Metalurgia, forja y fundicion

Where can you buy model size nuts that look right on small engines? I am looking for 4-40 &6-32 in particular but could use other sizes if available. Thanks Colin

Is there something one can do with a 3D printer that is like lost wax?

Ray

I use an optical punch as an aid when doing metalwork (see attached picture). It is one of my favorite gadgets! I broke the optical rod when I knocked the device of the table. I use it a lot and thought this is a good time for me to finally make my own improved version that does not require I swop the optical rob with the punch each time.

I have a short length of 10mm Perspex rob that I used to make the optical rob from. It worked well but the focus is completely out. I used a 13 mm radius...

Optical center punch formula

你好，
i'm looking for a boiler for this 3 cyl steam engine for my boat. but i have no idea which boiler matches it. and I can't find the right boiler for it. any suggestion. thanks in advance.
https://www.stirlingkit.com/collections/steam-engine-model/products/kacio-ls3-13s-three- cylinder-steam-engine-model-for-80-120cm-steamship

Introduction
Porsche 917 is a race car developed by German manufacturer Porsche
The 917 gave Porsche its first overall wins at the 24 Hours of Le Mans in 1970and 1971.
Powered by flat 12 engine, air cooled , of 4.5, 4.9, or 5 liters,
The Can-Am variant twin turbo was capable of 1100-1540 Hp

i find it from stirlingkit's blog. amazing

Intro
I’ve been working on this radial engine on & off for <ahem> more than a few years now. You may have seen some of my prior questions or random posts scattered elsewhere on the forum. Progress has been pretty slow with the usual factors - time constraints, distractions & learn-as-you go snail’s pace. I also had a few unwelcome interruptions with my machines. The drive train on my ’97 Taiwan 14x40 lathe developed problems which took some time to source parts & repair. Then shortly...

Ohrndorf 5 Cylinder Radial

I first saw this engine at the 2019 NAMES show. Can't remember for certain who had made it, but he also had a really nice Lanz tractor. I asked where I could get the plans and he said, "Be patient, watch Village Press ". If anyone knows the modelers name, help me out, that was some sensory overload, and while I took pictures, I didn't get good notes. Anyway I saw it again here, from Rustkollector, and he said the same thing, but now it was "very soon". and it was.
I got the book "The Engines...

25 HP Nash

Hi, what is the right percentage of oil to mix in the gas for these old and "big" 2-stroke engines and what kind of oil, I.E. standard oil for chainsaw, mopeds or other for modern engines?

I got conscripted to build a duck house for my mother's two ducks.

I salvaged pallet wood (7 large pallets - with her help) for enough wood to make it. Got left over insulation and some tar shingles somewhere to finish it off.

Figured I'd share.

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Here are the little buggers. They grow so fast
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I'm looking to find a milling attachment for my newly acquired hobby lathe. It is a chinese export lathe that i couldnt find much about it. I'm trying to get together what i need to build model engines and honestly i'm disheartened that a mill is also needed. I'm new to lathes so i dont know which milling attachments would fit this mini lathe. Most of experienced lathe users doesnt like or recommend cheap stuff and they are...

I'm looking to find a milling attachment

This time Success, one smart cookie, I learnt from failure! This time I double reinforced the mold with fiberglass threads (pulled sheet fiberglass mat apart and mixed it with the mud) And I even got a video so the safety officers here can fine me!
I think this was the best batch ever, I am over the moon!!



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This is my latest pattern making effort: a matchplate to cast a 30cm/12'' deep aluminium box using green sand. I plan to cast the box upside down with the top of the box being open sided, so the inside sand mould will be able to rest on the outside sand mould for support once assembled. So for such a small base to depth of the mould, the inside/core green sand mould will need some kind of steel bar reinforcement to prevent it breaking off during withdrawal from the pattern, flipping and...

Reinforcing 12 Inch deep pattern for green sand?

I watched this very interesting video about casting a iron cooking pot. They used a green sand core and never bothered to put in vents in that green sand core. I have used only two green sand cores in the past and worked well. Seeing how large this core was it would make no sense to make it out of epoxy resin because the casting is emptied from the mold while very hot, so there is very little time for the epoxy resin to burn out plus green sand can be reused over and over again....

Green sand cores.

Currently I am making such burners and now testing a Frosty T burner which appears to work well in my small cast iron furnace, but have yet to test a melting session. It gets hot enough to melt copper, but cast iron ? I think I need to use my already existing forced air burner.
But do some people melt cast iron with a naturally aspirated burner ?

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Propane is IMHO one of the best fuels for powering a melting furnace, although some prefer waste oil. But lighter refill fuel is mainly butane and in the past here in W-Europe cooking on butane (so- called 'butagas tanks') was common in places devoid of natural or town gas.
Now it is completely phased out for tanks similar to propane tanks.
I think it is due to its 'high' boiling point of 0ºC under normal atmospheric pressure, which means that under freezing temperatures in winter, the...

Are there users here using butane ?

This Youtuber has recently made a 300-500kW monster rocket burner where he 'breaks the temperature barrier' like the sound barrier in aviation as he calls it. He plays a trick with two oxygen nozzles inside the burner body making it so hot that it melts even the 2700 F rated refractory of his furnace, which is not a usual swirling around the crucible design as we all have, but a central burner inlet design.
Looks spectacular, but with a decent welder and carbon arcs the same temperatures and...

NOBOX7 channel: Epic melt down rocket burner

I have a project I am returning to after working on it several years ago. It's an axle cover with a very detailed winged logo on it. I have made at least 6 by sand casting with PetroBond and 4 with lost wax slip investment. I have a good silicone mold of the part for making my wax patterns.

I am seeking advice on the spruing of these wax patterns. When I cast them in sand I had a riser, a gate that fed the part and another riser on the opposite side. (See second try 2 ) These worked well...

Spruce design for lost wax slip investment casting?

Has anyone developed a PolyCast slip-investment burn out schedule they are happy with. I have downloaded both of the PDF files offered by PolyMaker.

Heat the kiln to 1100-1200 °C for an extended period of time (up to 40-60 min) to simultaneously sinter the ceramic shell and burn out the PolyCast™ patterns. The optimum burnout temperature and time may be determined by each foundry for the metal/part to be produced and the specific kiln or furnace used.

Is this supposed to be a slow rise...

PolyCast burn out schedule?

Thought we needed a thread where anyone can throw in random stuff that doesn't warrant a thread of it's own.