Trend router bit chewing up timber?!?

[Harrris303]

Hi everyone, I bought a large Trend router bit yesterday (1/2" shank, 50mm straight cutter) and tried it out on my new router table. I set it up to cut a normal rebate and as I was pushing the timber through I could see large splinters of wood being chucked out along with the usual dust. When I turned the workpiece over I found that the new bit had torn up the bottom of the rebate really roughly (the sides had cut as cleanly as I would expect them to.)
I thought maybe I'd been too ambitious with the depth of cut so I tried again with a shallow cut of 3-4mm and the same thing happened. Then I thought maybe it was something to do with the wood itself so I tried a completely different piece, and the same again!

Does anyone have any ideas what the explanantion might be? Or is it just a bit of a crappy router bit? (For £13 I would've hoped not!)
Thanks in advance for any suggestions.

 

[marcros]

Has it got end cutting blades on?

 

[carlb40]

With a 50mm cutter i would take a max of 1mm or less per pass.
Have you got the right speed setting for the cutter? Larger cutters need slower speeds.
Feed direction is also to be considered, if you are feeding the timber against the grain it will tear out easier than with the grain.

 

[custard]

Hello Harris. Have you made any successful cuts with your new router table?

If not the problem could be the table not the bit. Maybe the router isn't mounted perpendicular to the table, maybe the table isn't flat, or flush with the router table insert, each of which could cause the problems you described.

Then again it could be technique. If the work isn't held flat to the table throughout it'll tend to ride up, if you push it down part way through and don't have a bottom cutting bit then that could also cause the problem you describe.

 

[Giff]

Sorry if this is an obvious question. Are you feeding the right direction ?

 

[Benchwayze]

Sorry if this is an obvious question. Are you feeding the right direction ?

Not wishing to teach egg-sucking, but my thoughts too.

 

[Harrris303]

Thanks for all the replies, haven't had a chance to get online until now. I'll try and cover everything haha.

The bit has got end cutting blades. The table is set up fine, I've used a smaller bit to cut rebates on it which came out absolutely fine. I'm definitely feeding in the right direction, not forcing the timber through, keeping it flat against the table and fence the whole time.
I didn't realise larger bits needed slower speeds so that's probably worth looking at. And I'll try it again taking even less off with each pass.
Cheers everyone.

 

[Giff]

If it's a big cutter that may be it. If you look at the difference between the speeds of a spindle moulder and a router the SM much lower speeds. On the other hand although my SM will accept ½ router cutters it is useless as it won't spin fast enough.

 

[Harrris303]

Oh right, I've never used a spindle moulder so I had no idea about that. Seems like that's probably the most likely cause of the problem.
I hope so anyway! Cheers.

 

[Benchwayze]

Chats...

If you don't have a manual for your router, may I suggest you Google router cutters and related speeds. (or words to that effect) I'm confident you will find something, somewhere. If not perhaps Trend will be able to help.
HTH

 

[Harrris303]

I do have the manual for the router but unfortunately it's more like a long list of health and safety warnings with very little instruction on getting the most out of the router. I think the cutter itself came with some specs etc so I'll check that when I get home.

 

[Phil Pascoe]

Years ago I pushed a 36mm x 36mm (Wealden) into a piece of softwood with a 1700w Bosch router in one pass - it cut fairly cleanly. Mind, it probably spoke more for Wealden and Bosch than it did for my intelligence.

 

[Shrubby]

Some woods are just uncooperative and splinter a lot. Have you tried passing the wood in a different orientation - vertically against the fence rather than flat against the table ? For really awkward stuff, two passes against a slotting cutter (one vertical one horizontsl) works well. The larger diameter cutter should give a good finish and the Shaw guards or hold-downs on a router table make this a safer operation than most sawbenches
Matt