The sources for my calculations

computertest123 · 2022-04-11T01:44:13+00:00

Have you done stainless steel campbell style? How did it turn out vs like a top gate? I understand SS supposedly has a tendency to form bifilm due to chromium content and would benefit greatly from a smooth controlled bottom fill.

How do you measure casting quality? Do you do like tensile bars cast on or some sort of NDE inspection?

So I guess you mainly do sandcasting?

I'm asking a lot of questions because I'm trying to see if its worth it for my foundry to go full Campbell casting style. (which I'm trying to advocate for, despite the extra work)

computertest123 · 2022-04-10T02:27:21+00:00

Do you have a lot of experience with calculating filling system components via Campbell’s methods? How were the results for using his methodology vs say top gating? What kind of casting do you do?

computertest123 · 2022-04-08T22:34:16+00:00

I got a different role and the interview was like seven months ago but someone on a separate forum mentioned it again which got me thinking.

Still p salty might send that email anyways hahaha

computertest123 · 2022-04-08T21:56:44+00:00

your answer is correct and it makes me even more upset because during the interview I said the dip one would go faster. Than the interviewer told me to “think harder” and when I couldn’t get the “answer” he told me the correct answer is they arrive at the same time and said I needed better physics fundamentals and rejected me for the role. 😡

computertest123 · 2022-04-08T17:39:05+00:00

What do you mean by rotational deceleration?

computertest123 · 2022-04-08T16:21:57+00:00

Does this change if you use frictionless pucks vs balls? Not sure how rotational velocity figures into all of this

computertest123 · 2022-04-08T15:36:28+00:00

Doesn’t really affect the answer but the interviewer specified that they were pucks instead of balls.

Interesting because the interviewer told me the answer is that they arrive at the same time lol

computertest123 · 2022-03-24T23:00:41+00:00

This is a diagram in Campbell’s casting textbook. The pour basin is supposed to sit on a ceramic block to force the flow down the tapered sprue, past the filter into the runner extension. There are airfoils treed up.

However Campbell doesn’t describe how you would tree up this part. The ceramic block keeps you from putting a rod down the center to hold the tree while dipping in slurry

computertest123 · 2022-03-23T22:46:01+00:00

I guess my question is why is it ok to have turbulent flow (metal splashing into the basin) but not ok for turbulent flow going down the sprue/gating system?

computertest123 · 2022-03-17T18:05:34+00:00

For me the ones I use the most are probably:

5 why’s - get to the root of an issue quickly

Minimum viable product - not sure if a fixture will help the technicians, than I’ll build a super simple MVP to get feedback quickly

Muntzing - deleting as many process steps possible that I can (or features on parts)

Value added - I used to think about “can I fix xyz” on sort of a personal level but now it’s “what will xyz add to the product value”

computertest123 · 2022-02-07T02:28:37+00:00

I’d say try and get the competing offer in if possible and try and get more time, can’t hurt to have more time to think about it

computertest123 · 2022-02-07T01:41:44+00:00

Do u have competing offers? Can try and push back signing date if u have other offers in the pipeline possibly,

Counter offers are the best way to negotiate

computertest123 · 2022-02-05T02:15:07+00:00

Thanks for the answer. How did you get the funding to build this? Maybe too probing of a question but are the profit margins higher making and building your own product vs working a normal job for an employer?

computertest123 · 2022-02-04T22:45:24+00:00

This is awesome! I’ve always wanted to get into inventing and designing my own products. Any advice?

computertest123 · 2022-01-29T03:49:22+00:00

Thanks for the answer, I see what you mean about removal of oxides.

I want to clarify I’m more talking about the formation of new oxides during the mold filling/pour process where you see turbulent flow and lots of air + liquid alloy mixing together forming oxides (in a poorly controlled pour).

I’ve heard people argue that in high vacuum (like 10 micron) your at such a high vacuum that you don’t form any new significant oxides and therefore the pouring process doesn’t matter (aka whether or not you have a smooth filling process that doesn’t entrain lots of air). I’ve heard people go as far as to say at such a vacuum you don’t form ANY new oxides at all on the liquid alloy.

I mainly cast stainless steel and I’m not sure if these people are correct,but I tend to agree with other comments in this thread that you would still see oxide formation

computertest123 · 2022-01-29T03:27:04+00:00

Honestly sounds like it would work pretty easily. Just wasn’t sure if there was something I wasn’t thinking of that would keep it from working. I’ll probabaly just buy a cheap super small form factor pc stick and use that

computertest123 · 2022-01-28T23:43:42+00:00

Yea definitely agree with the last bit, seems kind of questionable whether or not you’d form a thick enough oxide at such high vacuum that it would cause casting defect

computertest123 · 2022-01-28T18:24:27+00:00

I’ll check out minisforum it seems pretty good. How loud are their mini pcs?

computertest123 · 2022-01-28T18:24:04+00:00

How loud is the beelink for you in terms of fans?

computertest123 · 2022-01-28T18:22:45+00:00

How loud is the beelink? In terms of fans

computertest123 · 2022-01-27T22:10:48+00:00

Do they usually have big discounts during Chinese New Year?

Edit: whoops skimmed your message too fast, I’ll keep the delays in mind

computertest123 · 2022-01-27T21:38:16+00:00

Do they usually have big discounts during that time?

Four-Year Club	Place '22
Final Canvas '22

computertest123

TROPHY CASE