20MM Router Bit for routing MFT holes

[segovia]

Can anyone recommend a decent 1/2" shank 20mm router bit for routing MFT holes ?

The Trend bit i bought would not cut butter

Thanks

John

 

[Derek Cohen (Perth Oz)]

I used a Trend bit for mine. Still cutting well after many dog holes. Perhaps you should contact Trend and get it replaced.

http://www.inthewoodshop.com/Powered Tools and Machinery/BuildingMFT1.html
Regards from Perth

Derek

 

[Ollie78]

I personally wouldn't use a 20mm router bit for a 20mm hole. Because a router bit spins so fast unlike a drill, it will struggle to clear the chips and burn as a result, prematurely blunting the cutter, smoking and making a black finish inside the hole.
Either buy a really nice sharp 20mm spur point drill bit or use a smaller router bit (12.7mm worktop bits are cheap) and a guide bushing. Centering the bit in the bushing is very important to actually cutting a circle, dust will build up in between the bushing and the template etc, etc.
Even this method will struggle with extraction. Favourite would be an up cut spiral bit or maybe a compression bit for a nice clean cut.

Ollie

 

[segovia]

Trend Craft Pro 1/2" Shank Straight Router Cutter Bit-Ref, C030DX1/2TC Diameter 20mm Cutting Length 50mm Tungsten Carbide Tipped, 1/2 inch 20 mm x 37 mm​

This is the bit I used but it scorches the wood, makes a lot of smoke and nasty smell which is now ingrained in my nostrils!

I did about 10 holes out of 20 and then gave up. I turned the speed down to 50%, but It didn't make any difference.

I have ordered an Axcaliber from Axminster for delivery tomorrow, see how I get on with that

 

[segovia]

I personally wouldn't use a 20mm router bit for a 20mm hole. Because a router bit spins so fast unlike a drill, it will struggle to clear the chips and burn as a result, prematurely blunting the cutter, smoking and making a black finish inside the hole.
Either buy a really nice sharp 20mm spur point drill bit or use a smaller router bit (12.7mm worktop bits are cheap) and a guide bushing. Centering the bit in the bushing is very important to actually cutting a circle, dust will build up in between the bushing and the template etc, etc.
Even this method will struggle with extraction. Favourite would be an up cut spiral bit or maybe a compression bit for a nice clean cut.

Ollie

Yes, I am thinking 20 mm router bit isn't the right tool for the job, but it has been used by others successfully. Maybe small plunges followed by a clear-out is needed.

 

[Spectric]

How are you aligning the holes? If you look at the templates like the one from RS in Wales they use a guide bush and smaller router cutter rather than a single plunge. A decent 20mm cutter should cut ok if you don't plunge to fast.

 

[segovia]

How are you aligning the holes? If you look at the templates like the one from RS in Wales they use a guide bush and smaller router cutter rather than a single plunge. A decent 20mm cutter should cut ok if you don't plunge to fast.

I have the trend MFT template, I thunk I'll remove some waste with a 15MM drill bit first and then go in with the router

 

[Spectric]

I have the trend MFT template

@petermillard has a video comparing these jigs and demonstrates the Trend version.

 

[ChrisWiduWood]

Trend Craft Pro 1/2" Shank Straight Router Cutter Bit-Ref, C030DX1/2TC Diameter 20mm Cutting Length 50mm Tungsten Carbide Tipped, 1/2 inch 20 mm x 37 mm​

This is the bit I used but it scorches the wood, makes a lot of smoke and nasty smell which is now ingrained in my nostrils!

I did about 10 holes out of 20 and then gave up. I turned the speed down to 50%, but It didn't make any difference.

I have ordered an Axcaliber from Axminster for delivery tomorrow, see how I get on with that

I think you may have a dud, i used the exact same setup and have had no problem cutting. i cut out a full 8x4 sheet and the cutter still has plenty of life...

 

[Jameshow]

How about drilling with an 18mm bit and reaming out with a 20mm router bit? Just a though so long as the outer bit will self centre??

 

[Derek Cohen (Perth Oz)]

All these suggestions. I do wonder if they are armchair or actual experience? As I posted earlier, I went through this quite recently, and I have found the Trent 20mm router bit to be excellent. No burning. And the MFT top I routed was 25mm thick Merbau …

One reason for using a router and template is to obtain perfectly perpendicular dog holes. Anything off vertical will affect the precision of a MFT.

The template was made for me by a friend with a CNC machine (influenced by the Trend template, which is half the size). The advantage of this method is that one can make as many tops as needed.

Regards from Perth

Derek

 

[pgrbff]

Whatever bit you use try the woodpecker method, should be better than trying to plunge in one go. I used a Wealden hinge boring bit and there was no burning.

 

[porker]

Is the Trend bit designed for a straight plunge cut? I’ve made a top with the RS Pro jig which is a similar method to @Derek Cohen (Perth Oz) with a guide bush, but my bit (not the Trend one mentioned) at least would not plunge as the cutter does not cut right across the bottom. Using a guide bush gives lateral movement of the bit and it can therefore cut as expected.

 

[brucew]

I'd get Trend to replace the faulty bit or go with the RS template and a 1/2 bit. I bought a Wealden bit and had to return it as is was 20.5mm rather than 19.95-20.05. They said most classic plunge bits err on the plus side assuming it is cutting a mortise. Whether they're right or not, I decided I'll go with the RS MFT Jig when it's time. It uses a 1/2" cutter and a 30mm bushing.