left-arrow

Europa #435 G-RODO Build Journal - 2019 06

 right-arrow
index sitemap advanced
search engine by freefind
tickgo to list of milestonestick Navigation & Acknowledgements
day notes hours
1 I was very dissatisfied with the outcome when trying to make a 14mm hole in the offcut of stainless steel firewall, using a step drill. As a different approach, I thought perhaps I had a 14mm blacksmith's drill but for some reason the sets have 2 off 15mm and no 14mm! I don't think a holesaw was very neat either on the SS sheet, so search online for hole punches. Find that Q-Max cutters are still available so order a 9/16" one from Cromwell, along with some drill bits.

Hold the 100-06 braided hose in the horizontal angle of the magnetic vise jaws and cut it at the marked line with a large reinforced cutoff wheel in the Dremel tool. Will have to make a bush for those large wheels because the hole is too big for the Dremel arbour screw and it's almost impossible to get it centred. Despite the resulting vibration, the cut is pretty tidy. Seal the end of the hose offcut with masking tape. Remove the masking tape from the new cut end of hose and tidy up a couple of tiny stray wires with gentle touches of the cutoff wheel. Remove hose from vise jaws. Hold #101-06 hose socket in horizontal angle of jaws. Carefully introduce hose end to it and rotate while pushing in. Quite easy to get started but doesn't feel as if it's going in very much further. However, a quick check at the thread end shows it's nearly all the way home - this seems much easier than before, but maybe practice makes perfect, and a really clean cut of the braiding was obviously helpful. Another twisting push gets it tight against the end of the internal thread.

Wrap insulating tape around the hose against the tail of the socket to monitor the depth of insertion. Hold in the vertical angle of the jaws and dribble some 10W-30 oil into the socket & hose. Likewise lubricate nipple. Carefully place nipple into hose & socket and start it on the thread while ensuring that hose does not back out of socket. Wind nipple in using 11/16" ring spanner, continually monitoring for push-out. Switch to grip in horizontal angle of jaws and tighten it until I just can't get my thumbnail into the gap between nipple nut and socket. All looks good, with slightly less damage to the anodized surfaces than the first assembly. Cap the new open end and store the made-up hose in box 27 again.

Identify an offcut of stainless steel firewall sheet material that could be used for sealing around the rudder pedal shafts. It would be good to have underneath it some of the rubber "firewall fabric" to seal closely to the shafts. The steel sheet will have to be separate top & bottom parts, but the rubber sheet could be one-piece with slits to get it around the shafts. There seems to be plenty of the 100mm wide rubber strip that would do for that, and there is also plenty of 50mm wide strip that can be used for the rudder cable seals. To fit the cable seals, I will have to dis-assemble the rudder pedal shafts to release the starboard firewall panel. But before that, I need to to mark on the firewall panels the lines of the rudder cables, over the full extent of travel. That should enable the rudder cable seals to be made and fitted without a trial-and-error stage in the process. Fitting anchor nuts for the shaft seals is also likely to be easier with the rudder shafts loose, but the hole positions need to be marked first with the shafts in the working state. 		3077.1
3 Hole punch delivered from Cromwell.
4 Check the size of pilot hole required for the 9/16" Q-Max hole cutter. The screw is 5/16" x 22 BSF and the head socket is not 7/16" as on the instructions but 7/32" AF. Remove the temporary screws holding the two upper stainless steel firewall panels together. Centre-pop the centre of the marked washer position on the port upper panel. Drill there 3mm and open in stages to 5/16". Grease all the Q-Max cutter parts and assemble onto the pilot hole. Hold the die nut in the bench vise while turning the screw with an Allen key. Cuts through quite easily and the hole is very clean on the cutter side, but there is a pronounced lip on the die side. It's resistant to the deburring tool, so clean it off with a step drill. Trial assemble the AN837-6D elbow on the panel with the M14 washers and AN924-6D nut. Looks good. Offer up the panel with the elbow assembled to the landing gear frame and it looks very satisfactory. 3077.9
5 Roll fuselage out onto drive. Assemble AN837-6D elbow on the port upper firewall panel with the M14 washers and AN924-6D nut. Blow out the hose assembled for the tunnel with the air line. Fit hose to back of elbow and thread hose aft through landing gear frame into tunnel. Fit lower end of hose to elbow at aft end of wheel well. Try the fit of the hose clamps with temporary nuts on the bonded-on studs. The lower 2 are OK, but the forward one is just out of reach from underneath. Undo the hose again from the firewall elbow to get at the front clamp.

Decide that it's OK now to fit the hose clamps with stiffnuts. Using a dab of grease to hold the washer in place, fit a stiffnut to the forward stud by reaching in through the landing gear frame. From underneath, remove in turn each of the temporary nuts on the other 2 clamps and fit a washer and stiffnut. Apply inspectors lacquer to each nut. Check that the hose can be connected to the firewall elbow by reaching up from underneath. It's fiddly but do-able (have to press the hose outboard to get it square to the elbow threads) and there is just enough room to get the aluminium spanner on the hose-end nut to tighten it. Disconnect the hose again, cap it and dismantle the elbow from the firewall panel.

