Slow Monster rebuild

[350TSS]

Today I have mostly been making ……………………………..swarf.
The fuel filler neck to be slightly more accurate from a 60mm long billet of 2.5” round bar to a c4mm wall tube with an ID of variously 45mm and 43mm. The fuel filler neck will be bonded permanently into the tank filler recess.

I made it a bit more complicated by deciding to make provision for a re-moveable mesh stainless steel filter. I found a supplier of the mesh on fleabay who offered various grades as follows:
Mesh Count Description Nominal
Aperture (mm) Wire Diameter Open Area (%) Weight kg/m²
4 Heavy 5.45 0.9mm (20 SWG) 74 1.61
8 Varroa 2.47 0.71mm (22 SWG) 60 2.00
10 Coarse 1.98 0.56mm (24 SWG) 61 1.51
20 Medium 0.915 355µm (28 SWG) 52 1.25
30 Insect Screen 0.567 280µm (32 SWG) 45 1.17
40 Vivarium Vent 0.411 224µm (34 SWG) 42 1.00
60 Papermaking 0.263 160µm (37 SWG) 39 0.76
80 Fine 0.178 140µm (39 SWG) 31 0.78
120 Filter 0.122 90µm (43 SWG) 33 0.48
200 Super Fine 0.075 53µm (47 SWG) 34 0.28
400 Metal Silk 0.035 28µm (49 SWG) 31 0.16

I opted for the 40 grade being a compromise between stopping rubbish (but not water) getting into the tank and not choking the filling process too much so that the petrol delivery pump does not sense the back pressure and auto stop. With only a 42% open area of the mesh the effective size of the hole at the bottom will have to be c2.4 times the surface area of the internal diameter of the neck. The neck can only be 60mm deep because on the original tank the space between the filler recess and the bottom of the tank is that big, the original air box is a massive intrusion into the tank capacity. My tank design is deeper but I have no way currently of measuring by how much so I decided to opt for the original Monster tank dimension. The limited original depth of the filler neck obviously restricts your ability to meet that ratio.
Thinking about it as I write I could probably have got away with the 60 grade mesh, however the mesh was only £2.99 for a 150mm x 150mm sheet so I could easily buy the finer mesh when I have some experience of the tank filling without auto stopping the petrol delivery pump.
The design I have come up with I think nearly makes that 2.4 ratio but still allows the mesh filter to be attached to the neck and be capable of removal for cleaning.
Water ingress is by far the most likely contaminator of the fuel and this will be alleviated by using a British bike style fuel tap (with reserve tap and with right angle exit hole also with mesh filter on the dual entry ports) threaded into an aluminium boss which will be bonded into the tank. This boss will have a “ditch” to trap any remaining water. Finally the original plastic circular filter will sit between the tank and the vacuum pump.
The tank will be vented via a boss on the blister on the top of the tank connected to non-return valve as per a 900SS. The original Monster tank also I think has a vent in the filler recess connected via internal pipework to a drain pipe that exits from the tank near the petrol outlet pipe and is connected to a drain tube and thence to atmosphere/road. I am reluctant to include this complication as it is another potential place where leaks can occur but you may convince me otherwise.
I did a check on the rear sprocket stud/swinging arm potential clash and I think the picture taken from directly above shows that there will be clearance, not much but a few mm as the spindle boss which is/will be bearing on the swinging arm clearly protrudes further than the sprocket studs. Chain alignment will obviously be checked on assembly.

image hoster

[350TSS]

Sorry the table above did not come out when posted but you can follow the numbers from the first line of the mesh details.
Darkness: I can confirm no elephants were harmed in the making of this bike - in fact a number have been preserved in Albie's monster rebuild

[Darkness]

Originally Posted by 350TSS

Darkness: I can confirm no elephants were harmed in the making of this bike - in fact a number have been preserved in Albie's monster rebuild

[Darkness]

Originally Posted by 350TSS

there will be clearance, not much but a few mm as the spindle boss which is/will be bearing on the swinging arm clearly protrudes further than the sprocket studs. Chain alignment will obviously be checked on assembly.

Clearance is an absolute, like pregnancy, taxes, rice pudding or death: there is or there isn’t!

