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New Pm 727m Mill
- Thread starter lpeedin
- Start date
I have been very happy since I figured out the issues with my mill stand / base twist and got things working smoothly. I haven't had time yet to try to fit one of the new gibs that Matt so graciously had direct shipped to me from China. I have since finished up a couple of new AXA / 100 sized tool holders for my PM1127-VFLB lathe and I did remember to snap a couple of pics while I was hogging out the slot for the dovetail on one of the holders. While this is not a Bridgeport or a Kearney and Trekker, it holds it own very well. I hogged those slots witha 3/8" roughing end mill at 320 rpm with full width .350" deep cut. Total slot depth was .385" so that left me a little clean up with a regular 4 flute end mill. Vibration and chatter are non-existent, especially with the roughing end mill. I am really loving this machine.
- Joined
- Mar 20, 2014
- Messages
- 440
That looks great, 3D, you are getting me excited all over again. I had my LAST radiation treatment today, and will be ordering mine soon. Looks like that machine will be perfect for my needs. I have a couple questions, (not about the mill, you've already sold me on that) . What material did you use for the tool holders? And what size dovetail cutter did you use on them? TIA, JR49
EDIT, Oh, and how about a pic of the finished product?
EDIT, Oh, and how about a pic of the finished product?
JR, here is a pic of two finished tool holders for you. I used what appears to be plain old cold-rolled 1018. I found a scrap yard locally that actually resells to the public. They have everything organized by material type: aluminum, brass, stainless, etc.. I found a piece of 1.75" x 1.75" stock about a foot long. I managed to get 4 holders out of it, although one is about .250" short, but I don't think that I will notice that I am .125" short on each end.
Oz, as far as increasing the travel along the X, this is easily achievable by nipping off the corners of the handwheel brackets as those brackets are what stop the table when they contact the saddle. This would easily add about 3" of travel, but you would do so at the expense of losing contact with the gibs on each end. That is why I haven't done this mod yet and I am doubting that I will actually do it.
Oz, as far as increasing the travel along the X, this is easily achievable by nipping off the corners of the handwheel brackets as those brackets are what stop the table when they contact the saddle. This would easily add about 3" of travel, but you would do so at the expense of losing contact with the gibs on each end. That is why I haven't done this mod yet and I am doubting that I will actually do it.
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I almost forgot, I used a 3/4" 60 degree dovetail cutter I got on ebay for $15. I just used two matching drill bits as dowel pins to measure the factory tool holders and then transfer that measurement to the new dovetail slot. Dovetail cutters are fragile, so I never took more than .020" cut for the first couple passes, and then went with .015" cuts. From what I remember, I ended up cutting about .140" in either direction once I got my center slot milled out.
- Joined
- Mar 20, 2014
- Messages
- 440
First of all, 3D, beautiful work on those tool holders ! Now, Oz's question about extending the X travel has brought up new questions from me. I can see where adding a 2" block to each end of the table will increase the table size by 4" (duh!), but, wouldn't you need a longer lead screw to increase travel? Also, the 727M has 15 " of X travel, does that mean that I can machine a feature (say a slot) into a work piece the full 15" without re-setting the piece? And, lastly, even if for whatever reasons (that I hope someone will explain), this slot can only be 10" with a 15" X travel machine, then wouldn't it be easier for the few times that this might come up (for me anyway), to cut the slot as long as the travel allows, then re-position the piece and continue the slot? What am I missing? Thanks again, JR49
- Joined
- Oct 27, 2014
- Messages
- 272
JR,
Great question. You are correct in that 15" travel means you can cut a 15" (give or take some error) slot along the x-axis. You should be able to cut the slot you need in one pass.
I don't think you're missing much. Multiple setups in the case of machining 10" of your 15" requires accurate locating and positioning of the work. You may need a fixture or jig of some sort to make the part. It would really be up to you to determine how to break down the cut for multiple operations.
You might want to look into machinist jacks as well depending on your workholding method.
Great question. You are correct in that 15" travel means you can cut a 15" (give or take some error) slot along the x-axis. You should be able to cut the slot you need in one pass.
I don't think you're missing much. Multiple setups in the case of machining 10" of your 15" requires accurate locating and positioning of the work. You may need a fixture or jig of some sort to make the part. It would really be up to you to determine how to break down the cut for multiple operations.
You might want to look into machinist jacks as well depending on your workholding method.