Europa #435 G-RODO Build Journal - 2008 11

index sitemap advanced
search engine by freefind
tickgo to list of milestonestick Navigation & Acknowledgements
day notes hours
1 Remove the first chuck with tank adaptor B and fit the 2nd with adaptor A. Start to turn it down but it's inclined to chatter again, so take small cuts for a while until it settles down and the diameter is slightly reduced. After about 1mm advance of the cross-slide can proceed with 0.125mm cuts as before. Complete the first diameter to the noted settings; measure the workpiece to confirm it has been brought to the correct size. Turn down the end to the smaller diameter again using the noted settings and confirm by measurement. Take the sharp edges off with emery board. Try to order Andair fuel selector and gascolator on their website; everything works fine until I click on the icon for payment and I get an HTTP error 405. 1158.1
3 Order Andair fuel selector & gascolator by phone and report the problem with their website.
4 Remove 2nd chuck and fit 3rd with tank adaptor C. Take first cuts very small (0.025mm), but still some tendency to chatter after about 0.2mm advance of cross-slide. Disappears soon and can use normal 0.125mm advance. Take down to the 2 required diameters in the same way as before. Remove toolbit and start to set up boring bar. Need to remove tailstock to get enough room. Needs a lot of packing to get it on centre height, or as near as I can guess with no centre left on the workpiece. (Must make a centre height setting device one day.) Doesn't seem to give a very nice finish, but cuts acceptably. Count 52 saddle feed turns in to the bottom of the hole. The drill point shape means it has to start cutting a bit back from where the mouth of the hole would indicate. 1159.8
5 Andair order delivered. All looks good except that they forgot to do the custom engraving on the fuel selector. Phone to ask and they admit it was written on the order but didn't get done, so they will send on a correctly-engraved fascia plate. Remove and send back in a Jiffy-bag the standard fascia plate. Start taking cuts on tank adaptor C with the boring bar. The drilled hole is not very well centred so the cut is interrupted over part of the length for several passes, tending to make the tool vibrate and chatter slightly. Eventually get a continuous cut with a decent finish. Stop at cross-feed dial 0.25, and measure the bore as about 14.25mm (have to retract the saddle quite a bit to clear the caliper). Target is 0.625", 15.875mm so another 0.8mm cross-feed should get it quite close. Order Loctite 577 thread lock (as advised by Graham Singleton for NPT fittings) and connectors for trim servo from RS. 1160.4
6 Review again the list of AN fittings for fuel system. Draw up the baggage bay support bulkhead in CADintosh and try to work out whether straight or elbow fittings would be more appropriate for the electric fuel pump to allow easy connection to the gascolator. I don't have the exact dimensions of the pump (LAS Aerospace catalogue says less than 3" cube) but it looks quite tight, and it may even be necessary to put the gascolator and pump on opposite faces of the compartment, so defer that decision until nearer the time. Order the fittings identified as definite, and a flaring tool, from LAS Aerospace. Continue boring tank adaptor C. Finish at cross-feed 0.575mm for final size. Swap chucks and bore adaptor A to size in the same way. 1161.9
7 Custom-engraved fuel selector fascia arrives from Andair. Loctite thread seal & 5-pin XLR connectors arrive from RS. Despite being advertised in the catalogue and shown on the delivery note as plastic, the plug is metal-bodied. I chose a plastic one, expecting it to be a bit lighter, but never mind. Phone GLR Distributors Ltd to find out what's happened to the order for 1.5" aluminium bar and die; they say the metal had to come from Holland and so despatch was delayed.
8 7/16" UNF die arrives from GLR Distributors Ltd, but no aluminium. Run the die down the AN840-6D that I had threadcut on the lathe to 7/16" - 20. Originally I hadn't taken the thread quite deep enough and it wouldn't fit in the ports of the horizon, but after meeting the die it now fits perfectly, although it will need to be shortened slightly for one of the ports. If the vacuum hose is 3/8" ID I will modify another AN840-6D for the second port, but if it is 1/4" I will use 2 off shortened AN807-4D.
10 The thought had suddenly occurred to me during the night that the flap operating pushrod has to go through the area where I planned to put the fuel valve. Offer up the valve and my suspicion is correct. I forgot that the pictures I have seen of other Andair valve installations have been in tri-gears, and so there is no flap pushrod at that point. Even so, I should have noticed the hole for the pushrod in the adjacent tunnel bulkhead when considering where the selector would fit. Contact Andair and order an extension kit, which also requires a new fascia plate, so getting the original engraved was a waste of time. Ah well, more haste, less speed! AN fittings and flaring tool arrive from LAS Aerospace. Cut of about 50mm of 3/8" pipe and make a flare to see how it works. It's easy, and the flared end fits beautifully on the AN833-6D fitting (for the first trial, used the end of that which will get cut off, just in case). Try out the AN822-6D elbows on the fuel selector inlet ports and see how it fits in the tunnel. With the elbows just screwed on firmly, the assembly won't go to the top of the tunnel, but has some leeway at the bottom - another reason for the extension. Remove a port to check how far the elbows go in; there's plenty of room to tap the port deeper - enough to take the fitting threads all the way in if necessary. That would allow extra clearance to get at the pipe fitting nuts, so probably worth doing anyway. Inventory the parts and add them to the parts database. Make the box they came in storage box 17 and put the RS & Andair stuff in it too.
