Maryak 10

[Maryak]

Richard, Dave and Bob,

Thanks guys for your support. :bow:

The only lumps I seem to find have a penchant for excessive mowing.

Best Regards
Bob

 

[Maryak]

A very little more progress

Finish cuts are on - Ready for lapping.

Lapping the crankshaft.

Not much else to say - Spent the rest of the day in Lapland :

 

[steamer]

Looking good....keep your lathe ways clean!

OK ......Lapland? ???

 

[Maryak]

Thanks Dave,

Finished lapping the crankshaft and cleaned up the lathe ways.

I think I will start on the conrod tomorrow

 

[steamer]

Sorry Bob....I have the skeavy shakes about lapping compound and lathes....I have seen what abrasive can do to a lathe..it's not pretty.

I usually do my lapping in the drill press.....as far from my lathe/mill as I can get! ;D

What's the conrod material?...and tell me about your bearings will you? Inquiring minds want to know.... ;D

Dave

 

[Maryak]

Dave,

No apology necessary, I don't have a drill press and I keep the ways covered in rag. When I took the shot, said rag had decided to wrap itself around the leadscrew : : Still its better than my jacket which also found its way there last winter.

The conrod will be mild steel with bronze bearing inserts push fitted to the gudgeon and big end. The gudgeon pin will be mild steel held in the piston with circlips and fully floating.

The bearing bushes in the crankshaft are also bronze, they are quite long pushed in from each end with a gap in the middle. I am sure I will have a good seal against air being pulled in and I will soon find out if they are too long and I get a friction problem, (push em out shorten em and push em back in).

Best Regards
Bob

 

[cfellows]

Nice work, Bob. What's the bore and stroke gonna be?

Chuck

 

[Maryak]

Chuck,

Thanks for your support and interest. :bow:

The bore is 7/8" and the stroke 1".

Best Regards
Bob

 

[Kludge]

The only lumps I seem to find have a penchant for excessive mowing.

Hmmm ... maybe acquiring smaller lumps would be in order? ;D

BEst regards,

Kludge ... proponent of minimal mowing

 

[Maryak]

Hmmm ... maybe acquiring smaller lumps would be in order? ;D

Kludge,

Thanks for your support and interest. :bow:

The bigger lumps are the free lumps, ( I take my lumps where I can :)

Made a start on the conrod today - elected to do the lathe work between centres so I can come back and reduce the diameters after milling.

The conrod set up between centres.

Machined down to the big end diameter.

Turned around and machined to the gudgeon diameter.

Set up in the mill for milling the flats and drilling/reaming the holes.

This was followed by a visit to our builder and things finally seem to be going ahead on the home front.

 

[Maryak]

Can't believe it's Friday again. (We wont speak about the date).

I was pleased with the way things went this morning and here it is.

Milling the first flat on the conrod.

And the other side.

The big end and gudgeon bush holes drilled and reamed.

Forming the conrod.

The conrod ready for the bushes and fairing of the ends.

Hope you all have a good weekend. ;D ;D

 

[gjn]

Bob,

probably a dumb question but why are you turning the conrod between centres rather than using the 3 or 4 jaw chuck? Are you driving the dog from a pin bolted to the face plate?

Rgds - Gavin

 

[Maryak]

Bob,

probably a dumb question but why are you turning the conrod between centres rather than using the 3 or 4 jaw chuck?

There is no easy answer to such a simple question. A chuck just didn't feel right : : It was also interesting to see how parallel or not the tailstock set up was, (it was out 0.003")

Are you driving the dog from a pin bolted to the face plate?

No - On the backplate is a 4th hole closer to the centre, (inside the register). I made a pin for this hole and that's what I use. The faceplate is still in the cupboard.

Thanks for your continued support and interest.

Best Regards
Bob

 

[kustomkb]

Looking good!

great progress.

;D

 

[Maryak]

Thanks Kevin, :bow:

Are you anywhere near Powell River ???

I have an Aunt and Uncle Living there, they are both well over 80.

Best Regards
Bob

 

[tel]

There is no easy answer to such a simple question. A chuck just didn't feel right : : It was also interesting to see how parallel or not the tailstock set up was, (it was out 0.003")

Beside, using different techniques has to be a good thing - helps keep us on our toes rather than settle in to some same old, same old, routine.

It's looking good Bob

 

[steamer]

Hi Bob,

Looks great!

Centers are great for when you want to keep concentricity, and want to put flats on both sides of a part ......like a conrod. : ;D

Dave

 

[Kermit]

Uhmmmmm, I think I understand your setup at the Chuck End. Is that a Live center or Dead center in the tailstock?


Please excuse my total lack of manners,
Kermit

 

[kustomkb]

Powell River is a beautiful stretch of coastline. Great place to retire. (and grow up)

'bout 200 KM from me but I'll be sure to say Hi if I'm ever up there

Cheers!

 

[Maryak]

Tel, Dave, Kermit and Kevin,

Thanks guys for your continued support. :bow: :bow: :bow: :bow:

Kermit,

I didn't feel any bad manners from you

When I started out I used a live centre in the tailstock. The one in the photo you are asking about is a hardened dead centre and is mounted with a smidgin of grease in the centre hole. Dead centres are a real pain - too tight and they bind, too loose and the job runs off. After every cut I check the "feel of the centre" and adjust accordingly.

Why did I change from live to dead? - I could not get close enough due to the bearing housing on the live centre to reduce the conrod to 1/4" dia at the big end. As it is there is much more tool overhang than is ideal to allow me to get to depth.

Best Regards
Bob