Europa #435 G-RODO Build Journal - 2015 08

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4 As Speedflow still don't seem to have the aluminium vise jaws for AN hose-ends in stock, order a pair from Motorsports Warehouse Dist. LLC on eBay.
7 Jack up steel fuselage dolly enough to straighten chipboard sub-dolly and clamp the broken piece with laths each side. Find a couple of lengths of steel angle that could be used to replace the chipboard. Will need bolts about 65mm long to secure it, but getting at the nuts could be difficult. Remove the split-pin on the starboard end of LG04 and replace with a temporary one from the commercial mixed assortment. Measure the one taken out; the replacements will need to be about 0.1" diameter.
8 Roll fuselage out onto drive. Find an unopened anniversary card left behind the seats since the party in June! Remove the port-side piece of chipboard joining the fore and aft parts of the sub-dolly. Offer up the 2 lengths of steel angle and mark where the bolts will go, clear of the wheel mountings. Cut off the 4th-side flanges in those areas with the angle-grinder and clean up with a file. Drill through 10mm in 4 places per length. Clamp the steel angles to the dolly parts and drill through 10mm. Fit 8 off M10 x 65mm coach bolts. Find another rough piece of heavier steel angle and similarly replace the starboard-side piece of chipboard with that. Remove brake line from slave cylinder; plug end of brake line and tape up exposed fitting on slave cylinder. Remove lockwire from brake and hub bolts. Dismantle brake caliper and undo all bolts holding stub-axles in place. Remove wheel and temporarily re-assemble brake caliper and stub axles to keep all parts together. Check that without the weight of the wheel, the retract lever can now be operated. Roll fuselage back into garage. Alas, when pushing dolly sideways to make room to pass, the port side angle pieces I've just fitted twist just as the chipboard piece had. Fortunately, can restore them by lifting the port side of the dolly, but will need to provide some means of preventing that in future - the single piece of angle across is not working as the bolts dropped through it are quite a loose fit. Probably by adding another crosspiece on the underside of the wheel supports and actually bolting through to secure it might do the trick - although it will be less handy and quick to remove when needed. 2314.1
11 Vise jaws for AN hose fittings arrive from Motorsports Warehouse Dist. LLC. Try them out and they seem OK. They tend to tilt slightly when a hose-end is clamped in the vertical vees, but are fine when the horizontal vee is used. Roll fuselage out onto drive. Realise that it would be less stressful on the sub-dolly structure as it now stands to have the castering wheels at the aft end. Jack up the metal dolly at each side in turn and swap the sub-dolly wheels fore & aft with each other. Find another piece of aluminium angle the same as the first one used as a crosspiece. Hold both in place, with vertical angles overlapping, and drill through original holes to enlarge to 6mm. Fit M6 bolts & nuts to secure. Drill vertical flanges 5mm in 3 places and fit rivets to hold angles together. Remove the temporary split-pin in the end of LG04 and drive out LG04. Couldn't recall what I used before, so cut a 270mm length of 8mm brass rod and use that as a drift. Drop LG02 swinging arm. With retract lever in down position, LG08S is hard against the stop on the LG01 frame, but LG08P has a gap I can slip a ruler into. So, starboard stop needs to be ground a bit shorter. For access, jack up the dolly as far as it goes, and remove again the new rear crosspiece just fitted. With the gear up, there is room to get the power file in to work on the stop, so grind a bit off with that. The edge of the welded-in end of the tube is becoming obvious. Check gear down position again. Needs a tiny bit more removed at the outboard side of the stop. Retract again and file more lightly at outboard side. Definite gap now around part of the circumference of the end piece - will probably have to remove it completely so the tube can be filled with thickened Redux. Lower gear and now both LG08 touching the stops together. Drive in LG04 pin to connect LG02 swinging arm and try operation again. Now when lever in down gate both LG08 are equal (small) distances from the stops. [Now as I write this up, I can't understand how in the previous sentence both LG08 could touch the stops when I checked before connecting the swinging arm - is there some movement in the mechanism that I haven't spotted? Will need to re-visit that and check.] Try filing the down gate with a Swiss file to allow more "down" movement but that is very slow and tiring. Change to the narrow belt on the power file and that fits nicely in the slot and grinds it back easily. Also file the up gate back to near the mark I made so that getting it up is easier too. Now find that the downlock latch is fouling the guide plate, preventing the lever going any further aft to reach the new end of the down gate. Don't know what to do about that, so stop and re-fit the aft crosspiece on the sub-dolly, then roll the fuselage back into the garage. Pushing it sideways is now easier and the port side of the sub-dolly does not twist, so at least that work is successful! 2317.4
