PM Research #3 Engine - Part 11

[@SteamEngines-Jim]

Nobby another enjoyable installment, can’t wait to see this eventually running! - Cheers Jim

[@MrFactotum]

hi Nobby nice job, tricky holes next. ive just been drilling some tricky holes too!! see you next time👍👍👍👍🚂🚂🚂🚂😉😉😉😉 atb Kev

[@nobbysworkshop]

@@MrFactotum The cylinder certainly was the most difficult part of the build Kev. A lot of thought (out loud) and planning. Cheers Nobby

[@EnglishHobbyMachinist]

Nice bit of precision engineering Nobby 👍

[@nobbysworkshop]

@@EnglishHobbyMachinist I wouldn’t call myself a precision engineer Mark. As Tubalcain says Beguess and Begosh 🤫 Cheers Nobby

[@TheKnacklersWorkshop]

Hello Nobby, As we know the order of operation is very important so we don't run into trouble holding the workpiece... but you reminded me that considering how you are going to measure your work when holding the workpiece in the vice is really important to... an enjoyable video, thank you. Take care. Paul,,

[@nobbysworkshop]

Cheers Paul, thanks for looking and the nice comments. ATB Nobby

[@julias-shed]

Great job Nobby I was crossing my fingers for that cylinder bore drilling and reaming. Your mill really doesn’t like slow speed does it? Maybe start faster and wind it down? 😀

[@daveticehurst4191]

Hi Nobby, too late now but the ideal way to get the cylinder to final lenght is as follows. If you had barely cleaned up one end to get a true surface, then drilled and reamed the 1/2 inch bore, and also did the valve bore too. Then on a 1/2 inch mandrel in your lathe, faced off both ends to final size. Doing it this way ensures that the ends are perpendicular to the bore, so that the end caps and piston rod are on axis. There could be the chance that when you fit the end cap, piston and rod, that it will not line up with your crosshead. I know that you still have to mark and drill it, but should the endcap be out laterally in the horizontal direction, the piston rod will run tight and loose in the crosshead. Depending on what tollerance you have set yourself for the cylinder block length, there may still be a few thou to spare to pop it on a mandrel and skim the end that fits the cap with the gland nut. The blanked off end does not matter it it is not parallel to the bore. Just my " 2 Pennies worth " of what ideally should be done to get an A 1 running piston and cylinder. Your choice so don't let me influence you if you are happy with what you have done so far to the cylinder. Regards from Australia.

[@nobbysworkshop]

Hi David, as you say too late now. I actually made this part of the build a month ago. Have already completed part 15 of the project. I have made a test fit and fortunately the piston and crosshead do seem to run ok. I do value your advice, which will help me in the future as well. I’m still learning every day. Thanks David, from your amateur machinists Nobby

[@EnglishHobbyMachinist]

Good advice, I hope you don't mind if I use it 👍

[@daveticehurst4191]

@@EnglishHobbyMachinist Please feel free. With the mandrel you could use aluminium and make it a very light squeeky fit, but take very light cuts as it may slip; or have a nice location fit, with a tapped countersunk hole in the end and split it down the middle both ways for a short distance to make a 4 way expanding mandrel. Or use a very small amount of Locktite, which can be released using heat, then clean off with Acetone. You could also use steel or brass for the mandrel, whatever you have in stock. Regards from Australia.

[@EnglishHobbyMachinist]

@ great advice, thank you 👍

[@RustyInventions-wz6ir]

Very nice work mister Nobby

[@nobbysworkshop]

I do my best Rusty. Don’t always get it right, but learning all the time. Cheers mate. ATB Nobby

[@RustyInventions-wz6ir]

@ oh I get that. Very much the same story with me,however your work is on a better level. Nice work

[@TrPrecisionMachining]

good video nobby

[@nobbysworkshop]

Appreciate your kindness Michel. Cheers Nobby