The Bucket Foundry

[WilDun]

Neil, what is the significance of the small "tit" at the bottom of the big end ring?

[Grumph]

Neil, what is the significance of the small "tit" at the bottom of the big end ring?

Guide peg keeping the bearing aligned ? Effectively, it's an overhung crank isn't it ?

[WilDun]

Guide peg keeping the bearing aligned ? Effectively, it's an overhung crank isn't it ?

I think it possibly will be a two sided crank, but I don't have many clues as to what the "tit" is for, except that it might be just temporary to hold in the chuck for machining the rod( on the lathe)!
No doubt we'll find out .....

[Flettner]

O, the tity, it's just a place to put the center when I was grinding the hard chrome shaft. Thought it best not to cut it off just in case I need it again.
Grumph, it not an over hung crank I just haven't shown the other half yet (cause it's not made yet), no, unlike other epicylic systems this has a fully supported crank.

[husaberg]

O, the tity, it's just a place to put the center when I was grinding the hard chrome shaft. Thought it best not to cut it off just in case I need it again.
Grumph, it not an over hung crank I just haven't shown the other half yet (cause it's not made yet), no, unlike other epicylic systems this has a fully supported crank.

I was wondering how you were hiding the overhung crank with those shorts Neil.
Have you seen the facing sand how to on the old foundaryman site?

[WilDun]

Well that's all "fine" of course (), but I don't think that guy was wearing any sort of mask at all - in my book that's a no-no in conditions like that and to tell the truth I reckon there could be better ways of spending a weekend!
On the upside or positive side he was ending up with a plentiful supply of good quality facing sand - enough to see him out really! (sorry, slipped into negative mode again)

[husaberg]

Well that's all "fine" of course (), but I don't think that guy was wearing any sort of mask at all - in my book that's a no-no in conditions like that and to tell the truth I reckon there could be better ways of spending a weekend!
On the upside or positive side he was ending up with a plentiful supply of good quality facing sand - enough to see him out really! (sorry, slipped into negative mode again)

I note he is using a natural sand that has a element of clay already in it.
You could of course just mechaically sieve sand using a vibrating set of sieves.
it will take more material but its a bit easier and less messy then add some ground bentonite.
You will remember someone ages ago linked a cement and oil mixture, Cement is very very fine plus easy to obtain rather cheaply.
From what i can undestand the oil doesnt actually cause the hydration process to start.ie what makes concrete set, so its not going to explode in a steaming mess. With these mixes you use oil so it makes sense to use a two stroke oil, for less smoke as in petrobond which tublicain uses in his videos.

Yes Will you are right regarding the grinding of sand as most NZ sands are silca based and it it is a real silicosis risk. Which for those who are unfamilar with it, is a rather nasty way to slowly die.

I came across the olfoundryman due to him advising some one about there feeders being uninsulated and thus cooling too fast and not feeding the mold correctly. like Fletner recomends he also uses the Mg powder in bigger pours.
the guy he advised ended up using thick plaster of paris feeders and risers with great success.

[Flettner]

https://youtu.be/cuSnfRgyEZk

backup linear crank assembly

[Flettner]

the insides of the HCCI head, I guess what you would expect to see. 16mm stroke

[WilDun]

the insides of the HCCI head, I guess what you would expect to see. 16mm stroke

At the risk of appearing incredibly stupid (or at least a little slow), I still haven't got my head around the "double speed OHP" concept!
Why double speed? and is there some benefit of having a blast (of whatever - spent charge?) coming from the OHP as the main piston arrives at BDC - or is it timed to be out of phase?

[Flettner]

yes I guess the small piston is a little out of phase. 2 to 1 so there is some urgency in the compression rise. Small piston is rapidly heading for it's TDC as the big piston loiters around it's TDC. Comes a point where pressure / temperature is just too much and ignition occurs.l

[WilDun]

yes I guess the small piston is a little out of phase. 2 to 1 so there is some urgency in the compression rise. Small piston is rapidly heading for it's TDC as the big piston loiters around it's TDC. Comes a point where pressure / temperature is just too much and ignition occurs.l

Yes, but what I'm meaning is that what will be happening at BDC (main piston) - are you hoping to also use the (as I see it) "wasted" stroke of the little piston to good effect, ie to perhaps introduce a buffer charge of air to shoo out the exhaust gas from the power stroke
- or something ...... somehow?

[Flettner]

Will, that information is restricted
The idea is the small piston helps with expansion, a little bit, but the big deal in my opinion is because the little piston is at it's BDC when the main piston is half way up (when the exhaust pulse is doing it's 'supercharging' there is more room to shove fuel air back in. But the small piston is not involved with the cc rating of the engine as it's at it's BDC when the main piston is at it's BDC and it's TDC.

[WilDun]

Ok, thanks, that's all good

[Frits Overmars]

yes I guess the small piston is a little out of phase. 2 to 1 so there is some urgency in the compression rise. Small piston is rapidly heading for it's TDC as the big piston loiters around it's TDC. Comes a point where pressure / temperature is just too much and ignition occurs.

The idea is the small piston helps with expansion, a little bit, but the big deal in my opinion is because the little piston is at it's BDC when the main piston is half way up (when the exhaust pulse is doing it's 'supercharging' there is more room to shove fuel air back in. But the small piston is not involved with the cc rating of the engine as it's at it's BDC when the main piston is at it's BDC and it's TDC.

Ok, thanks, that's all good

I'm timing the arrival of WilDun's next question:
"How can the small piston be at BDC when the main piston is at BDC, if the small piston is a little out of phase at TDC and it is geared 2:1 ?"