 size so it may not translate. Does anyone have this info to hand. Thanks, Andy. Quote Link to comment Share on other sites More sharing options...
Nigel Sharp Posted August 8 Share Posted August 8 There's a poor scan of Joker 60 by Wolfgang Matt on outerzone looks to show thrust line. https://outerzone.co.uk/plan_details.asp?ID=9572 Is that the correct aircraft? Quote Link to comment Share on other sites More sharing options...
kc Posted August 8 Share Posted August 8 That outerzone plan for the 60 has the thrustline specified as 2 degrees down, while the sidethrust is not specified but the engine mounts appear to have a lot of sidethrust. Seems about 2.5 degrees measured on the screen. You could always print out just the engine mount section from Outerzone and measure the sidethrust exactly, but I suppose it's normal to adjust that to suit the engine if overpowering with a larger engine. The wing and tailplane are both specified as zero on the 60 plan. Quote Link to comment Share on other sites More sharing options...
Nigel Sharp Posted August 8 Share Posted August 8 (edited) I can make out 3 deg right thrust on the drawing but it is very difficult to read. Edited August 8 by Nigel Sharp added screen shot image Quote Link to comment Share on other sites More sharing options...
Andy Stephenson Posted August 8 Author Share Posted August 8 3° seems like an excessive amount of side-thrust but it depends on the prop pitch and revs. Quote Link to comment Share on other sites More sharing options...
john stones 1 - Moderator Posted August 8 Share Posted August 8 3 degrees looks a good starting point to me, flying it will determine end numbers anyway. Quote Link to comment Share on other sites More sharing options...
Nigel R Posted August 9 Share Posted August 9 17 hours ago, Andy Stephenson said: 3° seems like an excessive amount of side-thrust but it depends on the prop pitch and revs. Given the Joker's era, Matt probably expected to use a 12x12 prop? Quote Link to comment Share on other sites More sharing options...
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