# It blew out in my hand.



## papasombre (Sep 22, 2011)

Hello, colleagues.
First of all, I am ok.
Yesterday I was planning to make three mortises to place the same number of hinges in a new PVC hollow-core door that I´m making.
I had a Chinese palm router that I put aside because its carcass becomes very hot and it is impossible to handle. I posted it in the forum as "Too hot"
I decided to give it a chance since it already had an up-cut quarter-inch bit installed. I just set the bit to remove less than 2mm of PVC.
I made a disposable jig for this purpose.
I was ready to start the activity when my wife brought a cup of coffee. I asked her for some help to support the door meanwhile I was making the first mortise. Almost to the end, the trimmer blew out in my hand causing some noise and damaging the door´s stile. Several pieces flew across the garage but, thanks to the Lord, fortunately, they didn´t touch either of us. 
My right hand was cramped for a while until I could drink my coffee. To continue the work I looked for my PC trimmer to finish the job.
I always had a bad feeling about this Chinese router.


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## DesertRatTom (Jul 3, 2012)

Overheating is always a bad sign. Glad you are both OK. I replaced all the interior doors in our house a couple of years ago, and a small trim router sure beats chiseling the mortises by hand, which is how I used to do it. We have a whole house evaporative cooler at one end of the house, with up-ducts in the ceiling of most rooms, so closed doors don't circulate the cool, moist air. So I cut openings and put 18 inch gratings on the bottom of 3 of the 4 doors, which makes it livable in those rooms. Given where you live, this might work for you too.


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## RainMan 2.0 (May 6, 2014)

Wow that could have ended badly . Glad to hear you and your wife came out unscaved


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## jw2170 (Jan 24, 2008)

Wow, that is some serious metal fatigue....


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## reuelt (Dec 29, 2008)

Glad, you are both safe.
We need to listen to Genuine and honest experts.
One of my Church member used regular hand routers to make hard wood mouldings and he and he brother became the No.1 seller of wood moldings in Malaysia.
He laughed at me for buying B&D and Ryobi tools and told me that the King of all Routers they used day and night and NEVER failed was the ELU 3.5HP (that later became the the Dewalt DW325).
Since I could not buy the ELU or the DEWALT in Australia at that time, he advised me to get the Hitachi M12V since Hitachi was the only company that had signed a contract with B&D for ELU Router knowhow.

I quickly traded-in my almost brand new Ryobi router and bought a Hitach M12V.

Since he owned a hardware store, he has used all brands and had data to prove.


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## papasombre (Sep 22, 2011)

The day after, I gathered all the pieces that I could find to do a failure analysis.
In the armature assembly, I noted two bright áreas that made me think of some kind of erosion that could be a reason for the overheating that led me to put this router aside. Inside the field, a corresponding áreas do exist.
Back to the armature assembly, I noted that there was a free space near the biggest ball bearing. This space was for the fan. I found all the pieces for the fan core but I didn´t find any wings. Looking closely at the broken core I noted that near to edge there was a hole drilled to balance this metallic piece. For me, this was the origin of a crack that extended to all the core thickness. I also noted that there were oxide spaces where the fan´s wings were supposed to be. The oxide signals made me think that the wings never existed, being this the main factor for the overheating.
The broken wires, carcass, plastic base, and fear were collateral damages.


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## TenGees (Sep 12, 2012)

It may have 'eaten' the blades. Glad that you're okay.


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## bob vaughan (2 mo ago)

Thanks for taking the time to post those photos.
That's a vary scary catastrophic failure.
For what its worth, those shiny ground spots on the armature up near the top bearing are ground at the factory. Those are balancing cuts to make the armature run smoother. That's a common detail on modern portable power tool armatures.


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## calabrese55 (2 mo ago)

The other scarry part is how the router body blew apart.
the grain in the casting and the cracks that are also evident there makes this part look like "pot metal"
Just a real crappy casting.
calabrese55


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## radio_davio (Apr 28, 2011)

So, the lesson is - if your router is too hot to use then something is seriously wrong? Or, is it to stay away from seriously cheap routers? Or, maybe both?

This post shook me up. Years ago, in the machine shop at work, an end mill collet fell apart on me at about 3500 rpm. Everything started shaking and wobbling really quickly. Not sure how I did it, but I ducked under the mill bed just before shrapnel started blowing everywhere. Whoa!

Bet you had Whoa! moment drinking that coffee afterwards! So glad you're both all good!


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## papasombre (Sep 22, 2011)

Thank you all for your concern.
As Tom wrote in his post, overheating is always a bad sign. The pictures that I posted back, in 2016, show the reasons why I did not use the router for a long time.
And yes, radio_davio is right. Overheating and low prices are reasons to keep away from chinese routers.


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## Rebelwork Woodworking (Sep 11, 2004)

I’ve seen routers do a lot things, but never blow up, I’ve ran router for long periods and got them hot, not unusual..


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## 4DThinker (Feb 16, 2014)

I've been using routers since 1974 or so. Everything from cheap crap to high dollar brands. In all those years I've never had or seen a router blow apart like you've shown. Currently knocking on my wood desk. 
4D


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## srjaynes49 (Feb 9, 2010)

reuelt said:


> Glad, you are both safe.
> We need to listen to Genuine and honest experts.
> One of my Church member used regular hand routers to make hard wood mouldings and he and he brother became the No.1 seller of wood moldings in Malaysia.
> He laughed at me for buying B&D and Ryobi tools and told me that the King of all Routers they used day and night and NEVER failed was the ELU 3.5HP (that later became the the Dewalt DW325).
> ...


I have 3 of the ORIGINAL Hitachi M12V routers. They are tanks. I can’t vouch for the current models. The Festool routers are also very tough, very expensive, and have good repair and spares availability. The OLD (pre 1990s) Porter Cable are very durable. I have one of their trim routers I purchased in 1986 that’s still as good as the day I bought it. I can’t say that for their last decade before they disappeared. Lastly, if I had to buy a dedicated trim router today, it would likely be the Bosch.


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