Router problems (on that weird wood stuff)

[chunkolini]

This has been driving me nuts for a few days now.
as well as sculptures I also turn out bespoke shelving units, mainly for Cd's etc. I use wooden shelves and brazed steel frames, I have made dozens of these things over the years.

I bought a new router a while back and some new bits to go on it, it used table mounted for one specific job. making a smal groove in the back of the shelf for the frame to run inside.

The groove is about 10mm wide and the same deep in the back of each shelf where the frame passes, there is a good close up shot at the bottom of the page in this link http://www.coolshelving.com/page2.htm . Not a huge amount of machining but it has to be right.

Anyway. The old router bit was getting a bit tired, so I bought a new one, 12x30mm twin flutes. It splits the wood to hell, delayering it along the grain, I bought another bit today, made by Trend,just the same result. I faffed about for ages trying going slower, speeding up the router, working with and against the grain. but the same bloody awful mess.

The I put the old bit back in and perfect! a bit of overheating but hardly any damage to the wood. You could see a stream of sawdust flowing into the vaccuum extractor thingy, with the newer bits it is a cascade of ships all over the place.

Any ideas? one theory is that the new bits are too sharp and are digging in and trashing the wood.

To feed the wood in I have one end pressed against the back stop on the table and slowly rotate the timber onto the bit, this avoids snatching etc.

Typically I have this problem just as I get a bundle of orders.

Chunko' the unhappy chappie.

 

[Dave Sherwood]

Are you making the groove in one pass,if so try two or three passes and watch you router speed. I had problems exactly like this and had to make smaller passes to get a neat finish.This could one reason for tearing the wood.

 

[TechnicAl]

im no help as ive always assumed the difference was the quality of the timber. i do quite a lot of faffing about with wood. Ive got 3 routers, one is a cheapo powerdevil and the best one is one like Norms on that woodwork programme. Sometimes the cheap one performs better than the very expensive one. I thought i had wasted my money but maybe its the bits.
I thought Trend were supposed to be good.

 

[pedrobedro]

I had something similar on some Pine I was using but the bits worked perfectly on everything else. I put it down to the wood being fibrous and it did work better in one direction than the other.

 

[Hitch]

I mess about with wood a fair bit aswell. I also assume its the wood mostly. It happens much more if using that whitewood rubbish, like they sell in the DIY stores.

Have you tried cutting the groove the other way, so the leading edge of the cutter pushes into the wider section, rather than the remaining edge...

 

[chunkolini]

I will post some photo's tomorrow, typically today I had left the camera at home, usually it lives in my work bag. What drove ma mad was the inconsistency of it, why does the knackered bit work fine? aaaaaaarrrgh!!
I had to detour via the cider farm o my way home.
Oh the old router was no name junker, the new one is a spiffy Hitachi model, when I bought it it annoyed the hell out of a carpenter I know, ''I am supposed to be the pro around here'' he huffed. te he he he.

The cut I am making is not so much a pass as just make a cut the width of the bit.
In fact here is the picture


Chunko'.

 

[knoba]

Nice shelves Chunko!

Long time admirer of your work!

The way you are cutting the rebate maybe the real problem. Instead of facing the side of the wood on to the cutter bit, using a router table, try it without the table.

A suggestion: Sandwich all the shelves together; true & flush, with waste wood either side, and clamp the entire assembly on to a bench. Clamp a hardwood fence, to the wood, along the line of cut to be made (and on the correct side for the direction of cut), and gradually swipe the lot out, in two depth & width passes using the router. Aim for about 5mm depth or width waste per pass and gradually increase to see what you can get away with. The router should "hum" through the cut rather than vibrate.

If this process goes well, consider buying a bit like this;

...and customising it by removing the bearing & grinding its boss off.

Your rebates should now be perfect & there should be little wispy feather gossamers teasing off the edges. Indeed, if one listens carefully; Angels can be heard singing for the joy of glancing at such beautiful cuts...

Trend are quite good, I have some custom bits, made to my designs, by them. Freud & Titman are good brands too. Only settle for TCT bits as a minimum. Those cheap crappy sets B&Q sell, made by trend, are rubbish. Expect to pay about 10 - 15 quid, per bit, if you want good quality.