11 Bore the final tank adaptor (B) to size. After Gloster Strut meeting Alan Twigg comes back with me to collect the Europa Club's 16.5mm Mod 72 reamer. 1162.8
12 The Mod 60 fuel gauge from Europa, the (now-redundant) 1.5" aluminium bar from GLR Distributors Ltd, and the fuel selector extension kit from Andair all arrive. Although the extension tap has a slightly larger fascia than the standard selector, it still just about sits within the width of the tunnel top. Sadly, it does not have ready-drilled holes for anchor nuts like the standard one, nor are the flanges large enough for standard anchor nuts. Will need to (acquire and) fit single-sided anchor nuts. Put all the fuel-related stuff in box 17 and enter details of parts received on the database.
13 Review the electric fuel gauge instructions and check how the parts fit. Take tank adaptor B out of the chuck, and find a scrap of thin aluminium to wrap around the small end and protect it from the chuck jaws when mounted big-end out. Start the 1/8" NPT tap into the end hole, supporting the back end of the tap on a centre in the tailstock to keep it square to the hole. Take it out of the chuck once well started and continue tapping. Have to use a rubber glove to get a grip on the workpiece. However, it needs a bit of tapping fluid because it starts to gall, and that makes it too slippery to hand-hold. Find a small offcut that will fit in the side hole and act as a tommy-bar. Run the deburring tool round the edge of the hole and try the AN914-1D elbow from time to time so that I can stop where it aligns well when tightened. Repeat for the end hole in adaptor A. Have to start the tap in the side hole of adaptor A by eye, but it's not too difficult to get it adequately square. Finish to depth, checking the fit of the AN842-4D. Looks like it will have to be tilted up a bit as it's so long it would cause a very sharp bend in the TU23RM against the adjacent face of the cockpit module. Tap the (redundant) side hole in adaptor C, checking the fit of the NP125 plug. Change to the 1/4" NPT tap and again use the tailstock to start the tap square in the end hole of adaptor C. Tap to depth for AN823-6D. Repeat for the side hole of adaptor C. Repeat for the side holes of adaptors A and B, checking with AN822-6D. 1165.3
14 After finding it very difficult to source 9/16" UNF bolts or set screws for the side fixing hole in the Andair gascolator, phone Andair to ask if they know of a stockist. They say LAS Aerospace should have them. There's nothing larger than AN8 hex bolts in the LAS Aerospace catalogue, so phone them. The tech guy says they have a few AN9 bolts in stock, but when I explain what it's for, he suggests using an AN pipe fitting such as AN832-6D instead. It had never occurred to me to misuse a pipe fitting in that way. Try the bulkhead side of the AN833-6D (which won't be needed to make a joint) in the gascolator and it goes in to about the full depth of the outer section of thread. Note that the gascolator must be mounted with the face containing the 9/16" tapped hole about 1" away from the bulkhead so as to leave enough finger room for unscrewing the cup.
