Muncaster's Simple Entablature Engine

He does do a nice job of casting them and the iron is nice and easy to cut.

Morning Jason, would appreciate your thoughts on increasing the crankshaft from 8 to 10mm its just convenience really. I have 10mm ground bar and my smallest boring bar will go down to 10mm. It would mean the bearings growing by 2mm but it looks as if the pedestals have enough meat. I would rather bore for the crank than ream, it would just look a tad heavier in the crank area but I don't think too much. What do you think..?

Ron

Should be OK,

You will only get 2mm wall thickness to the eccentric's boss for the grubscrew to hold into so may want to up the boss dia to 16mm which will mean it's not a full circle but should not matter.

Bearing pedestals will take the bigger bearing or you could make all the widths 2mm wider which would allow for a 10mm radius at the top and therefore keep the same thickness material.

Jason, would silver steel be ok for the crosshead guides or is it the wrong material, its the nearest size I have on the shelf. I have some 100 x 40 x 8mm pieces which I thought I could get down to size and most of the shape with the 25mm end mill, if its not suitable I will get some bright steel in.

I assume you mean gauge plate (ground flat stock) should be OK and no more likely to move than bright bar.

I quite fancy having a go at this

Is there anywhere I can download your plans Jason?
I can access previous back issues but can’t easily print these of the magazine viewer

thanks

Chris

Check your messages.

I'm confused about the vitron o ring.

I can't find any metric ones, or am I looking in the wrong place.

the usual model engineering suppliers use imperial, which the sizes in the magazine equate to 3/32 or 0.09375 section and 49/64 or 0.76563 id . they are nowhere near what I have seen online

(ps sizes rounded and taken from model engineers handbook)

can anybody point me in the right direction for these "elusive" o rings

thankyou

regards

Paul

They are not elusive Paul I got mine from Simply Bearings £4.29 for a pack of 2, maybe cheaper elsewhere I don't know, Jason will know. I have seen them on Ebay but went with Simply as I trust what they supply is the genuine item. 

Ron

Edited By Ron Laden on 04/05/2020 04:35:12

Crikey Ron you're up early but then so am I!!

Paul you can get them on ebay at sealsuppliesuk

They call them viton rings not vitron

I assume they are the same thing?

Geoff

Hi Geoff, good morning yes this is about the time I am in the workshop as I have got older my body clock has changed, to bed at 9.00 up at 4.00.

Ron

With most of the ME suppliers still living in an imperial world you are best buying from somewhere else in the modern world. As has been said any seal supplier or e-bay will have them. Just put "19.6 x 2.4 viton" into google.

A 3/32" nominal O ring is actually 0.103" section (2.62mm) not 2.4. though with changes to the groove an imperial BS116 ring would do as 15/16" is close to our 24mm bore.

Good listing of metric sizes here

Edited By JasonB on 04/05/2020 07:14:48

Jason that explains the 0.103 I thought about the 15/16" but that is a tad under 24mm wouldn't that not be any good?

thank you all

I will get some metric ones ordered

regards

Paul

You would have to play about with the groove dimensions a bit to get the 15/16" to work bit it could be done if nothing else was available but as there are plenty of the metrics about hardly worth the hassle.

These are the ones.

cheers Jason

i've ordered these, I think they should be ok, time will tell

**LINK**

many thanks

regards

Paul

Thats a good price Paul, I paid a fiver for 2 off.

Will have to remember that in case I build any more of Jasons 24mm engines..

Ron

That looks fine, I've used that seller before myself and now you have no excuse not to make another 5 engines

I'm already building 2 that's taking me long enough, it's only because of the lockdown i've managed to get some time to get back into my shed.

while we are on the topic where do you get your nuts from?

m2.5 self Colour seem to be very expensive from model engineer suppliers.

yet from other firms they only seem to supply them in stainless or bzp

regards

Paul

It's not just the colour but the size as well, I think I mention that the ones I use are smaller hex and a bit taller and look better on a period engine. Like good BA fixings these are fully machined not forged mass produced ones so nice and crisp too but obviously you pay for the more involved making.

Polly Engineering do them though I usually buy from the people they get them from who are GHW in Germany.

Mass produced M4 and M3 in the middle and the GHW ones on the outside

Thank you Jason thats given me something to think about

regards

Paul