[utopia]

And there they are .. studs and nuts holding the sprocket on, not bolts.
My hub has bolts into threaded holes in the ally hub which are helicoiled as std.
Presumably this is to avoid thread wear in the soft ally hub.
The thing is, I recall contacting dymag to suggest that the helicoil inserts were not really long enough and didn't give enough thread engagement.
At my request they fitted longer ones (or doubled them up, I'm not sure which). There was plenty of room in the hub casting.
The only thing I can't remember for certain is whether this was on the sprocket side or the disc side .. or both.
Anyway, this was about 18 months ago.
Now that I've seen your wheels and, given the timescale needed for a design modification to filter through to production, I'm beginning to suspect that they may have changed to studs following my discussions with them.

Of course this is all conjecture .. I may be entirely wrong.
But it has aroused my curiosity.
I might give them a bell.
Maybe I'm due some royalties .

[350TSS]

Today started well then just went a bit South.
I got the second layer on the tank recess pattern and the fourth and last layer of fibreglass on the air scoop moulds.
I tried Utopia’s shredding the glass matt before laying it out and I should have listened more closely to him a long time ago. It was miles better than cutting into strips, much faster to prepare , much faster to wet down and a better and more consistent finish with the added bonus because it was so much faster to lay down I did not lose the last 10 – 20% of the resin because it went into jelly. Doh!!!!
I then spent an hour or so rubbing down the repaired mould for the Ignitech enclosure and getting it to a smooth and polished surface. I can only take an hour or so of this every day a) because it is boring and hard work and b) because I am losing top layers of skin from my fingertips again and they are becoming painful.
Then I worked on my fuel filler neck. I have to open the bore out from 43 to 45 mm about 11mm below the top of the filler neck in order to provide a positive step for the locking latch to bite. I cannot bore from the other end as that will be closed with a bridge to retain the filter in position so I ground up an old boring tool to give a 90 degree angle on the reverse side of the cutter. The depth of the step is vital to ensure the cap latches so that it sits firmly on the rubber seal and therefore seals the fuel in the tank and also allows the cap itself to sit flush with the outer ring.
It then occurred to me that the latch is steel and the neck and therefore the step on which the latch locates is aluminium.
post images
In the long run the aluminium would wear and the cap would not close. I spent a good hour pondering the solution and finally came up with machining an internal circlip groove and fitting a carbon steel circlip. I have now ordered 2 from Simply Bearings. I need to know the thickness of the circlip to get the right distance from the top of the filler neck so work has stopped on the neck until the circlip arrives. This solution will also involve filing away the inner edge of the circlip groove where the latch engages, this will not be easy but I think a Dremel with a rotary file should make reasonably short work of it.
Finally I spent an hour polishing the filler cap and ring to a reasonable finish.

Unfortunately, I came back an hour later to inspect my handiwork and the aluminium was already oxidising and had changed from a polished aluminium colour to a titanium colour. I will re-polish it and then buff it up and I will then have to clear lacquer it immediately, remembering to mask the key position.
When I got back indoors the postie had delivered my SS mesh which looks to be the right granularity to work but it is incredibly stiff considering the gauge of wire used. My original (probably hopelessly optimistic) plan to cut a large circle then punch a cup shape into the middle of it is quite clearly not going to work.
I think I will have to cut a 40 to 42mm circle for the bottom then a strip about 40mm wide to go round the circumference of the circle. If it was brass it would be easy as I would simply solder or braze the circle and the circumferential column together but with stainless I have no means of attaching the two bits together apart from epoxy resin and that may not last in a petrol (with x% ethanol) environment. I do not want to give up in the idea of an additional filter. Both brain cells are working overtime on this one, wackiest solution so far is to cut the circle about 5mm wider than needed and un thread about a dozen strands form the circumference then knit them into the columnar bit – a definite non-starter.

[utopia]

Glad to be of assistance.
I had forgotten about the added bonus of being able to use up all of a mix of resin but yes, that too.
In fact when you actually do the job, it just makes loads more sense if its based on resin quantity, not matting, doesn't it ?
Its all coming back to me now.

On the fuel cap .. which looks great by the way .. I'm guessing that there is a fair amount of zinc in the alloy, to enable it to flow freely when its diecast.
That might be why it oxidises so quickly.

