45CC Wall Wizard

[Jo]

Just for Big E a step by step blow of the connecting rods: They are too short  and made of blancmange  This means that they are a right  to hold.


We need a jig  And because the two ends are different thicknesses one end will need packing up. What ever you do don't clamp in the middle  Did I mention they are made of blancmange? Two bits of steel will act as clamps.

Now we need to line things up: Having marked the jig with a centre line over its edge and put in two tapped holes for the bores, a point can be used to hold one end while the other end is lined up and clamped down. We can now drill and ream the small end through the hole that was drilled in the clamp for the job  It would be nice now to use a bolt with a bush into this hole but the tapped hole is going to be filled with swarf that even the shop vac couldn't dislodge 

Now I can hold the connecting rods to work on the big end. First borrow a slitting saw off of Sexy 

Jo

[Jasonb]

Will you be soldering a slip of bronze onto one of the faces to regain the lost length?

[Jo]

Yes

Jo

[Jo]

Sexy's slitting saw is 1mm thick, if only it had a zero thickness then it would have been possible to part off without having to add a bit 

The bit added was a .8mm piece of brass sheet, which was silver soldered into place and then cleaned up. The holes were supposed to be 5-40 UNC but 1/8th Whit is easier to come by this side of the pond and much, much easier than trying to find 5BA cap heads

The first rod is mounted up for the first day of the working  week.

Jo

[Bluechip]

Surely not 50 - 40  UNC ??

You can get 5-40 UNC A2 cap screws, and a lot more UN stuff, from here. Trawl around the site.

https://www.pts-uk.com/products/socket-screws/socket-cap-screws/inch-a2/u9125400500

Good people, used them when I was at w**k. 

Nice going BTW...   

At the risk of being strung up by the wotsits for heresy, why not M3?  Near enough 5BA IIRC.

Dave

[Jo]

You are right 5-40 not 50-40. Its been a bad day I started by tapping them 4-40 UNC and wondered why tap went in easy and the Whit screws did not fit  .

A lot of Westbury's engine use 5BA caps on the big ends which are rare as rocking horse Do-das these days. 1/8 whits are available - cheap as chips 

Jo

[Bluechip]

Its been a bad day

Jo

Too true ... Knee is now about shot after crawling about in the roof space     Stuff the transformers.   

J. still at home but not very good at all     

Thought I had two pies in the freezer, actual value = zero.     Emergency order to Sainsbury's.

Dittto Pork Scratchings.

Runny nose ..

Life here is so much fun I never stop laughing. Probably because I never start .. 

Have fun.

Dave

[Jo]

If you think you have problems just be thankful you don't have nuts that look like mine   

Jo

[Jasonb]

Couple of crackers you have there Jo 

[Stuart]

Jo
Obviously not had adult mumps they are the same size 

[Jo]

This is the first year for Wallnuts and I think there are another 3 on the tree 

Jo

[Stuart]

Oh they fit the wall engine 

Thought they were      

I will get back in my cage now

[Roger B]

Hi Jo, you described the connecting rods as being made from blancmange. Is this normal for bronze castings? I know a lot of the older designs used cast bronze con rods but this seems a little weak 

[Jo]

Sadly Roger yes the bronze castings are easy to mark and if you clamp without a solid support under the clamped part easy to bend 


It was soooo embarrassing: I came to make swarf only to find flat batteries on the camera - so please imagine the missing pics 

What with one visit or another I decided better not to bore the connecting rods so something easy - the caps for the valves. Now these are small and fiddly but only once they are removed from the bar stock so the aim is to do most of the difficult machining while it they are still attached to the parent metal.  Start by finding a suitable short piece of bar and machining the underside of the valve cap on both ends and drilling a hole in the centre. You now realise why it is a short length of bar as this is now mounted in a vertical support (like Tgs 5C collect holder) and the little slot milled using the central hole as relief for the cutter (so it does not break). Take the piece of bar back to Mr Silky and part the little caps off over length.

At this point I found a tooling feature  it took a while to find  I don't know if anyone has found this but some 5C collets seem to fit more snugly than others in a 5C holder the 7.5mm did not want to go in. At first I thought the slot might not be deep enough and the locating pin was too deep, I did find a bit of a burr on the end but having removed that it still was I then got a 5C block out and tried fitting the collet in it and  found the body of the collet was 31.8mm not the normal 31.75mm so it was that which was refusing to go in. Mr Silky taught it a thing or two and took the offending 0.05mm off 

This then allowed the tops of the valve caps to be held by the step that fits into the springs and turned to thickness. At this point I remembered to go check the camera battery had charged and took a pic of the final item

Jo

[Jasonb]

I notice you are using those inferior drawings again that don't show the counterbore, without it your spring retainers may slide off or at the very least won't stay central