13 Decide that starting to enlarge the down gate in the retraction guide plate was a bad idea and I should have just replaced the retract lever instead. I'm concerned about the integrity of any build-out I might make on the forward edge of the down gate, as if that crumbled or departed in service it would no longer hold the linkage over-centre. I really need to replace both the FL24 guide plate and the LG12 retract lever in order to get the retraction system working properly. It should be possible to remove the guide plate from the tunnel with carefully applied heat to soften the Redux - perhaps the resistors I used for Redux curing could be run at higher temperature, which sounds safer than using a heat gun, which could easily damage the tunnel. Nobody answering the phone at the Europa factory, so send e-mail to Karen asking for price and delivery info on LG12 & FL24. Check again the supplied SP90/F8 against the hole in LG04 pin and it definitely won't go in. The data tables on the LAS Aerospace website show that item as 7/64" diameter, which is 0.109375". The part quoted as equivalent in the kit is MS24665-306 is not only a different length but also 3/32" diameter (about 0.09375") so that should fit OK since the one I removed was about 0.1". Order some MS24665-302 (stainless, 3/32" x 1") from LAS Aerospace, and some zinc chromate primer to make up the minimum order value. Remove retract lever handle. Remove downlock latch and put parts in a plastic bag in box 4. The screw holding the guide plate will not turn. Remove, with some effort, the stiffnuts under the guide plate rubbing strip and store them in the bag with the handle etc. The washers stay bonded to the SRBF. Realise as I look at it that I don't really need to replace the guide plate. If I fit a new retract lever and arrange it to line up with the forward edge of the down gate when the linkage is over-centre against the stops, then the aft end of the down gate is not so important, and the space there can be filled without any fear of danger should the filling fail in service. Wedge the retract lever as far back as it will go using a split mixing stick jammed into the down gate. Check how stops fit against LG08. Port side will not admit a 1.5 thou feeler gauge (the thinnest I have available). Starboard side will admit a 5 thou blade but not 6 thou. Viewed from below with a light behind, the (somewhat uneven) gap at LG08S is clearly visible but LG08P appears to be just in contact with the bottom edge of the stop. The starboard stop can be over-filled with thickened Redux and fettled back to make contact at the same time as the port one. While underneath, try moving the swinging arm and there is very slight movement detectable. While trying to move the swinging arm, feel all the linkage joints and all are firm except for that between the LG08 and the LG05 top reaction plate that is secured by MS20392-5C37 clevis pins where very slight movement can just be felt. Rig a new length of nylon filament through the bore of LG09 pivot shaft and hang spanners on the ends as weights. Try to check visually with the nylon line if the clevis pins are over-centre with respect to LG09 pivot and LG04 pin, but it's very hard to tell because I can't get my head into the right place to see along the line. As best as I can tell, the axes of the 3 items are just about in line, not yet over-centre as I'd hoped after grinding back the starboard stop, so the port stop will also need grinding back. I'm coming round to the idea proposed by a builder from USA of machining up test bosses, with ends same diameter as LG04 pin, to fit on the ends of LG09 and the clevis pins. A straight-edge can then be rested on either side against all 3 items to check for over-centre. 2318.7
