Europa #435 G-RODO Build Journal - 2013 11

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1 Cut off 2 lengths of the steel plate and mill the ends square, finishing up with 2 pieces 20mm x 25mm. Support on a parallel together in machine vise and mill a slot about 2.5mm deep and 12.7mm wide along both, leaving the central portion 3.5mm thick. Mount each in turn on the prepared die pieces of the Swage-It tool and drill centrally 3.4mm. Enlarge the holes in the plates to 4mm. Tap the dies M4. Turn a piece of 1/4" steel rod down to 6mm for about 16mm long. Turn down to 4mm for 7mm from the end. Thread that part M4 with tailstock dieholder. Check fit of die and spacer plate on it - seems fine.
2 Remove intercom from main circuit diagram and update to v09. Continue modifying comm radio connexion diagram. Check operation of VSWR meter using Icom hand-held radio. Its short antenna shows a very poor VSWR, which is not surprising.
4 Remove threaded rod from chuck, hacksaw off, return to lathe and face to length. Assemble to die and spacer and try in the hydraulic crimper - seems OK. Repeat lathe operations to make 2nd threaded rod. Assemble 2nd die and spacer to rod and check fit in crimper - all OK. Pierce the holes in the overhead panel through the leathercloth from the back, then trim to edges of holes with scalpel. Fit to fuselage top moulding with AN525-10R8 screws - looks fine. 1662.8
5 Having investigated the Garrecht TRX-2000 collision avoidance device, including reading the manual and getting queries answered promptly from the manufacturers, decide that I need to sort out its antenna installation before putting the top on the fuselage. As there are minimum spacing considerations, that will potentially affect the transponder installation too. So, order a TRX-2000 from the manufacturers online store (seems to be cheaper than UK suppliers). Get intercom, transponder, groundplane copper sheet and antenna out of trailer. Advertise intercom on LAA sales bulletin board. The transponder would fit between the rudder cables, and the antenna could easily be the required 1m from the comm antenna. It is too long to fit under the rudder cables, so will have to be offset to one side or the other. For the TRX-2000 the ADS-B antenna must be 1m from the comm antenna and 2m from the transponder antenna, which could pose quite a problem! As it's only receiving, not transmitting, there is no issue with it being too near the cockpit, so perhaps it could be well forward and the transponder one well aft. The GPS antenna of the TRX-2000 must be 0.6m from any other GPS antenna, which should be easy. Decide to fit the transponder and its antenna well aft, near the containment bulkhead, accessible from the hole in the fuselage, but still 1m forward of the comm antenna. Start to design an aluminium mount for the transponder, but discard that idea and change to glass-fibre. Make blue foam pattern about 80mm x 150 mm x 25mm. Cut the minimum-size ground plane (120mm x 120mm) from 0.4mm copper sheet. Mark centre and drill to 12mm with step drill to avoid snatching, then open to 12.7mm for BNC socket of antenna with taper reamer. Make a blue foam pattern for ground plane support, but get angles wrong and have to start again. Mark positions of transponder mount and ground plane mount on inside of fuselage. Mark & cut 4 off pieces of BID 180mm x 250mm. Make formers from blue foam to surround the template and keep the flanges in contact with the fuselage sides. Cover template in polyethylene sheet. Lay template on a piece of polyethylene sheet and drape BID over it. Mix 60g (peg-3) batch of epoxy and wet out BID. Drape and wet out remaining 3 layers. Peel-ply in 2 directions. Add a patch of polyethylene to just cover the top surface. Fit the foam surrounds and clamp the whole assembly in place on the inside fuselage surface with pieces of wood each side to spread the load and keep the top surface of the mount flat while curing. Drape polyethylene sheet over rear fuselage and leave fan heater running. 34C, 18% RH by bedtime. 1667.5
6 Layup cured, remove clamps, polyethylene & peel-ply. I didn't notice when assembling everything that the piece of wood used to clamp the inside surface had a slot along it, so there's an unwanted ridge on the top surface of the mount! Sand it flat with a Perma-Grit block, and that cuts through the layup at one end, so will have to re-do the top surface layup. Cover the ground plane mount pattern in polyethylene sheet. Find a piece of aluminium sheet to keep the critical surfaces of the layups flat, and conduct a bit of heat to them. Cover it in polyethylene sheet. Mark and cut BID pieces 4 off each of 390mm x 100mm, 200mm x 175mm, 145mm x 70mm. Mix a 75g (peg-4) batch of epoxy. Place the small pieces of BID on top of the transponder mount and wet out each layer in turn. Apply peel-ply, invert onto covered aluminium sheet and weigh down with lead weights. Start to drape BID onto groundplane mount former, but applying 2nd layer around base disturbs the 1st layer edges that it's supposed to bond with, so take it all off and start again with just the top-surface pieces (now only 3). Peel-ply & invert onto covered aluminium and weigh down. Erect small curing tent around the layups and leave to cure. 34C, 27 % RH. 1670.8
7 37C, 17% RH in curing tent. Turn off heat. Get the RG400 and RG142 cable out of box 7 in the trailer. Although the RG142 centre conductor is single-core and so not good for situations where it could be flexed, it should be OK for the very short distance between the transponder and the antenna. Will need to check what the bend radius looks like when the mounts are completed.
