Rupnow-Johnno Vertical hit and miss

[awake]

As someone who has yet to try this - your results look good, and I predict the next one will be perfect!

 

[el gringo]

As someone who has yet to try this - your results look good, and I predict the next one will be perfect!

My thoughts exactly!!
RAY M

 

[110samec]

A quick google, one mob says it's a high grade mild steel another it's equivalent to 1040 another 1045
John

As an aside, the rudder stocks on Archer class boats (Royal Navy) have brass keys, mainly so that any slop in the system that develops wears out the cheap to replace key rather than the expensive steel steering arm. Had to machine a new key last week for one

 

[Johno1958]

Thanks guys I'll get there eventually .If I need to make a dud or two to get a good one ...well and good It's the only way I will learn.
I will try some different metals .The key steel was ok to machine but felt very dry and for me did not finish very well.I used a parting tool to cut
the crank throw so I will look into a better tool for that if there is one. I have some 4140 I can try...maybe a little hard .
John

 

[Brian Rupnow]

John-I just machined some 4140 for a fixture a customer wanted. It is really, really tough stuff. I'm not sure you could machine it with HSS cutting tools. I used carbide endmills to shape the part. Very nasty stuff. I have used 12L14 for my last two crankshafts. As far as warpage of the crankshaft from internal stresses go, it is much better to use hot rolled steel bar (Commonly called A36 here) than cold rolled steel.

 

[el gringo]

John-I just machined some 4140 for a fixture a customer wanted. It is really, really tough stuff. I'm not sure you could machine it with HSS cutting tools. I used carbide endmills to shape the part. Very nasty stuff. I have used 12L14 for my last two crankshafts. As far as warpage of the crankshaft from internal stresses go, it is much better to use hot rolled steel bar (Commonly called A36 here) than cold rolled steel.

Yes Brian,
I also had very good luck using 1144 stress proof as suggested in your vertical hit and miss engine build.
Ray M

 

[Johno1958]

As luck would have it a mate of mine had some 1' round cold rolled 1144 he bought from Amazon a couple of years ago and gave me what he had left a 7" length.
Milled it down flat and had another go.Cuts like butter. Problem with using the round is when I make the counter balance and fit them there will be a little day light showing in the corners .
All done.
John

 

[Johno1958]

I bought some 1214 steel to have another go at crankshaft making and this one I like. I will have to sand a little as the bearings are a bit of a tight press fit
at the moment. Hopefully It is the last crank I have to try make for this engine but I need the practice........
John

 

[awake]

As luck would have it a mate of mine had some 1' round cold rolled 1144 he bought from Amazon a couple of years ago and gave me what he had left a 7" length.View attachment 112315
Milled it down flat and had another go.Cuts like butter. Problem with using the round is when I make the counter balance and fit them there will be a little day light showing in the corners .View attachment 112316
All done.
John

To avoid the "daylight" in the corners, mill those edges flat - shouldn't take but a minute or two. Unless your shop skills are like mine, in which case it will take an hour or two, with much of the time spent trying to remember where I put the tool I just set down half a second ago ...

 

[Johno1958]

Yep I'm hearing you there lol

 

[minh-thanh]

Johno1958 !
What is happening with this build?

 

[Johno1958]

Hi minh-thanh.
Not a lot happening at the moment although I have started the con rod. Very busy a month either side of Christmas at work for me and family fishing trips .
It's is also very hot this time of year in the garage at over 100 farenheit degrees yesterday but when the energy level start to rise again ....
John