Shaun Walsh Posted October 10, 2020 Share Posted October 10, 2020 I was looking for something aerobatic to build during the autumn, the criteria were: Uses a 3s 3000 battery Low wing Aerobatic (sport not competition) Built up balsa construction. Kit or short kit, as don't have the patience to cut out ribs and formers. After a bit of searching I ordered the Loaded Dice 30 EP from Sarik Hobbies which seemed to fit the bill nicely. I ordered the short kit comprising plan, canopy and laser cut parts which arrived less than 2 weeks from order. Initial inspection revealed a nicely printed plan with outlines for all the laser cut parts which will be useful if repairs are ever needed and details of the materials needed that were not supplied, namely sheet, strip and block balsa, spruce spars, undercarriage wire, wheels etc. The quality of the laser cut balsa and ply parts looks good as does the (large) canopy.. The only minor improvement would have been to add somewhere a list of the materials needed just for convenience. Also included is a photocopy of the magazine article detailing the build process, a nice touch. Sarik don't offer an additional wood pack so it was off to Steve Webb's with my list. At this point I would like to thank the staff member who served me and appears to have selected the grades of balsa I requested and took a good 30 mins at the back of the shop picking the wood for me as customers are not allowed beyond the front section of the shop for Covid related reasons. Total cost was £70 including wire and wheels as my existing supply of balsa is minimal so I had to buy everything required. The motor recommended on the Sarik site is an Aeolin C3542 1450KV 850W. Now if the 850W means 850 watts then I think that's a bit generous in a model that should have an AUW of 1.5Kg! I have asked George at 4-Max for a recommendation and I think it may well be a PO-3541-1270 which should give about 130-150 W/Lb.. I shall post more (and pictures) as and when construction progresses but it will probably be protracted and sporadic. Quote Link to comment Share on other sites More sharing options...
Shaun Walsh Posted October 15, 2020 Author Share Posted October 15, 2020 The recommendations from George were: Motor PO-3541-1070, 11x6 prop, 40A ESC, 3s battery. Static thrust approx. 4.5 Lbs, Approx. max speed 47 MPH Motor PO-3547-960, 12x7 prop, 40A ESC, 3s battery Static thrust approx.4.4Lbs, approx. max speed 48MPH I opted for the 3541-1070.as I have this in a Riot with a 50 ESC and a 12x6 prop and the performance is excellent. Also, there is no COG marked on the plan and no mention in the printed magazine article so I put the dimensions into cgCalc and it gave a suggested range of 16.0-17.5cm from the LE. Measuring this on the plan shows a line drawn with no annotation at 17cm from the LE so I am guessing that this represents the recommended COG. Edited By Shaun Walsh on 15/10/2020 11:52:32 Edited By Shaun Walsh on 15/10/2020 11:53:23 Edited By Shaun Walsh on 15/10/2020 11:54:19 Edited By Shaun Walsh on 15/10/2020 11:54:44 Edited By Shaun Walsh on 15/10/2020 11:56:58 Quote Link to comment Share on other sites More sharing options...
Paul C. Posted October 15, 2020 Share Posted October 15, 2020 I am sure that I have the c of g listed on the plan I have, will dig it out and check for you . Quote Link to comment Share on other sites More sharing options...
Paul C. Posted October 15, 2020 Share Posted October 15, 2020 Found my plan and magazine article, I have written on the plan 4 and a half inches to 5 and three quarter inches from the leading edge ( 115 - 146 mm ) . Unfortunately I can't remember where I got the info from but I am pretty sure it originated from Terry himself on this forum, mine ballances close to the max any goes well . Use this as a starting point I would not recommend starting any further back. Hope this helps, Paul. Quote Link to comment Share on other sites More sharing options...
Shaun Walsh Posted October 15, 2020 Author Share Posted October 15, 2020 Hi Paul Many thanks for that I shall note it on the plan. Shaun Quote Link to comment Share on other sites More sharing options...
kc Posted October 15, 2020 Share Posted October 15, 2020 The leading edge is tapered isn't it? So Paul's measurement may be at fuselage sides and that could be near or same as 160 to 175 at the mid point of wing. Could be worth re- calculating using formula for tapered wing in various books. Also check for double taper - maybe TE is also tapered as it is in the larger Loaded Dice ( that plan is on Outerzone and shows CG position for that version ) Quote Link to comment Share on other sites More sharing options...
