The Home Machinist!

Absolutely gorgeous headlight and worthy of a PA1 ! Well done! Thank you ! I am trying my best not to be a rivet counter on this loco so I can get it done in a reasonable (that's a very ambiguous word) amount of time, I am doing that on a Shay that I am building, and just can't help myself. As much...

I got them at O'rileys auto parts came in a pack of 2, Seem bright enough for what I want, I have only hooked them to a battery in my shop. They are a spot light type. Biggest factor was they were the right diameter to fit the housing. https://www.oreillyauto.com/detail/b/nvision-3937/truck---towing...

I am also building a PA
Here is my headlight, it was machined

Your mold design isn't the problem, this is done all the time in the die cast industry. Look at the bottom left part in the picture, the big blobs along the edges of the part are there for a couple of reasons one being for the part to draw material from when it cools so it doesn't have as much issue...

You need someplace for the metal to draw in molten metal as it cools. With you pouring into the thinnest section, that section is cooling/ solidifying fastest and the rest of the part as it cools and shrinks has nowhere to get the extra metal to make up for the shrinking as it cools. If you put the ...

Yes 900F is good for the flask. Seems like you just need to turn the temp up a bit and get your vacuum working. I would use your furnace temp reading as a reference but not rely on it to be what the exact melt temp is. Did you remove the slag and other crap that rises to the top of the melt before y...

Do you have a way to measure the temp of the melt? This is the best way to know when to pour. I do not have anyway to do this yet, I just do it by by the highly sophisticated method of "that seems about right". I have a gas furnace so temp control isn't as good as your electric and wouldn't know how...

The ones I have seen/used the air just takes the place of the hand pump, you still have to use the bleed valve to lower the jack. There is a check valve between the pump and the cylinder, this check valve is bypassed by the bleeder valve to let the cylinder retract.

A few years back my Uncle gave me some 1/2" plate (hot rolled , rusting and flame cut edges) and he assumed it was just regular ole A36. After I got it home decided to look at it a bit closer and found some markings under the rust/dust and dirt. Turned out it was 4140, still have it as it wasn't sui...

Jim
Lima's standards do not have any info on port design.

Jim
In two stroke engines the racers will go with exhaust port widths up to 60-70% of the bore.
I have a copy of Lima's standards, don't know if there is anything in it about this but I will look tonight.

I have bought a spool of thus but haven't had a chance to print. Looks very promising.
https://us.polymaker.com/product/polycast/