Katsu trimmer issue - Bit slipping

UKworkshop.co.uk

Help Support UKworkshop.co.uk:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

bp122

Expert at Jibber-Jabber
Joined
20 Aug 2019
Messages
1,170
Reaction score
698
Location
Haddenham
Bought a brand new Katsu trimmer on eBay.

Needed to route a small rebate on a picture frame. So decided to use the unused rebate cutter I had lying around.

Fitted the bit, set a depth of 3mm for first pass. Three inches later, the bit kept dropping down and the cut started getting deeper, stopped it immediately and found out the router bit had slipped and had started to come out of the collet.

The collet nut was still tight and the bitbwas still secure when I tried to pull it away.

Removed the bit and refitted it at the correct depth. Tried the same thing again and same result.

Is this common or have I received a duff one?

I tightened it with the same way as the other router bits I have on my routers.
 
Is it possible you are using a metric bit and the collet is imperial or vice versa?, I gather katsu routers are available with both sorts of collet
 
Has the bit got the correct diameter of shank for the collet that is fitted ie 1/4" and 6mm don't actually go together
 
The bits are definitely 1/4" because I used to use the bits from the same set in my old 1/4" router.

And they wouldn't go into a 6mm collet I was told.

But I will do the test you guys suggested to see if the same happens with the other bits on a piece of scrap tonight.

Thanks guys.
 
Moving against the rotation of the bit. It causes more vibration and high loads on the bit. A but of grease or dirt in the collet along with climb cutting can pull the bit out. As ive just realised you are cutting a rebate, so yes, half your cut is climb cutting. Not the routers fault im afriad.
 
Moving against the rotation of the bit. It causes more vibration and high loads on the bit. A but of grease or dirt in the collet along with climb cutting can pull the bit out. As ive just realised you are cutting a rebate, so yes, half your cut is climb cutting. Not the routers fault im afriad.
Sorry, it is still not clear to me.

I route as one usually does, workpiece flat on the bench, I am routing the rebate on the right hand edge from bottom to top, with the router bit spinning in clockwise direction as observed from the top.

Is this wrong then?
 
It's a budget clone machine. The collets are not terribly good. Maybe buy a branded Makita one and see if that's any better.
I understand your point, but I only bought it after so many people here have used one and recommended it.
 
Is the bit dropping down? You mentioned the collet was still tight, are you sure the depth adjustment on the machine isn't moving? Put the router on the bench with the plunge locked and see if you can push the machine into the base
 


Im struggling to put 2 words together today. Long story, dont ask. Maybe stumpy can explain better than i can.
 
Is the bit dropping down? You mentioned the collet was still tight, are you sure the depth adjustment on the machine isn't moving? Put the router on the bench with the plunge locked and see if you can push the machine into the base
It is definitely the bit itself, as it was tightened up to the mark on the shank, then after the incident the mark was 5 to 6mm higher
 
I understand your point, but I only bought it after so many people here have used one and recommended it.
Just in case: i didn't mean the Katsu itself, they are good value, I meant put a Makita collet in it.
Neither the makita nor Katsu collets are anywhere near as sophisticated as the ones in say a dewalt dw625 (google some images) but the branded Makita might be better than the original ?
Collets are ultimately consumables.

Cheaper part CAN mean wider tolerances. Maybe this one collet is bottoming out or closing up in some fashion without achieving maximum grip on the cutter shank.
 
Last edited:
Just in case: i didn't mean the Katsu itself, they are good value, I meant put a Makita collet in it.
Neither the makita nor Katsu collets are anywhere near as sophisticated as the ones in say a dewalt dw625 (google some images) but the branded Makita might be better than the original ?
Collets are ultimately consumables.

Cheaper part CAN mean wider tolerances. Maybe this one collet is bottoming out or closing up in some fashion without achieving maximum grip on the cutter shank.
Ah, gotcha. This could be a good test.
 
Hi bp122. Page 6 of the Katsu trimmer manual shows the correct movement of the tool in relation to bit rotation when machining a rebate. Everything mentioned suggests that a 1/4" collet is being used with a 1/4" shank router bit. In your position I would check that each of the 4 collect clearance slots is free of manufacturing swarf or any other debris. It is also possible that if a collet is tightened down without a bit shank being present any distortion can reduce the clamping force when a bit is installed and tightened. For safety reasons obtain a replacement collet. AIM TOOLS are a source for Katsu parts.
 
I took the bit out of the collet last night, there were definitely wear marks on it with some burrs as well as scratches.

I took apart the collet and cleaned it properly with a rag, inside and out.

This morning I tried with a chamfer bit on a scrap piece and it worked okay.

Just to rule out operator error, I used the same rebate but, but this time tightened it ever so slightly more and routed a same depth rebate and the problem didn't come back.

Maybe it wasn't tightened down enough as some sort of debris was stopping it from tightening down fully, or maybe pure operator error.

But I will look into a better quality collet for the future.
 
A job well done bp122. Your Katsu trimmer is a good tool and its' use is greatly extended with the 2 column plunge base. Keep at it!
 
Back
Top