Softwoods (literal not genus) tend to breakout more than hardwoods. Softwoods require faster cutting speeds.

HTH

 

[pidgeon chit welder]

I'd also be tempted to make a simple slip over clamp on jig so that I could lay each pack of planks in it and route out identical cut outs with the router weight evenly spread and also supported for continuous gentle movement as you get to the edges of the pack .

Route it out in several passes of not nuch more that 4 mm per pass and don't go rushing .
Again have a sacrificial split out /run off board clamped either side of the pack and reposition it as new wood for each routing out .

You could also use a marking knife/craft knife to mark out the edges of the waste say cut to 1 mm deep all round the cut outs with another ( metal ?) marking out jig , this would also help stop break out/feathering so long as you are routing to a cats whisker inside the line on the waste side...You also get a fantastic edge / line.

Just had a brain distortion ..do you know what Forstener bits are ? If not
they are very sharp fabulous hole cutter on a 6 inch or so long stem that fits into a drill chuck and cuts soft wood exceedingly well as they are razor sharp.

Place two packs of planks laid flat clamped with sacrifical plank at the bottom plank ,facing each other at the rear edge where you want the cut out and bore out the grooves . Using a suitable Forstener bit and battery drill to drill a circular hole in the correct position on the centre line of the two packs rear facing edges ..you'll end up with a half moon / half circle on each rear edge where you want the cut outs.

 

[knoba]

@pidgeon chit welder - Making a jig is a great idea, especially as Chunko said that he had a large run to do.

Slow your roll, though pcw, we wouldn't want to scare them off that "weird wood stuff".

 

[chunkolini]

I had thought about making a pack of the wood and laying them on their sides and going cross wise. Today I shall have a go at thia as I have a bundle of spare damaged timber.

"Your rebates should now be perfect & there should be little wispy feather gossamers teasing off the edges. Indeed, if one listens carefully; Angels can be heard singing for the joy of glancing at such beautiful cuts..."

Knoba gets poetic image of the year award

Cheers all.
Chunko'.

 

[pidgeon chit welder]

@pidgeon chit welder - Making a jig is a great idea, especially as Chunko said that he had a large run to do.

Slow your roll, though pcw, we wouldn't want to scare them off that "weird wood stuff".

I'll keep this quiet ....just betwen us two....

I've had no end of metal stickers gaze in wonderment at my cabinet making skills for they usually need to weld some metal on and grind off to the correct size ..they couldnt work with wood to save their skins:whistle

 

[chunkolini]

I had another go at it today.
I bought a couple of cheap and nasty bits by silverline, and they work just fine, I can see a spray of dust rather then chips, there is a little bit of heat colouring on the wood, but yes there are whispy feather gossamers teasing of the edges.

So sorted, but why is the decent bit wrecking the workpiece? too sharp seems to be the only logical reason.

Bonkers.

Knoba, I quoted you to Chunkoletta, she is convinced tht we are all mad.
I will eventually post some pics of the chunkular router station.

Chunko'.

 

[pidgeon chit welder]

I had another go at it today.
I bought a couple of cheap and nasty bits by silverline, and they work just fine, I can see a spray of dust rather then chips, there is a little bit of heat colouring on the wood, but yes there are whispy feather gossamers teasing of the edges.

So sorted, but why is the decent bit wrecking the workpiece? too sharp seems to be the only logical reason.

Bonkers.

Knoba, I quoted you to Chunkoletta, she is convinced tht we are all mad.
I will eventually post some pics of the chunkular router station.

Chunko'.

I wonder ....... if it is the cutting and clearance angle .... the more expensive ones being made for cutting resin impregnated (read hard ) compressed sawdust and a laminate top sort of tradesmans tool and having a different angle .

PS
Router stations are not always the best solution. You tend to feed in too hard and too fast and you can't usually see what your cutting into ,that's where a jig set up comes in handy especially when you have say 400 plus such cut outs to make and every thing is standardized in size etc.