[kansaibear]

I have a question regarding something that happened today. I'm new to woodworking and trying to figure things out as I go. Currently I've used the "mega dado bit" from Infinity Tools to flatten two end grain butcher blocks and one cutting board with no troubles in the router planing sled/jig I made. My router is a brand new Bosch MRC23EVS.

I was using the {mega dado and planer router bit (#52-506)} to flatten an end grain butcher block made from walnut and hard maple today when the bit suddenly grabbed the wood and shuddered violently then causing the router to vibrate and make a terrible noise. Naturally I immediately shut it off. The bit had dug into the wood by about a millimeter. At the time I was only set to a cut depth of .6mm.

Now the router can't spin the mega dado bit straight yet other normal bits work fine.

Am I looking at a router problem or a bit/collet extension problem?


Sorry for the newbie question...
Any help is much appreciated.

 

[Stick486]

Welcome N/A to Router forums...

the bit digging in suddenly could be a result of the bit moving in the collet or the sled flexing/rocking/tilting from down pressures from you causing the bit to ''dig'' in...
since, as you say, the bit now causes the router to shake (vibrate) but not not normal bits I'd say the mega bit is now bent...
when you run a normal bit as a test are you just running it or cutting w/ it???
did you have at least 1'' of the mega bit's shank seated in the collet???
how does the router behave w/ another large dia heavy massed bit in it???

w/ you being new to routering and all, the next few post will have some PDF's that you need to read...

 

[Stick486]

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[Stick486]

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[Stick486]

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[kansaibear]

Thanks for the quick post reply Stick486.

Wow, didn't even consider it could be bent. I guess the collet extension could also be suspect.

I tested the router with a 1-5/8" 45 degree chamfer bit and a 1-1/2" cove bit; both spun perfectly fine and also cut with no trouble.
I did have at least 1" of the shank seated in the collet; it was in a collet extension that was fully seated.

Many thanks for the PDFs, I've got some reading to do...

 

[Multiwood]

Welcome to the forum N/a

 

[Stick486]

Thanks for the quick post reply Stick486.

Wow, didn't even consider it could be bent. I guess the collet extension could also be suspect.

I tested the router with a 1-5/8" 45 degree chamfer bit and a 1-1/2" cove bit; both spun perfectly fine and also cut with no trouble.
I did have at least 1" of the shank seated in the collet; it was in a collet extension that was fully seated.

Many thanks for the PDFs, I've got some reading to do...

ummmmm. YIKES!!!! you didn't say anything about the bit extension..
oh sure.. save all of the surprises for later... who made it BTW...
that's an awful lot of bit to be slinging on the end of an extension...
physics is not your friend here and I believe you have crossed into the danger zones..
you need to take the extension out of the equation and either lower the plane of the ski or raise the material up to the cutter.....
I trust you are turning the bit as slow as the router allows...
never set a bit as deep as it will go...
and the ''O'' ring thing you see so often mentioned.. skip that plan...
the better router bits say in the paperwork how deep to set them and many have a depth set mark on the shank..

snag those PDF's and make yourself up a library..

 

[kansaibear]

Is it actually possible for such a large bit to get bent?

I guess I'm thinking it may more likely be the collet extension. Both are from Infinity Tools, I purchased the set. The router speed was set on #2 of 1~6; nearly lowest.
As far as the bit depth is concerned, I was only cutting in .6mm and the bit is certainly capable of more than that.

 

[difalkner]

Welcome to the forum, David! Stick's info is a boatload to read but all good stuff where you'll probably find what you need. You can post photos of what you're doing and the bit and router in question. The photos need to be on your computer and not 3rd party hosting, though, until you have more than 10 posts.

David

 

[kansaibear]

Sounds good, thanks David.
I'll try to get some photos posted up soon.
The jig worked fine for the first three cutting boards I did.

I need to give the bit a try without the collet extension and see how it spins.
I'd prefer it were the collet extension being bent rather than the bit. Plus I'll look to raise the material so I don't need the extension.

 

[Stick486]

1... Is it actually possible for such a large bit to get bent?
2... I guess I'm thinking it may more likely be the collet extension. Both are from Infinity Tools, I purchased the set.
3... The router speed was set on #2 of 1~6; nearly lowest.
4... As far as the bit depth is concerned, I was only cutting in .6mm and the bit is certainly capable of more than that.

