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Europa #435 G-RODO Build Journal - 2002 07

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2 tickTake tailplanes off alignment jig and store on outboard-rib layup support. Remove torque tube from jig clamps and take out temporary 1/4" bolts. Check fit of TP14A & TP14B 1/4" pins and find most are good & tight at one end but quite sloppy at the other, with audible and visible movement if only that end is engaged. Drill a steel offcut with 9mm bit and ream with 3/8" reamer. New TP14C & TP14D pins fit OK in that, with a slight tightening up just under the head, so proceed to real workpiece. Start with one TP12. After removing TP11 bush, press a TP14B a short distance into the hole on the side that gives a good fit. Set up on drill table with other TP12 loose-fitted to level on v-blocks. Arrange pin to protrude down through table slot. After careful line-up, drill hole opposite pin out to 9mm. Transfer to bench and start hand reamer into hole, without going beyond the taper lead-in, so that TP14D fits really tight. No problem about damaging pin surface by being too tight, as it does not go in beyond cross-hole, so that part will be out in fresh air when installed. Remove TP14B leaving TP12 firmly secured by TP14D. Set up again on v-blocks but this time the pin head is just too big to fit the table slot, so swing table round and let it overhang the edge. Again set up carefully and open out second hole with 9mm drill. Ream out again, checking fit with other TP14D, and then remove 1st TP14D and run reamer right through. This gives a good fit without having to use excessive force, and there is no movement when home. Repeat exercise for 2nd TP12. Remove TP12s and fit TP9. Press one TP14A far enough through both sides to prevent movement. Set up and drill right through 9mm. Ream each side individually then right through after checking fit is not too loose already. Fit TP14A and repeat process for second hole of TP9. Clean up outer and inner edges of all holes with Noga deburrer. Clean swarf from inside of TP4 with tissue pull-throughs. Re-fit TP11 bushes to TP12s - quite tight over holes, even after deburring. There isn't a handy metric bolt that can be used as a temporary fixing to avoid wearing the TP14s, so need to get some 3/8" UNC (or UNF) bolts of suitable length from Moorhouse Fasteners; they will need to have at least 2" of unthreaded shank. 288.1
3 Buy 4 off 3.5" x 3/8" UNC bolts at Moorhouse Fasteners (£1.18). They fit the reamed test piece smoothly except one which will need a tiny burr taken off the end of the thread.
4 After filing burr off one 3/8" UNC bolt, fit them to reamed holes and they fit well, just starting to tighten up near the head. Chamfer torque-tube jig to allow room for bigger bolt heads. Fit tailplanes and set everything up again for positioning TP13 holes with TP12 pins levelled. Find that I can get tailplane TEs in line AND have 0 degrees on both incidence checks. Put dabs of Duralac on tips of TP12 pins and offer up very carefully. Some make better contact than others. Make alignment marks with felt-tip to assist later. Dismantle and extend marks to give best agreement with Duralac blobs. Drill holes first with small drill, then open out to 10mm. Fit TP13s and offer up. 3 out of 4 need re-positioning. Dismantle and file holes, re-assemble and check; repeat a couple of times until all TP13s are free to rotate on TP12 pins when tailplanes pushed nearly home. Wax TP12 pins and faces. Degrease TP13s in acetone. Mix 1 stroke epoxy and 2 small doses flox and apply to holes and faces of ribs around holes. Fit TP13s to TP12s, and slide on tailplanes carefully. Wipe off worst of squeezed-out flox and ensure TP13s are hard against rib faces. Check levels and leave to cure with fan heater and dehumidifier on. 291.6
5 Turn off heat and dehumidifier; about 21C and 56%RH. While showing tailplanes to Margaret, notice that the epoxy has secured the TP12 plates to the tailplanes. A bit of levering breaks the bond quite easily.
