Did I Damage My Pm932 Mill?

Today, I had a length of steel bar in the mill vise with the 1/2" thick edge facing up. I was using a small 3/4" fly cutter, with a 3/16" square HSS tool bit in it, and taking only light cuts of .010" per pass at the H-1 gear setting which was 670 RPM. Apparently, the grub screws holding the tool bit in the fly cutter slot were not tight enough (didn't check them before starting), and in the middle of the cut the tool bit slipped down and dug into the part. I heard kind of a " growling " sound, and saw that the fly cutter was not spinning, also, I'm pretty sure the spindle was not turning either. I immediately hit the E. Stop, which stopped the spindle motor. When I raised the quill the tool bit slid out of the flycutter, and when I re-set the E. Stop, the motor came on and the spindle started turning again as if nothing had happened. Of course, I turned it off, and decided to wait to hopefully here from some members much more experienced with these mills than I.

I'm hoping that someone will tell me that the "GROWLING" I heard was some kind of safety clutch or device to protect the gears from stripping. But, as I'm writing this, it occured to me that I'm really not all that sure if the spindle was stopped or spinning. There is only about an inch of spindle sticking below the quill, and in that quick second before I stopped everything, the spindle may have still been turning. That would mean that, either the fly cutter shaft was slipping in the collet, or the collet was slipping in the spindle (collet indexing pin removed).

Tomorrow I'll look closely for any signs of slipping in these parts, But for now, I welcome and appreciate any thoughts from all the knowledgeable members. Thanks, JR49

If it sounds normal with no cutting going on, put a drill chuck in the spindle and as large a smooth pin or rod as you can find. Nothing precision required, but something you can try to grab and stop the spindle by hand. Use the exact same speed and gear selection you were using when the accident happened. Turn it on, keeping one hand on the switch, and grab the spinning pin/rod with the other hand. If the noise you heard returns, or is constantly present, you have some digging to do. If you can stop the spindle with your hand, but the motor is still running, make sure any belts (not too familiar with your machine) if any are tight. Otherwise you need to see where the breakdown in the powertrain is.

Hope it isn't serious, but Matt's always around to help out, along with everyone else.

You actually bring out a fairly good safety point that is a secret pet peeve of mine. Set screws bearing against something harder than they are. If you have flat points, you can put a lot of pressure on clamped objects, to be sure. But you will never get a good bite on tool steel. I never use HSS in a flycutter. I do however, use brazed carbide, where the tool shank is soft enough to be held well in the cutter.

Tony Wells said:

Hope it isn't serious, but Matt's always around to help out, along with everyone else.

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Thanks a lot Tony, as usual, you and a select few other members are always there to help us new guys. Your advise on trying to slow the spindle by hand worked great and gave me the info I needed. Also, I will always remember what you said about the grub screws not tightening well against HSS tool bits. Now for what the problem was. I'll probably get scolded for this , but, at this point, I'm too frustrated to care, So Tony, if your curious what was wrong, I would be happy to PM you with the answer HOWEVER, I WILL NOT put it here for all the other PM932 owners to benefit from. None of them have ever bothered to respond to ANY, of the 4 questions, specific to the PM932, that I have asked in the 9 months since I've had the mill !!! Of coarse I always new that Matt from PM would be there to help, if needed, but I try not to bother him unless it is a serious problem, and I've had none. I'm very happy with this mill, but I originally chose it, thinking that there would be a lot of support here, with so many members owning it. BOY was I wrong! My sincere apologies for this rant go out to all the "pros" on this forum, who are always there to help with answers. Rant over, JR49

I for one am kinda shocked here. While I understood your frustration, it does nothing to support yourself or other owners. It contradicts the whole reason to be a forum member. While it is frustrating to not get answers when and as fast as you'd like, sometimes that's the way forums work. It's the nature of the beast.

I'm glad you figured out your problem and can go on. I for one will continue to help others when I can, if I can. I try not to respond with bogus information or something I haven't seen or done with my own two eyes and hands.

Machine on my friend.

Have you given any thought that people did not answer your post because no one knows or had the experience you encountered with your mill? It is disappointing that given the limited number of members in this forum and the diverse machinery they own, that one should expect every question posted at this site to be answered. I had a gear head mill, but very different then the PM932, and the one time I had the end mill grab in some work, stalled the motor and the electronic drive shut down. There is no electronic drive in the PM932.

I did give consideration to posting options, but honestly it would be shooting in the dark, and a large portion of what I have learned is trying to systematically think things out. There is no belt drive on gear head mills, not is there a clutch, so if something is going to go it is either the something is slipping, tool in collet or collet in spindle, or something broke. Beyond that, you might stall the motor, broken a pin or key, or worse had a gear break. Each one of these you can check. That you now do not want to share and berate other in this forum for not coming to your rescue, well than maybe this forum is not the right place for you.

I have posted several questions on various subjects not just in the PM forum that never received an answer. I just figured no knew the answer at that time but I always posted the solution once I found it so it may help others.

I think it would be better to just let this thread go. It's a little bit of an unusual situation, and I'd appreciate it if we could just let it drop and slide off the front page. It won't hurt anyone to do that, and I ask this as a personal favor.

JR49, With all respect.
How could you possibly know that; 1. Droves of PM932 owners saw your post, 2. One or more knew the answer (before some non PM932 owner did) and 3. ignored you. Honestly, that seems like pure speculation.
I looked back at the threads you started regarding you mill and couldn't find any question that went unanswered.
I know the online world can be frustrating at times but it's important not to let it get under your skin and cause you to become hostile.
Peace,

Eddy