You could stitch the two parts together with stainless locking wire (by hand, of course). If it went far enough into the tank, you could graduate it to see content in litres/gallons at a glance.
Tom

[350TSS]

Raven thanks, better than any incipient plan I have just now, the graduation idea is a good one but I only have 60mm clearance below the filler to the air intake cut out so not really a starter, also my design of filler neck is a cup with the bottom 30mm cut away on both sides of a central " 8 to 10mm bridge" that will stop the filter dropping into the tank

[350TSS]

This was my first day back in the garage after the “festivities” and a week in a ski resort. I used to love skiing, nearest thing to riding a motorcycle, but alas the arthritis has put paid to that, so I spent a week reading and plotting next steps while my kids enjoyed themselves.
After almost 3 weeks away from the garage it took some time to remember what I had last been doing and where I had got to with each component of the build.
First job tackled was to trim the excess glass fibre from the air scoop moulds and drill through the two halves so that they will align when they are put back together ready for the epoxy compatible gel coat and the carbon fibre cloth. I then split the moulds with mixed results; of the 8 halves 3 came out near perfect, 3 with minor damage/defects and 2 with damage that will not rub out but will need to be filled. This will add at least 3 hours to my ETTC.
The problem once again was the gel coat creeping between the pattern and the polypropylene base plate causing the pattern to be trapped in the mould. The gel goat is incredibly viscous when just mixed with the consistency of treacle and despite waxing the junction between the pattern and the polypropylene base plate it still manages to inveigle itself in between the two components. I will have to get better at this as the tank will be a very large mould and any mechanical locking due to this will be very difficult to resolve.


A bit disheartened I decided to modify my rear tank mounting to make it lighter, neater and probably a bit safer in an accident (previously it had been a fabricated hook to retain a bungee loop that would have attached to a narrow cotton reel bonded to the rear of the tank). Using the same principle for the bungee retention for rear chain tensioner, I knocked up a clamp from 10mm plate through drilled for 2 of the original hinge mounts on the frame then cross drilled it off centre and broke through with a hacksaw to provide a half moon that would clamp the bungee to the seat retention bridge on the frame. (picture to follow).

[350TSS]

forensic anthropology wages
The clamp is retained by aluminium button head socket screws for a Yamaha fairing - nice and light

[350TSS]

Looking at the picture above I need to turn down the heads of the socket screws so the outside diameter matches the width of the clamp, stupidly, I didn’t measure the screw head size before cutting the 10mm plate for the clamp.
I spent a couple of hours finalising the belt cover moulds yesterday which are now as good as I can get them. Filling (and finish sanding) internal contours is a lot more difficult, fiddly and time consuming than the external contours on the patterns.
I also finished fibre glassing the tank recess mould (to take the filler cap) which will now need to cure overnight before I remove the pattern from the mould.
Then I machined the internal circlip groove in the fuel tank filler neck. The 46mm OD internal circlips came with large internal “ears” which when fitted inside the filler neck were too big to allow the cap (which has a tapered lead in to the spring mounted rubber seal) to sit down far enough to seal properly or for the latch on the locking pawl to work at all. I ground the ears down as much as possible without turning the circlip plier holes into slots and that did not work, so I then made the circlip groove as deep as I dared whilst still ensuring that the circlip gripped the inside of the groove and that did not do the trick either. I think I will have to buy a 47mm OD internal circlip and deepen the circlip groove further and see if that works.
Reflecting on something Mr Gazza wrote about clip ons and sitting further back on the seat I have reluctantly concluded that I will have to lengthen my seat pattern. The original pattern length was based on the position of the original Monster seat with the hump located where the profile of the original seat changed from rider to pillion position. I will extend the seat pattern “deck” by c 50mm. Fortunately the deck will eventually be covered by foam and ambla so the finish of the extension is not in any way critical. At present I have nothing to sit on to test the right length for me. At least if it is too long it can easily be shortened before I cover it, vice versa is a bit trickier. The potential downsides of a longer seat are the aesthetic of the final design and possibly the positioning of the rear seat latch. This is the task for today

[Darkness]

Originally Posted by 350TSS

forensic anthropology wages
The clamp is retained by aluminium button head socket screws for a Yamaha fairing - nice and light

The wages are better if you can get on the Time Team, Christmas Lecture circuit, like Prof Alice Roberts?

[350TSS]

Food poisoning stopped any progress over the last few days, today however I did manage to fit the circlip to the tank filler neck,

check that the filler cap lock located on the circlip and the key could be removed.

Finally I cut the base of the filler neck to allow the petrol into the tank leaving a “bridge” to retain the in-tank filter. The bridge ended up about half the width I had anticipated due to my complete inability to cut a straight line with a hacksaw, fortunately I can file a reasonably straight line.
host pictures online free
I also ordered some fine brass mesh to make the filter which I should be able to solder into a cup shape to sit on top of the bridge

[350TSS]

The fine brass mesh arrived today and was duly cut and soldered to make the filter - the soldering could have been a bit tidier but overall quite pleased with the result. The circlip retains the filter from above.