6 Slide tailplanes off torque tube and clean up around TP13s with Perma-Grit wheel on Dremel. Cut off a small piece of the flexible Perma-Grit to sand down flox more smoothly around TP13s. Mix 1 stroke of epoxy with 1 dose of flox and apply fillets all round TP13s and under flanges where necessary. Peel-ply and leave to cure at room temperature (20C, 65%RH). 293.4
10 Remove peel-ply from TP13 flox fillets and clean off with scalpel the flash on the TP13 faces. As suggested in manual, put a little oil on torque tube before re-assembling tailplane; this makes it slightly easier to fit. Think about David Joyce's pip-pin fitting method as mentioned at Gloster Strut last night. He uses dowel pins loctited in place of the rings, and made a bayonet-ended tool for removing them so the access well could be much smaller. Check sizes of pip-pins for wing and they are same diameter but different length. Remove rings and collars from tailplane pip-pins. Body is 7/16" dia, so well could be 1/2" ID. Hole for ring is about #34 drill, 0.111", so could be reamed out to 1/8" (I have an 1/8" reamer in stock). Check catalogues for spring pins; Emkay do 1/8" x 3/8" which even if it migrated would be held captive by the 1/2" well. Look around the plastic and SRBP/SRBF tubes in stock; there is one which will do well for the drain hole on the bottom, but can't find one really suited to the top one. Decide to make a closed-end BID tube on a male mould instead. Find a piece of 1/2" mild steel and clean up the end face and outer surface. Find a piece of folded aluminium to support it vertically while curing, and drill 14mm hole for it to pass through. Calculate cloth size and cut a couple of pieces of BID 65mm x 80mm. Drill hole in one leg of tailplane jig as convenient place to hold mandrel. Wax mandrel, place in hole and clean hands carefully. Mix 1 stroke epoxy and wet out a pice of BID on polyethylene sheet. With some difficulty, wrap around mandrel and remove plastic sheet. Apply peel-ply with carefully-cut straight edge in line with end of mandrel. Trim end of BID and fold over to form end of well, adding peel ply before it has a chance to unfold, and placing vertical in prepared holder so weight of mandrel keeps end flat. Leave to cure with dehumidifier on and fan heater at 3.5. At Moorhouse Fasteners buy 10 spring pins 1/8" x 7/16" (29p) and at Buck & Hickman buy 2 long series 5mm drill bits (£2.81). 297.8
11 Switch off heat and dehumidifer. With heat and some persuasion by jam-jar opener tool, remove BID layup from mandrel. Start to think about how best to fit the layup into the well, and what sequence to do the drilling. Should I put the layup in the lathe and centre a hole in its base first? Also, how to clean up the base of the well in the foam before fitting the BID tube; have to ensure no buildup there so pin will engage fully. Clean up and re-wax mandrel. Do second BID well layup as for first, leaving dehumidifier and heat on overnight. 299.2
12 Switch off heat & dehumidifier. Remove peel-ply from pip-pin well layup and warm up to release from mandrel with jar-opener as before. Get out wing pip-pins and ream all 4 pip-pin holes to 1/8" and fit 1/8" x 7/16" spring pins. Think more about best material for tool to release pip-pins. Don't really want to have something very heavy such as a solid steel rod. Perhaps a steel working end with a lighter or thinner shaft; but how to attach that securely? Find piece of brass tube and cross-drill it 9/64" at 4.8mm and 8.8mm from end. Join holes with hacksaw cuts and file out. On first try against pip-pins, much more filing needed on angled part, so fit small mill in Dremel and clean up with that, which is just the right size and much faster (almost too fast in places). Now works OK, but as bore of tube is bigger than the 6mm needed to clear the pin actuating rod, it's hard to keep it centred on the spring pin. It flexes slightly under load, so thicker-wall stuff would be better from that aspect too. 300.9
16 Start to think again about exact sequence of events in drilling pip-pin holes. Checking position again makes me suspect that I may have mis-interpreted the drawing in the manual. Phone factory and Roger confirms hole centre as 13mm outboard from inboard end of TP6. Checking lengths shows my original mark was 13mm inboard from inboard end of TP6! Hole should go around middle of outboard rib flange, and thus be 13mm from both end of TP6 and back face of rib. Maybe hanging plumb lines from ceiling would be a good guide to keep drill vertical when drilling pip-pin holes. Will need to level tailplane jig for that, though, as it slopes down towards the front door about 0.8 degrees. Send e-mail to Roger suggesting manual changes to prevent ambiguity.
17 After thinking of drilling right through TP4/TP6 for pip-pin with long 5mm bit and then enlarging skin holes with step drill, decide that will not guarantee concentricity at the bottom of the well. Better might be to drill with a 14mm bit first, to just spot TP6 or the BID tube, then drill through TP4/TP6 with 5mm. Doesn't solve the concentricity problem on underside, but there seems no way around that anyway. Roger replies saying he'll pass my suggestion for manual changes on to Andy when he gets back from USA.
