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

[diyfixman]

⛔⛔⛔ warning! You must not try the next project! Before you read the description! ⛔⛔⛔
Dear friends, I started this project with great enthusiasm and everything went well. I did not do something that is not typical of me, and did not take into account some simple laws of physics.

At the request of some of my followers, I decided to make a video showing how to turn an angle grinder into a Wood Router. I started planning the steps and started working. Everything was perfectly built except for one thing. I did not take into account the speed of the whet motor, the rotation speed was too high!

My mistake was that I had to install a speed regulator and lower the engine speed. This would prevent the main axis of the engine from breaking! And the result you will see in the video In the 09:24 minute. Although the project failed I decided to upload the video so you can see how dangerous it can be when you do not keep the safety rules at work.

Dear Friends Safety at Work First of all !!! Smart people will watch the video and learn a thing or two about the importance of safety at work especially after changing its purpose to an electric tool. And this is the first project I failed and Today I learned an important lesson and it is definitely .a sad day for me! Tell me in the comments what you think it will help me greatly

[thehomeengineer]

Thank you for sharing and posting the video. I am sure if we were all honest we have all had near misses in the workshop when we have not thought about design or the consequence of taking short cuts etc. But this video is a great reminder on how dangerous both woodwork and engineering tools can be and we all should watch this video once a month
Again thank you for posting and glad this was only a near miss
The Home Engineer

[diyfixman]

Thank you very much for your support

[Claudio HG]

Hey dude, thank you for having posted this video. In my humble opinion the problem was not the speed, but the lack of support. The axis did break at the bearing point, may be because an excessive oscillation or more likely because the bit touched a vein with a sudden change in friction, because these shafts are hardened they are also quite brittle. Slowing down the speed would had not helped, on the contrary might have worsened the risk actually.
The problem could have been avoided by making a second bearing holding a much more ductile shaft that in turn would have held the mandrel. This last shaft would have absorbed vibrations and pressure shocks coming from the contact of the bit with the wood. Again, this is my modest opinion, I am not a mechanical engineer after all
Repurposing electric tools is cool but could be a serious danger as we do not know the calculations the engineers did when they designed the tool.
Glad you were not injured seriously.

Cheers & stay safe,
Claudio

[Brexit Boy]

I didn't see that coming! Even though you said it would happen at 9:24 I still jumped out of my chair. Very scary and luckily you were not injured. I've never video'd my projects so my major fails have gone undocumented. Fortunately I have learned more from my fails than from my successes. My homemade table saw is without doubt my most potentially dangerous piece of kit that I have created but has served me well for the last 12 years. If it does ever fail I hope to learn from it.... otherwise I'll be 6 foot under.

[crazypj]

Impressive amount of bouncing around from chuck. I guess it was too far out of balance for ~ 30,000 rpm? You could probably machine whats left of the rotor and fit a mini collet chuck into it?
It would still be spinning way too fast to use anything over 1/8" ~3mm dia carbide but may work for engraving/

[Crusty]

Chuck too heavy and put too much torque on the shaft and the shaft was too hard for the cutting shocks from a router bit.

[pfredX1]

People that don't make mistakes don't make anything else either. My last project came out meh. Like you I went into it pretty excited for decent success. It just didn't end up how I'd hoped it would. Was a router base too.

[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