Danny Fenton Posted September 18, 2014 Author Share Posted September 18, 2014 Hi Nigel, Ahhh that would be telling..... no I wont be going down the ply panel route, I enjoy making the panels too much to skip that bit I will let you guys take the lead on those Hi Ernie, a new line of models eh? ARTR, almost ready to rivet, my kinda model.... Cheers Danny Quote Link to comment Share on other sites More sharing options...
Andrew Price 2 Posted September 18, 2014 Share Posted September 18, 2014 Lurking. Quote Link to comment Share on other sites More sharing options...
Danny Fenton Posted September 24, 2014 Author Share Posted September 24, 2014 I think this is the motor I will go for, running on 6S A123 subject to tests in the garden Turnigy SK4240 Specs. Turns: 12T Voltage: 4~5S RPM/V: 620 Internal resistance: 0.017 Ohm Max Loading: 48A Max Power: 830W Shaft Dia: 5.0mm Bolt holes: 25mm Bolt thread: M3 Weight: 194g Motor Plug: Connector A suitable 60A ESC with BEC should sort the electrics. Cheers Danny Edited By Danny Fenton on 24/09/2014 11:03:44 Quote Link to comment Share on other sites More sharing options...
Tony Bennett Posted September 24, 2014 Share Posted September 24, 2014 nice. i is watching sir. Quote Link to comment Share on other sites More sharing options...
Dave Hopkin Posted September 24, 2014 Share Posted September 24, 2014 Not a sniff of balsa dust so far.. Watching with interest.... Quote Link to comment Share on other sites More sharing options...
Danny Fenton Posted October 1, 2014 Author Share Posted October 1, 2014 Well Chipmunk day is upon us so I snapped in a new No11 blade and dusted down the building board. I haven't done much balsa work for a few months so thought it would be best to start on something I could throw in the bin if I got it all Pete Tong.... So my gaze fell upon the rudder. First thing to note is that nearly every Chippy out there no matter what Mk will probably have a MkII rudder. The reason for the rudder change is something BEB has talked about lots, spin recovery. So unless you have a very rare subject you will have to make a new central core from 1/16, or do what I did and just apend a bit. 10 BA nuts bolts and washers are needed to assemble the hinges in case you hadn't already spotted that? Just for interest the 10BA's are small, but check out the 16BA's to the right!! the hinges are assembled using the blue medium threadlock, I hope its enough. So we have a rudder and we are under way at last Cheers Danny Quote Link to comment Share on other sites More sharing options...
Danny Fenton Posted October 1, 2014 Author Share Posted October 1, 2014 Slight DOH! moment, the hinges arewere not recessed enough, easily corrected Cheers Danny Quote Link to comment Share on other sites More sharing options...
Nigel Day Posted October 1, 2014 Share Posted October 1, 2014 Quick off the mark Danny! I guess that those of use who got the woodpack will not only need to follow you on the fin modification but cut longer fin ribs too? Is there a metric/21st Century equivalent to 16BA? Quote Link to comment Share on other sites More sharing options...
Danny Fenton Posted October 1, 2014 Author Share Posted October 1, 2014 Hi Nigel, all the ribs in the rudder you make yourself from sot 1/8 stock. The 1/16 core that you see in the first pic is the only part that come in the wood pack. It all just needs careful sanding to find the rudder within I suppose most will go with Solartex for the covering, of course I am tempted to go with tissue and dope Anybody used solartex rib tape over dope and tissue? does it work, and more important does it stick! I will tackle the fin next, seems logical..... Ooops sorry metric equivalent to 16BA is probable "very tiny" Cheers Danny Edited By Danny Fenton on 01/10/2014 17:52:26 Quote Link to comment Share on other sites More sharing options...
Danny Fenton Posted October 1, 2014 Author Share Posted October 1, 2014 Mmm well Nigel you are right, just found the rudder ribs while looking for the fin ribs, now how the heck have Traplet done that? They are not shown on the plans which is why I assumed they would not be cut. I can only assume they have drawn the model in 3D and extracted the rib shapes. Ah well they were very simple to do Cheers Danny Quote Link to comment Share on other sites More sharing options...
kc Posted October 1, 2014 Share Posted October 1, 2014 No equivalent to 16BA but Danny said 10 BA was used didn't he? And 10 BA is same as 1.7 by .35 ISO Fine according to Geo Thomas's book The Model Engineers Workshop Manual. Note that BA is metric dimensions ( it was the Swiss Thury system) Quote Link to comment Share on other sites More sharing options...
Eamonn Fahey Posted October 1, 2014 Share Posted October 1, 2014 Nigel, equivalent metric size to 16BA is 1.5mm. Good luck finding some. Conversion Table HERE As per kc's post 2mm is the closest metric size to 10BA. Edited By Eamonn Fahey on 01/10/2014 18:26:06 Quote Link to comment Share on other sites More sharing options...
Concorde Speedbird Posted October 1, 2014 Share Posted October 1, 2014 I will enjoy watching all these lovely Chipmunks blossom from various building boards around the country. The rudder looks superb. Flown the Hurricane yet? CS Quote Link to comment Share on other sites More sharing options...
Danny Fenton Posted October 1, 2014 Author Share Posted October 1, 2014 Not yet CS Dont worry you will know Well the discovery of the ribs made me question the rudder thickness and its wrong so its all been ripped apart and redone thats my fault for not thinking ahead. For you others the rudder ribs are too short and i think too thick. Use the fin post as a guide to get the shape of the rudder leading edge and then make ribs to fit.CheersDanny Quote Link to comment Share on other sites More sharing options...