8 Set up the coax stripper by a lot of trial & error on a piece of RG142. Once performing OK, make a good strip and crimp a BNC connector onto it. Take the peel-ply off the transponder mount. Clean up the edges with a Perma-Grit block and file. Mark and drill the mounting holes 4.8mm. Fit anchor nuts as usual. Remove peel-ply from groundplane mount. Trim edges. Spread a larger piece of polyethylene sheet on the curing tent base, and a place a piece of peel-ply big enough for the flat surface of the mount on it (to ensure no problems with epoxy runs underneath). Lay the groundplane mount on it. Mix 45g (peg 2) batch of epoxy and paint onto rear & sides of mount. Drape one of the 3 remaining 390mm x 100mm pieces of BID across the back and around the sides. Stipple to wet out fully. Add 2nd & 3rd layers, wetting out in turn. Add peel-ply to all 3 faces. Weigh down with wooden block and lead weights. Erect curing tent with fan heater. 30C, 32% RH, leave to cure. 1672.9
9 Fan heater making a nasty noise. Open it and find fan blades appear to have softened and bent over to contact housing. Try clipping off corners of blades but that leaves it a bit unbalanced and still rattles if moved. Possibly OK while supervised but not happy to leave it running overnight. Take peel-ply off ground plane mount. Prise out foam and remove polyethylene sheet from inside. Trim & smooth edges. offer up to intended position and it looks pretty level in both directions, although will need a bit of flox at one end as it doesn't fully match fuselage profile. Mark and bore 20mm hole with grit-edged holesaw for antenna. Get box 7 (all wire) out of trailer. Buy a new fan heater at Argos. 1673.9
11 TRX-2000 arrives. Order some solder sleeves etc from Stein Air and some butt splices with heatshrink from RS. ADS-B & FLARM antennae with TRX-2000 are dipoles rather than the expected 1/4 wave whips, and the leads are not very long. Send e-mail query about mounting & location.
12 Butt splices with heatshrink arrive from RS. Re-check transponder harness diagram and number wires. Try splicing 4 wires into one with the butt splices, but the crimp on the single 20AWG at one end is not holding. Adjust crimp tool, and then grind off a small amount from the tip of the jaws that is preventing it closing fully. Now the crimp holds OK on a single wire. Re-make the 4-into-1, with 3-off 24AWG and one 20AWG. Crimp DB-25 pins onto the 4 ends and insert them into the shell, with the 20AWG in position 14 as the supply ground. Run the single 20AWG forward to the firewall, across the firewall and back to the centre tunnel, which I think should provide ample length for routing to anywhere on the panel, and cut it off there. The total length is about 4.5m. Mark the forward end as wire 508 with a paper label wrapped round flag-style. Crimp another DB-25 pin onto 20AWG, insert it into position 15, run forward as before to measure length, cut & mark as wire 509. Repeat for remaining pins, using 20AWG for the power to the control head and 24AWG for the signal wires. For the RS-485 signals on pins 2 & 3, cut 2-off 5m lengths of 24AWG, mark both ends of each with numbered flag labels, and clamp one end of the pair in the vise. Grip the other ends in a hand drill chuck and twist them a few hundred turns while holding taut. Allow to untwist a bit before removing from chuck. The tefzel insulation is more resistant to taking a twist than PVC, but the amount of overtwist I gave it seems to have resulted in a satisfactory set. Cut off the crushed ends from the vise and chuck, and terminate as for the others. I decide to not insert pins in any of the unused positions, thus leaving some spares in case of disaster. Once all wires crimped and pins inserted, fit connector cover. Leaving all the wires lying along the fuselage and beginning at the connector end, start to lace the bundle with linen thread. One of the brands I got doesn't seem to be very much waxed, but it holds the knots OK. The other brand is well waxed, but more prone to breaking as I tie the last knot. Move the loom to the floor to keep it straight as lacing progresses. Take the lacing right along the loom to just before the ends of the wires. Fit transponder antenna to copper ground plane for centring, and stick it down to the mount with dabs of epoxy. Realise I forgot to put heatshrink on the wire bundle where it leaves the connector through the grip. Find a size of heatshrink that will just go over the lacing knots, and thread it on from the far end. 1677.7
