SOTHERN

[peatoluser]

After a fair bit of filling I finally got to the stage where the difference in height of the two ends was no more than a couple of thou'.
So, satisfied with the bearings, it was time to check how the guide bars lined up.
from the top, well , it's rather self evident what needs to be done

and from the side , you can just see that the bars aren't all at the same height, but the angle of incline is almost the same for all of them.

the first thing to do was to make a crude square out of some 1.5mm plate, select the best guide/frame assembly then file the guide so that it's square to the bearing axis.

then it's a case of fettling the other 3 until everthing seems to line up


I think next up are the conrods , big and little end bearings

thanks for looking

peter

[arnoldb]

Great going Peter

It's always inspiring to see how much and how well you do things with limited tooling 

Kind regards, Arnold

[peatoluser]

Thanks for the compliment Arnold , although if you could see my work up close I wouldn't say its well done!

on with the big & little ends
for the big end I followed the usual road of squaring up  2 pieces of bronze and soldering them together.
I marked the centre for the bore , centre popped it, then centred in the four-jaw.
after drilling and boring I then transfered it to a split Ramon mandrel and turned the outer lip.




rather than file the outer edges round, I decided to drill the ends, hacksaw and file back, then solder in pre-drilled ferrules with a base - so much neater than filing


for the little ends I tried a different tack.
I made a fixture for the face plate to help in boring out this type of bearing, but it can be a pain trying to get the bearing spot on the lathe centre line , especially if the bearing has been machined to it's finished width - you then have to bore it out spot on centre.
so , I soldered some scrap pieces of bronze that where the right thickness, but over length, together

I then set up the faceplate fixture to the right height.
I have pieces of tube turned down to various thicknesses to give the required offset. the 6.0mm refers to how much the fixture is below lathe centre height.
the important point to bear in mind is not how accurate the 6mm offset is , but that once the plate is fixed in position , all bearings fitted to it will be bored out at the same height in relation to thier base - so long as you remember to mark the lower half so you know which way they went onto the fixture!

it's then a case of drilling and boring to size




once that's done , well I'm becoming a big fan of Ramons mandrels



I then filed the outside edges down to the right size in relation to the bore. measuring much like I measured for the main bearings.
To drill for the clamp bolt holes, rather than scribe a centre line, I turned up a small bush whose diameter is the same as the thickness of the bearings.
I then used a small marking punch to centre pop the hole positions. I have a number of these, all turned down to various diameters that correspond to BA diameters.
Ideal for spotting thru' pre drilled components.


then it's a case of drilling them

heating up to split the two halves and soldering on a base. For small components, I find a small 'lazy bird' is better than trying to clamp them together.

and here is a cleaned up big end next to a small end just soldered

now for the con rods themselves

thanks for looking

peter

[Jo]

Those are looking nice Peter, I like the curves on the outside of the centre section.

  I like that Lazy bird, I might steal the idea  .

Jo

[peatoluser]

Yes, I think the big ends turned out quite well
here's another photo. you can see the brass ferruls reasonably OK.
the dimple mark on the bearing surface was caused by too much clamp pressure trying to hold everything together. Hence the cobbling together of the lazy bird


yours

peter

[Johnb]

I like that. Thanks for the new ideas to be filed away.

[Don1966]

Just caught up reading the latest fabrication work and I must say you do some very impressive work Peter. I will be tuning in on the rest of this built, so pulling up a chair. 



Don

[peatoluser]

Finally finished the con rods.
I could have altered my drawing slightly so I could use 20mm square. It would be easier to keep the ends aligned making from square bar, but
it would mean a lot of interrupted cuts before it starts turning round, and its also difficult to get in free cutting grades.
with a good bit of filing to do - and the free cutting stuff does make this easier - i opted to use 30mm round instead.
first job is to turn the middle part down to 8mm. having roughly centre drilled the end in the drilling machine

remembering to scim the two large bosses left so everything is concentric

next is to cross drill for the pump operating spigot. I need this hole to be parallel to the crank axis, therefor I need a flat edge on one of the ends to set it up for drilling in the lathe.So I filed the big end part square, then realised I should have filed the little end square first, as it would make lining up easier. Still, both ends have to be  squared up, so no set back. I just had to file one edge flat and parallel to the big end part .I used two pieces of square bar and sighted by eye to help in the filing.

then it was a question of setting up on the cross slide with a small square, and drilling the hole

Then it was a case of filing the end to a square block, drilling and hacking out the middle bit,

then out with the files and emery and tart up the ends

although having seen rivergypsy's beautifully finished crosshead, I think I need to buy me some No 2 & No 4 cut needle files - as well as some finer grades of emery!

thanks for looking
peter

[Kim]

Nice job on the con rods!

Wow, Peter, that was a lot of steel to remove on a little lathe!  I know they can do it, I've done it before.  You just have to go slow and steady and take LOTS of small passes.  You have my respect!

Kim

[steamer]

Peter!

I have a new name for this engine when it's done!........"Determination"


Respect!,

Dave

[Don1966]

Wow! You sure pushed the limit of that lathe. Very impressive Peter and you are very persistence. I like.............


 
Don

[fumopuc]

Hi Peter, nice job. It is impressive what you are able to do with this small lathe.

[ths]

I love the handwork Peter, just like cabinet makers winding sticks.

Hugh.

[zeeprogrammer]

Nice stuff Peter.

I'd like to know more about the 'lazy bird'. How's it made? What kind of adjustments there are?

[peatoluser]

Zee, it's quite crudely made . just some pieces of 8mm bar welded together, the beak bit being a piece of 2.5mm welding rod with the flux knocked off.
although there's no adjustment , it's best used with the head part vertical, so I just bend the welding rod to suit or sometimes just weld a different length on.
It can be so much easier to set up and see the joint than with using clamps.
to give a bit more grip, I have a small bar with a blind hole I can pop on the end.
I first saw one of these being used over 30 years ago by a welder to hold parts together while he tacked them up - although his was considerably bigger!- asked him what it was and he called it a lazy bird . well, that's what was left after you took out all the expletives.
hope this photo shows it a bit clearer.


peter