18 Check if Tewkesbury Saw Co have TC-tipped lip & spur bits - not in stock and Trend one is over £30 to order, so forget that! Order 14mm one from Axminster Power Tool Centre, and piece of 7/16" silver steel for pip-pin extractor tool among other stuff. Get new bearings for bandsaw guides.
19 Axminster Power Tool Centre order arrives. Fit bandsaw blade support bearings and cut a pair of wedges to lift south end of tailplane jig. Slide them under jig baseplate and set in place with hot-melt glue. Tack TP4 assembly with hot-melt too, but not very successful as quite a soft hold. Check drill a layup offcut with 14mm drill and try the BID wells for size. Should be OK with minor cleaning up. Cut off 30mm length of 7/16" silver steel, face and bore 6mm. Cross-drill 9/64" orthogonally at 4.8 & 8.8mm from end as limits of taper slot. Cut one of the 1/4" round steel shelf supports from old Hygena QA kitchen units at Trimley to use as handle, and turn long end down to 6mm to fit bored hole in silver steel. Cross-drill assembly, ream to 1/8" and fit spring pin. Cut out slots with hacksaw & use one of the new TC rasps in the Axminster Power Tool Centre order with the Dremel to fettle slot to size. Hard to avoid scratching outer surface & ruining the looks of it, but it works OK. 304.4
22 Philip Paull comes over to take some video footage of the tailplanes being set up for drilling the pip-pin holes. Seems much easier to slide the tailplanes on this time - can it be just that the jig is prevented from sliding about? Press tailplanes home well and check level with incidence jig. Make a couple of hooks from an aluminium offcut and pop-rivet them to the hardboard ceiling in the right place to hold the plumb-lines for sighting fore-and-aft. Screw a small hook into a joist to take the plumb-line for sighting spanwise. Hang M20x35 bolts & nuts on light string of suitable length. Wilma sights spanwise & I sight aft while drilling with TC-tipped lip-&-spur bit in cordless drill. Makes a good spot-hole in the BID tube both times. Centre-pop with long 3/16" centre-pop from Axminster Power Tool Centre. Not sure if 5mm bit will catch pop-mark so try first with long-series 2.5mm bit. It just seems to be polishing rather than cutting. Switch to 5mm long-series bit and it gets through eventually. Change to mains-powered drill with higher speed after starting bottom hole and that goes through a little faster. Drill bit looks a bit the worse for wear, so swap to second one for second hole. It goes through much quicker, both top & bottom. Re-chuck bit almost fully out of chuck and take holes through to lower skin. Decide it would be a good idea to drill the holes in the bottom of the BID wells in the lathe before fitting, to get reasonable concentricity. 305.9
23 Try BID wells for size in holes. With a bit of fettling they fit. Trim BID wells to 50mm long and centre-drill bottom faces in lathe. Open up to 5mm. Spend some time looking for suitable dowel to hold alignment while putting BID wells in place. Has to be either something fairly soft that can be sacrificed if it won't release and I have to drill it out, or else something I can wax and guarantee to get out. Not wanting to turn up a mandrel and polish it, eventually find that long plastic wallplugs in green size are just about right. Check by calculation and measurement whether pip-pin is long enough to clear both the BID tube around TP6 and the bottom of the BID well. Looks like it will be marginal, so consider how best to shave BID tube down a bit to let well sit closer to TP6. The 14mm lip & spur bit is no good, as the centre point is much too small for the 5mm centre hole. Decide to buy cheap spade bit and butcher it to form a counterbore by filing down centre and flattening faces so they don't cut first at the perimeter. 307.3
