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climb-milling-vs-Conventional-milling-9Ok, let’s take our first face milling cuts on some piece of aluminum. But that looks like climb milling or what? Actually it’s not.

 

 

 

 

climb milling vs Conventional milling-10  Let’s take a closer look. Notice that the highest point of the cutter matches with the highest point of the work piece. The cutter has been placed strategically that way. From the point “A” that the cutter begins to cut and until point “B” performs conventional milling when from point “B” to point “C” performs climb milling. A good question at this point is, are we facing any problems since at the half way our cutter performs climb milling? The answer is no. Why? Because each tooth of the cutter penetrates successfully into the work piece before point “B”. From so on the tooth itself prevents the work piece from moving, so the backlash doesn’t affect our work any more. This is the preferable way of face milling since we can remove a lot of material with less vibrations.

 

climb-milling-vs-Conventional-milling-11  When you reach at the exit point reduce the feed at the one quarter. What feed? That’s a good question.My experience has shown to me that at 500 RPM the progress is slow and at 1000 RPM or more things is getting too dangerous. So, my suggestion is simple, start with 700 RPM and take a light cut in depth of 0.3mm. Increase the feed progressively until you get a nice sense to your hand, not too fast or too slow and comfortable to work with. Face off the entire surface without making any changes in the depth of cut.Now in the second pass you can increase the depth of cut to 0.6mm and test if you are getting any vibrations. Make several passes and keep increasing the depth of cut progressively until you start to feel some vibrations. At this point you should take one step back and decrease the depth of cut a little bit. Now you have determined the maximum allowable depth of cut at this speed with a nice and comfortable feed.Let’s talk about what other factors affect the depth of cut, speed and feed.

  • Diameter of the cutter. The larger the diameter, the less the depth of cut we can achieve. I will talk about how to choose the cutter diameter shortly and how will that affect the cutting speed. Keep in mind that the above speed recommendation is for a 12mm end mill.

  • The hardness of the material. Obviously we can’t achieve the same depth of cut in a piece of aluminum and a piece of steel. Take smaller steps in depth of cut with harder materials. Consider of using smaller in diameter cutter. The type of the material will affect our cutting speed also.

  • The dimension of the work piece. The bigger the work piece, the sooner the vibrations will start.
  • How long the work piece is extended from the vice. That distance it will affect dramatically the depth of cut. Take only very light cuts if the work piece is extended too much from the vice or don’t take any cuts at all.
  • Run out of the cutter. The grater the run out the sooner the vibrations will start. Consider of buying an end mill holder rather than holding the cutter on the chuck.

  • The number of flutes (tooth’s) of the cutter. At a certain speed and feed each tooth of a 4 flute cutter it will remove the half amount of material than a 2 flute cutter. That means that a 2 flute cutter must work harder than a 4 flute. So we have to reduce the feed when we are working with 2 flute cutters. Why then to choose a 2 flute cutter you may ask. We use then on soft materials like aluminum where we need the chips to clear out fast and easy.

Buy some small bars of Aluminum, Alloy 6061 is an excellent choice or 5251 and buy also a few HSS 2 Flute or 3 Flute End Mills especially for Aluminum or Non-Ferrous materials. Start practicing and test all of the above by yourself.

 

climb-milling-vs-Conventional-milling-12Raise the work for the next cut. Notice again that the highest point of the cutter matches with the highest point of the work piece. I mean from the portion that has been left. Like the exit point reduce the feed on the entrance also.

 

 

 

climb-milling-vs-Conventional-milling-13

Ok, I just finished the second pass but there’s still something left, 1mm of material or so. I used a 10mm End Mill but maybe I should have chosen a 12mm End Mill instead. Usually we prefer the biggest end mill possible for face milling since we want to remove a lot of material fast. But it’s a good idea to take the height of the work into consideration. For example In this case the 10mm end mill is not enough to complete the operation into two phases and with a 16mm end mill at the second pass we will use only some portion of the end mill which is not ideal. Keep that in mind when you choose an end mill for face milling. As I mention earlier the diameter of the cutter will affect the cutting speed also but bear with me I will talk about this later.  

climb-milling-vs-Conventional-milling-14Although is not always possible to complete the face milling operation with even cuts and some material could be left over. We know that we can’t use climb milling but I will not recommend conventional milling ether. The milling attachment it will observe more easily the horizontal cutting forces than the vertical.

 

 

 

climb-milling-vs-Conventional-milling-15So I will place the end mill in the center of the remaining material and I will reduce the feed for the final cut.

 

 

 

 

climb-milling-vs-Conventional-milling-16We are just complete our first face milling operation.

 

 

 

 

climb milling vs Conventional milling-17Next I will lower my work for side milling. I will use the same speed but I will reduce a lot the depth of cut.

 

 

 

 

climb milling vs Conventional milling-18Notice again the rotation of the cutter and the feed direction. Yes, this is conventional milling.End of page 2

 

 

 

 

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10 Replies to “Milling on the lathe”

  1. Hello and greetings from Switzerland!
    Thank you so much for all your videos which are helping me a lot!!
    I’m also very interested about your milling attachment. Will you make a video on that subject or do you have any sketch?
    Thank you very much in advance!
    Yves

    1. Hi Yves, Thank you for your kind words. You can find the schematics from my attachment on the Download section of this Blog. I already took some pictures and my plan is to add more details on this post but it takes more time than I thought. Check back soon for any updates and ask me if you have any questions.
      Kind Regards
      Jim

      1. Thanks a lot for the file , Jim !!

        Just one more question about the machine vice. Which model do you use or where did you buy it? Jaw width 60mm, 75mm or 100mm ?

        Yves

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