Europa #435 G-RODO Build Journal - 2016 07
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|1||Clamp the landing gear frame corner simulator in the vise and try tapping the starboard stainless steel firewall piece on it with a ball-pein hammer to get it nearer the required shape. Somewhat promising - also tapping on the inside of the bend seems to help. Rather tricky to get the firewall piece in and out of place against the landing gear frame with the engine installed, but do-able. The stainless steel sheet is starting to split at the bottom corner where it's being asked to stretch over the protruding stub of the horizontal member. It might be possible to let the split open a bit more to get the best shape and then apply a small patch over it, which could be less of a compound shape and attached with stainless steel rivets. It would probably be best to tackle it after removing the engine again.
Some of the wires which will pass through the firewall had not been labelled at the terminated end, so do that now with the printed labels under clear heatshrink.
|2||Long M3 capscrews delivered from ModelFixings. Alas, neither length is fully-threaded so the threaded pillars I have in stock would not work. Could easily turn up some plain pillars, though.|
|5||Have been trying without success since May to contact Neville Eyre to get a price for the cowl baffles. Try phoning but the number I have for him is defunct. A query on the Matronics e-mail list elicits a current number for him. Try that one and at last get in touch. He says he's still overloaded with other stuff and has been on holiday but hopes to make up a set of baffles next week and will let me know a price once he's done that. He confirms that there is another piece, not included in the templates he sent me, which fits across between the footwells and is top-hat shaped to clear the engine mount etc. It should fit close to the composite firewall but can have a gap at the forward end to allow cooling air for the alternator. I can see that I'll probably have to re-make the starter motor wiring to clear that - will need to order some more M6 terminals for 4AWG as I'm running low on those.
Take off exhaust downpipes, replace closures on exhaust ports and take exhaust system back to trailer.
After some consideration of pipe runs and space needed for clamps etc, cut the coolant pipe between the header tank and #2 cylinder (port forward) with a junior hacksaw. Remove a small slice of pipe to allow for the branch of the T-piece. Slide clamps onto pipes and (with some effort) fit the double T-piece. Push end of small pipe onto branch of T and offer up to port heater to check length. Cut to length and slide on 2 clamps. Check that pipe will fit onto the heater then remove again as this is the last connexion to be closed. Push the pipe onto the inboard connexion of the port heater, offer up to inboard connexion of starboard heater & cut to length. Fit 2 clamps and push pipe onto connexion. Requires considerable effort, even after lubricating the mating areas, and care has to be taken not to bend the copper pipe. Position and tighten up clamps. Fit tie-wraps to secure pipe to balance pipe at each end and to ignition leads in the middle.
|11||Having decided to use it for the fuel vent to atmosphere under the fuselage, cut off the nipple end of the AN838-4D with a fine hacksaw and clean up the cut edge with a needle file. Drill 2 holes 2mm in what will be the aft face. Order some more 6mm ring terminals for 4AWG wire; the Davico types I originally got are no longer available from Farnell, so choose an alternative make.||2601.1|
|13||M6 4AWG ring terminals delivered from Farnell. They are made of much thicker material and larger OD than the ones I got before - will have to do a check to make sure crimping is done correctly, and what die to use.|
|14||Get both cowl parts out of trailer and file off the obvious lumps and uneven areas from the mating flanges for each. Assemble, with spring clamps holding aft ends in place, to check fit. Not too bad already but identify areas where material still needs to be removed, separate, file some more and repeat until fit is more acceptable. File down the nibs at the mould joint lines. The one across the bottom is quite hard going so use the power file for that.
Measure propeller to check spinner clearance from cowl. Edge of spinner is 16mm aft of mating face on prop hub. Neville says space cowl from spinner using 3 mixing sticks which is 5mm, so front face of cowl should be 21mm aft of front face of prop driver. That puts the flat circular part of the cowl just about on the parallel section of the propshaft, which measures 40.3mm diameter there.
Measure along edges of cowl for fasteners. Manual calls out 6 on each side along the horizontal join line, but that does not appear to include the ones at the aft end which go into the fuselage. Neville had marked the forward positions when I picked up the cowls - one between the spinner and the air inlet, and one well forward on the side. Space 4 more vertical marks evenly along each side of the bottom edge of the upper cowl, about 170mm apart. Measure width of aft edge of upper cowl (1320mm) with steel tape wrapped around it. Mark centre line at 660mm and other lines 337mm up from each side. Mark lines 1/2" up from bottom edge at aft edge, and on each of the positions already marked to give hole centres. Lower cowl is to have 6 fasteners each side (not including the ones through both cowls). Measure and space marks along aft edge about 110mm apart.
