Repair and Maintenance of a Drascombe Lugger

Fixing a loose centreplate axle (page 2 of 5)
Extracting the loose Axle

Extracting the loose axle

First of all remove the floorboards on one side of the centreplate casing to enable access to the lower part of the inner shell (Fig 1.) where the axle is located. It is not a good idea (and it is not comfortable!) to stand/kneel directly on the hull or the floorboard supports. Temporarily replace the floorboards by some shorter softwood planks which allow close and comfortable access to the side of the centreboard casing from the hull to the top.

The first step is to determine the position of the axle on the outside of the inner shell of the centreplate case:

This should be quite obvious as a tell-tale 'bulge' on the lower part of the case about 2 1/2" from the base and about 2 1/2" from the front edge (See Figure 3).

Measure as carefully as possible the distance from the base of the casing to the centre of the 'bulge' and also the distance from the front corner of the casing to the centre of the bulge. Use a fine fibre-tipped pen with black ink to mark the position with two intersecting lines. These measurements will be needed to replace the axle in the correct position.

Photograph of Lugger centreplate casing and position of plate axle Figure. 3 Centreplate casing showing position of axle.

This photo shows the lower part of the inner shell (See (Fig 1.) for definition), of the centreplate casing, below the floorboard supports and near the front of the casing. The position of the sealed in axle for the centreplate is clearly visible as a distinct bulge the centre of which is shown on the photo by the label and associated marker.

(Click picture for larger view)

Photo of centreplate axle exposed in side of centreplate case Figure. 4 Photograph of axle head exposed in the side of the centreplate casing.

Using a 0.75" wide wood chisel, it was extremely easy to very carefully and gently shave away about 1/16" thickness of GRP to expose the head of the stainless steel axle. Note how raising and lowering of the plate has resulted in the GRP originally in contact with the axle head to be worn into a wide hole by the gouging movement of the axle . Extract the axle by taking the weight of the centreplate off it (most easily achieved by someone lifting the plate arm), and pulling it out of the side of the case either by hand or by using tweezers.

(Click picture for larger view)

Photo of centreplate axle Figure. 5 Photograph of extracted centreplate axle.

This is the extracted stainless steel axle which is 0.5" diameter, 1 5/8" long and with a 1/4" wide 'v' groove at each end to facilitate locking into the supporting GRP. Note the 10 mm wide brown rust stain derived from the centreplate

(Click picture for larger view)


The hole for the axle on the other side of the case was then exposed by the same method. The floorboards were removed, the tell-tale bulge located and its position carefully measured with respect to the base and front of the centreplate casing. A wood chisel was used to very carefully and gently pare away the GRP in the centre of the bulge to expose the recess for the axle.

Obtaining a replacement bolt

It was decided to replace the original axle with a 12 mm A4 grade stainless steel bolt. It is important that the bolt has a smooth shank (not threaded) where it is supporting the centreplate. Careful measurement of the thickness of the case indicated that the shank should be 45 mm long.

Diagram of replacement plate axle Sketch of bolt dimensions required for replacement axle

This sketch shows the required diameter and length of shank required for the bolt replacing the original plate axle.

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Photo of replacement plate axle bolt, nut & washers Stainless steel bolt and accessories replacing the original plate axle

The M12, 70mm replacement bolt nut and washers. Note the additional rubber washers required to make the bolt holes waterproof. The washers are made out of black rubber (the same rubber as domestic water tap washers are made of) and measure 35 mm outside diameter, 12 mm inside diameter and 6 mm thick. They were made up by a local shop specialising in industrial rubber products. A good alternative is a 12mm washing machine tap washer which is readily available from a DIY store.

(Click picture for larger view)

continued

[Back to page 1, identifying the problem and deciding on the method of repair] [Forward to page 3, repairing the centreplate case & fitting the new axle]