Brassy babe engine - beginners questions #2

[student123]

Hi all,

I'm still working on my first project the brassy babe engine:

http://www.davegoodfellow.com/plans.pdf

There's a spring referred to that should keep the cylinder block against the frame, but where exactly does it go?
(I'm guessing on the other side of the frame to the cylinder so it pushes the pivot rod away from the frame.).

Also, is there a preferred way to find the centre of a circle on a piece of metal round? Neither my schoolboy geometry or 'cut a cardboard circle template' approaches worked well!


Mike

 

[shred]

Hi all,

I'm still working on my first project the brassy babe engine:

http://www.davegoodfellow.com/plans.pdf

There's a spring referred to that should keep the cylinder block against the frame, but where exactly does it go?
(I'm guessing on the other side of the frame to the cylinder so it pushes the pivot rod away from the frame.).

The spring goes around/under the #2-56 bolt/screw and holds the cylinder block to the frame (hole C, in the countersink). A bit of ballpoint pen spring works pretty well.

Here's a front view of mine. I played with the design a little:

full size at: http://www.homemodelenginemachinist.com/index.php?action=dlattach;topic=4043.0;attach=2164

Also, is there a preferred way to find the centre of a circle on a piece of metal round? Neither my schoolboy geometry or 'cut a cardboard circle template' approaches worked well!
Mike

You want the center of a round rod? The easiest is sticking it in the lathe and drilling a center hole with the tailstock, but there are a variety of center-finding gizmos around. I've not had great success with mine, so others should jump in with what they use.

 

[black85vette]

I use one of these with the center head:

http://www.starrett.com/pages/1316_combination_square.cfm

They show an example on the web page. You can find these pretty cheap.

 

[student123]

Thanks to you both. Shred love the look of your engine, mine will end up a multi-metal cross-breed. No problem, part of the learning.

Mike

 

[tony_m_baker]

I'm trying to build this engine, but I can't find the pdf file with the plans. The website in the link seems to be gone. I found a drawing with part of the plan, but it's missing information. Do you or anyone here have a copy of the plan?