The SS Minnow - Vespa PX200E

[GT6MK3]

Yep.  We had a case leak out of hotel quarantine (again), so Melbourne has been locked down for about a fortnight.  Should be mostly over this weekend if the number stay low.  75+ lawyers and staff across 4 firms all working from home on my slop chip, so it's less than fun when they figure that working from home = 24 hour, 7 day support. 

[GT6MK3]

Seal is now driven into place and bonded with some 603 to guard against it spinning.

 

That was it for me today though.  The building owners at work chose winter to institute works to replace the roof.  What was supposed to be a 14 day project has now stretched to 6 weeks with no finish date in sight.  Frustratingly, the very first move made by the roofers was to remove the aircon and heating.  The place is currently positively arctic, and I've now come down with a head cold.  With the current protocols, that of course means staying isolated at home till I get a negative covid test.

Pity there's no sick pay when you're self employed, so I'll be WFH for a day or two. 

[Nick Jones]

Trust it is only the seasonal snots and your test comes back negative…….

Gather you’ve been having a “bit of weather” down there too?

OTT weather naturally, in the best Oz style!

[GT6MK3]

Yep, wasn't worried, just cautious, Test results back in 7 hours, and back to work.  Weather's been very woolly!

Wanted to get on with assembly this afternoon at work, but lockdown has not been kind to my desk. 

So I got it back to the point where I could mostly see it.

Then I assembled my fancy new Italian primary drive.

An Loctited in the screws, which is much more civilized than the usual rivets.

Looks pretty doesn't it. 

It's made by Crimaz, I suspect translated as "Beautifully made, quality Italian parts which almost fit, every time".

I was planning to use my fancy crankshaft assembly tool to pull the crank in, but the threads are too fine for any of the adapters I have, (off to the lathe soon!), so I resorted to a blast on the bearing from the hot gun, and a squirt or two of freeze spray on the spindle.  With the frost wiped down and replaced with a smear of oil, they slid together and married up with a satisfying clunk.

Inside

Outside

Time to install the primary.

Which almost fitted.  But not quite.

The spindle is in the slot cut for fitting

And is almost all the way in

But the outside teeth for 3rd gear hit the casing at their cutout, just...

and no amount of jiggling is getting it past.

So I'm going to have to relieve the casing slightly where it hits (Red), and check the width of the spindle slot too (green).

3 different manufactures involved, so no huge surprise, but annoying nonetheless.

 

 

[Nick Jones]

16 minutes ago, GT6MK3 said:

quality Italian parts which almost fit, every time

Just like the majority (it seems) of aftermarket parts.  Irritating, but not surprising.  Looks fixable without undue effort though?

Imagine your desk..... pre-tidy..... on the scale of my garage....  I don't have to imagine it unfortunately It's not pretty.  Mostly my fault...... but not entirely!

[GT6MK3]

Ah yes, but this was all my own work, I have no junior associates to pin the blame on with management.

More progress today.  Massive wrapping and taping of anything with a bearing, followed by some dremel work to relieve the case.  Then lots of washing out of swarf.

Primary now fits

Nifty new tool to fit the loose needle bearings without them spraying everywhere

Works a treat

And despite the wafer thin tolerances on the back side

It spins nicely

So in with the oil flinger

and the driveshaft bearing

Time to pull in the driveshaft

And this half is ready.

On to the flyside

Driveshaft bearing in

O ring in for the kickstart

Kick start quadrant and buffers in.  They were fun...

And Kickstart gear spring in place ready for the cases to marry up.

Getting close.

 

[Mark]

Nice work. Spotless.

[Nick Jones]

Looks good…..

Takes patience and skill to do stuff like this right. Touch of OCD doesn’t go amiss either. 

[GT6MK3]

On reflection, I just couldn't risk the primary rubbing on the case.

So out came the gearing.  Looking at the case, there are witness marks on the risers that are machined away from the clutch opening.

So out came multiple layers of tape, cloth, more tape, more cloth, more tape, cellophane wrap and glue.

The position of them made it hard to get a tool in, but by being really cautious with the power file, I was able to lower them to a better level.

