Thanks to my kind fans on Kofi, site sponsors and paid video work from Element14 Presents, I’ve managed to save up for a milling machine. It took a few years to reach the target but that’s also given me a chance to research the kind of machine to buy. Thanks also to everyone who gave me advice either directly or indirectly.
Choosing a milling machine
There were several factors that I used when picking a milling machine. My first choice was new vs ex-industrial. I did look to see if there were any ex-industrial machines in my area and it was just massive or high tech machines. These had a matching high price, perhaps due to this part of Scotland being renown for mining and aerospace engineering. The other key issue with these machines is that some come with 3 phase motors so there could be an extra cost to swap that out or to get an invertor. Having to “collect” would also be an issue for me, particularly for the big mills like the Bridgeport or Senior that I trained on as an apprentice.
It used to be a big issue getting metric machines vs imperial but in the UK at least this seems no longer to be a problem with most machines being metric.
Size and weight were also important. I really wanted a machine that would fit on my bench and that I could move by myself. Even some of the smaller looking machines are over 100kg and would really need specialist handling gear or disassembly to move. However, I didn’t want to go too small and not be able to machine steel and bigger pieces of metal, although I did spend time looking at the lovely Cowells machines.
Whilst researching, I also discovered that the taper of the machine was important. Although older machines have a morse taper where the cutters and collets fit by friction alone (they still have a locking drawbar for safety) there was also an R8 taper. The R8 is apparently is less prone to jamming, it has a keyway to stop it twisting. These are both quite old standards with modern industrial machines using an INT30 taper. But the R8 seems more common for hobby machines and most users seem happy with it.
The motor and drive chain for the milling machine is also important. Some use metal or plastic gearboxes and I’ve heard these are noisy. The life expectancy of a plastic gear set wouldn’t be good. So the alternative is belt drive which is quieter and machines with a brushless motor still have good torque at low speeds. This is important for bigger cutters and harder materials.
Probably the last thing to mention is that this is a “vertical” milling machine. Horizontal machines do exist but they require much bigger cutters and are not particularly common in the hobby machine size range.
The machine I purchased is the Sieg SX2P. A bench top machine with a good sized table and some great features. This machine is a collaboration from ArcEurotrade / Sieg. The key upgrades from earlier machines are that they have swapped the gearbox with a belt drive and brushless motor, the tilting column has been replaced with a fixed version and the MT3 taper has been replaced with the R8.
There are a few things you really need to be able to use such a mill, some are obvious and some less so.
Vice, collets, milling cutters, dial gauge, parallels, gloves, brush.
Firstly, you need something to hold your work, a vice will handle most things except if you have irregularly shaped items like castings. You’ll also need some T-Nuts and bolts to hold that to the table. It is possible to make T-Nuts by hand and you can buy threaded rod or bolts to hold down the vice. One of my first projects was to upgrade the bolts. You may find you can manage without a comprehensive clamping kit and make parts as you need them.
To securely hold the milling cutters, milling machines use collets rather than a chuck. These give a more even clamping force and hold the cutter more tightly. They do however, need to be matched to the size of the milling cutters you require. The Sieg came with a drilling chuck but so far I’ve not used that, I have drilled some holes but with the drill bit in a collet.
Milling cutters come in all shapes and sizes and it’s more than I can go into in this article. I’ll likely cover these in future articles so let me know if you want more detail. I have a few cutters collected over the years that I’ve used in the lathe. The key ones are end mills that are good for straight cuts, and slot drills which can be used for plunge cuts. There are also a range of specialist cutters for cutting T-Slots etc. You can also use regular drill bits in a milling machine for accurate holes.
Another tool I had already was a dial guage, this is useful for ensuring that the vice or any parts machined are square to the table. It is possible to do this with a T-Square although it will be a little less accurate. So perhaps a dial guage is something that can be bought later.
Another vice accessory is the parallels, these allow work to be supported and can be used for positioning the work in the vice. I got a simple set of parallels last year for use with the drill. These can be made with a milling machine although you are unlikely to reproduce the accuracy of even a cheap set.
A couple of less obvious accessories and the brush and gloves. The milling machine creates lots of little chips from whatever it cuts, so you’ll constantly be cleaning your machine down after use. A brush makes this job easier and saves you cutting up your hands. Gloves are also a good idea as a lot of the parts of the milling machine are oiled up or sharp or both. I got a set of thin cut resistant nylon gloves and they’ve saved me from a few scrapes already and generally reduce the amount of hand washing needed.
I had been looking at getting the “starter kit” with the mill, this consists of a milling vice, collects, cutters and a clamping kit. Just as I came to purchase it, Arc had bundled these together with the mill so it was a great deal.
So far I am happy with my selection, and again many thanks to everyone who’s helped me get to this point. I’ve been doing quite a few things with the mill already so expect some more milling posts over the next few weeks.
It is worth noting that this is not a sponsored post and I have no affiliation with the companies who make and supply this mill. Also, I’ve only just got the mill so ask me again in 6 months…