Assemble cowl with clamps and holding the parts together very firmly, drill 3.2mm at the port forward outer mark. Insert cleco and with some fiddling fit washer to it. Prepare to drill corresponding starboard hole, but the fit doesn't seem so good there. Dismantle again and file the inside of the front corner of the upper cowl a bit more. Re-assemble and it looks much better. Re-insert the cleco in the port hole and holding it firmly together drill the corresponding starboard hole. Insert cleco and with much more fiddling get the washer onto it. Likewise drill and cleco the 2 holes between the air inlets and the spinner. Drill and cleco the remaining holes, alternate sides in turn. Remove clamps and set up cowl on aft end. Mark centre of flat circular area. Drill and cleco 2 more holes close to centre (but clear of proposed 40mm hole for propshaft). Drill 3.2mm on the marked centre.
Not sure how to make the hole 40.3mm - nearest holesaw in stock is 38mm. Leave cowl assembled in trailer.
Get a 40mm holesaw from Screwfix. Do a test crimp on an empty example of the new 4AWG M6 ring terminals and it squeezes down OK but the central hole is smaller than a similar test on the original Davico types. Do a test crimp on the end of the 4AWG wire stock. It looks fine; the side "wings" are slightly wider than on the older types but perfectly satisfactory.
Take the assembled cowl out of the trailer and drill the propshaft hole with the 40mm holesaw. Clean up edge of hole with half-round Perma-Grit file. Take complete cowl round to front drive and open garage door for access. Remove clecos and open up hole in lower cowl flange to allow it to slide onto propshaft. Place upper cowl onto propshaft with aft edge on fuselage and it fits beautifully, with a slight overlap of the fuselage joggle. Lift lower cowl into place and while holding in position fit front outer pair of clecos (no washers). Still supporting it with my knee, fit clecos with washers to middle holes each side. Fit clecos to front face holes then to rest of side holes, fitting washers on the ones I can reach. Looks great and measuring from the front of the prop flange to the flat circular area gives 21mm as planned. However, the aft edge of the lower cowl is only just reaching the fuselage joggle at its upper ends and on the underside is quite a bit shy of the joggle - about 5mm on the starboard side and 10mm on the port side.
Phone Neville to ask for advice and he says I should need to trim about 5/8" (15mm) off the aft edge of both cowl parts, so something must be wrong (I knew that!). As the problem is worse at the bottom it almost looks as if the engine is tilted up too much - although I'm sure I double-checked that. Neville says that from memory the standard dimension between the prop flange and the aft face of the spinner backplate on the Warp Drive is 1", and the Airmaster is similar, so therefore the cowl has to be 30mm aft of the prop driver instead of the 21mm I have set. In order to achieve that the centre hole will need to be enlarged to clear the nose of the gearbox. Neville says the hole should finally be enlarged to leave about 2" of the flat area all round, except where it may need to be further cut away to clear the prop brushes. He has no experience with the Woodcomp prop. I thought I'd asked Woodcomp for the dimension to match the Warp Drive but cannot recall the details. Neville suggests that if there's enough room on the joggle to fit an anchor nut the gap could just be filled. He hopes to have a price for the baffle set by Monday so I will speak to him again then. Carefully take out clecos while supporting lower cowl then take it off. Centre upper cowl (equal measurements to fuselage join line each side) and mark centreline of cowl on fuselage. Trace around aft edge of upper cowl onto fuselage before removing cowl. The line is about on the edge of the joggle at the starboard side and about 10mm aft of the joggle at the port side. Put the cowls away in the trailer.
Check my correspondence with Woodcomp and find that I requested a spinner suitable for the prop driver front face being 25mm forward of the cowl front face (Woodcomp had quoted 20mm to 25mm as OK for Europa XS). With the 16mm distance I measured from prop flange to edge of spinner, that would imply a gap of 9mm between spinner & cowl, which is much bigger than it should be. Neville said again this evening that the gap should be only 2 or 3 mixing sticks. It looks as though I will have to move the cowl further aft until the shortest edge meets the joggle, but I now remember noticing that the fuel pump was quite close to the cowl and so it may not be able to move very far aft anyway. If it can be moved aft, I'd have to build up the front of the cowl to close the gap as described by David Joyce in correspondence around the time I ordered the propeller. David said Andy Draper recommended a gap of 3mm.