15 Check the bore of the male end of the AN914-1D and find it is 3/16". Put a 3/16" drill bit in the bench drill chuck and slide the AN914-1D onto it, then clamp it in the machine vise with strips of wood on the jaws to protect the fitting. Wind the drill table down, remove the 3/16" bit, and replace it by a 1/4" bit. Check how far it should go in (don't want to go into the corner, but leave a rim for the tube to butt against) and put a temporary mark on the depth gauge. Drill it out and check how the 1/4" aluminium tube fits. It needs a fairly firm push. Repeat for the other AN914-1D. Set up one AN823-6D in the same way, using a 9/32" drill for alignment in its bore. Drill it out to 3/8". This is a heavier cut and needs some lubricant as well as regular withdrawals to clear swarf. When done, there is a funny smell and it turns out to be the plastic protector on the flared tube end melting because the fitting has got really hot! Cool it in running water and try the offcut of 3/8" tube in it. It won't go in with any amount of persuasion, so decide to enlarge the hole slightly. Letter V drill bit looks ideal, but the one in my el-cheapo Chinese set does not run true. An attempt to straighten it (as I had successfully done with another one from that set) just breaks it - it was "glass-hard" all the way down the shank. The letter W drill does run true, so make a trial hole with that in an offcut to check how well the tube would fit. Seems OK, so go ahead and enlarge the hole in the fitting. The tube is now a somewhat sloppy fit, but at least that will leave room for the Redux. Thinking again about the fit of the 1/4" tube in the AN914-1D, decide to enlarge those too since there would be no room for the adhesive. Set each one up again using the 1/4" drill for alignment and drill out using a letter F bit. 1166.7
20 After a break in aeroplane building for some days because of work to meet a deadline on a database system for the local U3A, take the tank out of the cockpit module and lay the cockpit module on its back on the table, using the plank of MDF to support it between the headrests as before. Measure and mark out the hole centres in the tank top and the port headrest base for the fuel gauge sender unit. Check carefully to make sure orientation and relative positions are correct. Drill a pilot hole in the headrest base and then make the hole with a 102mm / 4" holesaw (for once, I actually had the required size in stock already). Clean up the edges with emery cloth. Check ID of sender mounting flange and of split ring. Mark the cross-lines with ticks at the radii of each hole. Screw the sender into the flange. It's very stiff as it contacts the O-rings, so unscrew and apply a smear of petroleum jelly. Don't have an open-end spanner (or even adjustable) wide enough for the sender flats so set the vise to just fit it and support it upside down on the jaws. Wind the flange onto it using gloves to get a good grip and it goes on much more easily and a bit further. Mark the position of the wire exit and dismantle again. Position the flange on the tank using the radius markings and set the wire exit pointing directly inboard. Mark through the mounting holes. Remove the flange and replace it with the split ring, aligning it on the radius marks and upon the mounting hole marks. Tape it down with duct tape, avoiding the mounting holes. Warm up the mains soldering iron and use it to melt a slot around the inside edge of the split ring. After pulling out the central waste, run the iron around again to clean off the edge and remove some excess lumps. The bit is just too big to pass through the mounting holes, but it reaches deep enough to melt location spots on the plastic. Trim the underside edge of the hole with a scalpel held as flat as possible to remove sagging lumps and bring it flush, taking care not to cause nicks. Try not to drop any, but of course some scraps fall in. Bring down to the garage the Weller temperature-controlled soldering iron which has a smaller bit and push it through the mounting holes. Still a long way off getting the mounting screws into the holes, though. Set up the vacuum cleaner hose in the main sender hole to catch swarf and drill out the mounting holes with a 4.8mm bit. Remove split ring and duct tape. Trim top edges of main and mounting holes flush with the scalpel. Mark the split ring for orientation. Clamp the first captive nut to it with toolmakers clamp after ensuring it is well centred on the hole. Drill the first rivet hole, with some difficulty as the 2.4mm drill bit is missing from the set (did I break it a while back?) and the 2.5mm bit is blunt. Eventually give up and switch to a 2.3mm bit which cuts well and then run the 2.5mm through to bring it to size. Countersink and check rivet fits flush. Unclamp and paint face of captive nut flange with Duralac. Re-position and hold in place with one of the short capscrews I use for the trim tab and aileron hinges. Paint a rivet with Duralac and set it. Drill second hole, countersink & set Duralac-coated rivet. Decide to give up on that job until I can get some sharp drill bits. Try to reach the insect cocoon on the front face with the aluminium metre stick, but can't dislodge it. It seems quite hard and crackly and some small pieces break off. Likewise the others near the top port corners. Vacuum out the parts of the tank base that are accessible from the sender hole. Consider that the cocoons or wasps nests or whatever they are may have hardened because they have dried out and that maybe a soaking in water will make them easier to remove. Pour about 6 litres of water into the port side and upend tank so that all 3 shadow areas at the port side are now under water. Put a bungee around the tank to hold it upright against a stool. After that notice another shadow on the front starboard face almost opposite the filler hole. Squinting in there, it looks more like a melted bit of plastic than an insect cocoon. Maybe the others were too! Leave the water in anyway - it can't do any harm.
21 At Buck & Hickman buy a 2.5mm drill bit and order a 2.4mm bit. Halfords still don't have Loctite 5922 in stock, and Karparts does not do it either, so search for a supplier online. Order a pack from Grampian Fasteners.
25 Phone Europa Aircraft to see if they have any comments about the strange things inside the tank. John says he has not heard of anything like that and asks if I can send a picture. Manage to get reasonable shots of the one near the filler hole. Take pictures of one "thing" both inside and out. Phone Michael Engineering in Michigan to check on availability of spares for the resin pump. Order a refurb kit including gaskets and other stuff as well as both containers. Send the fuel tank pictures to John & Roger at Europa by e-mail.
26 Collect 2.4mm drill bit from Buck & Hickman. John Wheeler replies to my e-mail of the tank pictures saying they would like me to send the tank for examination by the manufacturers. Drain water out of tank.
