Member postings for Ken Ratcliffe

Hi Andrew, I ended up getting one from Carlo Groce (two in fact because I dropped one !). Manythanks though

" Also, the cutting tip should be aligned exactly to match the helix angle of the thread."

That now makes sense as to why the cross slide needs to be angled at 14.5degrees - I think

I have one more piece of free cutting steel, so will give a whirl with all the suggestions (many thanks), but have also ordered one (Thanks Martin)

Thanks Martin, just dropped them a note. Much as I hate not making, this one could be beyond me - and the rest of the clock isn't easy !

Yep David, it is the trickiest yet, for sure. Putting my lathe skills to the test. That and a traction engine on the go !

Hi again......have you guys built the Marlin Band Clock ?

I am coming unstuck on the 8tpi thread on the centre arbor (TBH struggled to turn 6" of free cutting silver still down to 3/32" first time I tried). I have just put a post out asking for any help / hints, but then thought you may have built one and have some suggestions ?!

Any help welcomed

Ken

I think I will try the 650 degree and then clean up......here is a photo from the build book, clearly better lathesmiths than me - but then again I thought making a wheel was impossible the first umpteen times I tried and messed up, I can usually get them first time now

Ken

Hi All,

It is "only" 3/4" long thread. Just checking the instructions and it is 8tpi and 5/32" stock, it suggests a depth of 0.05" for the cut.....and fully admits it isn't going to be easy !

Maybe I should explain what it is for, it is a worm drive on a clock, so the thread drives a wheel, so, the depth of cut only has to allow wheel to engage, hence 0.50" cut.

The book also suggests a tip on the acme tool of 1/32", again maybe not standard. I think I will give Clive's suggestion a go and lots of shallow cuts from reading around

Ken

Hi All,

I am trying to cut an 8tpi thread in a 5/32" diameter silver steel bar. I am using free cutting silver steel as the instructions suggest. I have ground an ACME tool in HSS and have a live centre and travelling steady for support and turning the lathe by hand......but tool keeps catching (digging in) and warping the bar.

Any thoughts or suggestions, as always welcomed !

Ken

Hi Rolf,

I haven't got to the drivetrain yet, so can't help on your specific questions. However, I am English, have a couple of degrees - and at times find the book difficult to follow ! Throughout there are errors, notably in the early parts where the metric and imperial don't match. It keeps you on your toes though, doesn't it !

Ken

Hi Jim,

Thanks again. I put a small bend in the pushrod inside the chest, so it is a little bit closer to the block, made sure it has some play...….and yep, I now have a working steam engine !

Still a lot to do, but a pressure tight boiler and a working engine means I am on the home straight !

Ken

Hi Jim,

Glad you said that, it was my first thought, just because so much steam was just heading straight out the exhaust. I have skimmed some of the chest walls to make sure the valve was in good contact with the block.....so there doesn't seem to be a reason it held off the face and both are smooth faces, but that is not to say there isn't a reason.

I will have another play with the valve seating tonight when I get back from work as a starting place !

It is a side valve and yep, the flywheel turns easily BTW.

Ken

All,

Any help welcomed ! I have posted previously about building PYRTE. I have my boiler all sealed up and holding pressure (last post !) and all the steam piping to the engine and out to the exhaust tight. When I pressure it up and open up the steam to the timing valve, all that happens is a lot of steam comes out of the exhaust and there is no feeling of the piston wanting to move on its own as I spin the flywheel. I am fairly sure the valve timing is OK - if not perfect not that far off.

I am wondering if my piston isn't sealing well enough, i.e. steam is passing the rings and going to the exhaust irrespective of where the valve cover is ? The rings look well seated and the inside of the piston is smooth, but when I pressure up with air (using a footpump) some does pass the rings. Being as this is my first steam build, I am not sure what is acceptable, i.e. should the rings pretty much be "air tight", or is some leakage OK........

Sorry if this is a bit vague, but just hoped someone may be able to give some guidance (as you all have with my previous novice questions)

Ken

I feel so dumb ! Yes, the cutters are pictured on Page 66. I read and read, but didn't go to the back on lathe tools. Thank you ! Any tips on cutting the screw in the arbour welcomed !

Its always good to have some pictures to look at, I have been using the You tube video a lot https://www.youtube.com/watch?v=-xGWCN8k6Sg

Hi All,

My Merlin Band clock is progressing (having fun with Archimedes screw on the main arbour, but hopefully that is just a bit of practice). This is a question about the crown wheel. In the book by John G Wright it states to use a fly cutter with the dimensions given...….the only "given" is a sketch of the teeth and it has x2 above it. Not sure if it X2 scale, if this is an accurate shape and it seems a critical part of the clock (escapements always give me trouble).

So, I guess I am asking if anyone out there has built this clock and what should the fly cutter look like - ir what should the teeth on the crown / escapement wheel look like!?

Many thanks

Ken

I will bite the bullet and go for a PP Thornton wheel cutter-this wil not be the last clock I make, so hopefully years of use. Couple of questions though before I part with hard earned cash...….I was assuming square bottom, but is there ant advantage to round bottom for a Module 0.6 ?

Also, looking at the picture it doesn't appear to have the usual slot to hold it in place on the arbor, am I missing something - i.e. id it is just a round hole, how does it get secured on the mill ?

Hi All,

As wells a PYRTE traction engine on the go, I am working on a Merlin Band clock, but have come to a bit of problem. The construction book says to use a Module 0.6 cutter, but a quick search shows that these are not easy to come by. I am able to make a fly cutter to create these gears....I think ! But I need to know what size and shape to make the tool to be equivalent to the module 0.6 cutter. So.…...if any one can help - or if anyone knows of a source of a module 0,.6 cutter, I can progress this project while waiting for some materials for PYRTE !

Ken

Thanks all - I suspect mine will also leak like a sieve - the build-book starts with the boiler, perhaps the most difficult silver soldering part for a complete novice. It does hold water without leaks (not under pressure, which is a start.

Good point on water to see leaks, I was going to submerse it and look for air bubbles

Cuttings threads is no problem, but won't the coupling need a non return valve to pump it up......could be me being dim here, it not then I am good to go - is there where the inner tube valve comes in ?

For now I will be doing nothing more than getting it running in the garden.....MAYBE if that is successful I may take it out and would get it steam tested professionally first.

Pictures...…..sure, but don't all hold your breathe, the speed I go would make PYRTE look fast !

Hi All,

About a year ago now I asked for help with silver soldering a boiler as I was starting a PYRTE steam engine - my first attempt at a steam engine. Well, it is nearing completion, almost all done but I haven't tested if my boiler holds pressure. Why ? I didn't think I would get this far, so never really worried, it would make a good garden ornament, but now - I WANT TO SEE IT RUN - so, I was initially wanting to use a car tyre foot pump to check for leaks, but what seems simple - I am struggling......how can I connect a tyre pump to the back of my boiler - where I have 1/4" x 40 bushes - or any other suggestions.

Joe just got back...…..probably my bad, using the wrong e mail - apologies all round !

Thanks all. I tried calling and leaving a message, and e mailing, really just trying to make sure the order was all OK, but complete radio silence. Difficult times and from what you all say, Macc are doing their best, so I will sit back and chill !