13 Shrink the sleeve at the DB-25 connector and re-assemble the cover. Much better with the heatshrink as that prevents individual wires migrating out to the edges of the grip and getting crushed. Spend some time figuring out how to support the transponder antenna groundplane mount while it is being bonded to the inside of the fuselage. Eventually drill a 3mm hole in the top aft corner for a cleco, as that is where the fit is snuggest. Some wooden blocks can then be used to support the opposite corner to get it level. Abrade all bonding areas for both mounts. Mix 25g + 10g batch of Redux 420 and add 1 dose of flox. Spread thinly on transponder mount and the mating area inside the fuselage. Place in position and clamp lightly with pieces of wood on both sides to spread the pressure. Add another dose of flox to remaining Redux and spread it onto the groundplane mount. Offer that up to the fuselage to check coverage. Spread over both bonding faces, thinnest along top edge and lower aft where contact is good, and thicker towards forward lower corner where there is more of a gap. Fit in place, holding with a well-greased cleco and washer. Check level in both axes and adjust as needed with supporting blocks. Press last of Redux under bottom forward corner and smooth off. Set up curing tent with new fan heater set to half-power and thermostat 1.5. Quickly gets to 46C, 11% RH under tent so reduce thermostat to 1. After more thought, take heater out and try modifying internal wiring so fan runs continuously. Circuit different to the older fan heater, but add a wire strap in what seems to be an appropriate place. Replace in curing tent and turn thermostat down to 0.5. Get tailwheel fork XTW07 out of box 9 in trailer. Hacksaw off redundant steering horns and smooth cut edges. Mark and drill holes for mounting Mod 77 horn and stop, starting 3mm and opening up to 1/4". Assemble, painting all mating parts with Duralac. Tighten stiffnuts. Wipe off excess Duralac with white spirit. Cut a suitable length off the end of the RG142 terminated with the BNC and apply heatshrink over the crimp. Still pretty hot at bedtime so turn off heater. 1680.8
15 Remove clamp, cleco and wooden supports from mounting brackets. Re-fit antenna to ground plane. Plug in the cut-off length of RG142, check the bends are tolerable, and mark required length on it. Strip it (with some additional manual work, as the automatic stripper does not produce the appropriate lengths) and crimp on the TNC connector. Abrade some home-made cable clips and the bonding areas. Mix a small amount of Araldite clear instant and try bonding a couple of the cable clips to the fuselage while holding them in position with gloved fingers. Takes rather longer than the specified 90 sec because of the lowish temperature. Cut some small pieces of wood to form U-shaped pressure pads, and some small pieces of polyethylene sheet to prevent unwanted bonding. Mix some 5-minute epoxy and lightly clamp 6 clips in place on the transponder loom using the wooden pads. A bit fiddly to assemble them square and correctly positioned. While tugging the loom to keep it straight, the 1st clip pops off so re-stick that with a pad and clamp. Mix more epoxy and do 2 more clips to bring the transponder loom up to rear baggage bay area, as for trim cable on the other side. Cut 4 pieces of BID about 150mm x 30mm. Mix 30g (peg 1) epoxy and paint onto edges of ground plane and mount. Lay on BID strips, one on each side, and wet out. Add peel-ply. Remove clamps from clips and find that on a couple the polyethylene sheet has got folded under the clip and so it's not bonded. Paint on some of the leftover epoxy from the layup and re-clamp. Set up curing tent with new fan heater an half power, thermostat 0.5. Gets to 41C, 11% RH very quickly. Take out fan and re-check operation - my wiring mod has also by-passed the thermostat for the heating elements! Remove the extra wire strap as I can't think of a way emulate what I did with the older fan heater wiring and return fan to curing tent. 36C, 16% RH by bedtime. 1683.9
16 37C, 12% RH; turn off heater.
