Hobbyhorse. Some more work on the Stirling Single

[45609]

Hi Simon,

Thanks for the extra photos and info. That all makes sense. I figured that you might have a common reference point on the horizontal and vertical copy master. Successful machining of parts is mostly about the planning the steps. I'm mostly working in 4mm scale so I have the added challenge of some very small components. So far I haven't attempted something with more than one profile plane. Where I've needed the depth I've split it into layers. But obviously you're not able to get any scallops or blended profiles with this method. I did some replacement brake gear for a Comet Ivatt 2MT recently (photos below). You don't really need 3D profile in this case but I do have some coupling rods to make soon and would like to have a thinner section between the bosses blended in/out correctly.

Cheers...Morgan

 

[Hobbyhorse]

Hi Simon,

Thanks for the extra photos and info. That all makes sense. I figured that you might have a common reference point on the horizontal and vertical copy master. Successful machining of parts is mostly about the planning the steps. I'm mostly working in 4mm scale so I have the added challenge of some very small components. So far I haven't attempted something with more than one profile plane. Where I've needed the depth I've split it into layers. But obviously you're not able to get any scallops or blended profiles with this method. I did some replacement brake gear for a Comet Ivatt 2MT recently (photos below). You don't really need 3D profile in this case but I do have some coupling rods to make soon and would like to have a thinner section between the bosses blended in/out correctly.

Cheers...Morgan

Those look good Morgan,
Machining valve gear can be successful cut on the panto, but side and connecting rods with blended bosses and h section are another challenge. I was lucky to spend some time with Tony Reynolds who walked me through his methods. The basic rod cut on the panto with fluting/ boss shaping cut with fly cutters, it’s still a challenge for me. Also getting free cutting Nickel silver sheet in the required thickness is difficult, I tend to use bar machined to size.

Simon

 

[45609]

Thanks Simon. The finished brake gear on the loco is hardly noticeable but I'm much more satisfied with the way it looks.



Funny you should mention Tony Reynalds. He also showed me his set up for fly cutting coupling rod flutes on the one and only visit I had to his workshop a number of years ago.

Cheers...Morgan

 

[Hobbyhorse]

Morning Morgan

Loco looking good, it’s always nice knowing the small additions made to any model is your own work.
I always treasured my visits to Tony’s plus working with him under the Hobbyhorse banner for a few years was very rewarding.

Simon