You might try casting with the head flat in the upright position with as long a feeder as possible and feed thru what will be the spark plug location. The heavier base could keep heat flowing up in the fines to give the fill a longer time before freezing off.
You need multiple gates to speed up arrival at all points, you still have to use a vacuum system that you can use your vacuum cleaner, only then will you be successful with so many fins.
As a retired Engineer with little foundry knowledge let alone experience, this is great to watch, to see how Bones deals with the process problems step by step. Have a great time on holiday. If you are anywhere near Leighton Buzzard pop in for a cuppa.
Hello my friend. You are getting closer each time with the casting. I know nothing of casting but fully appreciate and support your attempts to get it right. Thank you so much for the mention, never expected it! Have a great time in the UK!
Hi Mate..........was saying to Dean I think I'm close. Just need to turn the brain off and enjoy the holiday. I'm bringing friends over to the UK who haven't been there before and I'm looking forward to having a look at the continent. take care and get that turbine done!
Kelly Coffield definitely has that knack for making it look easy. It's a shame the pour didn't turn out as planned. But, it's all part of the learning curve. Machining it out of Billet as someone mentioned, wouldn't have that original factory look that would spoil the whole build. I'm sure you will have a great 2 months away. The good thing about a long holiday, home looks so much better when you finally come back to it 👍👍
Adjust the height of your fins when cutting the foam head.. it looks like you just need a little bit more space to make way for the foam that gets trapped and turns into carbon
Pack the pattern like green sand with the fins down, make a ring-shaped access gate with four others Connecting to a single central one, place a vacuum cleaner to form a vacuum - ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-Iz6MmiG2o7k.htmlsi=A374JbwfBpsfBK56
Great video mate. Awesome to see the third generation is out in the shed working on super cool bikes . Kee0 up the fantastic work greatwork on the casting
You are getting close on the head casting 2 things crossed my mind when looking at it, either the alloy is cooling to quickly or the gasses from the foam aren't escaping quickly enough and there is a bit of a gas pocket. Perhaps using a slightly larger feed sprew diameter in combination with your twin gates might help as the larger volume of metal won't cool as quickly. In traditional sand casting you use risers to vent of any gas out of the mold I'm not sure how it would work with lost foam but it may be worth some consideration.
Hi Frank.........You can't use a vent in lost foam as you'd have vaporising gases spewing back out on fire. But I think you're right on the money with temperature at the fins. I'm going to reduce the pattern volume as the base is thicker than the original and split the entry gates. The position of these will be a critical factor as well. Sprue size may be increased however I am now running close to the capacity of the crucible. I'll keep trying and thanks for commenting.
Você precisa de portões múltiplos para acelerar a chegada em todos os pontos,ainda tem de ultilizar um sistema de vácuo que poderá usar o seu aspirador de pó só assim obterá êxito com tantas barbatanas profundas veja os meus vídeos passei pelo mesmo calvario
Very close. Not sure what alloy you are using but I suspect 50-75F higher pour temp would have yielded a complete casting. Fins can be tough because they are designed to transfer heat and they do.....to the mold too. I wouldn't go out of your way to make the sprue round. -Probably better off square. I'd probably tilt the head slightly fins down and branch the sprue where it contacts the head to distribute the hot metal. If so the previous pour temp might get you there. Best, Kelly
Thanks Kelly......I agree with the pour temp, it could have been a bit hotter. I'm having another set of foam heads machined so hope to get a pour in soon. A branched sprue is a must to get the metal to the extremities.........But I'm getting closer!
like the casting, yep its a bit hard to make it work but then if its easy then anyone could do it! Don't get with putting metric screws in imperial inch machine? Got a Herbet 2D turret lathe here to set up for a job no one with a CNC wonted to do. Have fun LOL.
Thanks........Not sure about what you mean with putting metric screws into imperial machines?? Like you people often ask why I don't get parts CNC machined. It's because I can't justify putting an order in for 2000 items. I can punch a couple of hundred in a day and that's all I need.
Larger ID sprue, e.g. 25+ mm - with three or more connections at the very bottom, and three “bleeder” vents at the top?? Also, you want to feed into the thickest part of the casting, with a big reservoir of molten metal to feed the casting as the metal filling the pattern shrinks. Not done *lost foam* in Alumin(i)um, but have done a lot of green sand in it. My brass hammer head was lost foam, done in a college foundry over thirty years ago. Finally, go about 10 degrees warmer. Fins can be tricky - and I have done finned castings.
It was pretty big to start with.........I think the single point entry into the mold was the issue. I'll split the sprue into 2 and have 2 entry gates next time.
Hi have you though of puting a vent on eather side of the outer fin to alow anay traped gasses to flow out of the mold ?? but its gettinh brtter every tme will also have a look round for carb bits and bobs for you .
Hi.....The trapped gasses are getting out. I think the issues is getting enough metal into the mold quickly before the metal is cooling. carbies have been organised as I'll fit up Mikuni's.........Thanks for the offer and commenting.