18 Add wire label numbers to comm radio wiring harness and tidy up some other drawings. Look at various avionics items in trailer to see if I need to buy any D-sub connectors for other kit, and check serial numbers. Notice while checking D-sub connector orientations that the PDF of the Trig transponder instructions (issue AA) shows the pin numbering incorrectly on the 9-pin connector for the control head. The paper copy (AD) is OK. Download a fresh version (AK) of the PDF and bin the old one.
19 Add wire label numbers to wing leveller wiring diagram. Start to do the same with the prop controller but find that the tacho area needs to be updated for the new hourmeter.
20 Cross-checking tacho wiring, I find that while the tacho connection on my diagram is marked as both wires white/yellow (which came from the diagram in chapter 5 of the Europa manual), the ones on the engine seem from the photos of 2013-06-17 to be one blue and one white. During a break in the rain, open the trailer and check. Blue and white is correct, and it's terminated with a peculiar female connector that I don't recognise. While the trailer is open, take the instrument module F14 and the main panel to the garage, with box 24 for the flight instruments. Remove the flight instruments from the panel and store in box 24. Offer up the TRX-2000 to the hole vacated by the hourmeter to see how much it needs to be enlarged. Enlarge it mostly downwards with scrapers and coarse half-round file, checking progress at intervals against the instrument. Eventually get a hole big enough, but it's not very round. Also, the bottom corner of the TRX-2000 is fouling the altimeter - should have moved the hole more up and right than simply downwards. Enlarge it a bit more to get the corners of the instruments clear of each other. Draw up the fixing-hole layout in CADintosh and print it onto a piece of transparency film. Lay the film over the rather irregular hole, aligning the instrument fascia outline to correspond with the non-interfering position, and centre-pop the hole through the film. Drill them 3mm and do a trial assembly. Just about fits, but could do with slight easing. 1685.3
21 Dismantle everything again and pull the TRX-2000 fixing holes slightly sideways with a needle file. Mark the positions of the 4 additional warning lights required, by extrapolating from the 3 existing ones, and drill them 2mm, then open up to 1/4". Continue with tacho wiring updates on prop controller diagram. 1686.0
22 Solder sleeves etc arrive from Stein Air (after paying the VAT & handling charge online last night).
25 Re-check the radio panel drawing, amend some small errors and send off DXF files of the holes and engraving to get another quote for water-jet cutting, anodizing & engraving/etching. Also ask the original quoter if he can anodize the main panel.
26 Reply to my panel query says the DXF files have errors. Mark & drill a hole near the starter switch for the starter engaged warning light. Mark out hole for digital hourmeter, Drill in one corner and cut just undersize with Abrafile in junior hacksaw frame. File to marked lines & check fit. File edge of opening in instrument module F14 to accommodate the hourmeter. 1687.2
27 Continue adding wire numbers to diagrams.
28 Continue adding wire numbers to diagrams. Get some slim oval conduit in 2 sizes for enclosing wires in various places. Planning for the splash moulding to support the lid over the fuses, realise it should be polyester resin, not epoxy, and then wonder if that might react with the cling film I plan to use as a release layer. Make a small layup of a couple of scraps of BID and polyester resin on cling film to see what happens. That layup cures in less than half an hour and the cling film can easily be peeled away with no sign of chemical interaction. The tray of the instrument module F14 is about 210mm deep, 240mm wide at the aft end and 190mm wide at the forward end. The taper is about 45mm at the outboard side and 5mm at the inboard side Mark this shape onto polyethylene sheet and turn over to keep the ink away from the layup. Cut 4 pieces BID about 220mm x 250mm and layer onto the polyethylene sheet. Mix a batch of polyester resin and wet out the BID. Apply peel-ply and another sheet of polyethylene. Turn over and cut to marked lines with Tuff-Kut scissors. The polyethylene sheet is curling away from the layup which makes it awkward to handle but easy to peel off once cut to size. Lay on a piece of cling-film and try to place onto bottom of shelf, but it's curing too fast and won't lie flat. So put it back on the layup table and weigh down to keep it flat. It may be usable, as the underside of the shelf is fairly flat, but it may not be in good enough contact all round to support the trapdoor when it's cut out. If not, will have to use less hardener next time to give slower curing, and maybe do the layup in-situ - although that looks pretty difficult in such a restricted space. 1688.6
29 Continue adding wire numbers to circuit diagrams. Reply from water-jet cutting firm says they could anodize the main panel but can't remember how they were going to do the lettering.

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