14 No response yet from Karen at Europa. Leave another phone message and send another e-mail adding a MS20392-5C37 clevis pin to my requirement. Split pins and primer delivered from LAS Aerospace. Check that the split-pins fit in LG04 - they do - and store in box 4. Start to think about how the stub fittings might be made. LG04 pin measures 3/8" diameter and head of clevis pin measures 1/2" diameter. Bore of LG09 pivot shaft is hard to access for measurement but appears to be about 1". Find some lengths of aluminium round bar in various sizes. Cut about 40mm off a 1" bar and try it for size in LG09 bore - feels slightly sloppy, but movement barely visible. Only goes in about 7mm because of the roll-pin. Will need a collar of about 100m to bring it out into line with the end of LG04 and a 3/8" diameter boss about 10mm long. Cut off a 30mm length of a 1.25" bar. It will be necessary to take the workpiece out of the lathe to check the diameter that is to fit into LG09, so for repeatability will need to hold the 3/8" end in a collet. The Cowells collets only go up to 1/4" and I don't (yet) have a lathe adaptor for the ER25 collets, so I'll have to make a custom split collet. Find a previously-made split collet that can be bored out to 3/8". Make 3 hacksaw cuts across the end of the 1" bar so it will have a bit of spring when bored out to fit on the head of the clevis pin. 2319.5
15 It would be useful to have an ER25 lathe adaptor anyway, so have a look at what Arc Euro Trade offer. The "proper" lathe adaptor is quite expensive and will need a chuck faceplate to attach it to the lathe spindle, but there is a much cheaper adaptor with a hex body that could be gripped in the chuck, so order one of those. Hacksaw the 1" piece of aluminium bar to about 30mm then grip on non-slit end and face off slit end. Double-check size of LG04 using the Tesa metric micrometer and it is pretty exactly 9.5mm. Reverse workpiece in chuck, face off to about 25mm long then turn down the outer 10mm length to 3/8" diameter. Face off both ends of the 1.25mm workpiece to about 27mm long and turn down the outer 10mm of the second end to 3/8" diameter to form the test boss. 2321.6
17 Still no response from Karen at the factory. Phone again and this time she answers and takes my order for a replacement LG12 retract lever and a MS20392-5C37 clevis pin (to make the checking of the bore in the test boss easier).
18 Replacement retract lever LG12 and spare clevis pin MS20392-5C37 arrive from Europa factory, and ER25 collect chuck fitting arrives from Arc Euro Trade. Mount ER25 adaptor in lathe chuck and try to true up with dial gauge. After several attempts, it seems that a run-out of about 0.05mm on the inside of the taper is the best I can manage. 2322.1
21 Put the 3/8" end of the 1" diameter workpiece in the 9-10mm ER25 collet and tighten carefully so as not to disturb the position of the ER25 adaptor in the chuck. Centre-drill just over 10mm deep with largest centre drill. Remove tailstock for access and start to bore out 10mm deep with smallest boring bar. 2322.8
22 Continue boring out 1" workpiece to 0.5" to fit the head of the spare clevis pin. I had intended to make it a push-fit (hence the sawcuts to give it a bit of spring) but didn't reduce the depth of cut enough when I got near to size, and the spare clevis pin is a sliding fit in the bore. Remove the workpiece and try it on the heads of the clevis pins installed on the airframe. Fortunately it turns out the tolerance on the heads of the clevis pins must be quite loose, as it fits onto the port one with a light push but won't easily go onto the starboard one. Resting a straightedge against the fitting and the LG04 pin shows that the fitting needs to be shorter. Return workpiece to lathe and get running as true as possible in the collet (which is harder than I expected - should have marked it for orientation). Turn down most of external diameter to about 17mm, leaving a flange of about 2mm at the original diameter. This should make the "fingers" more springy, to compensate for the shortening in the next operation which will make them stiffer. To save a lot of facing, hacksaw off the end and then face to about 6mm long, leaving about 3mm bore depth. Remove from lathe, try fitting again and port is now a bit tighter to push on; starboard is still impossible. Run scraper around the end of the bore to see if a slight chamfer will help, but it makes no discernible difference. Replace in collet and rotate in collet until bore running true by eye. Take a few very light cuts with the boring tool until the head of the spare clevis pin just slips in without friction. Remove from lathe and try again on the airframe. This time it will just go onto the head of the starboard clevis pin with some effort, and is still tight enough on the port one to stay in place unaided. Check with straightedge how long the full-diameter collar should be on the top fitting - about 10mm. Fit the 1.25" diameter workpiece to the collet on its 3/8" boss. Start to turn down the outer 10mm but can't find a spindle speed and feed rate that avoids chatter. Eventually give up, as it seems to be a combination of the large turning diameter and the long overhang of the ER25 collet adaptor that is causing the resonance. Remove the collet