Slow Monster rebuild

[350TSS]

Along with the usual fibre glassing, I machined a blanking plug for the alternator case today from some 1” hexagon aluminium bar. (I could not find any 25mm hexagon so I shall end up with one (probably two) non metric fixings on the bike).
I shall be running the FastBikegear hall effect ignition trigger which operates from the cam belt pulley (half engine speed so no wasted spark and better recovery time for the coils) so the original Monster flywheel ignition triggers are redundant and the trigger lead which exits the alternator case through a gland in a brass threaded component is also no longer required The brass component is 22mm x 1.5mm. It is the same thread as the sump plug which is cast brass and has a tendency for stripping its internal hexagon (due to the sides of the hexagon not being parallel but rather slightly tapered to facilitate removal from the mould during manufacture.
I bought a die off fleabay for about a tenner to make the blanking plug and also to make a hexagon headed sump plug
Unfortunately I cannot locate my largest die holder (put somewhere safe no doubt) so I had to improvise. Those of you of a nervous disposition/ mechanical sensitivity should look away now.

Not subtle but in any event it worked and a good and concentric thread was formed which was nice and snug when fitted in the alternator case i.e. no need for thread tape. I parted it off with about a 4mm depth of head and took off the machining marks with some wet and dry.
I then buffed up the head to match the “chrome” powder coated alternator case. Just as I was putting the finishing touches on the buffer I snagged it and it shot out of my hand, hit the fluorescent light fitting at about 100mph ricocheting floor-ward into the bowels of my garage never to be seen again. It could have gone anywhere and I spent about an hour looking in all the likely (and even some unlikely places) it could have ended up but it was not there. Tomorrow I shall have to do it all again

[utopia]

Originally Posted by 350TSS

Unfortunately I cannot locate my largest die holder (put somewhere safe no doubt) so I had to improvise. Those of you of a nervous disposition/ mechanical sensitivity should look away now.

You're not joking there.
I'm extremely surprised that the resulting thread was concentric.
At least you've arranged the stillsons such that they don't squash the split die though.

[350TSS]

Utopia:
I spun the work piece and used a file to provide a lead in then forced the die onto the lead in by placing a billet of aluminium between the die and the tail stock so the die could only escape the pressure by following the lead in.
The stilsons would only grip the split in the die so Hobson's choice really

[350TSS]

More 300g chopped strand fibre glassing today and I discovered a more effective way to lay this mat which is quite stiff and resistant to following any curves/corners. Previously I tried to cut shapes to fit the pattern but when stippling they migrated and I always ended up with either gaps or the mat not running to the edge of the mould. Also with larger areas it is quite easy to find that one side has stippled down nicely but the other has developed wrinkles / air pockets so you address these only to find the previously good side now has wrinkles /lifted edges/ air pockets and so it goes on.
New technique is to first you put down a layer of resin over the whole area as thick as it will go without running off the job, cut the mat into 75mm wide strips and lay the longest run first, stipple with more resin until the mat becomes translucent. The next strip is overlapped by 10 to 20mm depending on the curvatures/corners/crevices and the process repeated. Each strip is cut to length before being stippled down.. With vigorous stippling the ridge formed by the overlap can almost be eliminated. When the next layer of glass and resin is applied it can be applied with the direction of the overlap at 90 degrees to the underlying layer which should make it stronger.
Further coats will be laid tomorrow and Monday then the dividers can come off and the exposed area treated to 5 coats of release agent, tooling gel coat followed by 2 layers of 100g and 4 layers of 300 g mat.
Next I thought about trying to get the stuck patterns out but the shed I was working in was full of resin fumes so that will have to wait until next week.
I re-made the alternator case blanking plug, which turned out better than the first one (now lost somewhere on my garage floor) so not a complete waste of time. Pictures to follow.
My final hour and a half today was threading the ends of some 10mm titanium bar which will be used to replace the 135mm and 95 mm bolts which act as the pivot for the rear suspension rocker and attach the hoop to the rocker. There is a 50g weight saving over the existing steel bolts.

[350TSS]

To avoid itchiness from working with fibre-glass moulds, I machined some titanium parts today:
from 12mm bar a) a stud that will connect to the exhaust end can and also hold the rear brake master cylinder and b) a component that will actuate the rod that works the rear brake master cylinder
from 8mm bar front and rear disc pad retaining pins saving a full 17g over the steel items – a lot of effort for not much gain, although the old steel ones were corroded and had wear ridges in them.
The 8mm bar I bought off e bay as a job lot of 10 in various lengths between 200 and 230mm for £11.00 originally to make some new inlet and exhaust manifold studs but the old exhaust manifold studs are not shifting.


