Biggles' Elder Brother - Moderator Posted February 16, 2014 Author Share Posted February 16, 2014 So, today we start by fixing on the wheels. I was going to simply use collets to hold the wheels on, but I decided the wheels looked so pretty they were worth the extra effort of doing it neatly with soldered washers. First trim the axle to length, leaving about 3mm or so sticking out when the wheel is in place and up against the back washer. To put the front washer in place we need to solder it very quickly if we are not to get the wire too hot and start melting the wheel! So that means we need to tin all the parts. We start by tinning the end of the axle. Clean the axle stub with a solvent of your choice - I use either acetone or IPA - this gets all the grease off the stuff. Next burnish the last 5mm or so of axle up to remove any oxidant layers, use a fibreglass pencil. Then wipe the axle with a clean piece of kitchen towel. Now we need a bit of a trick here to tin this end very fast - here's how. Apply heat from the iron, as soon as the wire heats apply the solder. It won't flow - it will just sit there in a blob. Fine. now remove the iron, let it cool a bit then add flux - I use a 9% acid liquid flux, now bring the iron back onto the solder blob - tshhhh! - and the solder flashes around the axle stub. Easy and very fast. We now need to tin the washer - hold it in the forceps,.. Apply the flux, then heat and finally solder. Both sides. Once that's done place the wheel on the stub and then push the washer on. Insert a piece of card behind the washer as both a spacer and to protect the wheel from the iron. Apply flux to the washer an stub. Now we need to be in and out with the iron really fast - put the iron on the joint between the washer and the stub, the instant the solder flows get the iron out of there! The result,... Nice and neat! Now, fuselage aside for a while and on with the wings - in particular making up the ailerons. This is a flat bottomed wing but aileron stock is made for symmetrical wings! So we have to re-sand the hinge side in order that it will sit flat bottomed. The easiest, and most accurate when to do this is to lay the aileron on the building board edge and use the fact that the Permagrit block is an accurate square,... Next we sand up the aileron to shape,... Mark the centreline,... Then sand the hinge side using the line as a guide to keep the curved form constant along the length and equal either side. Next we need to make two more of our homemade control horns - one for each aileron,... Now you can see that these two have slightly different profiles. I could spend time fettling them so they are identical - but it isn't necessary. The only really important things are that: a. the distance from the shoulder to the hole is exactly the same in each case. b. The position of the hole relative to the hinge is the same in each case. The rest of the shape simple doesn't matter - not worth spending time on, as long as they are not so different that they would draw attention to themselves! We now cut the slots for these in the ailerons - notice the hole on the tab in each control horn to give the epoxy a key,... This isn't glued in yet - just inserted for size - but we want the slot to be in place before we cover the aileron. Work on the wing is on-going. BEB Edited By Biggles' Elder Brother - Moderator on 16/02/2014 23:35:51 Quote Link to comment Share on other sites More sharing options...
Robin Kearney Posted February 16, 2014 Share Posted February 16, 2014 BEB, thanks for taking the time to explain the soldered washers, I've often thought a collet is a little ugly and fancied trying soldering a washer on instead, but have always lacked the confidence. What is the IPA you mention for cleaning? I'm assuming you didn't stick the end of the axle in the nearest pint of ale? r. Quote Link to comment Share on other sites More sharing options...
Stevo Posted February 16, 2014 Share Posted February 16, 2014 Yes indeed... a good 101 on soldering that washer!I use the brass tube and split pin method myself...As a degreaser I use carb cleaner.. it also jets out engines very well. Quote Link to comment Share on other sites More sharing options...
Stevo Posted February 16, 2014 Share Posted February 16, 2014 However all I now have to do it jet real ale over it... Quote Link to comment Share on other sites More sharing options...
Biggles' Elder Brother - Moderator Posted February 16, 2014 Author Share Posted February 16, 2014 No problem Robin - my pleasure. IPA is Iso-Propyl Alcohol (a bit more potent than beer!) - usually comes in a spray can - useful solvent and general cleaner. Often sold as "switch cleaner" etc. BEB Quote Link to comment Share on other sites More sharing options...
Danny Fenton Posted February 16, 2014 Share Posted February 16, 2014 Nice soldering tutorial BEB Can you let me know the 9% acid liquid flux you use? I need to get some and try your technique Cheers Danny Quote Link to comment Share on other sites More sharing options...
Plummet Posted February 16, 2014 Share Posted February 16, 2014 A couple of comments... IPA - I recommend Ilkley Brewery's Lotus IPA - but you won't find me wasting it on piano wire. Trailing edge stock. Actually, BEB, I have seen trailing edge stock that has been cut symetricaly - as an isosceles triangle - as well as cut as a right angle section. The magic here, is that if you want one the supplier will only stock the other plummet Quote Link to comment Share on other sites More sharing options...