adaptor and fit the old home-made split collet in the chuck, marking its orientation. Face it true then bore it out to 3/8" to fit the boss of the workpiece. Insert the workpiece and tighten the chuck; now it runs much truer on the outside diameter and turns smoothly. Mark the workpiece for orientation and turn down outer 10mm to about 26.5mm. Remove from lathe and check against LG09 bore - still well oversize. Return workpiece to lathe; swing topslide 15 degrees and turn a short taper on the end of the workpiece to help gauge the fit. Remove and try for size in LG09 - will need most of the taper removing. Return workpiece to lathe, reset topslide and take about another 0.5mm off the diameter. Check fit again - getting quite close now. Take repeated cuts of 0.025mm, checking between each one for fit, until it just can be pushed in with some effort. Take one more turning cut of 0.0125mm and face off turned section to about 6.5mm long. Now it fits just about perfectly and measures 25.66mm diameter. With both test bosses in place on port side, check with straightedge for over-centre. With the retract lever in the original down gate position, the shafts are definitely are out of line in the wrong direction - ie the clevis pin axis is still too far aft. Jamming a mixing stick in front of the lever brings it to the state where all 3 shafts are pretty exactly in line - no rocking of the straightedge can be detected on either forward or aft sides. I'm so glad I took the trouble to make these test bosses - they make the checking of the over-centre easy and give much more confidence in the result than trying to sight along the ends of the shafts, with their different diameters and different lengths. 2326.5
27 Open garage door for better light. Drive out LG04 pin with brass drift and drop LG02 swinging arm. Move retract lever to full up gate to allow access to over-centre stops. Notice that the joysticks (resting fully to port) move slightly at the last bit of forward movement of the retract lever, and it's quite repeatable. Pause to investigate what's touching. The contact point is between the underside of the central aileron link rod CS12 and the top side of the flap pushrod FL20, close to the aft-most bend in the pushrod. There is slight contact with the sticks over to starboard but a bit more with the sticks to port. The pushrod will need to have that bend increased very slightly to keep it clear of the aileron link rod. Once it's out, I should trace the current shape of the pushrod onto a flat surface so I have a reference to check how much the bend has been increased. Looks like as little as 10mm relief at that point would solve the problem. Put the retract lever back in the down gate and do a visual check from underneath of the gaps between the stops and each LG08; touching at port (where the stop is so far untouched); not quite in contact at starboard side (where it has been ground back). Move retract lever to up gate again and crawl underneath with power file. Lightly dress the end of the port stop, trying to keep the power file true to the angle at which LG08 meets the stop - which actually means chamfering the stop very slightly at the bottom edge. Find that with the downlock latch removed I can quite easily move the retract lever between the gates from underneath, which saves a bit of crawling out & in. Pressing the LG08 assembly forward, it appears that both LG08 are now touching the stops together. From my trial with the test bosses I feel that just a tiny bit more movement is needed to ensure over-centre. Move retract lever to up gate again and lightly brush both stops with the power file, being careful to stay clear of the brake pipe at the starboard side. Get a cigarette paper and place it between each LG08 and its stop while pulling the retract lever aftwards. The cigarette paper is gripped firmly at each side, proving that the LG08 are contacting the stops equally, a very satisfying result. Lift up LG02 swinging arm to align with LG07 etc and drive the LG04 pin in again. Fit the test bosses to the port-end bore of LG09 and the head of the MS20392-5C37 clevis pin. Ensure the retract lever is fully aft in the down gate. Crawl underneath as it looks easier to check the lineup from there. Lay a steel rule against the forward faces of the 2 test bosses and the LG04 pin, and it rocks slightly (~1mm at the end) on the centre boss, proving that the clevis pin is forward over-centre with respect to the axis of LG09 and LG04 - an even more satisfying result! Swap the test bosses to the starboard side and do the same test there. Similar movement that side. Drive out LG04 pin and drop LG02 again. Examine the faces of both stops carefully using a mirror. The port one shows no signs of breaking through the edges of the end plate so should be fine with a coat of anti-rust primer. On the starboard one, the end plate is detached over quite a lot of its circumference. Lever it out and I can pull it off in my fingers. Clean up the inside edge of the tube with a scraper. Tube is about 40mm long by 15mm ID so internal volume is about 7cc (=7ml). Won't need much Redux to fill it. To be sure I've got enough, mix 20g + 8g Araldite 420 (Redux) and add 2 doses of flox to thicken it to non-slump consistency. Fill starboard stop tube with it, using a split mixing stick to push it as well in as possible and minimise voids. Leave it slightly proud of the end and wipe excess off the outside of the tube. 2329.5