Tony Bennett Posted October 1, 2014 Share Posted October 1, 2014 oops Danny. glad to see you are human like the rest of us. Quote Link to comment Share on other sites More sharing options...
Terry Walters Posted October 1, 2014 Share Posted October 1, 2014 Good on you Danny - nice neat job! Now you have a rudder you can 'steer' us through the rest of it. I've started the tailplane and if you are using the cut parts you need to read this. Terry Quote Link to comment Share on other sites More sharing options...
Danny Fenton Posted October 1, 2014 Author Share Posted October 1, 2014 Thanks Terry, well I have just arrived back where I was a few hours ago with a complete rudder. Put Roisin to bed and effectively built another rudder only keeping the core and the 1/4 inch block at the top. New ribs and leading edge Might have been quicker to start afresh than clean up the old parts..... Couldn't let an error like that go right from the start, hope this isn't a sign of things to come... The first one to say it looks like the previous one gets detention and lines.... panel lines... Cheers Danny Quote Link to comment Share on other sites More sharing options...
Danny Fenton Posted October 1, 2014 Author Share Posted October 1, 2014 Not sure who it was that was wanting to see the clutter that is the building bench...... well here you go it shames me to show such mess but you asked for it Tim Hoops if you are looking in cover your eyes! Cheers Danny Quote Link to comment Share on other sites More sharing options...
john stones 1 - Moderator Posted October 1, 2014 Share Posted October 1, 2014 That's a tidy rudder Danny it looks like those hinges are worth the effort. Rudder looks strong and light. John Quote Link to comment Share on other sites More sharing options...
Danny Fenton Posted October 2, 2014 Author Share Posted October 2, 2014 The hinges are really nice, worth every penny to get them cut though I could never have made them so acurately. Okay for the benfit of Dennis, I will go a bit more slowly on the finas its not straightforward. You could add building tabs to the ribs and this would be a good way to go but the fin post is curved too so this is always going to be difficult to build, bear with it and you will get there. This is perhaps where CA comes to the front its quick and if you get it wrongs its fairly easy to crack the joint and remake. I thought I would follow Dave Platts advice as Terry has done and build vertically. Dave explains in one of his videos that a skinned assembly such as a tailplane or wing does not really need jigging until the very last piece of sheet goes on. Now I have found that this is true, right up until that last sheet there is stil the ability to twist the thing a bit. The secret here is the word a bit. Yes you can still bend it but don't be so far out that you cannot get it true. Anyway I digress. I am going to build this freehand, lets see how it goes (fingers firmly crossed) I strongly suggest you wait to see how this comes out before following Firstly lay the fin post on the plan and carefully mark the rib positions. On mine the fin post was a 1/16th too tall allow for this and line up the hinge points. Rib 1 is not at 90 degrees to the fin post, make a jig from the plan as a guide. Tempoarily tack the jig to the fin post and glue rib 1 and the other ribs, use a set square to get things accurate Quote Link to comment Share on other sites More sharing options...
Danny Fenton Posted October 2, 2014 Author Share Posted October 2, 2014 Once they are all true, (remember to site along the leading edge to make sure they are in allignment in that plane too) remove the jig piece I pinned the assembly to the board, not pinned flat just pinned enough to hold it still more than straight, the next bit is going to appy quite a bit of force. chamfer the ends of the ribs to match the leading edge that comes next Lay a piece of V soft 1/4 balsa along the leading edge, keeping the one surface flat against your building board. Rock the balsa onto each rib in turn and mark the wood for width. Starting at the tip glue the leading edge to the first rib and hold till dry, then curve to the next glue etc etc. Quote Link to comment Share on other sites More sharing options...
Danny Fenton Posted October 2, 2014 Author Share Posted October 2, 2014 Until you have this. Now we have a slight snag here, the curve is stronger than the fin post and it is pulling it into a curve, we don't want this. There are a few things we could have done to avoid this, one would have been to wet the leading edge and pre bend it. Another would have been to use an free flight trick and split the wood lengthways along the curve to allow it to bend more easily. this could then be rejoined/laminated once bent. However we didn't do that so I am going to use another method. Soak the outside of the leading edge with water and clamp the fin post to a nice straight piece of wood to hold things true while the leading edge dries. If this doesn't work, I will remove the leading edge and split it lengthways and do it again. Fingers crossed and we will see in the morning See I really haven't a clue what I am doing Quote Link to comment Share on other sites More sharing options...
john stones 1 - Moderator Posted October 2, 2014 Share Posted October 2, 2014 Very helpful Danny, I will follow your method, but split the l/e strip John Quote Link to comment Share on other sites More sharing options...
Terry Walters Posted October 2, 2014 Share Posted October 2, 2014 Wow Danny - what time did you get to bed? Thanks for the pics of your bench - it does me good to see I'm in very good company! Clever the way you dealt with the bend in the fin posts -useful to know and also heads up for when we get to build that piece. Starting to move logs today so won't be at the bench until this afternoon. Terry Quote Link to comment Share on other sites More sharing options...
Danny Fenton Posted October 2, 2014 Author Share Posted October 2, 2014 Thanks Terry, yes it was a little late last night, but you know how it is The good news is the the fin post is now nice and straight, well as near as its going to get. I would suggest you laminate two strips of 1/8 to make the curve, that should be fairly straightforward and avoid the mountain I made from a molehill Cheers Danny Quote Link to comment Share on other sites More sharing options...
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