Overview
With the co-pilot's throttle installed the final installation of the pilot's throttle / quadrant could now be undertaken
Installation
A series of careful measurements were undertaken to allow the Bowen cable to be cut its correct length.
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| Mounting bushes |
After trimming the wire lock collet was fitted, nipped up and both quadrants connected to test their operation which seemed smooth, once completed it was time to finish the installation of the throttle and choke cables.
Holes were drilled in the bulkhead at the time of the console manufacture.
To locate the cable ends two [2] T washers were machined from aluminium bar with a 0.5 mm boss, alodined, assembled as shown.
The cables chosen were McFarlane 101D072 - 6 foot Dual Cable allowing the choke and throttle to be directly connected to the carburetors without having to install splitters or cranks at the firewall.
These cables ends were fitted with AN665 Threaded Clevis to permit attachment of links from the lever's in the quadrant.
With the lever and cables placed in the neutral position the connecting links length were calculated. Both links were then fabricated from 3.2mm x 12 mm strip of 2024-T3 with strips of 0.040'' 2024-T3 riveted at one end with 3/32'' pop rivets to form a fork with all parts alodined before final assembly.
Note: links were installed to reduce the chances of binding caused by alignment and to place the connection point at the two [2] access openings.
The choke link was a straight link but the throttle required a turtle link to clear part of the upper throttle frame with the rear throttle clevis directly attached to the throttle arm.
To make assembly / disassembly easier the throttle quadrant was modified with a cutout in the back plate to allow the throttle clevis pin to be pushed out, additionally two more access openings were cut at the front and one at the rear.
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| Front view main access hatch Front plate of throttle deleted to improve access to connection points |
After many - many and did I say many installation of the console it was found that leaving the wire attached provided the most efficient means of re-assembly. Also it was found that the front cover of the throttle could be deleted and was removed replaced by packers at each of the mounting points providing a significant improvement in access to the mounting points.
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| Link and cable attachment from rear Both links attached using a AN3 bolt and nut Wire cable attached to the throttle for ease of assembly Front plate is deleted here |
The next task was to manufacture four [4] covers from 2024-T3 0.025'' sheet, cut size, painted to match the console except one [1] which was painted black and will be used to mount the headphone plugs.
To check operation of the cables the console was mounted and the throttle and choke connected. A issue was noted with the operation of the throttle with a distinct small bind and it was determined that deflecting the cable at the bulkhead solved the issue. An angle was fabricated from 0.040'' - 2024-T3, alodined and the throttle cable was secured with a clamp in the deflected position and this seemed to solve the issue.
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| Bracket pilots quadrant |
Note: No reason could be found as the choke was smooth when checked but may have been that cable but I did not want to swap at this point.
Next the rear throttle was disassembled and re-connected and it was now found that it now not as smooth as when tested, I suspect the McFarlane cables. Again an angle was fabricated to support the outer to hold it in position in operation. This was fabricated from 0.040'' - 2024-T3 aluminium, alodined and mounted to the fuselage side. A rubber grommet supported the cable outer limiting its movement under pressure. This seemed to smooth up the systems operation.
At this point the covers were fitted, fixed using anodized M4 aluminium screws with X-large head M4 used to secure the console just because they look cool..!
Mounting bolts for the rear were changed to black M5 aluminium again just for appearance.
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| Pilots Console |
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| Throttle handle and keyed mounting bracket fixed using M4 cap head screws to lever with three [3] x M3 cap head screws at handle |
Comments
It's finished with a lot of work requiring with a number of changes while maintaining the original concept.
A push rod as supplied with the factory kit would be the best way to connect the two quadrants but at the time a cable seem the simplest way to connect based on the point of airframe assembly.
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| That was fun ! |
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