27 Roger also replies to my e-mail saying they have forwarded my pictures to the manufacturers and await their comments. Weigh tank (6.5kg) and measure it (1050mm W x 400mm H x 315mm D). Check on Royal Mail website and find it won't be as expensive as I thought to send it parcel post.
28 Start to consider exactly where the fuel selector should be mounted. Mark out and drill holes for rudder cable pulleys and harness on sides of tunnel. Unlike in the diagram, the pulley actually overlaps the harness bolt head, but is just clear of it with the specified 3 off AN960-10 washers. Could change one for a AN960-10L, but no less thickness would do. Check PDF manual to make sure the dimensions called out there are the same. Remove inlet ports from fuel selector and tap one a bit deeper so the AN822-6D goes in a bit further, still leaving over 2 threads clear. Need to use aluminium sheet soft jaws as the wood ones are not up to the torque needed for tapping. 1171.4
29 Tap the second inlet port of the fuel selector a bit deeper as for the first one. Clean up and re-fit with a wipe of grease on the O-ring. Check positioning of selector with elbows in place. Initially looks like it could be placed with the mounting flange about 115mm from the underside of the tunnel top. However, that will depend on the bend radius can be made, and how close to the end it can be formed. After some theorising, decide a practical test is needed. Consider what the correct sequence needs to be; the sleeve will not go around the bend, so must be in place first; thus the flare must be formed before the bend. This means the bend cannot be very close to the end. Deburr the end of the main length of 3/8" pipe and form a flare on it. Notice as I do that, that the casting in which the cone runs is cracked around one of the mountings. Widen the coils of the tube slightly and slide on the sleeve and nut from the other end. Fit it into the small bender in the 10mm recess with the nut up against the stop and form a 90-degree bend. Clean end and fit lightly to the fuel selector outlet (the worse-case as it protrudes more). Straighten enough of the tube off the coil to allow offering up the selector to its intended position. With the horizontal run of tube against a straight-edge across the tunnel, the selector flange is now about 100mm from the tunnel underside. That leaves the back edges of the nuts securing the pipe on the elbows just clear of the tunnel shelf - probably just about OK for spanner access. The bend could be made closer to the end of the tube by inserting a mandrel into the tube and holding that against the stop on the bender. A piece of 1/4" aluminium rod is nearly large enough to fit, but it would be better to turn down a larger rod for a good fit. Mark lines on the insides of the tunnel at 100mm from the underside of the tunnel top and parallel to it. Check the cutting schedule for the 3mm plywood (including the tailwheel spring support which is not shown on the diagrams in Annex A-2) to confirm that I can take a piece out of sheet 1 for the selector mount plate. It has to be about 90mm wide but I'm not sure how long (fore-and-aft) it should be. Making it as short as possible will leave more access around it, but don't want to overdo it and compromise strength. The plan at present is to put a layer of BID on each face of it and attach it to the tunnel sides with BID flanges. This should be adequately strong even at a length of 80mm which is only just larger than the largest dimension of the selector flange itself. There's enough plywood to make a test piece and test it to destruction. Of course with the extension shaft in place some load will be transferred to the tunnel top, but it would be conservative to assume the entire mass of the valve and its associated pipework is to be supported by the ply. I'd like to determine the ultimate load on the the ply alone without BID sheathing and see what G-loading of the valve mass that represents. I note that the tunnel bulkhead goes across the non-foam area where the inspection cover is supposed to be. I think the hole should not go forward of the bulkhead so intend to make it a circle with a chord cut off. Obviously the selector mount cannot not attach to the inspection area, even if it protrudes into it, so that's another reason to keep it short. However, the selector mounting screws would be much more accessible if it was opposite the inspection panel. (It's sometimes easy to forget that much of this will become very hard to reach once the cockpit module is bonded in to the fuselage bottom, even with the mandatory access panels.) The selector mounting plate could be supported on an aluminium angle attached to the starboard tunnel side further back and cantilevered over the inspection hole. At the port side, it could also use an angle fastened onto the hard-point, rather than BID flanges. Looking at the tunnel while considering all this also makes me wonder about the best route for the fuel line forward of the tunnel bulkhead, and thus the best place for the bulkhead union. I think I need to look at a completed XS and get a feel for where various things fit. 1173.1

left-arrowgo to previous page of journal listgo to list of narrative pages list go to next page of journalright-arrow
Return to Rowland's home page

This page last updated 2014-04-09 20:28. I try to make this page as accessible as possible, by adhering to HTML 4 standards. Valid HTML 4.01! Valid CSS!
I welcome comments on this website. However, because of the amount of spam it attracts, I no longer post a direct e-mail address on any page. Instead, please click here to contact me. You will have to confirm that you are human before the message will be sent on to me.