1... yes, at the shank/bit body intersection especially if it is a two piece bit...
2... agreed... I said bent bit before I knew there was an extension involved..
3... good... but I'd slowed down to the #1 setting..
4... where the bit dug in.. did you hit wild grain or a knot... is there any flex to your ski at all???

the chart says 1617 but the 23's speed settings are the same...

...

 

[kansaibear]

Good to hear answers, much appreciated.
I'll slow it down to the lowest speed when I give the bit a go tomorrow.

It doesn't seem to be hitting a knot in the wood from what I can tell. It is end grain if that makes any difference in the cutting ability/capacity of the bit.

I've attached a few quick photos I took; granted I'm no expert and I'm sure the jig can be improved, but I have flattened three boards previously with no trouble. The ski as you can see has metal rails which I figured would be adequately stiff as to not flex. However, I suppose the MDF side walls may flex. The span is 55cm if I remember correctly.

 

[Stick486]

David, looks to be a more than adequate and well done ski...
believe now that the bit and now to figure out as to why....

 

[kansaibear]

If the bit is okay and still serviceable, I'll run it at the lowest speed and raise my work piece to eliminate the collet extension which is likely the bent culprit (I'm hoping).

That being said, what kind of feed speed should I be doing with that low a router speed?

 

[harrysin]

Good to hear answers, much appreciated.
I'll slow it down to the lowest speed when I give the bit a go tomorrow.

It doesn't seem to be hitting a knot in the wood from what I can tell. It is end grain if that makes any difference in the cutting ability/capacity of the bit.

I've attached a few quick photos I took; granted I'm no expert and I'm sure the jig can be improved, but I have flattened three boards previously with no trouble. The ski as you can see has metal rails which I figured would be adequately stiff as to not flex. However, I suppose the MDF side walls may flex. The span is 55cm if I remember correctly.

The only problem that I can see with you jig is that it isn't adjustable for height which is probably the reason you used the extension. I only use my extension on very rare occasions when there is no alternative. This is how I plane wood. The pdf shows how I make router skis.

 

[Cherryville Chuck]

You can check the cutter for straightness by lowering it onto a flat surface just enough for the cutters to start scratching it (turning by hand). If it's bent parallel one cutter will make contact first and if it's bent enough to make a difference then you should be able to see the difference in height. If it's bent perpendicular to the cutters then only the tips will make contact first. I You can also do a side to side test the same way. One cutter will make contact with something set up to the side of the bit and the other one won't or only the tips will make contact (provided they are vertical to start with). You can check both the cutter and the extension that way.

I call what you are using a sled rather than skis. Harry's setup is skis. When using it to plane like that you should only need light pressure downward. Let the router do the work. You can still flex those angle irons. I usually make the sides taller to stiffen the bottom plate more. I also agree with Harry about using the extension. Don't unless you have to. The longer the distance from the cutter to the bottom bearing the more pressure you put on it it. It's like using a longer pry bar on something, i.e. more leverage.

 

[kansaibear]

Thanks Harry for the planing ski plans, I'll have to give those a shot.

Quick update...
It seems both the bit and the collet extension are bent. I tested the bit only in the router and it still vibrates and causes the bearings to make some noise; as well the extension when used with another smaller cove or chamfer bit still vibrates and the bearings are noisy. However, when running a normal bit in the router there is no vibration or bearing noise when spinning freely or cutting into wood.

Lesson learned, I need a better jig setup or to just get a planer.
Thanks for all the input guys!

 

[DaninVan]

Hey, David; welcome...I'm a bit late to the party (I see all the smoked salmon and craft beer is gone).
The thickness planer also has limitations, width of panel for starters. The weight of a solid workbench top would also really be an obstacle, should you need to plane it down.
Hand planing is good, electric portable planers are an economical alternative, and router planing is ideal. Having said that, you might want to consider a vacuum/dust collection system to control the debris.
HITACHI Power Tools: Products > Woodworking > Planers > P20SBK 3-1/4" Planer
https://www.boschtools.com/ca/en/boschtools-ocs/planers-pl1632-119307-p/
https://www.makita.ca/index2.php?event=toollist&categoryid=3&subcategoryid=56

 

[whimsofchaz]

Welcome to the forum David. There is also a wealth of information in the archives and learning how to search for answers will help you a lot. There are a few discussions on the physics of using a heavy or large bit and the added torque created by having a large bit on the end of a extender. Some good reading also...just use the search feature. Learning is part of the fun!!!