homemade Wood Router - project failed And almost got me seriously injured- READ DESCR

[Frank S]

I watched the video at 3x speed right up to the point when you installed the router bit then dropped the speed to .25 even at that speed when the chuck came free it was near relativistic speed. I even viewed it frame by frame in less then 2 frames the chuck was there then it was gone.
Thanks for sharing this video really brings to light the things that can go wrong even on well thought out builds.
Like was stated a slightly extended nose to the grinder with another bearing and a shaft extension could and would help.
A long time ago I had a 5" angle grinder that the gears wore out in this was a 9 amp grinder so it was quite robust about 2/3rds the size of the 9" grinders
I had been needing a pencil type grinder for a while so I made a nose cone out of aluminum billet about 5 inches long and a shaft with 5/8 11 thread to accept the cone and cob stones most are rated for 24 to 36,000 RPM and I bought only the better grades anyway. I used 2 bearings in the nose cone and a short coupling to connect the motor shaft to the arbor shaft the grinder lasted me for many years pre grinding welded up bearing bores before I line bored them

[stubb]

wow , could have turned out a lot worse than the tool breaking

[pfredX1]

What broke? The chuck just flew off. That's to be expected. Some JB Weld-It can fix that right up.

[Henk Bannink]

Most people find it difficult to say I messed up but this post has probably taught a lot of folks a most valuable leson. Thanks for a visual warning, besides the shaft failing the rest looked great

[thehomeengineer]

Hi
Another issue is side loading a drill chuck.
This is also why you should never mill using a drill chuck as they are not designed to take side loading. I have seen several people snap chucks off arbours while milling. One was my boss last year.

[pfredX1]

I've heard you should never side load drill press bearings. I mill with a 3 jaw chuck in my mill all of the time. Not a problem. I have collets for my mill too. Just not enough. The last slot I milled the day before yesterday I put an end mill into my drill chuck. I don't have a 5mm collet for my mill. I needed that slot milled though. I didn't know if that end mill could cut steel, or not. It was an el cheapo import jobbie I'd bought for my CNC engraving machine. I have all of the collets for it. It only has an ER11 holder though. And there's little chance it can mill steel. I never tried and I doubt it can. It's a soft materials machine. Wood, plastic, stuff like that. Maybe some aluminum. The OZ25 on my mill is a bit harder on the wallet to fill out the set on. I'm thinking about picking up an ER32 holder for it. I could get the holder and a 9 collet set for about what 3 OZ25 collets would cost me. I feel burned either way so I haven't done anything. I've heard some bad things about some of them ER32 holders too. Which makes me leery to get involved. I know my OZ25 holder is good. I've been using it for decades now. Collets for it are just so damned expensive though.

[LeeHael]

Diyfixman,

I don't think the speed was too fast for routing, just too fast for your under spec'd connection with a too heavy lump of non-concentrically turning metal. Tiny, short shaft, loosely fitting sleeve, held on by set screws. Couldn't expect that to resist all the forces trying to tear it apart. Because of the length of your chuck and bit combination, the effect of the first little bits of deflection, due to imbalance and the load on the cutter, rapidly became magnified and ran away. Lee

[diyfixman]

Thank you very much dear friends for your support and detailed comments. I learn from each and every one of you and this is an amazing site !!!

[olderdan]

The start of your build looked reasonable but I knew what was coming as soon as I saw that drill chuck being attached, not meant for side forces thats why all routers use collets. A classic case of enthusiasm getting the better of judgment but I am sure some of us have visited that place.
Thanks for posting that warning lesson to think more before you leap.

[pfredX1]

I have a RotoZip tool that has a factory 3 jaw chuck on it. They're 30,000 RPM so as fast as most routers go. Dremel makes a 3 jaw chuck for their rotary tool too and it works. Collets can be made a lot lighter than 3 jaw chucks can be and theoretically they have a better grip. We all know what Yogi said about theory and practice though. All of this did get me thinking about a spindle for my CNC machine. I don't want to shell out for what a water cooled spindle costs. But I'd probably run an ER16 collet on it.

The only wrong thought anyone can have is thinking that they can think of everything. You just have to try stuff and see how it really goes. Because often in non-trivial matters it'll likely be a lot different than you think!