Advice - trim flush router bit scuffing

[Mike_5]

Hi,

I have a trend trim flush router bit (part of a collection for about £30), I have toyed with the idea of buying a higher quality router bit due to my issue.

When I use the flush trim bit, I get a lovely flush trim, however, the guide sometimes leaves scuffs in the wood it is running against. I have tried to tighten the guide in an attempt to reduce the spinning that must be creating the scuff, but it didn't work.

Any advice, or should I just get a better trim flush bit?

Thanks

 

[woodbrains]

Hello,

Might not be the bit, but the template/guide you are running against. If there is any variation in profile of the template across its width, then the flush trim bit will, well, trim it! It is basically correcting any errors in your guide, but it should only do that once on the first pass, provided you don't set the plunge depth on the router differently on subsequent passes.

Mike.

 

[sunnybob]

If the bearing is imprinting on the wood then you are pushing too hard.

Use a bandsaw to get pretty close to the cut line and then just use the router to lightly trim. Use enough pressure to stop it skipping, but dont force the wood against the bearing.
If that fails, its easy to just sand the whole side to remove the bearing track.

 

[Mike_5]

Thanks, I should have used better wording, the bearing is imprinting on the wood. I would imagine I do apply pressure while performing the trim. Will give it a go on some scrap and see how I get on.

Thanks!

 

[Steve Maskery]

If the bearing is imprinting on the wood that suggest that it is rubbing. It should not rub at all. You don't want the bearing tighter, you want it to be as free as possible. It should spin freely, without having to apply any pressure at all. I would fit a nw bearing and see if the problem goes away. Bearings are not expensive and are easily obtainable.

 

[Adam9453]

The hearing may have seized or become stiff, as Steve says replacing the bearing is a great good start.
It does sound like you're pushing too hard, what material are you trying to trim and how thick is it?
A lot of people try and trim really slowly which often leads to bearing failure, try doing the cut faster with less pressure and see if that helps.
How much have you used the bit, it could it be blunt and therefore leading you to applying more pressure to get it to cut.
If all this fails, buy a new better quality bit.

 

[custard]

One of the tests for a decent quality router is to ask the question, "can I easily buy replacement bearings?" It's important because bearings are consumable components, they often get clogged up with saw dust and need swapping long before the cutter is worn out.

This is one reason why Wealdens is so highly rated,

https://www.wealdentool.com/acatalog/Be ... es_84.html

 

[Eric The Viking]

1. note the comments about only using a flush trim cutter for clean-up, i.e. shallow passes.

2. take the bearing off, clean it thoroughly with meths on a bit of rag, and check it. Is it grabbing at some point in its rotation, or rough when it rotates, or wobbly? It may be some crud is impeding it and at 10,000 rpm, that will cause rubbing.

Don't overdo the meths - just dampen the cloth - bearings for this application should theoretically be sealed but in practice can't be, and you don't want to wash the grease away.

If in doubt, you'll have to replace it (the bearing, that is).

 

[Mike_5]

The last project I used it on was 4mm hardwood, so only thin material to flush trim. I do recall lowering the speed setting to about 2 out of 5. I have tightened the guide close to max, still allowing it to turn by hand. I was worried that it was coming loose.

I have barely used the flush trim bit, easily less than 50 meters of length. It didn't used to do it when I first used it, was only on my last project I noticed it.

I've had the intention to buy better bits when needed, but only started the hobby in the last year so didn't want to go too crazy to find out I didn't enjoy it!

Thank you for the comments, I'll do some troubleshooting soon and see if the problem goes away. Otherwise I'll look into getting a new and better bit.

 

[Phil Pascoe]

You say you have tightened the guide - do you mean you have tightened the bearing? You shouldn't be able to.

 

[Steve Maskery]

Phil's right. Are you able to nip the bearing up so that it won't turn, simply by tightening the screw which holds it on? If that is what you mean, that is your problem. That screw should be tight, but it should bear on just the inner race, holding that tight onto the cutter. The our race should be unaffected. If the outer race is affected by that then I bet that there is a washer missing, or too big a washer, or something like that.
You say it wasn't like this when new. Have you had the bearing off at all?