Not the prettiest work, but given their position I was just happy not to damage anything else.  Unwrapping was a 5 layer process, dusting off any swarf as I went, and the last 2 layers were nice and clean.

Primary now has plenty of room.

Now I'm waiting for a replacement oversize o-ring which is in Germany today, but might just be in Aus at the end of the week if the UPS gods smile.

[Nick Jones]

That looks better, I nearly commented on the closeness of those parts in the earlier pic…..

[Hamish]

I love seeing such precision and lovely looking “bits” 

such patience 

[mpbarrett]

very nice work.  Enjoyable to watch the build, love the attention to detail.

[GT6MK3]

My o-ring arrived from Germany.  Apparently admitting the problem is the first step.

[Nick Jones]

 O-ring……. Minimum order quantity is a bitch……..

 

……. or maybe a little will-power failure -just need to get to the free shipping threshold 

[GT6MK3]

Hard to believe what this comparison cost me, but I really don’t want the kickstart leaking.

[Nick Jones]

Still a bloody big box for two O-rings….. or was that two minimum order quantities? 

[thebrookster]

39 minutes ago, Nick Jones said:

Still a bloody big box for two O-rings…..

I was thinking the same.

Could get multiples of these in there: https://www.machinemart.co.uk/p/cht314-universal-o-ring-set/

(And I never knew that Machine Mart were selling these kits! Not that they are any use, even onboard with our multiple uses we only ever seem to use about three sizes!)

[GT6MK3]

I work on the theory that if I'm already paying for shipping, I may as well stock up.  I've done the maths - I've actually paid more for shipping for upgrades than I did for the original bike.  

I needed to spend the afternoon crunching some of the numbers that let the skydiving club members jump through clouds - the authorities make us redo this every few years, and it's a monster statistical challenge to work out, so, since I needed a bit of a distraction now I figured continuing the engine build might help ;-).

More engine power and torque demands the best solutions for the little things like engine mounts, so I invested in some PLC Corse polyurethane mounts that have the added bonus of incorporating bronze bearings to alleviate twist wear.  They also have a spacing ring to make precise locating easy, and an inner tube the correct length to run on, so engine positioning should be correct.

My 20 ton press is downstairs, but I wanted to do this a little more subtlety, so went with easing them in using

some silicone spray, all-thread, washers, sockets, nuts and wrist power.

Till both were in, and the inner tube was in and lubed with long lasting Inox

Purdy!

With my numbers crunched, I moved on to serious business, closing up the crankcase.  I found a nice clean bench to set up on, set everything out, and got to work.  

I super cleaned the already clean flanges with some carb cleaner, and gave them a run over with the heat gun to cook of any residual traces, drizzled some oil over anywhere I thought it might assist, and did a final check everything was in place.  I also re-read the Malossi manual to make doubly sure I was ready to go.

With everything ready, I gave the flyside bearing a little pre heat with the hot gun, and pre-cooled the crank stud with some freeze spray.

Time to load a syringe with Threebond, and lay it in place on the crankcase.

With that done, no time for photos.  Time only to rewarm the Flyside bearing center, blast chill the crank stub, and marry the two case halves.

Which went beautifully.  Within minutes, the two halves were one, with all the bolts torqued and checked at 14Nm.

Normally, that would be job done.

But, sadly, the crank will only turn 270 degrees, and is binding somewhere on the flyside case (the one I relieved out to 100mm).

After giving myself time to turn the air blue, I calmed down, and started troubleshooting.  It's clearly wrong, and rubbing top and bottom.

One of the things I figured early on with this build is that things will go wrong.  I made a self rule that I'm in no rush, so I'll walk away and think when it does, even if that means replacing parts, rather than rush and break stuff.

So I re-split the engine, leaving the crank in the flyside, and set on a mission to clean off/up the Threebond.

I don't know why it's binding - I cut 100mm around the bearing void center, and went down to the base.  I may have screwed up, the machine may be out of calibration, or something else may be at play.

I'll find out later.  Cleaning up was no fun, so stuck it out till I finished, plonked it all on the naughty shelf of my office, and went home for a feed and some red wine.

[Nick Jones]

Bah! 

