New Rego-Fix collets and collet nuts

[Michael Burnside]

I was cleaning my collets since I've been using them pretty hard lately and two of them rolled off onto the concrete floor, bouncing and rolling around...sigh stupid me. As Murphy would have it, they both took a good ding on the face. I really don't want to risk some expensive bits and they're getting old, so I decided to pickup some ER25 collets (standard TIR) and I figured why not a matching set of collet nuts from Rego-Fix. These guys are the "R" in ER, so I figured they might now something about designing ER collets/nuts.

All I can say is wow. I've only been able to use the 1/4" so far, but wow do they clamp smoothly and securely. Not to mention, the fit and finish is impeccable. The collet nuts are just awesome. I also swear that during the spindle warmup they were quieter. Could be placebo, but I'll use them again this weekend, so we'll see after I get done milling 8/4 coffee table legs out of red oak.

Just figured I would share these thoughts since I couldn't find much in the way of recommended collets/nuts. I can definitively say that the saying "a collet is just a collet" couldn't be further from the truth.

[Jim Becker]

Good quality collets are definitely an uplifting enhancement! I'm glad you chose to dispose of those that got dropped, too...that's kinda a best practice for both performance and safety.

[Michael Burnside]

Confirmed on the noise. I did several cuts today. There is a slight, very slight, vibration that resonates the metal shroud on the spindle fan when using 3 of the original collet nuts I got with the machine. With the Rego collet nuts I cannot feel anything when touching the side of the spindle or gantry and the shroud is silent. Very cool!

What wasn’t cool though, I was milling this really hard stock of oak and I broke two 1/4” bits at 75 IPM and .22” pass depth. I thought was decent l for this piece as I’ve done the same job with walnut at 100. The first was an older bit so I grabbed a new one. About half way through snap again. Sigh. Cut the job again at 35 IPM and it went fine.

[Jim Becker]

Good that the new collets are well balanced...it really can make a big difference.

For the tooling breaking, check your chip load as that's what takes away heat. Also consider less of a bite on the really hard stuff if you continue to have the issue.... Did they both break at the same point in the file? That's also something to look carefully at.

[Michael Burnside]

I was cutting out 3 parts and it definitely didn't happen in the same part of the job. My chip load was probably a little low but I don't think it was heat as when I slowed down the bit didn't break, but maybe. I've used this setup before, but maybe I need to fine tune more? I was running a 2-flute 1/4" compression at 16k RPM and 100 IPM (I thought it was 75 but it wasn't). This is roughly 0.0031 which is on the low side. I'm a bit paranoid to increase the feed rate, but maybe I should have slowed down the spindle speed instead and left the feed alone. Problem is that it's a $35 mistake every time LOL. I guess I need to do a bit more research with hardwoods like this. Just wish I could tell if the bit was breaking due to IPM or heat

[Jim Becker]

I run between 12-14K for my .25" compression tooling. Your depth is correct as that's about the minimum for most .25" compression cutters in order to get the benefit at the top surface from the switch to the down-cut area that preserves the edges. Ramping in, if on the cut line, will miss on that on the first pass, but it's a necessary evil, especially in hard materials. "Plunge and move" can stress the cutter a lot more than we might expect. Then again, with hardwoods, perhaps the compression cutter isn't the best choice. It may be more practical to do the first pass with a down cut for a clean edge and then switch to an up-cut for the remainder. That first pass can be a very light cut and done quickly. And non-compression tooling is more affordable should one, um...you know...have to say bad words.

[Michael Burnside]

Thanks for the reference. I do think 12-14k is a better speed that will increase chipload and should keep the bit closer to optimal. In this case I am using a short flute compression, so the transition is 0.185". You make a good point that perhaps the compression might not be the best choice with hardwood this "hard". I'll run a few experiments this weekend to see if increasing chipload slightly actually helps keep the bit cooler. I do think 16k was too fast. I've done this setting several times with walnut, but this stuff was surprisingly hard. I also noted that both times the bit broke it was milling along the long-grain path. I think that would indicate perhaps it was heat that broke the bit. Who knows, I"m just super happy with the new collets and collet nuts.