Thread: 1/4" router bit to level uneven timber?

Hi You would need to make a simple sled type assembly and find some way of securely clamping the timber to your bench.
A bottom cleaning bit or planing bit is ideal.
I would recommend only taking light passes of maybe 1-2mm deep and slightly overlapping them,Your small router should be ok.
It can take some time to do if the workpiece is large and the finish will probably be far from perfect and would still require final sanding depending on what you are using it for.

I think that you'll find that a 700 Watt (just under 1 HP) router will not have anywhere enough grunt to spin a 22mm bottom cleaning bit. The other issue is that the bottom cleaning bits that I've seen all have a 1/2 inch diameter shank, so they won't fit your router anyway. If you do find a supplier that has a 1/4 inch shaft 22mm (or whatever size) bottom cleaning bit, I'd be concerned about how much flex you'd get on a little 1/4 inch router bit shank. The other issue is router speed ----- bottom cleaning bits usually start at around 18mm diameter, and even at that size will have to be spun at a reduced speed and by the time you get up to a 50mm bottom cleaning bit, you should be running it at ~8,000 RPM according to Carbi-Tool, so make sure you're using a variable speed router.

I have both 25mm and 50mm (Carbi-tool - a good Australian manufactured brand) bottom cleaning bits, and they give my 2400 Watt 1/2inch collett router a fair old work-out when smoothing hardwood slabs (e.g. Forest Red Gum, and Tallow Wood). Even with the big router, I only take cuts of around 1mm to 2 mm depth at a time to avoid the router motor being overloaded, and the final finishing cut has to be a very fine skim cut of around 0.5mm to get a nice clean surface ready for sanding. That was on slab cut timber, surfacing the faces of the slabs - i.e. along the grain.

However, you've mentioned that you have a "eucalyptus ..... stump". If that means that you'll be smoothing across the end grain of the stump (i.e. a slice taken horizontally through the tree), then smoothing the end grain using the bottom cleaning bit seems in my experience to put substantially more load on the router (requiring slower cutting and reduced depth of cut to avoid overloading the 2400 Watt router), so it's even less likely that a 700 Watt router will be able to do the job.

If I were you, I'd look for a powerful router in the range 2000 Watt to 2400 Watt, and with a 1/2 inch collett.

Hope that info helps.

Regards,

RoyG

Especialy if the wood is a little green still, you may find that a handplane will do the job with less fuss. A longer plane - anything from a #5 - #7 will work well.

On a train from London to Devon

Derek

I have to thoroughly disagree with Roy.

A 22mm bit will be fine in a 1/4" 700w, at full rpm, as long as you don't try and push it too hard. 1-2mm passes shouldn't pose a problem.

I've run a less-than-sharp 18mm bit, cutting 5+mm deep with a 450w trimmer; the noise was horrible, but it didn't show any signs of giving out. Yes, I know it's not ideal, but you have to work with the tools available at the time.

A 50mm bit should also be run at 18k rpm for surfacing, not 8k (have another look at the Carbitool catalogue), NO wood cutting bit should be run that slow, they're not designed for such low speeds.

Originally Posted by l2oBiN

I have a cut stump from some sort of a eucalyptus that I have been drying for a while and would now like to level out the very rough cut that had been done to it with a chainsaw.

you may want to start by leveling up the chain saw cut -- either with skilled hands wielding the chain saw or a Green shed coarse tooth cross cut saw

will make the subsequent trimming with the router soo much easier

Originally Posted by elanjacobs

I have to thoroughly disagree with Roy.

A 22mm bit will be fine in a 1/4" 700w, at full rpm, as long as you don't try and push it too hard. 1-2mm passes shouldn't pose a problem.

I've run a less-than-sharp 18mm bit, cutting 5+mm deep with a 450w trimmer; the noise was horrible, but it didn't show any signs of giving out. Yes, I know it's not ideal, but you have to work with the tools available at the time.

A 50mm bit should also be run at 18k rpm for surfacing, not 8k (have another look at the Carbitool catalogue), NO wood cutting bit should be run that slow, they're not designed for such low speeds.

People who wish to use unsafe practices in their own workshop (i.e. such as running large router bits at excessively high speeds) are, as far as I am concerned, welcome to do so in their own workshops, so long as they injure or kill only themselves!

BUT, it is totally wrong for someone to be recommending unsafe work practices to anyone - especially to those woodworking new comers who may be challenged to identify the difference between safe and unsafe practices!

Elanjacobs - are you prepared to take full and complete responsibility in the event that a forum reader who follows your recommended unsafe work practices manages to injure or kill him/herself as a result ?

Signed:

RoyG

Originally Posted by RoyG

Elanjacobs - are you prepared to take full and complete responsibility in the event that a forum reader who follows your recommended unsafe work practices manages to injure or kill him/herself as a result ?

