Slab flattening router bit question

[Gmb27]

Hi all,

I've recently upgraded my cheap brand 1/4 router for an Erbauer 1/2 as I've got some lovely slabs to flatten by hand. I also purchased a 1/2 bit advertised as for 'flattening' however the opening at the base of the router is only 40mm and won't allow the bit to plunge past.

Locked in the max depth position the bit will fit but it seems to me that 1) there's then no adjustment possible and 2) it seems dangerous in the event of the plunge lock failing.

I'm not sure there's a lot of point in having a more powerful router if I'm still having to use the smaller 1/4 bit and a collet for flattening. Any guidance or views would be much appreciated as I'm not overly experienced with flattening by hand! Thanks

 

[Inspector]

Get a router with an opening in the base that will fit the bit. Doesn't need to be a plunge router. Or get a bit that fits through the hole in the base of the one you have. This dish bit for example is 1 1/4" / 32mm. https://www.leevalley.com/en-ca/shop/to ... rving-bits

Pete

 

[Eric The Viking]

Is the Erbauer only intended for kitchen fitters or something?

It doesn't sound like much of an upgrade to be honest.

But it shouldn't stop you completing the task. If you are using it to flatten boards, you will probably be using a trammel arrangement - two parallel rails (made of practically anything) either side of the workpiece, and a box-section (usually U-shaped) that will slide along and across with the router mounted on that, with the bit sticking out downwards. Since you aren't going to retract the bit, it shouldn't matter if it can't go through the actual router baseplate, although obviously you have to be careful not to release the plunge while it's on.

Plan B might simply be to enlarge the hole in the plunge base - why is it so small, and could it be enlarged without weakening the base too much (or losing things like dust port mountings)?

After all, they're only big motors on a frame really...

E.

PS: I just measured the aperture on the T11 - roughly 75mm diameter. To be fair, it's one of the biggest baseplate apertures around (intended for mounting in a table), but that's still rather a difference.

 

[Gmb27]

Thanks for the replies. Not sure why it's quite narrow. I've attached a pic of it. Not sure if links are allowed here but it's the
ERBAUER ER2100 2100W ELECTRIC ROUTER 220-240V I've bought. I am using a homemade flattening jig yes.

 

[sunnybob]

Seems to me that the router is a normal sized opening, just what bit have you bought?
Very large bits are very dangerous at high speeds, they should only be used on routers that have speed control.

Check your bit diameter against this chart
https://www.woodmagazine.com/woodworkin ... tep&page=2

 

[siggy_7]

I can see the problem you have - the mounts for guide bushes are part of the metal frame of the router not the plastic base. I would install the bit with the router plunged and use the plunge lock. You don't want to adjust the bit height in work anyway for this job - it relies on a constant cutter height being maintained.

Sent from my SM-N960F using Tapatalk

 

[Eric The Viking]

You might simply put a removable strap over the back end of the router's motor, to prevent it rising too much if the plunge is accidentally released.

I use "builders' band" for that sort of thing as it's very convenient. Cut either with tin shears or a junior hacksaw (or a Dremel). Obviously a wooden restraint would do just as well, but remember the motor needs its air cooling.
intakes.

 

[Sgian Dubh]

I also purchased a 1/2 bit advertised as for 'flattening' however the opening at the base of the router is only 40mm and won't allow the bit to plunge past.

You've purchased a bit too big for the router, one (slightly possibly) intended for use in an overhead router or even a CNC machine. I say slightly possibly because I don't know what bit you've purchased.

Buy a bottom trim bit that will fit, e.g, like one of these, or an alternative similar type at this link. Alternative sources might be Trend or Axminster.

If you need to butcher the base of the machine to make the bit you've bought work, or devise alternative cobbled together work-arounds, then that should be a clear warning sign that you're entering into dangerous territory, either trying to work outwith the capability of the machine, or outwith your knowledge and experience. In addition, Erbauer power tools are barely middling quality, let alone top of the range machines, so you need always be careful to work within their relatively limited tolerances and abilities. Slainte.