Choosing A Mill

I just got a Sieg SX3, but it was no easy decision. Choosing your first vertical mill is a difficult decision you'll probably end up spending weeks and countless hours researching on the Internet. This describes the selection process I went through.

Before You Start Looking

First I needed to make up my mind about three things:

What tasks must it absolutely be able to perform
What is the range of your budget
What size machinery can I successfully install in my basement

What Will You Actually Do With It?

Can you make do with a Sherline or Taig, or do you need something bigger? The quality and finishing of Sherline and Taig mills is great, but their small size significantly limits what size of projects can comfortably be completed, and you don't want to always work near the upper limit of the machine's work envelope.

I quickly realized, I had tons of things I really would like to do on a vertical mill, and I hesitantly accepted that I probably wouldn't be able to do half of them on a mill I could actually afford. However, there are many other reasons why I will probably never be able to complete those projects: lack of time, cost of materials, insufficient electrical installations [for the required machine], unable to get the machine into my basement, etc.

The type of material you want to machine is imho less important. Everybody wants to take deep, fast, and clean cuts in stainless steel, but I don't think even a Bridgeport size machine will do some of the stuff you can see on Youtube. All vertical mills handle wood, plastics, and aluminum quite easily, so it really comes down to the size of the things to be machined.

In the end I decided, that I mostly work on things that are too large to fit in a Sherline size mill, and so I need something bigger.

Price!

Some people only care about if a certain tool or piece of equipment will perform the task at hand - and some people really enjoy using the very best tool that will perform the task at hand. I'm very much one of the latter: I enjoy quality tools just for the sake of their quality, and I select accordingly. If possible, I select and buy tools that are at least one "class" better than what is actually need, and this strategy has payed off many times - and many times not :-)

I don't believe in setting a fixed price as an upper limit for how much to spend: Another $100 may make a huge difference, and the added cost of a more expensive machine can be offset by postponing purchases of additional tooling. On the other hand, tooling make things possible that would otherwise not have been, and so I quickly discovered that within days of getting my mill, the total price tag of my tooling-wish-list far surpassed the cost of the mill itself.

When I set out to by a new piece of tool, I often end up with something about twice as expensive as what I originally had in mind, and that also ended up being the case with the mill, but the market for vertical mills, although growing, is still very small and consequently the available offerings are comparatively few - an living outside the US, they are an order of magnitude fewer!

In terms of actual budget, it means that a budget of $500-2.000 will buy pretty much any model that weighs less than 200kg, and there's generally a proportional relationship between weight and cost.

How Big Can It Actually Be?

This is a sanity check. Ever tried moving a 165kg piece of somewhat fragile machinery?

Before getting a Sieg SX3 I hadn't, and it proved to be quite a task. I knew in advance that I wouldn't be able to get it down into my basement in one piece: That's not possible without a crane which I don't have and nor do I have the room to operate a crane to get the Sieg SX3 into my basement. That meant taking the thing apart (I can highly recommend this guide by Arc Euro Trade) which is a project in itself, and even so the "big pieces" were still 40kg and more.

Bottom line, unless you have a way to move >100kg machinery into position or is willing to take the thing apart, go for a smaller model. I can dream about an RF45 clone, but getting it into place would be a nightmare!

New vs Used

I've read a lot of forums threads where people ask which vertical mill to get, or if so and so [cheap Chinese import] mill is any good. Invariably, some seasoned machinist will point out that the same money can buy an old used mill that is much better. While the "much better" part of that argument seems true, I find the realities to be less clear cut.

First of all, I've yet to find an old used mill that can be had for the same money as a large Chinese benchtop size vertical mill. Almost all old used mills I've found, have cost at least three times more than a new large Chinese benchtop mill. The few I've found that cost only twice as much, were so covered in rust, that they would require countless hours of tender loving care to function properly. However, 2 or 3 times the price of a Chinese benchtop mill is way beyond my budget.

Second, an old used mill is enormous compared to a Chinese benchtop mill. Of course that's a major advantage, but it's also a major impediment: There's no way I'm getting that size of machinery into my basement (and if size isn't an issue, then the weight of at least 500-800kg definitely is). Unless you have a large ground level garage to put it in, and old used mill really isn't a tenable solution.

Third, an old used mill is expensive and difficult to service and maintain. Spares for such a beast, if they are even available, are very expensive - some parts will easily cost more than a new Chinese benchtop mill :-) That means making the parts yourself, which takes significant time and skill.

