Recent content by Till

The simply genius aspect of a poppet valve is, that it does not move on the sealing surface when exposed to the maximum pressure of hot combustion gas. It stands still. The second genius aspect is, that the hot exhaust gasses do not pass an oil film at any time with high velocity. In fact, the...

There have been barrel-engines for over 100 years now. They all share difficult lubrication conditions, difficult thermal conditions, extra tight tolerances and lack space for maintenance. In other words: These are expensive to make, have a short lifespan and expensive maintenance. I don't...

The conrods in real engines are made of (forged) steel, because the weak E-Modul (Youngs Modulum) of aluminium won't allow for stiff supporting structures around the bearing bushes. The bushing will deform and thus wear out quickly. This is unimportant in model engines. For illustration...

Cr = ( 9953 + 1058 ) / 1058 = 10.4

Use a compound (polymer resin with a high percentage of metalpowder for enforcement ) specially made for that purpose such as Diamant Metallplastic DHW to provide force-fit cover on the whole mating area. You can use WD40 as a parting agent for most products (check this prior to use!).

Well there are already small power plants established to supply trucks, especially for the refrigeration units (at least in Europe they are). So they clearly aimed at the military market. Military? Funding comes from the taxpayer → if there’s a problem, continue to throw money at it until...

Niels, that crankshaft design will wobble unter load conditions because of the bearing layout. There will be lots of undesireble sideeffects, including periodic noise (and wear) of the bevel gears. And I think that the amount of power supplied to each prop is not equivalent (at least with...

This is a pipe dream. It will be expensive to develop and to purchase because of the small lot size. Plus engines with hot exhaust gasses passing hot, well lubricated parts such as piston rings will never meet emission standards. If there’s is any future for new small aircraft in the...

Lubrication oil and manufacturing techniques made great improvements over the centuries. Steam engines were built for industrial work and had to be reliable for a long time. Lubrication was a great problem for decades. To tackle this problem in a piston engine, you’ll have to reduce the...

Yes that's the usual way in every cad program. Elements on the screen must be defined precisely so the program can create unambiguous data you can perform operations with later. I recommend using one of the big established cad-programs, too (if you can afford it). Here are some reasons for...

Even the objects are called solid, they aren't. They are made of surfaces, the programm calculates the boundaries and hides everything outside of the boundaries. The solids are hollow. Hide one of the faces and you can have a look inside. I installed the programm some time ago but never...

It is there, but you've accidently typed your text in between the

In most countries it depends on whether you sell it from your private use property or from your commercial use property. You usually buy a license to build one (or several) piece(s) of xyz and this includes using the plans. As a commercial user, you’re usually not allowed to pass...

Cheap electric cooktops (the ones with a cable attached) are getting red hot if left at maximum for some time. I use one of the white ones like these https://www.google.de/search?q=elektrische+doppel+herdplatte&btnG=Suche&gbv=1&um=1&hl=de&tbm=isch&tab=wi for heating up the workpiece when...

The picture on top of the page is a featured user project, called "project of the month". In the past the picture had a link to the nomination thread which obviously is absent now. Maybe Austin can fix this? The engine is a Hoglet and you’ll find plenty of information on the net and...