The Bucket Foundry

[Flettner]

Ok, the failed castings were what should probably be called FOS/ High pressure+Direct to open air transfers. FOS/HPDT ? Perhaps?
On closer inspection it appears there is an area around the water core that is slow to fill trapping air, the cause of the bubbling problem. Shell Sand would solve the problem but a modified CO2 water core might be a better first try?

[WilDun]

On closer inspection it appears there is an area around the water core that is slow to fill trapping air, the cause of the bubbling problem. Shell Sand would solve the problem but a modified CO2 water core might be a better first try?

How about a silicate sand "biscuit"? - Would it be possible to use the silicate as an adhesive for loose sand ? (I have heard that silicate can be very sticky at the right consistency), ie making a core by a basically similar process to shellsand, but instead of a hot corebox, use gooey (thick) silicate painted on the inside of the corebox, then blow in normal silicate sand and finally pass Co2 through it, there could possibly be a problem finding a suitable release agent though!
Maybe I'm in cuckooland again!

[Flettner]

First let's look at some shortsightedness in the mold runner layout. For convenience I usually put the in gate (the part of the runner that connects to the mold cavity) in the bottom sand mold, this has an upward effect on the aluminium as it enters the mold cavity. This in gate is quite large and there will be a high flow rate into the mold, splashing up in this case, not a smooth controlled flow in. This alone will cause problems but it seems with my other molds I get away with it. More room in them perhaps as this mold is full of intricate cores with potential gas traps. The in gate needs to be wider, thinner and slow the feed down a little so as to get a smoother more even fill. You can see this in the first picture. Also interesting to see (second picture) that the water core print (top) is uncovered by aluminium, this is good as it means the gas coming up this core can escape directly to the holes I've drilled above them, for this purpose. I also see the core prints around the outside (exhausts and direct inlets) are uncovered (mostly) by aluminium, so gas can escape there.
More thinking and I've come to the conclusion that a ring gate might be in order with say six or three small feeds into the mold to join the cavity to the ring gate. Way more even filling, that's where the problem is and some better venting from some of these potential trapped cavities in the water core.
Another reason to have small in gates is so that when the runner / in gate freeze off they don't try and pull aluminium out of the mold with shrinkage.

[ken seeber]

Slider update. A little bit of noise.

https://youtu.be/dT4btNAmjz0

Turns out that the stud that actuates the sliding cylinder broke, probably as a result of bending load reversals due to the fore and aft vibration of the (relatively heavy) lever.




Something to be addressed for the future. Notwithstanding, this meant that the cylinder running in the vid was in its down position, meaning that the ports were low: approx 160 deg exh & 66 deg transfer durations.

Really means that there is a lot more noise to be had.

[Flettner]

Nice, Sounds the business.
So just end caps on the chambers and load up the dyno? Too easy

[husaberg]

Slider update. A little bit of noise.

https://youtu.be/dT4btNAmjz0

Turns out that the stud that actuates the sliding cylinder broke, probably as a result of bending load reversals due to the fore and aft vibration of the (relatively heavy) lever.

Something to be addressed for the future. Notwithstanding, this meant that the cylinder running in the vid was in its down position, meaning that the ports were low: approx 160 deg exh & 66 deg transfer durations.

Really means that there is a lot more noise to be had.

, maybe bolt down that engine before you run it next time. plus great work

[Flettner]

Frits, are you watching?

[TZ350]

Slider update. A little bit of noise. https://youtu.be/dT4btNAmjz0

Hi Ken, sounds good, the engine rpm, was it being controlled by the cylinder sliding action?

[Frits Overmars]

Frits, are you watching?

Yep , and listening . And celebrating .

[WilDun]

Well done so far Ken, you got it revving this time - keep it going, you and Flettner have got on to something other than the old mundane designs (all inspired by Frits of course!).

Thought I would point out a couple of links posted by Husa. on the "Oddball engines" thread, (post #1148) https://www.kiwibiker.co.nz/forums/s...totypes/page77

The second one is very interesting in that it describes the Aluminium casting hurdles encountered in the development of the Hillman Imp engine.

[breezy]

Slider update. A little bit of noise.




Something to be addressed for the future. Notwithstanding, this meant that the cylinder running in the vid was in its down position, meaning that the ports were low: approx 160 deg exh & 66 deg transfer durations.

Really means that there is a lot more noise to be had.

nice work ken....

[husaberg]

Well worth a look at the detail of the casting water jackets etc
http://www.f1technical.net/forum/viewtopic.php?t=15385

[adegnes]

nice work ken....

+1 to that!
It looks so cool! I'm really excited to see how it behaves with the pipes done!

[WilDun]

Well worth a look at the detail of the casting water jackets etc
http://www.f1technical.net/forum/viewtopic.php?t=15385

You always manage to dig up some very interesting stuff Husa! and "state of the art" too (well state of the art 4 years ago)........... and not two stroke, but comes a good second!

[ken seeber]

Gotta agree with Willy, good find Hewsa.