Re-fit all stainless steel firewall panels.

Measure the rudder shafts for the seals. At the starboard side, the forward shaft is 19.12mm OD and the aft one 19.14mm OD. Between the shafts is 13.84mm and across the outside of the shafts is 52.10mm. At the port side, both shafts are 19.12mm OD. Between the shafts is 13.54mm and across the outside of the shafts is 51.88mm.

Swing rudder hard to starboard and mark horizontal and vertical lines around the slots in the firewall panels for location of the rudder cables. Repeat with the rudder swung hard to port, and then also check at centre.

Centre-pop and drill 2.4mm the tabs on the bottom firewall panel that overlap the undersides of the footwells. Drill out to 4.8mm. Remove lower firewall panel. Open counterbore in footwell to 5/16". Countersink the back sides of the anchor nut rivet holes with a 7mm drill bit. Squirt some red Hi-temp silicone RTV into the 5/16" holes. Place the port anchor nut, drill a rivet hole through it and set a TAPK36BS rivet in it. Drill 2nd hole, set rivet there while pressing anchor nut firmly against footwell. Repeat process on starboard side.

Remove the rest of the stainless steel firewall panels - have to dismantle the rudder pedal system to get the starboard panel out. Roll fuselage back in.

Draw up the rudder shaft seals in CADintosh. 		3081.6
6 Amend the rudder shaft seal drawing slightly, print out and cut one each port & starboard to shape for the stainless steel outline. Offer up to rudder shaft holes in side of footwells and the sizing looks fine.

Cut a piece of 50mm-wide rubber sheet "firewall fabric" to cover the area around the rudder cable slot in the starboard stainless steel firewall panel. Centre it on the slot from the aft side and mark the slot outline on it, and the line and extent of the slit for the cable. Check fit, ensuring that it will remain clear of the underlying patch. Punch holes (largest available on punch pliers) near each corner and with the slot outline aligned, mark through one of them with a fine felt-tip pen onto the back of the firewall panel. Centre-pop that mark then drill 3/16". Fit a temporary 10-32 screw through the firewall and rubber to maintain alignment, check slot mark alignment and mark a second hole. Remove screw and repeat for remaining 3 holes.

Soak the card template off the firewall panel with unleaded petrol and wipe off residue of 3M Photo Mount adhesive. Apply some red Hi-temp silicone RTV to the overlap outboard of the cable slot and to the forward face of the rubber. Offer up rubber to aft face of firewall panel and insert a stainless steel 4.8mm x 8mm rivet in each hole. Fit a M5 washer to each rivet in turn and pull it. First rivet fails to set because I hadn't bothered to run the compressor at first - I was just using the residual tank pressure from yesterday. Rivet sets OK once tank up to full pressure. Clean off excess RTV with kerosene. 		3083.2
8 Cut a piece of rubber "firewall fabric" to size for port rudder cable seal. Attach the lower firewall panel to the starboard upper one with a temporary screw, so as to align the marks made for the rudder cable position. Position the rubber sheet behind the panels and mark it in a similar way to the starboard one for location and cable slit.

Only 3 rivets can be used here because of the way the lower panel overlaps and abuts the upper one. Punch the rubber in 3 places. Clamp it to the panels with cleco clamps and mark through the holes in the rubber onto the steel sheet. Remove the temporary screw to separate the panels. Centre-pop and drill the marks 3/16", then deburr.

With unleaded petrol, remove the card template from the lower panel and wipe off the adhesive residue. Place the rivets through the panel to hold the rubber in alignment. Fit a washer to each in turn and set the rivet.

Realise after doing it that I didn't apply any RTV to the rubber-steel interface, but I don't think that is really vital and anyway I think I can probably squeeze enough into the edges of the rubber to make a seal. 		3084.3
15 Print out 3 copies of the rudder shaft seal drawing; one for the rubber parts and 2 for the steel parts.

Cut 2 pieces about 105mm x 80mm from the "firewall fabric" rubber stock.

