Measureing a blind surface

[James81]

I currently have a cylindrical housing that should mate against another cylinder that sits in the base of the housing. the second cylinder has a location boss on the base.

is there a way of measring if there is a gap between the two bases of the cyclinders as it is impossible to get access to the uderside of the location boss?

 

[MintJulep]

Plastigage.

 

[HDS]

plastigauge

http://www.plastigaugeusa.com/

You can buy it at any auto parts store. It is used to check the clearance of assembled bearing on the crankshaft.

Put it in the bottom of the hole. You can determine the gap buy how much it squishes.

If you can not see the bottom of the hole use machinist blueing compound on the bottom of the plug. If it rubs off it is touching the bottom.

http://en.wikipedia.org/wiki/Engineer's_blue

 

[hydtools]

Install until contact, then withdraw for the amount of clearance required. Measurements are made at the surfaces you can see.

Ted

 

[DiamondDave]

measure depth of the housing then use this to get the length of the other cylinder(is it a piston?)