As far as I'm concerned, my suggestion of 1-2mm passes with a 22mm bit on a sled is 100% safe. I would have no problem doing it myself or recommending it to others.

Just one question before I bib in
How big are we talking
What's the dimension of said stump
Cheers Matt

Originally Posted by elanjacobs

I have to thoroughly disagree with Roy.

A 22mm bit will be fine in a 1/4" 700w, at full rpm, as long as you don't try and push it too hard. 1-2mm passes shouldn't pose a problem.

A 50mm bit should also be run at 18k rpm for surfacing, not 8k (have another look at the Carbitool catalogue), NO wood cutting bit should be run that slow, they're not designed for such low speeds.

Originally Posted by RoyG

People who wish to use unsafe practices in their own workshop (i.e. such as running large router bits at excessively high speeds) are, as far as I am concerned, welcome to do so in their own workshops, so long as they injure or kill only themselves!

BUT, it is totally wrong for someone to be recommending unsafe work practices to anyone - especially to those woodworking new comers who may be challenged to identify the difference between safe and unsafe practices!

Elanjacobs - are you prepared to take full and complete responsibility in the event that a forum reader who follows your recommended unsafe work practices manages to injure or kill him/herself as a result ?

Signed:

RoyG

Originally Posted by elanjacobs

As far as I'm concerned, my suggestion of 1-2mm passes with a 22mm bit on a sled is 100% safe. I would have no problem doing it myself or recommending it to others.

to add some numbers to the above discussion

from CARB I TOOL Australia Pty Ltd.:. Safety Tips & Hints


from 10 Tips for Making Clean Cuts With Router Bits / Rockler How-to


from Router speed control - Router Forums


I'll let others determine what the consensus is, but what does the manual for I2oBiN's router recommend?

Ian, I'm aware of all the numbers.

Most (all?) single speed trimmers run at 30k rpm. To date, I have never seen a 1/4" bit rated above 24k - do you suggest we stop using trimmers? I actually asked one of the toolroom guys at Carbitool about why their 1/4" bits were rated to a speed less than most 1/4" tools run at and he was left scratching his head.

Originally Posted by l2oBiN

I have a cut stump from some sort of a eucalyptus that I have been drying for a while and would now like to level out the very rough cut that had been done to it with a chainsaw.
Since I do not have a planer or a sander, I thought I could give this a go with a router.. I saw this being done somewhere online..

I have a router that takes 1/4" bits and would like to know which bits would be most appropriate for the levelling/cleanup?

I saw some "bottom cleaning" bits on eBay and thought they might be most appropriate but I am a bit worried that the straight edges might not be able to cope with cutting both bottom and sides if there is a lot of wood to clear?

I was also wondering whether the larger bits ( bottom cleaning to ~22mm) woukd be too much for the 700w router I have?

Firstly, I wouldn't be confident using a no name bit from ebay, especially where the seller is based outside Australia. The price might be right, but the consequences of Cheap manufacturing are just too great for my risk appetite

secondly, I can't see any bits from Carb-i-tool larger than about 20mm that would be suitable for what you want to do.

Perhaps buy yourself an inexpensive 100 or 115mm angle grinder (and the appropriate PPE) and use an arbortech turboplane Arbortech TURBOPlaneTM

Originally Posted by elanjacobs

Ian, I'm aware of all the numbers.

Most (all?) single speed trimmers run at 30k rpm. To date, I have never seen a 1/4" bit rated above 24k - do you suggest we stop using trimmers? I actually asked one of the toolroom guys at Carbitool about why their 1/4" bits were rated to a speed less than most 1/4" tools run at and he was left scratching his head.

one of the Bosch trim routers has a fixed speed of 35,000 RPM
The machine's user manual says
"Max. Cutter Diameter must be at least 1/4” smaller than opening forthe bit and cutter."
which from the diagram looks to equate to a max 19mm cutter.


I don't really want to crunch the numbers for tip speed in metres/second, but if a well made 25mm bit smashing into wood is "safe" at 24,000 RPM, then a well made 12mm cutter should (purely on the basis of relative tip speed) be safe at 35,000 RPM

I'm sure that in the past I've seen speed charts which included recommended max speed for bits as small as 1/4"

but I did,

using the data already posted ...

Originally Posted by ian

I don't really want to crunch the numbers for tip speed in metres/second, but if a well made 25mm bit smashing into wood is "safe" at 24,000 RPM, then a well made 12mm cutter should (purely on the basis of relative tip speed) be safe at 35,000 RPM

I don't doubt that it's safe - I regularly run profile bits up to 32mm dia. in a 30k rpm Makita trimmer - but if you rely solely on the speed charts you end up with a tool you can't use.