Cut the offcut of stainless steel sheet into 4 pieces each about 100mm x 60mm. 		3084.5
17 Although ProjectLibre provided a good forward view of the remaining work, it doesn't seem to work well when I come to entering actual dates. It doesn't accept changes to the calendar either. Look around online and after dallying unproductively with a couple of cloud-based products, find another open-source item, GanttProject. I hoped I might be able to export in MS Project format from ProjectLibre and import that file to GanttProject but that process does not work. Anyway, it's not too troublesome to copy & paste tasks from one to the other, and the GanttProject interface is much nicer. The only drawback is that it doesn't seem to have some useful printing capabilities such as printing the whole project on a single sheet of A3. While re-creating the project in GanttProject, modify the structure in a few places for better reflection of dependants etc.
18 I tried making a hole in the "firewall fabric" rubber sheet with a 20mm grit-edged holesaw (the only tool I had anywhere near the right size). That worked, but the edge of the hole was pretty rough. Order a 20mm hollow leather punch from an eBay seller. For the hole in the steel sheet, order a 22mm holesaw from Screwfix.
19 20mm hollow punch delivered. 22mm holesaw collected from Screwfix.
20 Test the 22mm holesaw on an offcut of the stainless steel firewall sheet. First attempt ends with it snatching badly as it breaks through and wrapping it up around the drill. Straighten out the workpiece and try again with a flood of lubricant and very gentle pressure; that works OK. Check the size of the resulting hole against the free end of a rudder pedal shaft and it looks good, with satisfactory clearance.

Snip off the corners of the 4 pieces of SS sheet with the Tuff-Kut scissors, file off burrs and smooth all round on the ScotchBrite wheel. Cut out 4 of the paper templates and stick them onto the SS pieces with a light application of Evostik.

While the adhesive is setting, test the 20mm hollow punch on an offcut of the "firewall fabric" rubber sheet. It cuts easily and cleanly with no problems. The sample hole fits the end of a rudder pedal shaft nicely. Drop an offcut of the rubber sheet into a small container of unleaded petrol to see if will be OK to use petrol as a solvent for Evostik on the rubber.

Centre-pop and pilot drill 2mm the 8 marked centres on the SS pieces. For each of the holes in turn, carefully align the holesaw pilot drill with the pilot hole, then clamp the workpiece firmly to a sacrificial wooden block on the drill table. Flood the cutting area with lubricant and slowly advance the holesaw in short presses, re-lubricating if necessary, until it breaks through.

The rubber in the petrol appears totally unaffected so it will be OK to stick the templates to the rubber sheet with Evostik.

Deburr the edges of the holes in the SS sheet pieces with a fine half-round file. On the port lower piece, cut from the edge near the holes into the holes with Tuff-Kut scissors to form round-ended slots. Soak the part in petrol to remove the paper template, wipe off remaining adhesive and dry off. Markings now gone, so mark it again as port lower. Deburr with fine file, round off sharp corners and flatten some uneven edges with a ball-pain hammer on the anvil. Smooth off with ScotchBrite wheel. Repeat the process on the port upper piece. 		3087.6
21 Cut out and stick the 2 remaining paper templates to the "firewall fabric" rubber sheet blanks.

On the starboard lower stainless steel piece, repeat the process used on the port pieces: cut to make slots, soak off template in petrol, flatten edges, deburr, smooth off and re-mark. Repeat again for starboard upper piece.

Working on a piece of sacrificial hardboard on the vise anvil, for each of the 4 holes in the rubber pieces, carefully align the hollow punch with the circle on the template and punch out the hole.

Soak paper template off port rubber piece with petrol and clean up. Mark it port. Check alignment of slots in SS pieces with rubber. Clamp SS pieces to rubber in alignment. Centre-pop for fixings near corners and drill 2.8mm through SS and rubber. Drill out to 4.8mm. Try not very successfully to clean up holes in rubber with punch pliers. Assemble with temporary screws to check alignment - looks OK.

Repeat process with starboard rubber piece. Alignment with SS pieces does not seem so good; file edges of slots in SS pieces to improve it. Drill and insert temporary screws to check alignment. 		3090.1
22 Noting yesterday that some hardware supplies seem to be running low, order some rivets, anchor nuts and washers from LAS Aerospace. While on their site, also order some parts that will be needed for fuel pressure checking. Order some extra hose and ends from Speedflow.

Roll fuselage out onto drive for access.

Loosely screw rudder shafts together and screw down bearing blocks. Slit port rubber part from bottom edge up to holes. Fit to port end of rudder shafts. Offer up lower SS part. Put screws in each hole to check alignment with shafts - OK. Leave 1 screw in & drill through other hole. Re-insert screw, re-check alignment and drill 2nd hole. Offer up upper SS piece. Drilling forward hole OK, but aft one is obstructed by LG diagonal tube. Tight Fit drill it will not even go into the small space, so spend a long time making a custom 1/4" hex drill bit for hex angle driver. It works but not very well. Eventually give up and drill a new 4.8mm hole near the top centre. Realise afterwards that I could probably have put the SS part on the inside and drilled from there. Put temporary screws in all holes.

Repeat process on starboard side, except I can just get the Tight Fit drill in to make the upper aft hole.

Roll fuselage back into garage. 		3093.6
26 Poke around among the electronic odds and ends and dig out a couple of 25-way D-type connectors, both male and female - can't remember which is needed for testing the transponder loom to replace the missing identifier flags.
28 Hose and fittings delivered from Speedflow.
29 Hardware delivered from LAS Aerospace.
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 2019-08-04 21:00. 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.