[tmarks11]

the Shoptasks and Shopmasters I have owned over the past 20 + years, they have all been quite rigid for the size of machine they are.

Good to know. It just seems me, looking at the arrangement of the bridge supported the way it is that it would be difficult to make a structure that was rigid enough, and would be subject to a lot of twist under load.

[tmarks11]

What do you think about charter oaks/ IH mill?

Go take a look at the Charter Oak forum on this website. Pretty much a ghost town. I would be careful about purchasing chinese equipment in the absence of a vocal group of enthusiastic users.

The Charter Oak machine has had a checkered past. The company changed hands about 4 times since it started, and each transition left unsettled customers in its wake (it started life as Industrial Hobbies). I notice the current owners have started to sell the Syil product line as well.

As far as Syil is concerned, again I recommend you go look at the Syil forum on this website. Also a ghost town. This has mostly been because of a lack of in-country customer support, so hopefully Charter Oak will fill that role and start selling some serious equipment numbers. Competition is great for the end user, as it drives innovation (as long as it doesn't drive the innovators out of business in a price war).

[MichaelHenry]

Not sure if that was directed at me or just anyone. All the machines on these forums, Charter Oak, Novakon, Smithy and Tormach are essentially re-branded or slightly modified versions of Chinese designed machines.

I don't know about the other brands, but am pretty sure that the Tormach mills have all been designed here in the States and are built with custom castings from China.

[instructor37]

Good to know. It just seems me, looking at the arrangement of the bridge supported the way it is that it would be difficult to make a structure that was rigid enough, and would be subject to a lot of twist under load.

Actually in terms of physics, the opposite is true. When calculating twisting loads, a wider support profile is better, so the 6 columns of the Mill Turn, spaced widely apart would have a greater resistance to twisting than a single column. As a simple home test, place your feet tight together and ask someone to try and turn you around while you resist, then place your feet in a wide stance and have them try it. Before we bought the Patriot machines, we had a couple of those small Chinese mills like the Sieg and the 440, and the Patriots were considerably stiffer even though they only had the 4 column support.

[tmarks11]

trust me, 25+ years of engineering, I understand the concept. It really is a simple statics problem.

But looking at the machine, the long bridge un-supported along it's length seems like it would not be as stable as the short height of a dovetail column like you find on an RF45 type mill. There are definitely few right ways and a lot of wrong ways to design a small bridge-type mill, good to know that Shipmaster put some thought into getting it right.