Routing rebate in Tassie Oak

[tony2096]

Hi,

I'm having problems routing a rebate in some Tassie Oak.

I am using lengths of 42 x 19 mm (for a door frame) and am trying to route a rebate 6 x 13 mm. When I set up my router table and practiced with radiata pine, all was well, but when I moved on to the real wood, the router keeps catching and pulling out small chunks (in the yellow area in the diagram). There is also a photo but it's difficult to see the area in question.

I tried nibbling off smaller amounts of wood each pass but had the same problem.

I tried with a new router bit (Timbecon Torquata 12mm straight) - same problem.

Any suggestions?

Is this what I should expect with Tassie Oak?

Would orientating the wood 90 degrees on my router table make any difference?

Tony

[Jack E]

You could try turning the timber the other way so it is standing on edge.
This may mean you would have to move the fence each time rather than just raise the bit but if it fixes your problem I am sure you won't mind.

Cheers, Jack

[outback]

Your'e right. It's really hard to pick up from the pics, but at a guess it looks like you may be going against the grain. Perhaps try the 90 degree thing, smaller cuts with several passes, try to orient the grain to avoid the tear out, adjust bit speed, adjust fed speed, swear like a sailor, try spiral upcut bit, it will give a cleaner cut.

Just a few ideas from a caveman

[echnidna]

Outbacks right on,
You're cutting aganst the grain.
or it is curly grain.

[jaspr]

tony - just looking at the picture - are you sure you are feeding it through in the right direction?

sorry, if this is stating the obvious - but I notice the 'bounce' in the cut in the photo - tassie oak should cut much smoother than this

if that's not the problem, you could also try a first pass at full height, but only taking off a couple of mils - then start taking off the rest by moving the fence away and dropping the router down - thenworking up into the rebate

jas

[tony2096]

Thanks for your replies.

I hope I'm feeding the stock the right way: right to left across an inverted router.

I rotated the wood to feed it through on its edge and that got rid of the breakout on the edge about which I'm concerned ('cos it's on the face of the door). It still tended to tear the rear edge but I followed Jas' advice and made the first pass really shallow at full height and then proceeded in much smaller increments and now it's a lot better.

One problem was that my idea of taking off smaller amounts of timber was still too aggressive. I thought 3 passes of 4mm would have been OK but now I see that the direction the bit is spinning will always tend to push the edge away from the stock on the edge closest to the blade - espaecially on deeper cuts. Using 1mm increments at a time works a lot better.

Incidentally, is a 12mm straight bit the best to use for this task or should I use a larger diameter?

Now off to Bunnies to replace all the Tassie Oak I've ruined :(

Tony

[Harry72]

Is there any support above the cutter or open air?, ideally in this situation you get as much zero clearance as possible.
Make an sacrificial fence and push the cutter through it at the needed set height and then use a feather board to hold the stock against the fence.

[tony2096]

Harry,

I see what you're saying. I do have a fence with a hole in it but the hole is not punched through by the bit - just a large square hole to cater for all my bits. So effectively there is air next to the wood that is being attacked by the bit as the blade leaves the stock.

Unfortunately I'm using a home-made router table which is fiddly enough at the moment with lots of clamps to loosen/tighten whenever I move the fence. I can see it getting even more time consuming if I follow your (correct!) advice :((

Maybe it's time to start thinking of a building a better fence + fence control mechanism...

Tony

[Cruzi]

Have severe probs with tearout on Tassie Oak box, ended up with zero tolerance fence and sacrificial wood clamped on outer edges to fix it.

Wasted a lot of wood before it finally came right:(( :doh:

[felixe]

I would suggest a better quality router bit, as well as taking stock of all the good advice given so far.:clap2:
Don't use the timbecon bit, they are cheap like the archer and carbatec bits,:no: go for a quality bit - I found that after upgrading my router bits to CMT:2tsup: and carbitool :2tsup: I minimised a lot of tearout, this is based on my experiences with the tassie oak I got from Lazarides in Brisbane.
This should help but may not be the only answer.
Unfortunately tassie oak does have a tendency to tear and splinter.:~ :D
Also, you should find a local supplier as bunnies are expensive :yikes:for tassie oak/vic ash.
Good luck.:fingerscrossed:

[ernknot]

What? Tear out on Tassie oak? No way, must be Vic mountain ash!