Vince's version of the MEM Corliss

[vcutajar]

Hi Baron

I actually thought about that but as I was not certain if this setup would work, I did not want to risk ruining them all at once.  When I did the first one and it was done in no time at all, I decided to play it safe and do them all one by one.

Vince

[BaronJ]

Hi Baron

I actually thought about that but as I was not certain if this setup would work, I did not want to risk ruining them all at once.  When I did the first one and it was done in no time at all, I decided to play it safe and do them all one by one.

Vince

I don't blame you    There is a lot of hard work gone in to doing this engine.  It isn't mass production.

[vcutajar]

Finally, managed to finish the valve bonnets.

First thing I did was a temporary prick punch from a length of 6mm stainless steel.



I also marked each valve, valve hole and valve bonnet so that each one always goes in the same place.  Fixed the valve bonnets in place and using the prick punch, marked for the 3mm holes to be drilled and reamed.



At the end I ended up opening up the reamed 3mm hole with a 3.1mm drill for a better fit.

Next, a simple fixture was made to machine the front part of the bonnet.  Clamped a piece of aluminium in the lathe and faced it off.  Drilled and tapped for 3mm. Used also a 10mm diameter aluminium washer I had also previously made.









All four valve bonnets finished and also made some gaskets for them.

Vince

[Ramon Wilson]

Hi Vince  - more nice work and another step further 

I see you have punctured your gaskets - have you thought about making a small tool like this as the end result is certainly worth taking the time to do so


By running it in a drill press and bringing it down onto one of those self healing cutting mats - the depth stop is set so it just cuts through the paper - you get very easily created 'perfect' holes. It's surprisingly easy to align it over marked positions 'by eye' too


The slugs are readily picked out of the hole with a piece of wire.

Hope this may be of use

Regards - Ramon

[Don1966]

Hi Vince, still following you buddy. The end is getting closer bud and the parts are looking good. I do like Ramon's hole cutter very ingenious setup.

 

Don

[vcutajar]

Thanks Ramon and Don for the comments and encouragement.

Ramon, that idea has been filed, although I do not know if it will work on these very small gaskets.

I still have not received the miniature (1.4mm) hardware I ordered from France and I would like to have them available before work starts on the last four identical arms for this model.  So, during this week I have made a dozen plans, a bit of experimentation (mostly unsuccessful) on what will work and what will not, and a lot of head scratching.

I was subconsciously trying not to rush these last parts, but yesterday I said what the heck, and started doing something on these arms.  The original plans for this item called for a miniature grub screw to fix it to the valve spindle.  From the outset, I thought that this method will not work for me.  The revised plans changed to fixing the arm by either loctite or a pin.  I still did not like this method because there is no possibility of adjustments.  What I liked is Arnold's method of clamping it to the spindle.

The only thing I am going to use from the plans is the distance of 0.313" between both holes.  I used stainless for these parts and here they are with what I managed to do till now.



I still have to stop and wait for the 1.4mm bolts to arrive.  Hopefully this week.

The big hole is a 3mm reamed hole and the small one is a 2mm tapped hole.  During tapping I broke the second tap so now I have two sets of 2mm taps with the second tap broken.  Still I managed to do all of them using the first and final tap.

This occurrence made me change plans (again).  There is no way that I am going to tap four 1.4mm holes.  So most probably, I will be doing a 1.4mm clearance hole and using a bolt and nut for clamping.

Vince

[vcutajar]

Last Monday, the miniature hardware arrived from France and today I made two temporary spanners for them.



The bottom one is a 1.4mm bolt and the top one for comparison is a 2mm bolt.  Really small.  I have to be careful not to lose them!  Do miniature spanners exist for these sizes?

Now I can continue on the arms.

Vince

[Jo]

Vince, I have spanners down to 3mm A/F (10BA) and 3.2mm as metric sizes. Smaller ones I have had to make myself.

Box spanners are easy to make just use a cap head screw. I have also been toying with the idea of possibly converting them into spanners by silver soldering on a handle but have not tried yet.

A 1.4mm should be the same size as a 12BA, it depends if it has a 12BA sized head which is 2.3mm A/F. Which is near enough a 3/32" hex to get away with any cap head that fits that size Allen key  .

Jo

[sco]

Vince,

What was your source for those bolts?

Simon.

[vcutajar]

Like yourself, Jo, my smallest spanner is 3mm AF.  These bolts have 2mm AF.  I love your idea of using metric cap head screws.  I wonder which size of metric cap head screws uses 2mm AF.  I have to investigate this.

Vince

[vcutajar]

Simon

This is their website:

http://www.micro-modele.fr/

Vince

[vcutajar]

After a quick search on the internet I think I found that 2.5mm socket head screws have a 2mm AF.

No chance of getting them here.  Anything less than 3mm is a no-no.

Vince

[Jo]

I wonder which size of metric cap head screws uses 2mm AF.  I have to investigate this.

Vince

I have some 6BA cap head screws which take a 2mm Allen screw. But sadly BAs are not what they used to be to get hold of 

M3 cap head is too big, I don't have any M4 grubs  .

Jo
- - -
P.S. I could post a couple to you...

[arnoldb]

Good going Vince  - love the bolts!

M3 grub screws uses 2mm AF allen key as well   You'll just have to turn the threads off a bit, but shouldn't be a problem.

Kind regards, Arnold

[vcutajar]

Thanks for the offer Jo but I can manage with my homemade spanners.

Arnold, I think that 3 mm grub screws use a 1.5 mm socket but I will check it tomorrow when I go to the garage.  4 mm grub screws use 2mm sockets. Will check tomorrow.

Vince