Biggles' Elder Brother - Moderator Posted February 16, 2014 Author Share Posted February 16, 2014 Hi Danny, well I bought the stuff I have now from a model railway supply place called "C&L Finescale" a long time ago - but I believe they have recently gone out of business The bottle does have a name of the original supplier - Barrie Stevenson. So I did a quick search on that and bingo! You can get it here. I've ordered another bottle myself as I'm nearly out of it! This flux is excellent - it supports the most difficult of joints. But there is an important thing to bear in mind. It is quite an aggressive substance - obviously use with care! And most importantly you must thoroughly wash, under running water, any joint you make or residues of the flux will surely rot it away!! But it is great stuff - highly recommended and at £3 a bottle (which will last you years) good value. BEB Quote Link to comment Share on other sites More sharing options...
Danny Fenton Posted February 16, 2014 Share Posted February 16, 2014 Thanks BEB, a bottle is on its way to me too hope the shipping isn't as estimated Cheers Danny Quote Link to comment Share on other sites More sharing options...
Danny Fenton Posted February 16, 2014 Share Posted February 16, 2014 Glad to see you are as bad as me at creating identical glass board horns Quote Link to comment Share on other sites More sharing options...
Biggles' Elder Brother - Moderator Posted February 17, 2014 Author Share Posted February 17, 2014 The shipping may well be a bit on the pricey side Danny as I think they may have to use a courier. I seem to remember reading somewhere that Royal Mail won't accept corrosive substances in the ordinary post anymore. We'll see! Yes - I even traced one horn from the other and they still come out different! So I just align the shoulders together and put the two in the vice and drill the clevis pin hole in both at the same time! That way at least I know they are functionally the same - and hopefully with them being at opposite ends of the wings no one will notice they are a slightly different shape! The problem of course comes when you need two elevator horns - they're much closer together so much fettling ensues, then I usually end up making another pair because I mucked the first pair up trying to get them the same! BEB Quote Link to comment Share on other sites More sharing options...
PatMc Posted February 17, 2014 Share Posted February 17, 2014 When making horns or any identical part from epoxy board - stick the two blanks together with double sided tape, mark up, drill any holes, cut the rough shape, finish with sand paper &/or a file the seperate them. Result two identical parts - simples. If they're for a very lightweight model - make one then carefully split the epoxy board into two using a Stanley knife. Quote Link to comment Share on other sites More sharing options...
Vecchio Austriaco Posted February 17, 2014 Share Posted February 17, 2014 Be carefull with the liquid flux - as nice as it works for the soldering as bad it is for your tools. Especially during winter. The acid vapour condensates on cold metal parts such as pliers and they get rusty in no time. Why do I know it? Well I did a lot of little soldering jobs in the past - I cut 200m of zinc coated steel wire into small pieces and soldered them together again.... **LINK** VA Quote Link to comment Share on other sites More sharing options...
Biggles' Elder Brother - Moderator Posted February 22, 2014 Author Share Posted February 22, 2014 I don't do quite as much soldering as in that link VA - impressive BTW. So up to now I've been OK provided the parts themselves are given a rinse in running water afterwards. Well a very busy week, working until after midnight most nights, so nothing done since last weekend And as we'll see progress has been temporarily halted today . I've covered the ailerons, and glued the control horns in with epoxy,... Then I moved on to covering the bottom of the wing, including the aileron servo hatches, fiddly but straightforward,... And there we stopped. I have been using an old 2m roll of Antique Solartex which I had started previously for another model some time ago but only used a bit. Seeing as how the Dawn Flyer doesn't need the fuselage covering and is quite a small model I estimated that I would have enough covering to finish the job,....I estimated incorrectly! I'm about 4" short of enough to cover the upper wing surface . So I shall have to order some Solartex, BEB Quote Link to comment Share on other sites More sharing options...
Darran Posted February 22, 2014 Share Posted February 22, 2014 BEB Did you have to deepen the recess that the paddle sits in. My paddle is thicker than the recess by about 4mm so would need to take away around 2.5 mm after taking into account the addition of the 1.5mm sheeting. This seems a lot and will interfere with the bottom of F4. Also the wood supplied for the uc mounts is considerably deeper than The precut holes in the fus are at least 6mm to shallow of the single piece, the strengthened double piece will be even more. Quote Link to comment Share on other sites More sharing options...