These things are sent to try you….…….…

   ….. and they bloody do! 

 

[PeteStupps]

Ah, balls. That must be very frustrating.

On 6/19/2021 at 4:23 PM, GT6MK3 said:

One of the things I figured early on with this build is that things will go wrong.  I made a self rule that I'm in no rush, so I'll walk away and think when it does, even if that means replacing parts, rather than rush and break stuff.

I hope you're able to observe this rule throughout!

[GT6MK3]

Having got the texta out, it was pretty obvious that something was rubbing.  

Given the finish of the wall, I'm leaning towards the used cutter I'd run being slightly undersize and irregular.

So time to go back to the mill.  My buddy Alan who owns it has a new toy, and he was working on ironing out some bugs in the tool changer.

I sense it's going to be fun to play with!  

I'd pulled the flyside bearing, but left the rest in, sealed them up, and clamped the piece down again.

Out with the edgefinder to roughly set the center.  This get me to about .25 of a mm.

Then really true it up with the .0005" centering indicator.

This time I went with a shiny new 12mm carbide cutter.

Which cleaned up the wall beautifully, and took another .25 of a mm most of the way round.  This should be better.  I followed up with a 2nd case I'd done at the same time as the first, and it took exactly the same cut.  Same program, same technique, different cutter, so I'm hopeful I've found and fixed my error.

Since I was at the mill, I also took the opportunity to get started on modifying some wheel hubs.  Standard Vespa wheels of the era have metal rims and tubed tyres.  There's a risk with those that if the tyre spins on the rim, it can rip the valve out which results in an instant deflation.  Bad at 40-50km/h, catastrophic at 120+.  The answer is to run alloy tubeless rims, which are excellent, but all the wheel hubs available have wheel studs that are just too short for comfort.  The studs are staked in at the rear, so a few hubs went up and I milled the backs down to release them.

Final job in the shed was to clean up the center spigot on a genuine Piaggio hub that had been machined out of round.  15 minutes of setting up, 20 seconds of milling.

That was it for the shed, but before I left I borrowed a bit of kit from Alan to play with as well.  The crank I'm using has had a previous life in an engine that had a seize, and it's been in and out of cases more than once, so I grabbed Alan's centering stand to let me check it.  Handy having a metrologist as a friend.

The result wasn't perfect.  There was .035mm total runoutat the bearing surfaces, with the high point in line with the bearing.  That wasn't terrible, 'cos it's just pinched a little rather than spun out of true.  I needed to draw myself a diagram to figure out the correct fix.

High on the bearing side when between the centers means it's pinched opposite the bearing, so it needs spreading.  Time to make a tiny screw jack, and a couple of slim spanners

And in it goes.

Slow and steady was the rule of the day, and it took a few goes, but the runout is now less than 0.005 mm (basically it just slightly wobbles the needle now.

I call that a win.

 

[Nick Jones]

NIce!

15mins set-up for 20s cutting time sounds familiar.....  And Dennis used to wonder why I'd reach for the dremmel / file / angle grinder..... 

[Hamish]

22 hours ago, GT6MK3 said:

 

 

 

  Handy having a metrologist as a friend.

 

that is some ace engineering work - some of which i understood.

 

if he is one of the friends that you throw out of perfectly good aeroplanes ??

i reckon he would do anything for you to stay safe 

[GT6MK3]

Alan is one of the gifts that playing with cars has given me.  This is him back in 2010, the day I met him, taking down a T50 bellhousing.

I had instructions for what was needed to build a frankenbox, but no idea how to do it.  I was introduced to Alan by a mate, and he did all the work for a bottle of red, and showed me how to do each step along the way.  We've since become firm friends, and he's taught me how to run his toys, and when he was happy with the lessons learned, handed me the keys to his toyshop.  My skills and achievements with cars and bikes, such as they are, have all been built on the lessons and generosity of friends.

Gem of a guy, but I'm not about to take him skydiving - he's "gravitationally blessed"...

[Nick Jones]

58 minutes ago, GT6MK3 said:

he's "gravitationally blessed".

Doesn’t like heights…… Has very heavy bones…… down to earth….. whatever…