Machining the port face of V10 cylinder

[Steve RowbothamParticipant @steverowbotham77083]

Having machined the 2 flanges and bore of the cylinder I now need to machine the port face. I set the cylinder up on an angle plate as per attached photo, and attempted the first cut, with the result that the angle plate moved and caused the tool to mark the face (I have circa 1/16 to remove so not a problem). I had thought to bolt bars either side of the angle pate to ensure it couldn't move but decided that would be overkill. So now my plan is to bolt the bars either side, but I am now worried that the cylinder could rotate on it's axis when the tool makes contact, and potentially cause damage I wont be able to rectify. Any advice before I proceed would be appreciated!

 

Edited By JasonB on 10/08/2022 10:43:50

[Steve RowbothamParticipant @steverowbotham77083]

[JasonBModerator @jasonb]

A single fixing holding the angle plate is not ideal and what has allowed it to move. A bit of jiggling about and you should be able to get a second clamp in if you set the angle plate between two slots rather than at right angles to one.

An alternative if you have a slotted cross slide would be to clamp the angle plate to that and flycut the port face.

I'm assuming you don't have a mill.

Edited By JasonB on 10/08/2022 10:44:44

[Tony Pratt 1Participant @tonypratt1]

Definitely need at least two clamps or screws on both the angle plate and component.

Tony

[roy entwistleParticipant @royentwistle24699]

If you can, use bolts through angle plate rather than clamps.

[Paul LousickParticipant @paullousick59116]

Hold it in a 4-jaw chuck ?

[Clive Brown 1Participant @clivebrown1]

A further point, from your picture the pressure from the clamp bolt looks to be much nearer to the spacer than to the angle plate so the spacer is taking most of the clamping load.This type of arrangement needs to be the other way about, ie the bolt force nearer to the angle plate. This alone won't cure your problem in this case though. As said above, more / better clamping is still required. If your angle plate is of a type that doesn't have bolt-holes in one face, then I'd drill some or get a bigger one that does.

[Martin ConnellyParticipant @martinconnelly55370]

Have you drilled and tapped the flange stud holes in the cylinder? If so then a plate with matching holes can be mounted on the end away from the angle plate and, if made to the correct dimensions, can be used to both orient and secure the cylinder together with the angle plate.

Martin C

Edited By Martin Connelly on 10/08/2022 11:30:13

[roy entwistleParticipant @royentwistle24699]

Also when bolting to an angle plate or cross slide, interpose a sheet of notepaper between the job and what it's being bolted to.

[HopperParticipant @hopper]

Posted by Paul Lousick on 10/08/2022 10:57:28:

Hold it in a 4-jaw chuck ?

^^^^^ That's how I would do it.

I would also grind the hard skin off the cast iron first to make the interrupted cut a little gentler.

[Steve RowbothamParticipant @steverowbotham77083]

Thanks all for your very helpful responses, which have enabled me to complete the cylinder machining satisfactorily with all of the tooling marks caused by the angle plate shifting thankfully being removed in the process. I started with the angle plate mounting approach as that is the method recommended for beginners in 'Building A Vertical Steam Engine From Castings' which details the manufacture of the 10V. I did think about using the 4 jaw but thought it may be difficult to achieve correct alignment due to the jaws getting in the way of the square, so went with the recommended approach. My problem was a small angle plate and large faceplate; locating the angle plate such that the cylinder was central to the faceplate meant that I couldn't bolt it directly so ended up clamping, and the bolt securing the clamp ended up closer to the spacer than to the angle pate as pointed out by Clive. I knew this wasn't ideal but thought it would hold – a key learning point here! Further to the above suggestions I had a go at setting up in the 4 jaw, inserting paper on the flange faces as suggested by Clive and having first ground off the hard skin as suggested by Hopper. I haven't yet drilled and tapped any of the castings as I decided to complete all of the facing and boring of the castings first so couldn't use the method suggested by Martin, though I do appreciate the effort of producing the drawing. I am very pleased with the end result, all square and dimensionally correct. I am now moving onto machining the flywheel casting, so stand by for more beginners questions!

[HopperParticipant @hopper]

Good result! Keep us posted.

If I may offer a further tip: try to minimise the amount your tool sticks out of the toolpost. It looks a bit too far in the pic. It will be much more rigid if you pull it back in so the amount of "stick out" is about one or maybe at max two times the thickness of the shank.

Have fun!

[Bruce VoelkerdingParticipant @brucevoelkerding91659]

instead of paper between the Packing Pieces and the Cylinder I use double-sided Scotch Tape. The nice thing is the Packing Pieces don't shift or fall off as one adjusts the 4-Jaw Chuck.

I live in the USA, I'm not sure that Brand name is used in the UK. I think you have Sellotape. Normally it has the Adhesive on one side only, but the double-sided variety is easy to obtain.

Bruce

[Steve RowbothamParticipant @steverowbotham77083]

Thanks again for the tips chaps, I'm on quite a steep learning curve! I will certainly keep you posted Hopper, I decided to have a break from facing & boring tonight having completed those operations on the Boxbed, Soleplate, Standard & Cylinder, and decided to start on the steam passages. I have just milled the recesses and then calculated the drilling angle (which isn't on the drawings), though will check my trig again in the morning – I have now invested a lot of hours in this cylinder!

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