Biggles' Elder Brother - Moderator Posted February 22, 2014 Author Share Posted February 22, 2014 Hi Darran, No I don't remember any problem with the "paddle" that fitted fine as shown here, If you find the recess is too shallow you will need to deepen it - but don't thin the paddle. But I did have to deepen the recesses for the U/C bearers as I said on page 1 of the blog about 3/4 of the way down. BEB Quote Link to comment Share on other sites More sharing options...
Darran Posted February 22, 2014 Share Posted February 22, 2014 This could be something to do with me using a new F4 cut to the plan size instead of the short cnc cut one. This might have then widen the gap between the to fus sides and would mean the edges would be higher as they slope inwards. Quote Link to comment Share on other sites More sharing options...
Biggles' Elder Brother - Moderator Posted February 23, 2014 Author Share Posted February 23, 2014 Darren - have you added the bottom sheeting yet? If not remember you need to allow for the thickness of that. OK, well I've ordered more Solartex, but obviously I'll have a wait, so I need to find something else to being getting on with. This is going to please Phil,....let's "do" the nose job! This is a sheet of litho plate,... Its rolled aluminium and its sometimes used in the printing industry - but of course its main use is in aeromodelling . Seriously if you know a printer he can get you loads of this - once its been used they just throw it away! I don't know any printers so I buy mine - this is one of 50 sheets I bought as a job lot on ebay about 4 or 5 years ago. I still have 49 of them - including the one in the photo. So this stash will probably out last me! On the other side there is usually an emulsion with a etch mask - and in this case it looks like this,... This stuff can be washed off with the use of a little solvent such as acetone. Not essential; but some adhesives dissolve it, so it can get a bit messy if you leave it in place. First step then, we cut two pieces for the sides,... Litho is quite soft and very thin so it can be cut with a strong pair of scissors. Fixing it in place is best done with a contact adhesive,... Next we cut a piece to go over the top. I used a piece of card to make a pattern for this. Now we'll want to bend this, litho isn't very stiff in the form it comes - but having been made by cold-rolling it is in a "work-hardened" state. We can restore it to its soft state by annealing it. Basically rub a bit of soap on the back face - you don't have to cover it - just sort of "scribble" on the back face with the corner of a bar of soap. The soap has no chemical role here - we will use it purely as a temperature indicator. Hold the plate in a pair of pliers or forceps, then heat the other side until the soap turns black. Then its "done". You don't have to quench it, just let it cool naturally. We want this piece to go over the top and slightly down the sides as an overlap. The part that overlaps the sides would look good I think if there was some fasteners there. So, taking a nail punch, which has a hollow tip with a sharp rim, we punch a row of indents to represent the fasteners - giving us this,... We do this along both sides,... If it curls up a bit on you, its easy enough to flatten - just place a piece of balsa over it and tap with a hammer. Form it to shape - can be done easily my hands in this softened state. Then glue in place with impact adhesive again,... Now that looks quite smart - but I thought it was a bit "plain jane". So how about a few access hatches? We just cut them out - making them different shapes and sizes - then add some "fasteners" again,... And glue them in place like this,... And this,.... Not bad. I need to just fix the very edges down with a drop of CA but I'll do that tomorrow once the impact adhesive is fully cured. BEB Quote Link to comment Share on other sites More sharing options...
David Ashby - Moderator Posted February 23, 2014 Share Posted February 23, 2014 That's looking very nice indeed Dave Quote Link to comment Share on other sites More sharing options...
Phil Winks Posted February 23, 2014 Share Posted February 23, 2014 Brrrrrrilllllliant Dave absolutely brilliant, something new to put in my arsenal of finishing methods, now where's the number of my friendly local print shop One quick question to save me trolling back through your thread, what kv motor and bty have you got in there? Edited By Phil Winks on 23/02/2014 21:44:00 Quote Link to comment Share on other sites More sharing options...
Devcon1 Posted February 23, 2014 Share Posted February 23, 2014 I like it, nice match with the prop nut... Quote Link to comment Share on other sites More sharing options...
Steve Hargreaves - Moderator Posted February 23, 2014 Share Posted February 23, 2014 Looks very good Dave....most authentic... Quote Link to comment Share on other sites More sharing options...
john stones 1 - Moderator Posted February 23, 2014 Share Posted February 23, 2014 looks the business with the domed nut as usual nice tips BEB just seen it, I agree John Edited By john stones 1 on 23/02/2014 21:59:39 Quote Link to comment Share on other sites More sharing options...
Chris Bott - Moderator Posted February 23, 2014 Share Posted February 23, 2014 Very nice "bonnet" BEB, I like it Quote Link to comment Share on other sites More sharing options...
Kevin Fairgrieve Posted February 23, 2014 Share Posted February 23, 2014 I have a domed nut to go on mine. Not as shiny as BEB`s though. Kev Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.