Benford Single Drum Pedestrian Roller Clutch Fix

[awemawson]

I've had this roller for many years, and all that time the engagement of the clutch that drives the vibrating feature has been rather hit and miss.

The clutch is a simple single friction plate held compressed by a spring. A hand lever pulls on a cable operating through a bell crank that presses on a rod that disengages the clutch. All very simple but the far end of the cable and the bell crank / spring and rod are buried deep in the workings and are totally inaccessible without a major dismantle.

Recently I had to order a new battery as it's sat for probably two years unused in an open shed, so I thought ok, time to get to the bottom of the clutch issue.

I knew that if I poked the bell crank with a lath the clutch would engage, but this is a dangerous thing to do as it means inserting the lath down the side of a fast rotating pulley.

So - first job, get her in the project area of the workshop - this involved a big tractor battery in  a wheel barrow to jump start it and drive her up the ramp to the workshop. Looks rather out of place in juxtaposition to the other contents 

Then to start digging and delving. There is a top cover that was obviously designed to come off easily as it is held on by spring clips, but the 'ignition box' is mounted on it with a flexy conduit with loads of wires dissapearing into the bowls of the machine. Judicious coaxing proved that the cover could 'just' be inverted and flipped onto the engine exposing what I needed to get at without disconnecting all those wires. Just as well as the far end of those wires terminate behind the water tank that some bozo has welded on

[awemawson]

So having got in so far time to see what the problem is. Well the bell crank is VERY stiff, in fact so stiff that the bolt is turning on its mounting thread rather than staying still and the crank rotating on it 

Needless to say, from it's position it wasn't coming out without a struggle  Eventually bolt and crank came out pretty well fused together. A quick application of heat from a propane torch got it moving, then when apart the bolt was sandblasted to get the rust off, and the sleeve bushes in the crank cleaned up resulting in a nice free movement.

Loads of 'copper slip' on the bolt and I started to re-fit the crank. It was at this point the top cover decided to slip off the engine, fall to the floor and stretch all those wires pulling the conduit out of its bush 

OK carry on putting the clutch back together and worry about the wiring later. Fairly simple - re-connect the cable and rod and crank. Adjust the spring to what looks right, refit the battery retainer that came off to give better spanner room earlier and check the hand lever operates the clutch reliably, which it does 

Right lets sort the electrics if we can . . .  no diagram but how hard can it be  The flexy conduit had actually broken at its gland, so that was re-made - and it looked as though only one wire was torn, which I remade. Will she start?

In a word NO! A quick check with my AVO showed that the ignition key switch had power coming in, coming out when in run, and a power feed for the starter solenoid when turned to 'start' but this 'start' feed wasn't making it down to the solenoid itself.

There are two junction blocks sandwiched between the engine and the water tank (which has been welded on!) and you can only get at them by either removing the tank or the engine 

A bit of poking with a very  long screwdriver restored the solenoid feed - presumably a plug / socket not quite home. Now the engine starts but the warning buzzer (that I assume is oil pressure) and the charging circuit aren't working 

Now not charging isn't the end of the world - the battery is only used for starting and can be independently charged, but it's flipping irritating 

I'd had enough and as the new battery had just been delivered and fitted I put it all back together and crawled into the shower with much relief.

No doubt at some future date I'll cut the (grotty) welds back and remove the tank and sort the charging issue - but not today I think as I'm knackered

[Pete W.]

Hi there, Andrew,

Looks like a novel project, if a bit mucky!  I look forward to the next instalment.

A bit heavier than my latest - a friend who happens to be vet to our various four-legged friends over the last few years recently acquired a third-hand surgical microscope and asked me to minister to it!  I think the essential optics are OK but it's VERY different from any of the microscopes I've previously met.  Because the surgeon can't touch manual controls without prejudice to his 'scrubbed' hands, the main motions (focus and zoom) are motorised and controlled from a foot-switch unit.  So it looks like it's mainly a tart up the wiring job.  Early days yet but I'm praying that the grease hasn't congealed and caused stripped gear-teeth anywhere.  It can happen!!

I'll probably start a descriptive thread when I get a bit further on with it.