24 Buy 10mm & 13mm spade bits at Homebase.
27 Altimeter arrives from Airworld (£183.07). Vacuum-clean thoroughfares in garage as Wilma suspects dust kicked up when moving around may be contributing to my coughing at nights. File down 13mm spade bit so cutting edges are parallel instead of raked forward, and centre spike fits in 5mm hole easily. Try it out with cordless drill on starboard side and it cleans down to metal quickly. Hole is slightly offset to aft & so metal visible only in forward half. Repeat on port side with identical results. Check BID wells for fit and decide to coat circumference of bottom ends with 5-minute epoxy where fettling of the corner has caused small air holes in the weave. It's important to keep any resin from getting into the inside of the wells and preventing proper seating of the pip-pins. 307.9
29 Re-check BID wells and find some pinholes left, so re-coat outsides with 5-minute epoxy again. 308.1
30 Decide that the plastic wall-plugs will not provide enough security against epoxy getting inside the BID wells, and I will have to make something to fit properly, so cut off a couple of 125mm lengths of 1/2" aluminium bar. (Could have made just one, but having 2 allows both BID wells to be fitted in at the same time.) Set to run as true as possible in 3-jaw chuck with less than 25mm gripped. Centre-drill end and support on hard centre. Turn down 100mm length from end until cutting over full circumference. Check size & it fits BID well nicely. Turn down 45mm from end to 5mm OD. Have to hand-chamfer the end as tailstock and centre prevent starting the last few cuts right at the end. Try first one and it fits the BID well beautifully, but seems reluctant to pass right through second hole in TP4/TP6. Easing the top of the hole with the carbide-grit file towards the direction of tilt helps, but mandrel still not going home fully with BID well attached. Eventually realise that the BID & flox around TP6 has not been cleared quite enough (the spade bit was only 13mm and the BID well is about 14mm OD). Running the 14mm TC-tipped lip & spur bit into it again seems to chip off enough to let the BID well seat properly. Notice that both sets of holes are somewhat off the vertical, despite my efforts with plumb lines. As they are both tilted towards the south at the top, guess that the 5mm drill must have walked slightly on starting both bottom holes. It now becomes clear that the mandrels I am making will be essential to ensure correct angular alignment of BID wells and holes - something the none-too-straight plastic wallplugs would not have provided. Make second mandrel as first one. Dig out foam to form small recess around top of well and vacuum out waste. Degrease BID wells in acetone. Mark mandrels P & S as they seem to be a better fit one way round, and wax them. Clean hands and dry off BID wells. About 24C and 70% RH, so turn on dehumdifier and set fan heater to 3.5. Mix 2 strokes epoxy. Add a couple of small doses of flox, leaving it still fairly runny. Decant about half off, and add another small dose which makes it pretty thick and non-slump. Fill recess with this thicker stuff, and paint all inside of well with it. Fit BID wells onto mandrels and paint outsides & bases with thinner flox. Insert and add more runny flox around it. Wiggle around to release air bubbles. Trying not to overdo it, gently warm with hot-air gun to reduce viscosity and help bubbles out. Leave to cure. At bedtime, still around 24C but humidity down to 64%. 312.9
31 Turn off heat and dehumidifier. Everything looks well cured, although a couple of tiny pinholes have appeared. They can easily be filled. Remove mandrels reasonably easily with slip-grip pliers. Cut off protruding parts of wells with hacksaw, and smooth off with TC file, trying not to cut into surrounding peel-ply. Start to drill out holes in TP4/TP6 to 1/4", but bit seems to be having a hard time. Swap to a newer bit and things go better & faster. Check pip-pin for fit and it seems to be unwilling to go fully home. Remove tailplanes from jig and turn over so drain hole can be enlarged. Find that there are some lumps of flox around TP6 pushing the drill off-centre. Remove them by a combination of drilling with small bit and chiselling. After cleaning up TP6 surface thus, pip-pins go through (unmounted) tailplanes OK. One drain hole has opened up so much that I can reach the tip of the pin with a finger & so put it in and out without tools. Extractor tool does not work without friction to restrain pip from rotating while trying to engage bayonet, but no doubt with tailplanes mounted, the positioning of TP6 on TP4 can be used to apply some friction. Deburr outside of holes on TP4 (alas, very obviously not central!) which were causing slight stickiness as tailplane was slid off. Decide that with the vindication of the mandrels for aligning the BID wells while curing, a similar approach is worthwhile for the drain hole tubes, to ensure that they do not obstruct the balls at the tip of the pip-pins. Cut off 2 50mm lengths of 5/16" ID paxolin tube. Find a 3/8" bolt which has had its head cut off and make a mandrel from it. Turn about 25mm length of 5/16" (= ID of paxolin tube) and 45mm of 1/4" (to fit pip-pin hole). 316.1

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