|Curtis Rutter||12/10/2016 19:42:40|
|127 forum posts|
Does anyone have a link to help me understand the various terminology and measurements used for when I'm comparing machinery I'm looking at. For example what does throat distance, end milling capacity and Quill stroke mean, to name just a few!
|Michael Gilligan||12/10/2016 19:55:44|
14783 forum posts
This, on YouTube might be a good place to start: **LINK**
|Steve Pavey||12/10/2016 20:02:58|
|280 forum posts|
Sounds as though you might be referring to a vertical milling machine. Throat distance is the horizontal distance between the vertical spindle axis (where the cutter is held) and the column behind it. End milling capacity will be the largest recommended diameter of end mill cutter that can be fitted in the spindle (an end mill is just a type of milling cutter). Quill stroke is the vertical distance of travel of the cutter, ie how far up and down you can move the cutter.
To be honest, much of the terminology you can probably pick up by browsing suppliers catalogues and web sites. If you have a particular machine in mind see if you can download an instruction book as that may well have a labelled drawing showing the main parts.
|Curtis Rutter||13/10/2016 19:21:59|
|127 forum posts|
Just watched all their videos and know can't wait to get a milling machine!!!
|Pete Gilbert 2||20/09/2019 10:19:52|
|1 forum posts||
Sorry to resurrect an old thread, but when you say quill stroke is the vertical distance of travel of the cutter, does that mean the maximum travel of the machine or the maximum cutting depth? I'm looking at getting a milling machine myself but I've noticed some citing 24mm as the "quill stroke". This seems like quite a small amount to me, even for a smaller machine.
|Howard Lewis||20/09/2019 15:48:28|
|2747 forum posts|
Quill Travel is the distance that you can move quill, up and down. If a cutter is mounted in the quill, and with the quill up, there is 100mm between the end of the cutter and the workpiece, you will need a quill travel greater than 100mm to allow the cutter to contact the work.
The dept of cut is NOT the quill travel. The depth of cut is determined by several factors, among which are:
the type of cutter in use, the size of the cutter, the material being machined,.the rigidity of the machining set up (Machine and Vice or workpiece clamping arrangement ) and the power available.
Stating the obvious, a machine powered by a 200 watt motor is not going to run a 50mm diameter cutter on a 1mm depth of cut.
For end mills, the rule of thumb tends to be a depth of cut not exceeding a quarter of the diameter of the cutter, ( i e, 1.5 mm for a 6 mm end mill. ) Bear in mind that this a maximum, which may reduce if the material is particularly hard. Also, feeding too fast under those conditions .could break the cutter. Start off by being cautious, and gradually increase as you gain experience.
Feed rate should be set by the type of cutter in use, and is usually determined by the "Feed per Tooth", which will vary according to the type of cutter used. As a very general rule of thumb, work on the basis of 0.05 mm per tooth. I E a 4 tooth End Mill would be fed, at maximum, 4 x 0.05 mm = 0.2 mm per revolution of the cutter.
The speed of the spindle will be determined by the type of material being machined, and the material from which the cutter is made. (in our case, usually dry ). For mild steel, 30 Metres / minute is a not unusual Cutting Speed, with High Speed Steel. Carbide tips can be run at much higher speeds, but with different feed rates and depths of cut.. If the steel is harder, the speed needs to be reduced. Carbide tips tend be fragile, compared to HSS.
For softer materials, such as Aluminium, speeds can be higher, but Aluminium can weld itself to the cutter, so is often lubricated with paraffin, (Kerosene ) WD40, white spirit, or something similar.
The figures quoted by the suppliers of cutters are often related to industrial conditions, where machines are much larger, heavier, more rigid,and powerful than our hobby machines. You cannot treat a 40 Kg mill in the same way as a an Industrial one weighing 2 tonnes!
Buy some of the books in the Workshop Practice Series, you will then gain a better understanding of terms and processes.
H T H
Edited By Howard Lewis on 20/09/2019 15:50:49
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