Hey y'all,
as a first milling project, I'm making some T-slot nuts for my 1967 Deckel FP2. I'm making these from 4140HT, which is probably a sub-optimal choice for a starter project, but I'm using it as it's what I had. I'm just using the vertical spindle for now.
I squared the stock with a ~1 3/4" HSS shell mill I got with my mill in a dedicated holder, and I used the same cutter to cut the shoulders, no problem. I feel the finish from facing is sub-optimal, so I think I'll need to measure and adjust the end play on the spindle when I go in to re-grease it. I'll have to scare up a tenths indicator first, though.
When side-milling the shoulders, there seemed to be a fair amount of runout in the cutter or the holder. Is that to be expected with HSS shell mills and/or holders, or should I be expecting better?
To square up the ends of the pieces I side-milled (with the Y ram) with a 3-flute 3/8" bright carbide endmill. Initially I fed too slow (1000RPM, 1IPM, or 3tenths/tooth), and by dropping the speed and increasing the feed everything sounded and looked much happier.
When test fitting the nuts, I found they jutted above the table surface a little, so dropped them back into the vise and proceeded to face off some of the excess with the 3/8" carbide mill. I milled the nuts in pairs (hehe), but when comparing the lots, I found their heights to be inconsistent. Eventually I noticed that one of the nuts had a ridge on it, and it dawned on me that the cutter was retreating into the U2 collet. I put a little more gronk on the drawbar and did another pass, and everything came out peachy.
However, I wonder how much gronk (torque) is appropriate on the drawbar?
Also, to tighten or loosen the drawbar, I've been dropping the mill into low gear having the gear train resist me as I give it a yank.
Is this how it's done(TM), or am I going to wreck something?
Siggi
as a first milling project, I'm making some T-slot nuts for my 1967 Deckel FP2. I'm making these from 4140HT, which is probably a sub-optimal choice for a starter project, but I'm using it as it's what I had. I'm just using the vertical spindle for now.
I squared the stock with a ~1 3/4" HSS shell mill I got with my mill in a dedicated holder, and I used the same cutter to cut the shoulders, no problem. I feel the finish from facing is sub-optimal, so I think I'll need to measure and adjust the end play on the spindle when I go in to re-grease it. I'll have to scare up a tenths indicator first, though.
When side-milling the shoulders, there seemed to be a fair amount of runout in the cutter or the holder. Is that to be expected with HSS shell mills and/or holders, or should I be expecting better?
To square up the ends of the pieces I side-milled (with the Y ram) with a 3-flute 3/8" bright carbide endmill. Initially I fed too slow (1000RPM, 1IPM, or 3tenths/tooth), and by dropping the speed and increasing the feed everything sounded and looked much happier.
When test fitting the nuts, I found they jutted above the table surface a little, so dropped them back into the vise and proceeded to face off some of the excess with the 3/8" carbide mill. I milled the nuts in pairs (hehe), but when comparing the lots, I found their heights to be inconsistent. Eventually I noticed that one of the nuts had a ridge on it, and it dawned on me that the cutter was retreating into the U2 collet. I put a little more gronk on the drawbar and did another pass, and everything came out peachy.
However, I wonder how much gronk (torque) is appropriate on the drawbar?
Also, to tighten or loosen the drawbar, I've been dropping the mill into low gear having the gear train resist me as I give it a yank.
Is this how it's done(TM), or am I going to wreck something?
Siggi