28 Redux/flox sample appears well enough cured to sand, although obviously it won't have developed full strength since it has been curing at room temperature. File off the Redux/flox at the end of the starboard stop tube to bring it flush with the metal. Using an ordinary file allows me to feel when I'm getting down to the edges of the tube. Drive LG04 pin in, then remember I need to do the cigarette-paper test again without the weight of the LG02 swinging arm, so drive the pin out again. Check that a piece of cigarette paper is held between each LG08 and its stop when the retract lever is fully aft in the down gate - satisfactory both sides. Lift LG02 and drive LG04 pin in again. Review in what order things need to be done. Now that the linkage is going correctly over-centre, next need to fit the new retract lever to LG08P, also the Mod 51 LG11 strut, then check if the up gate needs further relief to prevent the wheel or tyre contacting the brake master cylinder or anything else in the tunnel. That would best be done with the flap mechanism disconnected to prevent any interference. Replace the stiffnuts on the 2 screws holding the retract lever guide plate (although, having tried to remove it, I don't think that assembly is going anywhere with or without the nuts!). Remove FL19 flap horn plate from LG08S and horn assembly from end of FL20 pushrod. Remove AN5-11A bolt securing MW5 rod-end bearing at aft end of pushrod, and replace bolt & washers temporarily in lugs for storage. Start to pull pushrod out forwards then realise it won't come out because I've replaced the fuel tap assembly that prevented it being inserted in the first place! However, a little more thought and some wiggling shows that extending the chamfer I had to make on the tunnel bulkhead support layup should let it come out. Try filing but that is a bit slow and awkward. Instead cut off a sliver with a hacksaw blade in the pad handle, smooth cut edge with TC file and now the pushrod comes out without much bother. Undo (with some effort as they had Duralac applied on assembly) the bolts holding LG12 to LG08P and the bolt at the top of the LG11 strut. Remove LG12 and compare it with the new one, which is tumble finished rather than brushed. New one is also slightly larger profile in a few places, but that should not be a problem. Mark fine felt-tip lines on it 50m from the bottom end and at the start of the curve at the corner. Find a piece of steel bar 0.375" x 1.5" x 24", and an aluminium bar 0.5" x 1.5" x 31". Clamp LG12 in vise with the first marked line lying along the top edge of the aluminium soft jaws. Clamp the 2 bars to it, one each side, leaving the rear one slightly up from the vise jaws for bending allowance. Double-check that I am bending it in the correct direction. Even with the extra leverage, it's quite a push to make the bend. Do it in small stages, checking against the original until it looks about the same. Remove from vise and offer up against original one; the bend is just a little more, so put that section in the vise and squeeze it slightly to straighten the bend a bit. Clamp the LG12 in the vise on the second line. For this bend, the front lever will need to be spaced off to clear the first bend, so cut off about 95mm of the aluminium bar and clamp it against the front face together with the rest of the aluminium bar, and the steel bar behind. Bend as before, checking with original. Remove from vise and place both LG12 together to check - looks quite good, although the new bends seem slightly sharper than the original ones. Put bottom end of lever on flat surface and check offset of upper part - about 13.5mm. Manual calls for 10-13mm so again straighten the bottom bend slightly in the vise until the offset is about 12.5mm. Notice that there are small marks where the ends of the steel bar was - I had not checked the smoothness of the end of the bar and some burrs on it have made small dents in the surface of LG12. Dress them out with a fine Swiss file, then smooth off with wet-and dry and finally the ScotchBrite wheel. 2332.9

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