|16||Set fuselage level thwartwise using jack to raise it and wedges under dolly wheels to hold it. Check fuselage fore-and-aft angle with digital level (6.9 degrees nose-up) and then check angle of square clamped against prop driver (7.1 degrees nose-up) so only 0.2 degree error by that measurement. Check angle of prop driver (83.1 degrees) and re-check fuselage fore-and-aft angle (6.8 degrees), so error by that method is 0.1 degree. Bring upper cowl out from trailer and position as before. The aft face of the cowl front is about 15mm forward of the fuel pump so probably could afford to take the cowl back 10mm. Diameter of gearbox boss at that position is about 64mm. Would need to attach a blanking piece to the aft face of the assembled cowl to provide a centre for making the new larger hole. After thinking about all sorts of possibilities for filing the resulting gap between spinner and cowl, perhaps a ring of balsa sheet of the right thickness would be easiest. It would need to be about 10mm to 12mm thick, and like the Flettner strips on the trailing edges of the trim tabs, could be painted with epoxy to weatherproof.||2609.8|
Neville Eyre phones to suggest that (a) I don't enlarge the hole in the cowl (at this stage, anyway) because there should be no need to have the flat part of the cowl further aft than the propshaft and (b) that I try an assembly with the spinner backplate in place. In my case, that means the whole propeller as there isn't a detachable backplate on the Woodcomp spinner.
Take cowls out of trailer and round to front drive. Take propeller out and offer it up to engine just to check if it would fit inside the garage, which appears possible.
Clear accumulated tools etc from underneath the fuselage. Roll fuselage out onto drive. Remove stiffnuts and washers from propeller and bag them. Fit dowels to prop driver with a smear of grease as recommended by Kevin Dilks. Offer up propeller and fit plain nuts. They seem to tighten rather early, but then there is a movement and they go further. I think that initially the dowels had not entered their sockets in the propeller hub.
Place upper cowl in position. The flat face behind the spinner is scraping slightly on the propeller bolts, even with it firmly aft against the gearbox housing. Lift lower cowling into place below the engine and after some false starts pull it up into place using a ratchet strap. Fit clecos (no washers this time), some with considerable fiddling to get the inside hole lined up and remove strap. Amazingly, the lower cowl is now just aligned with the fuselage joggle at the port lower side and overlaps slightly elsewhere. The gap between spinner and cowl is 9mm (as predicted from my earlier measurements) so it will only need a ring of balsa 6mm thick to close the gap to the recommended 3mm. Mark the aft edge of the cowl on the fuselage using a green felt-tip pen. Take plenty of pictures at various angles. Tie a rope around cowl (faster than the ratchet strap and less likely to scratch) for support and remove clecos. Remove lower cowl then upper. While propeller is in place, fit the brush bracket and check that the brushes can easily be adjusted to the centres of the slip-rings and square to them. Remove brush bracket.
Remove propeller and return to trailer, keeping the plain M8 nuts and washers with it for the moment. Some dowels don't want to come out so safety-wire them all in place to make sure they don't get lost. Mark a line with a red felt-tip pen, aft of the edge of the fuselage joggle by the width of an old steel rule, all round fuselage. Re-fit upper cowl then position lower one below engine. Without the propeller in the way, I can support the lower cowl with my knee sufficiently while inserting the first 4 clecos at forward and aft ends of each side. Insert remaining clecos. Insert wedges between prop driver and cowl to persuade cowl back into line with green line on fuselage. Lay the steel ruler on the cowl aft edge and keeping the ruler aft edge aligned with the red line, mark a black line with a fine felt-tip pen against the forward edge of the ruler on the cowl, moving all round the cowl in stages. Remove the wedges and cowls.
Trim the upper cowl just shy of the black line with a padsaw. Smooth the edge and chamfer the inner side of the edge with Perma-Grit files. Likewise trim both sides of the lower cowl and finish the last tapered bit with Perma-Grit block. Chamfer inner edge. Re-fit cowls and they seem to fit quite well. There is a bulge where the upper & lower cowls overlap because there is no corresponding recess in the fuselage moulding for the double thickness there. There is a also a slight gap just above that where the upper cowl doesn't conform well to the fuselage profile, but that could probably be fixed by pulling it tight when making the holes.
Remove the cowls and put them back in the trailer. Roll the fuselage back into the garage. Send a quick e-mail to Neville to let him know that things have gone well.
|19||Send a more detailed e-mail to Neville with report of yesterday's procedures and some pictures, and queries about the gap at the "shoulder", the double-thickness problem at the cowl joint and the question of how much clearance is needed for the fuel pump. Neville replies saying that the double thickness problem arises with the factory cowl too and the answer is to remove the inner flange locally. The cowl can be cut away to completely expose the end of the pump if necessary. He also quotes a price for the baffles.|
|20||Reply to Neville's e-mail asking if I can have the baffle set he has just cut, and later send him a sketch of the shape and size of aluminium I think I will need for the aft section of baffle.|
|29||Nothing heard from Neville so re-send the last message asking if he'd received it.|
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