Interestingly, I've noted that there are remarkably few used Chinese benchtop mills on sale given the considerable popularity these have gained over the past 10 years, so hopefully that means people are too happy with them to sell them. However, this may just be because I live in Denmark where the market for Chinese machine tools is generally non-existent.

In the end, a cheap Chinese benchtop mill was my only viable alternative.

The Chinese Origin

It's important to realize that pretty much all benchtop size mills that cost less that $3.000 are manufactured by one of two Chinese companies:

Sieg Industries (maker of X1, X2, X3, etc. models), and
Weiss Machinery (maker of BF16, BF20, etc. models).

The two notable exceptions I know of, are Sherline or Taig, and if their small size is not a limiting factor then I would recommend them over similar size Chinese manufactured mills (they do however cost twice as much).

Sieg have been most popular in the US (sold through Harbor Freight and Grizzly), whereas Weiss have been more popular in Europe (either Weiss branded or through Optimum Machines), but this seems to be changing and Grizzly now also carries e.g. the BF20 (Hossmachine has a nice comparison of the models from the different manufacturers).

Which One?

If you have $10k to spend, just buy a Wabeco F1410 LF HS, and be done with it :-) If you "only" have $5k to spend, and a way to move a 250kg piece of machinery into position, get a nice RF-45 clone. For the rest of us, a different approach is needed.

Initially it seemed quite easy. Just get the best within the budget, and bigger is almost always better, pretty much regardless of dimension. However, the sub $3.000 vertical mills start at about $500 and then get incrementally better and more expensive and so I ended up going through a long winded "trade off" process e.g. is another $200 better spend on a 4" milling vice (tooling), or a slightly large mill table (better mill). I ended up listing all relevant models in a spreadsheet (web view here) to get a better overview, and I included models that were cheaper, and models that were more expensive than what I hoped for, if they for some reason seemed relevant.

I didn't actually make any of those artificial trade offs, but it helped me understand what my two "real" and hard requirements were: Proven design and belt drive.

Proven Design

I've read a lot of negative comments about Chinese made machine tools, and most comments either relate to sub-standard finishing or flawed design. I decided that I can deal with sub-standard finishing either by accepting or by improving it myself, but a flawed design is difficult to compensate for. I'm no expert on machine construction so my only way to avoid a flawed design was to get a mill of a proven design, which means a mill that's been in production a long time and has a lot of users.

The Sieg models fit this description. They've been in production for 10 years, have been continually improved, and they have a lot of happy users.

Belt Drive

This one is less obvious. I actually have two reasons why this is important to me.

The first reason is practical: I only get to use the mill at night when my two young children have gone to bed. Keeping the noise volume down is imperative, and gears make a LOT of noise, which makes them undesirable. I don't think the noise level from a gear driven mill would actually have been a problem, but it's nice not having to worry about it.

The second reason is about enjoyment and a relates to the proven design. I wanted to be reasonably happy with the mill as delivered, and I wouldn't have been fully happy with a gear driven Sieg X1 or X2 until I had converted it to belt drive. Small Chinese mills use plastic gears and they break, easily! There are untold stories of users, who've stripped the gears in their Sieg X1 and X2 models. Getting a replacement gear wheel in Denmark is next to impossible, and easily costs $30. So it sums up to:

I don't want to have to spend the time doing a belt drive conversion. Workshop time is quite a premium for me.
I don't want to have to worry about or deal with broken plastic gears (again, workshop time is a premium).
Getting a LittleMachineShop Sieg X2 belt drive conversion kit is very expensive when ordering from Denmark (shipping, import taxes, Danish VAT, etc.)

Consequently, I needed belt drive!

Selection

One might argue that the hard "belt drive" requirement doesn't offer any actual choice, but Sieg had just introducet the SX2 (an X2 with upgraded motor, and belt drive) when I started looking, so at least I had a choice between two models, the Sieg SX3 being the only other model with belt drive.

I was very tempted by the Sieg SX2, but I always felt a table depth of 95mm just wasn't enough and it was quite unclear when it would actually become available. On top of that the Sieg SX3 just seemed sooo much better, and it's work envelope was much closer to what I was hoping for, and so that's what I ended up with.

blog comments powered by Disqus

Published

27 March 2010