Fowler BB1 in 2"

[Jo]

Model Traction Engine, with some stationary engines: http://www.basingstoke-dmes.co.uk/Traction_Engine_Rally.html We are not sure how manymodel stationary engines will be there as they do not have the main hall this year.

This was last year: http://www.modelenginemaker.com/index.php?topic=1799.msg26463#msg26463

It is free to get in 

Jo

[Stuart]

Jo

OT
In your pic of the T and C I can see you use a finger to control the rotation of the EM , how do you control the length way movement,

As you have seen I have a quorn and I use a finger in the same way with the cutter in a collet and then use the collet holder to move it in and out

Stuart

[Jo]

Hi Stuart, I think all TC use a "click" to position the cutting edge of the tool and the direction of the grinding wheel pushes the tool against the click. The length is set by adjusting how much that dowel sticks out behind the cutter: the one secured by the Allen key in the photo, no point in removing it as it needs adjusting for each cutter size.

The click being used here is a piece of an old rule which has just the right amount of spring  , I have also known people use bits off a mechanical hacksaw but handsaw blades are a bit too weak  .

Jo

[Stuart]

Jo

Thanks for the info it's basically the same method as I use, I thought you had a cunning method that I could pinch 

That BB1. Is going to be a big girl or is it a fella or do traction engine take on the female gender as do loco,s

I do like reading your post as you often apply a different slant on to your methods very instructive

Stuart

[Jo]

That BB1. Is going to be a big girl or is it a fella or do traction engine take on the female gender as do loco,s

Engines are always females: despite all their bad habits you can only love them and want one of your own

you often apply a different slant on to your methods very instructive

You mean my haphazard techniques sometimes produce what I hoped for 

Jo

[Tennessee Whiskey]

Jo I'm and following along. I've got to try that contour function on my DRO sometimes. Don't be trying to steal my "haphazard machining techniques" now, that's my MO.

Whiskey

[Don1966]

Hi Jo, I have been following along  but can't help much but give you moral support. But don't be picking up Eric's bad habits. 

Don

[Jo]

Thanks Guys for looking in It can get lonely in the shed.

A bit more curving, this time on the ends:



So this is another XY axis curve being cut with the help of the DRO radius function. The trick again is to find the centre of the curve relative to the datum of the piece (centre). Then position the tool so that it the radius plus half the diameter of the cutter out from the centre of the curve and then follow round for 54 co-ordinates  :



As the evening got later the chance,  ok the number, of miss twiddles of the handles increased so I had to abandon it for this evening half way through the upper plate.



The Perch plate is now ready for a prime but the temperature is still too low for the paint to go off correctly  once it warms up I will be back on the S&P as that needs some painting then I will be able to finish her off 

Jo

[Heffalump]

What kind of paint is it you're using Jo? What temperature does it need?

[smfr]

Good progress, Jo! I know what you mean about the number of wrong twiddles of the handles; I seem to make most of my mistakes late on Sunday evenings when a) I'm tired, and b) I'm in a rush to get things finished. Sometimes it's better to just close down the workshop when you're ahead!

Simon

[tvoght]

Great work Jo. I do love the DRO contour function.

I cut quite a few arcs in the XZ or YZ plane using program-generated step-off tables before I realized the contour function would work just as well in the vertical plane using a ball-end mill!

Keep up the good work (building and documenting).

--Tim

[Heffalump]

? would create a hemisphere when coupled with a rotary table?

[Jo]

Jim, I will be using best aerosol car spray paints from the auto factors  But it is acrylic so it doesn't dry well under 15 degrees 


Strangely enough the upper plate the "Forecarriage socket" goes with the "Forecarriage ball" so I am due to be machining a ball and socket shortly. I still need to decide how 

Jo

[Jo]

Finally the bottom perch plate and the beginnings of the Forecarriage socket could be fitted on to the axle.
I found that the slot in the perch plate was too narrow, so having taken off the required 0.1mm on the over width side  :



So on to the next bit the socket itself. The challenge is to cut a 80mm diameter socket:



In this piece of steel that I have just taken down to diameter:



Not a job to start later in the evening 

Jo

[Jasonb]

Have you modified your design Jo? Your drawing that I have has it as a 2" bar with 81mm radius to the socket.

J