I was thinking of machining up a titanium clutch push rod but the longest bar I have is 15mm too short, however I recall a thread on here about early monsters suffering from the clutch rod spinning the slave cylinder and ruining the seals so I thought I could make a two part push rod with an 8mm ball bearing in the middle which would solve the spinning problem. I think it would work as I recall working on old British bikes Matchless G80 or RRT2 on a Triton or even Burman/AMC boxes cannot remember which) where a ball bearing was used to stop the push rod welding itself to the thrust plate. An 8mm ball bearing would be used which will fit inside the clutch main shaft (it cannot go anywhere else once in there) and if it wears the titanium too fast (I never hold the clutch in unnecessarily) it could easily be changed back to standard.
The proposed titanium pushrod would therefore comprise 3 bits, 1) slave cylinder end 8mm diameter, 2) ball bearing 8mm diameter, 3) clutch actuating end, initially 8mm diameter to bear on the ball bearing, wasted to 7mm for majority of its length returning to 8mm before two O rings grooves and then rounded end to fit in clutch pressure plate. Can anyone foresee any issues with that design?

[Mr Gazza]

I think the thread you refer to is this one?
http://www.ukmonster.co.uk/monster/s...oberon+leaking
There's a lot in there about the pushrod and also the tunnel in which it sits, regarding oil passage through it... Well worth a read. it has an easy solution to pushrod spin.

Commando owners with the AMC 'box, sometimes cut the rod and insert a 1/4" ball bearing in there, but this is supposed to stop gearbox oil migrating into the clutch and is nothing to do with anti-spin.
But taking a leaf out of AMC's book.. The actuating end of the rod is pushed by a giant 1/2" ball bearing. It begs the question; could you get a ball bearing into the hollow slave piston for the rod to bear on?

[utopia]

On the fibreglassing, for what its worth, these are my findings ...
I find it best to tear chopped strand matting rather than cut.
It leaves a feathered edge which is much easier to blend with adjacent pieces.
Precise sizing of the pieces also becomes less necessary. In fact they can often be quite random.
And crucially, in a structural part at least, you aren't creating loads of short strands in the matrix, which would weaken it. Though that's not so important in a mould perhaps.
Tearing the pieces makes the bonding between adjacent sections of mat much better, without relying solely on overlap of subsequent pieces.
I might cut in certain areas, when trying to eliminate voids in tight, internal corners for example, but even then I would only cut the first layer or two.
And finally .. it means that you can use up all your odd offcuts.

Are you using a roller ?
I made one out of a bit of bent stainless rod, an old file handle and a turned, ridged roller, held on by a piece of neoprene tube fitted tightly over the end of the rod.

[350TSS]

Titanium clutch push rod idea now canned because I cannot accurately work out where to put the ball bearing in the system. Also, when I finally finish it I would like to take the bike to the south of France to see my mate resident out there and I do not want to have to carry the original push rod in case the titanium one wears out.
Last couple of days have been spent on the moulds, I managed to get the shorter of the belt cover patterns out of the mould but not without destroying the original rubber/plastic belt cover and with a bit of damage to the mould where too enthusiastic use of the wood chisel eroded the crispness of the edges.
I think the reasons for the difficulty in removing the patterns form the moulds in most cases was to do with mechanical locking, i.e. somewhere on the pattern where the sides were parallel or where there was a nib that prevented the mould withdrawing from the pattern. The other significant problem with the patterns was an inadequate seal between the edge of the pattern and the base layer of polypropylene sheet allowing the gel coat to get between the two and then sealing the pattern into the mould. Finally, I think there is a possibility that the application of the release agent to the pattern some few days before the gel coat was applied might have contributed to the difficulty in removing them, i.e. the spirit base to the release agent evaporated off taking some of the active ingredient to the release agent with it, but that is merely conjecture on my part.
This does not augur well for removing the carbon fibre pieces from the moulds when I eventually get round to making them. The last couple of days have therefore been about repairing the chisel damage to the edges (by filling, rubbing down and polishing the edges with progressively finer wet and dry) and removing any possible places where mechanical locking could possibly occur. The other strategy will be to make the carbon fibre pieces with only one layer of carbon fibre before removing it from the mould. This, I hope, will ensure that the CF workpiece is still relatively flexible and therefore able to be eased out of the mould. Second (and third coats if necessary) of CF will be applied with the piece outside the mould.
Utopia: Shredding glass fibre is undoubtedly best for ease of application (and for the aesthetics of the finished mould) however it is very difficult to work out once the glass has gone translucent how thick the layer you have applied is. My cutting into strips loses the strength of the longer fibres but possibly gains on certainty of coverage and uniformity of thickness across the whole piece.
To date I have not used a roller because all of the moulds have been too small/fiddly and required a brush to stipple into corners anyway and using a roller on the relatively small flat areas would have just meant something else to clean afterwards. I think the tank and seat moulds will get a roller treatment just to ensure good lamination. I cheated and bought my roller from EC.
Interestingly, Easy Composites recommend the use of a plastic scraper to apply the epoxy resin to the CF when wet laying CF to ensure the resin is forced between the fibres, probably because I think the epoxy resin is a bit more viscous/glutinous than the polyester resin