Shaun Walsh Posted October 15, 2020 Author Share Posted October 15, 2020 Posted by kc on 15/10/2020 14:13:17: The leading edge is tapered isn't it? So Paul's measurement may be at fuselage sides and that could be near or same as 160 to 175 at the mid point of wing. Could be worth re- calculating using formula for tapered wing in various books. Also check for double taper - maybe TE is also tapered as it is in the larger Loaded Dice ( that plan is on Outerzone and shows CG position for that version ) The leading edge is swept back and the trailing edge is perpendicular to the fuselage centre line. However, the wing sweep starts at the wing/fuselage junction so it should not make a difference to the COG measurement. Quote Link to comment Share on other sites More sharing options...
Paul C. Posted October 15, 2020 Share Posted October 15, 2020 Yes I measured on the fus sides and used the c of g stickers to mark the for and aft measures, I think the first flight was about the mid point then moved the battery back to where I felt comfortable with how it performed, not flown mine for a while now though I am a bit of a ic guy 😂 Quote Link to comment Share on other sites More sharing options...
Shaun Walsh Posted November 2, 2020 Author Share Posted November 2, 2020 After much cogitation, the build has begun with the wings just in time for lockdown 2. Many thanks to barryt who sent me details of the wing jig which is one method described to construct the wing, however I opted for the second method which was to pin the sheet TE to the board and build off that. All rib positions were marked on the TE and sub LE prior to construction, the full ribs were glued to the TE first, then the aileron sub ribs and aileron facings. The sub LE was then glued to the front of the full ribs and the part ribs in front of the aileron were then attached. It appears to be straight! The only problem I have found so far is that the spar cut outs on rib 1 are in the wrong place, but only a few mm out so easy to fix. Haven't figured out why the spar slots in rib 3 are a bit bigger than the rest, any suggestion? Quote Link to comment Share on other sites More sharing options...
Shaun Walsh Posted November 2, 2020 Author Share Posted November 2, 2020 Also, the LE and aileron facings are tapered from root to tip, so these were cut from sheet after careful measurement. Quote Link to comment Share on other sites More sharing options...
Shaun Walsh Posted November 17, 2020 Author Share Posted November 17, 2020 Ok, an update. Wings almost complete, a few points of difference from the plan. I have added some TE section to the ailerons as I wasn’t happy that the top and bottom sheet join would be robust enough without it. I have also added TE section to the third rib bay for the same reason and to strengthen the root joint. The instructions seem to show the 4 inch LE sheeting extending beyond the main spar at the wingtip but the illustrations in the magazine article shows it cut off at the spar, I decided to follow the illustration and not the plan, the bonus is that the cut off section fills the gap in the sheeting at the root 😊. There are no details regarding the servo fitting so I constructed a box between the ribs with square section balsa to accept the servo holders (from Banggood). I will not add the top LE sheeting until the wing halves are joined and I will probably add a centre rib to support the sheeting aft of the spar. Regarding the method of joining the wing halves, it appears to rely on a 3/8ths medium hard balsa sheet in the space between the first ribs and the upper and lower spars, a support for the front wing locating dowel and the leading edge joiner. Nothing extends beyond the first rib on each side which makes me a bit nervous, normally used to a ply dihedral brace extending to the second or third rib. I will probably add a ply brace to the trailing edge and reinforce the centre brace by laminating it with some thin ply. Quote Link to comment Share on other sites More sharing options...
Paul C. Posted November 17, 2020 Share Posted November 17, 2020 Looking good Shawn, I used a ply wing joiner as well 👍 with all the sheet on the wings they are realy strong , I think Terry aways built light and only added strength where needed. Paul, Quote Link to comment Share on other sites More sharing options...
DaveB1 Posted February 3, 2021 Share Posted February 3, 2021 Here's my version, close to completion. Just planning a battery mount / tray and realised there was no CG shown, quick search here and found this thread with the info I needed - brill, thanks all for sharing. I have a spare 3548 900KV Thumper going spare that I'm planning to use with 4S. Might be a bit much as I don't want it too ballistic, but I can always throttle back. Really enjoyable simple build and I'm looking forward to taking time over covering and experimenting with a Terry style scheme as there's no hurry to get it ready with the Lockdown Quote Link to comment Share on other sites More sharing options...
DaveB1 Posted March 3, 2021 Share Posted March 3, 2021 Here we go, here's my version complete. Build no. 5 - Took an enjoyable 3 wks to build and then another 4 wks to cover ! Have to say I'm pleased with how it's come out. All with Hobbyking film. Really useful having a glass dining table to cut the film trim shapes on (don't tell !?). Built in some Nav lights for a bit of fun. Just need the field to open now 2 Quote Link to comment Share on other sites More sharing options...
extra slim Posted March 3, 2021 Share Posted March 3, 2021 Blimey Charlie, that’s a Bobby dazzler. Let us know how it flys when restrictions are lifted, or we’ll tell the boss about the glass table!! Quote Link to comment Share on other sites More sharing options...
