Webster Build Questions and Progress

[minh-thanh]

Here is a picture I took at x4 magnification on my phone, 19.7mm diameter cylinder 60mm long with a 2x10 mm HSS tool bar
With a "straight" cylinder you will see they are almost touching everywhere
"Straight" : in quotes because I am not sure if they are 100% straight but good enough .
If there is a taper they will not touch at the BDC position of the piston
No need to be mirror like, just smooth
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[Jasonb]

Have a read of this thread of mine starting with machining the cylinder, it then goes onto lapping it, making the piston and lapping the piston into the cylinder. This is what I do for IC engines with no rings.

https://www.model-engineer.co.uk/forums/topic/jasons-firefly-46-build/#post-93931

 

[Danuzzo]

Here is a picture I took at x4 magnification on my phone, 19.7mm diameter cylinder 60mm long with a 2x10 mm HSS tool bar
With a "straight" cylinder you will see they are almost touching everywhere
"Straight" : in quotes because I am not sure if they are 100% straight but good enough .
If there is a taper they will not touch at the BDC position of the piston
No need to be mirror like, just smooth
----
[Photo removed]...

Thank you. Will put a small lathe tool in mine later to see if I can duplicate what you are showing. Will report back accordingly.

 

[Danuzzo]

Have a read of this thread of mine starting with machining the cylinder, it then goes onto lapping it, making the piston and lapping the piston into the cylinder. This is what I do for IC engines with no rings.

https://www.model-engineer.co.uk/forums/topic/jasons-firefly-46-build/#post-93931

Thank you. I like Ramon's lapping tool. Is there any instruction or diagram available? In the meantime, I intended to fabricate one similar to the one on https://www.adriansmodelaeroengines.com/catalog/main.php?cat_id=178.

 

[Jasonb]

This thread of Ramons should give you some weekend reading.

https://www.modelenginemaker.com/index.php/topic,1908.0.html