Another Sunday working day that was a cold one but marginally warmer with the hangar doors closed.
T86 The underside of the tow bar was cleaned and corrosion treated. There is always a temptation to not bother with things that are ‘out of sight’ but not for us. Accompanying photo shows work in progress on the tow bar.
The tow bar rubber bumpers on the front of the cabin have now been repainted with rubberised paint to meet the quality of our restoration work.
The rubber sheet RAM previously refitted to the aerial assembly pedestal base has now been sealed along its bottom edge in the drainage channel. The last task on the RAM is to seal all the surface cracks and paint with rubberised paint to eliminate any water ingress into and behind the RAM.
Preparing and repainting the chassis of the T86 chassis continues, best described as not one of our favourite tasks. Two accompanying photos give a before and after priming with an anti-corrosive paint.
As we have been working on the T86 chassis the cover of the front spirit level was removed. The photo below illustrates the standard of our restoration.
LCP The simulator was run and the only problem noted was one of the four display monitors has an occasional jitter on the vertical hold.
All spare Argus 700 boards have now been removed from the LCP for winter storage. The installed Argus boards will be removed during the next visit. The damp environment in the hangar, especially over the winter months, is a sure way to cause computer faults.
One motor, the less corroded of our two, has now been completely dismantled. The rusted brake mechanism was secured to the top bell housing of the motor by three rusty Allen screws. I managed to get an Allen key in the socket of the screw and a tap with an hammer breaks the corrosion seal and luckily all three were removed. The brake disk itself was pulled from the shaft by screwing down two ¼” UNC bolts using holes for that purpose in the disk – see last Work Day report.
The next challenge was to remove the top and bottom housings. Corrosion around the joints looked like problems ahead but the solution was to tap around both end housings on the motor body and then using a block of wood to knock out the shaft from the brake end (top), gradually easing out both bearings and the shaft.
The job was a bit more tricky than described above, the following photos shows the progress:
Photo 12 – The top bearing after the brake mechanism has been removed. The bearing is rusted solid and doesn’t move.
Photo 13 – The bottom housing removed. Note the condition of the bearing which is A1 and still packed with original grease.
Photo 16 – Removing the bottom gear wheel that engages with a gear in the gear box.
Photo 17 – The rotor removed.
What next? The focus is getting one good motor for now. One replacement bearing is needed (so far) but I’m confident I can get replacements, due to age they are imperial bearings on a 5/8” shaft. I said ½” before but that is the shaft diameter for the gearbox gear. I am pretty sure the motor bearings are the same as used in the gearbox but I need to check. The other issue is that the stainless pins in the brake mechanism have rusted in to the steel parts. I need to give these parts a good soak in penetrating oil before I attempt to remove the pins. The last thing I want to do is break a cast brake fitting.
I’ve resistance checked the coils which look to be OK.
The next pedestal motor report will be when I have one reassembled and ready to run.
Resealing the edges of the RAM on the pedestal base was carried out. It was necessary to tape the edges in an effort to carry out a neat job.
Two more tasks remain the sealing of the RAM in the ‘trough’ of the pedestal base and the sealing and securing the RAM around the top of the base. This RAM has not been removed and has lifted slightly in places as shown in one the second photo above.
Time was taken out to remove the brake disk from the top of the spare pedestal retraction motor.
The task of restoring one good motor from two is taking place at 3rd Line but the necessary bolts to remove the brake disk were in the hangar stock.
Removing the disk revealed the next problem; it doesn’t look as though the Allen set screws will take a key. When our T86 was recovered, as well as the abandoned radar at Luffenham (from which our spare came), the RAM cover had been removed exposing it to the elements. With the motor upright rain water would have created a pond in the concave plate under the brake disk, hence the condition of the set screws.
Further corrosion treatment carried out in a wheel arch. Treatment is carried out after removing any loose rust (there’s no paint left in parts) using Hydrate 80 https://bilthamber.com/product/hydrate-80/ , apparently a superior product for corrosion treatment but time will tell.
The simulator was given a good run and remains serviceable. Before the LCP/simulator is switched on it is heated through using a fan heater for a few hours, essential this time of year.
To enable restoration of the Type 86 aerial assembly it was necessary to get power to the bearing and elevation brakes so they could be released to enable the hand cranking of the aerials to position them for different restoration tasks. Powering off the brakes was one of the first tasks. The pedestal has also been raised and lowered slightly following the restoration of the pedestal motor gear box on which a hand crank spigot is available, another task undertaken some years ago.
Hand cranking the pedestal is a slow and awkward task so the obvious answer is to restore the pedestal motor itself so the pedestal can be raised and lowered from in the cabin, as it was in the past. We have two pedestal motors, both recovered, their condition is not good but worth a go as they say. See the accompanying photos of the complete motor in ‘as recovered’ condition.
The manufacturer was Normand Electrical Limited. They were incorporated 25 Jul 1949 and ceased around 2005
They traded from Necoworks, North Street, Clapham Common, London S.W.4., Under the trade name of ‘Neco’ they had led in the field of geared motor units which they had pioneered in the 1920s. In the 1980s they were taken over by the Henderson Group and then passed to FKI, now Melrose, based in Birmingham.
First task is to is to dismantle the motor which is a bit of a puzzle if you don’t know how it was put together but a start has been made.
See accompanying photo of the brake mechanism being dismantled. Corrosion is obvious and will explain why the shaft does not rotate!
With the brake dismantled (almost) it is a case of working out so what’s next?
The bronze brake drum needs pulling off the shaft and unfortunately the puller doesn’t fit under the wheel and gentle prizing does not move it. Looking inside the case the coils look to be in reasonable condition so the main problem is bearing corrosion under the brake mechanism. The problem now is getting at it. The second motor will be retrieved this coming weekend to assess its condition.
How about a new motor? The original motor is imperial and new motors are metric and nothing is compatible. Wonder if there is a flange converter available?
A check on the RAM on the base of the pedestal to ensure it is all securely stuck down. The corner of one piece was then stuck down with Evo-Stick, the RAM had been slightly bent up on this corner and needed impact adhesive to secure in place. Next job on the RAM is to seal the edges and joins and will hope to do this next Saturday.
Repainting the tow bar took up most the day and is certainly no quick job with removing loose paint and corrosion, corrosion treatment, priming and top coating.
The air pipes and towing eye will be painted black.
Restoration of the top of the jacks and handles was started.
This restoration gives us the chance to restore such items as labels as can be seen in the photo above, it still requires a second top coat.
Note: The paint used is NATO brown as per the late Cold War period. The quality is ‘vehicle paint’ and resin based and good quality. Despite appearances it is matt, it has a shine which reduces over time.
The heater was left on during the day to warm everything through. Unfortunately I ran out of time to test run the simulator.