Shaun Walsh Posted March 5, 2021 Author Share Posted March 5, 2021 Just a quick update: Not very much progress recently, the workshop/garage is cold in winter and glue doesn't set! However, I have started making the fuselage. Each side comprises 3 parts, front (top and bottom) and rear. After I had assembled each side I realised that the two sides didn't match. The right side corresponded to the plan but the left side was about 3mm longer and the rear fuselage was at a slightly different angle meaning it wasn't possible to make a square fuselage and the tailplane incidence was wrong. Contacted Sarik who said that it was possible that the rear fuselage sheet had moved during cutting and they would replace the parts. Later they emailed to say that they had recut the parts and the sides still didn't match so they would get their CAD person to sort it out. Just waiting for the outcome. Can't fault Sarik for their customer service though. I wonder how many other builders of this kit have had a problem and then worked around it without letting the supplier know. 1 Quote Link to comment Share on other sites More sharing options...
kc Posted March 5, 2021 Share Posted March 5, 2021 My first thought ( without seeing the plan ) is that the fuselage sides might be meant to be longer one side to allow the engine bulkhead to have some right thrust built in. Just a guess! Quote Link to comment Share on other sites More sharing options...
Shaun Walsh Posted March 5, 2021 Author Share Posted March 5, 2021 23 minutes ago, kc said: My first thought ( without seeing the plan ) is that the fuselage sides might be meant to be longer one side to allow the engine bulkhead to have some right thrust built in. Just a guess! If I joined the tail together level, the wing mount would be skewed and the wing would not seat correctly. Quote Link to comment Share on other sites More sharing options...
kc Posted March 5, 2021 Share Posted March 5, 2021 My comments were made because the larger 66inch Loaded Dice for a.61 glow has one fuselage side longer than the other to produce a 3 to 5 degree offset at the engine bulkhead. I thought it probable that the 30 would be similar. Quote Link to comment Share on other sites More sharing options...
Shaun Walsh Posted March 5, 2021 Author Share Posted March 5, 2021 59 minutes ago, kc said: My comments were made because the larger 66inch Loaded Dice for a.61 glow has one fuselage side longer than the other to produce a 3 to 5 degree offset at the engine bulkhead. I thought it probable that the 30 would be similar. That would work if the extra length was between the engine mount and the leading edge but in this case its between the trailing edge and the tail so the fuselage would be bent. Also the tailplane cutouts don't line up. Quote Link to comment Share on other sites More sharing options...
kc Posted March 5, 2021 Share Posted March 5, 2021 I suppose thats how they made the error - put the extra on the wrong area. You would expect they would try out the cut parts before selling or at least sell a set at a cheap price to someone who would build it and report any errors. All you need now is two sides the same to build a plane. Whichever side fits the plan must be the replacement part you need. Quote Link to comment Share on other sites More sharing options...
DaveB1 Posted March 5, 2021 Share Posted March 5, 2021 That's really odd Shaun, I built mine from the Sarik short kit too and it worked out ok. I remember fiddling around a bit to optimise the doubler and former positions and before joining the sides did the usual sighting / clamping / lining up process to get the tail straight. One side was a little longer than the other (don't remember which), but certainly not 3mm. Overall I put it down to minor inaccuracies rather than any major issue. The tailplane slotted straight in and I was delighted to find it was dead level with the wings with no tweaking required. Best of luck - hope you can sort it out Quote Link to comment Share on other sites More sharing options...
Shaun Walsh Posted March 8, 2021 Author Share Posted March 8, 2021 Received the replacement parts from Sarik on Saturday, unfortunately Royal Mail managed to break both of the replacement fuselage sides in transit. Piecing the broken parts together, they appear to now be the same length but they are both now approx. 3mm too long compared to the plan. Quote Link to comment Share on other sites More sharing options...
Andy Stephenson Posted March 8, 2021 Share Posted March 8, 2021 Don't forget that the plan would show the foreshortened fuz profile and not the developed fuz (as cut). When they have been assembled with the taper towards the tail, this should explain the difference. Quote Link to comment Share on other sites More sharing options...
Shaun Walsh Posted March 15, 2021 Author Share Posted March 15, 2021 Received a full set of replacement fuselage side parts from Sarik, packed in a cardboard box this time so undamaged. Fuselage construction underway. 1 Quote Link to comment Share on other sites More sharing options...
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