Silly question

[StirlingSingleParticipant @stirlingsingle]

I need to fit a 1/16″ Taper Pin between my crosshead and piston rod…..What is the best method? And do you drill 1/16″ or smaller?

 

Many thanks in advance

[StirlingSingleParticipant @stirlingsingle]

[Eric CoxParticipant @ericcox50497]

I would imagine drill to the smallest diameter of the taper pin then ream with 1/16 taper reamer

[Clive HartlandParticipant @clivehartland94829]

On my cross head I used a taper pin and also left the pin with a slight protusion at both ends.

I also made a jig with a screwed pin to allow me to remove the taper pin in situ.

An open mouth ‘C’ shape with a hole drilled through and then one end threaded for the screw pin. this allows you to remove the pin which travels through the hole and can be retrieved.

It can also be use to push it back in as well.

 

Clive

[michael howarth 1Participant @michaelhowarth1]

Some time ago I bought a set of tapered drill bits at a car boot sale, not really knowing what they were for. I was subsequently  told that they are used after a normal drill bit, the size of the minor diameter of the taper pin has first drilled a parallel hole. I haven’t used them often but they do work well. I know it doesn’t help Stirlingsingle but I thought I would throw it in. I have never seen tapered bits offered for sale in catalogues etc .

Edited By mick H on 04/09/2011 13:42:29

Edited By mick H on 04/09/2011 13:49:54

[michael howarth 1Participant @michaelhowarth1]

Having said that I haven’t seen them advertised, they are in the Tracy Tools catalogue.

[Chris TriceParticipant @christrice43267]

SKF/Dormer make some and they also do Morse Taper drill bits (yes, drill bits, not reamers).

[DustyParticipant @dusty]

Stirling Single

Before you fix the crosshead to the piston rod make sure that it is in the right position. Turn the motion over by hand and ascertain that you have equal space at either end of the piston stroke. Many a model engineer has found that having made everything as per drawing the piston rod is to long / to short and needs to be remade. The best method is to step drill the hole so that you end up with a hole that has 3/4 steps a few thou appart on dia (depending on size of taper pin) and length of hole. This can now be reamed to size, if you do not clean up all the steps it is not disastrous but the aim is to just take out to the drilled holes. Drilling is a lot easier than reaming.

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