[Dukedesmo]

With regards to a spinning pushrod, I have an 'Evoluzione Cyclesports' master cylinder on my 916 and this has a bearing in the actuating piston, the claim being that if the pushrod were to spin it wouldn't 'drill' the master cylinder.

I can't vouch for the claim because AFAIK the rod's never spun? but the cylinder has been fitted for almost 20 years without any bother whatsoever, it gives a decent weight reduction and is the only master cylinder I have seen where the clutch fluid doesn't discolour - I have an Oberon on the Monster which also works fine but the clutch fluid goes black after a few hundred miles as do the original Ducati parts.

Unfortunately Evoluzione, a US based company are no longer trading.

[350TSS]

Had a play on the lathe today and knocked up a third mount for the case saver. It started as a 30mm length of 25mm aluminium bar and was machined down to 24mm to match the boss on the crankcase then 12mm for 14mm and then threaded 12mm x 1.5mm. The crankcase rear most hole was drilled 10.7mm and then tapped 12mm x 1.5mm.

In an ideal world I would have re-made the SS case saver with the lug for the third attachment point made sufficiently long so that it could attach to a centrally mounted stud, but the 2mm stainless steel was a swine to bend to shape so I made do with the same width lugs and an eccentrically drilled/tapped hole. I obviously still need to drill the remaining holes in the case saver lugs and then trim them to fit the alternator case mounting holes. I may also have to trim the top of the case saver as it may foul the frame engine mounting tube when I come to put the engine back in. In any event the return bend will need to be adjusted for a better fit to the engine bolt boss.
An hour or so standing at the lathe meant I needed a sit down job so I took the gold anodising off the rear wheel adjusters. Picture also shows the titanium rocker spindle and hoop attachment and suspension unit studs

Tomorrow its back on the fibre-glassing, repairing and polishing moulds, I find I need to run my garage clothes twice through the washing machine afterwards and even then they are still itchy when I put them back on.

[Luddite]

Originally Posted by 350TSS

Tomorrow its back on the fibre-glassing, repairing and polishing moulds, I find I need to run my garage clothes twice through the washing machine afterwards and even then they are still itchy when I put them back on.

Some good progress being made there.

When I insulated the loft, I wore some of those disposable paper overalls from Screwfix https://www.screwfix.com/p/3m-4515-4...-chest-l/7047f OK, so you might look like an extra from CSI Tonbridge, but they keep the fibres out and it's very convenient to just throw them out after use.

[350TSS]

Yup good idea! sometimes you cannot see the wood for the trees although my ingrained aversion to spending money (tightness) prevented rational thought, collect 5 from Screwfix this pm.

[350TSS]

I know early 900 Monsters/SS had problems with cylinder head studs breaking and that you can get improved studs. I am pretty sure my engine has never been apart before so I almost certainly have the “defective” studs.
Does anybody know if there is any way I can identify whether or not the studs I have are the old or new type?
Before I take the heads off I would like to order the studs if I need them, but obviously do not want to order the new improved studs if they are already in there.

[utopia]

As far as I'm aware, the brittle ones are silver coloured and the stronger ones are black.

[Luddite]

As well as the colour difference, as Utopia said, aren't they also identified by a code letter? I think it's 'M' for the old ones and 'O' for the new.