Speeds and feeds for surfacing bit

Hi All,

Been a while - things have been going ok, with the machine until I tried to make a batch of trays yesterday.

Cutting about 14mm deep pockets and using my 1-1/8’’ Amana 3 flute surfacing bit to hog out the bulk of the material. This particular cut was a hard Blackwood. Ive had issues in the past with burn marks on my wood duering the ramp moves, but then nothing during the full speed cut. For this cut, i kept the feed and the plunge rate the same to try and avoid the slow ramping (spoiler: it didn’t help).

There was a horrible smell during the cut and once completed, i noticed that it wasn’t just the wood i could smell, but my Makita router had started smoking and was extremely hot to the touch.

Please could someone help with advice on getting the surfacing bit working for me. Such an important tool in the arsenal. Below are photos of the burn marks as well as my tool data from Vectric Pro.

Would love to hear any advise please. Possibly need a new/different bit as well? Feeds & Speeds way out for hardwood?



The fan speed is the same as the spindle speed, if you are running it at low RPM that will reduce the cooling of the router. Also if the brushes are getting near the end of their service life they will begin to arc more and can cause excessive heat, sparking and smoke from the router. The router is rated at a max of 1.25 HP which might be insufficient for the load the bit is placing on it - you might be able to achieve the same material removal rate with a smaller bit and larger DoC value that will require less torque from the router.

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The makita router is not strong enough to push this bit. It struggles to push the 1/4 bits a full speed so anything bigger than that is going to be a strain on the router. There are countless posts about people burning up the makita and almost all of them did it while using a surfacing bit. I would only use the surfacing bit to surface your wasteboard and use smaller bits for everything else.

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Agree with above. Interesting, i would not think of using a surfacing bit this way due to its name. So a good experiment, push the envelope.:smile:

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Hey Kyle,

this is not the right bit for this. I would mill such pockets with a 8 mm bit, not a 29 mm bit. And at 24,000 rpm.

Also the milling motor you use is not made for this, neither for such large diameter bits, nor for stationary use in a cnc machine. It’s a hand router!

I fully agree with what the others said.

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Thank for the reply and the useful info. I was doing my pocket clearance with a 1/4 em - but I found it was taking a long time. On small pockets [especially with 90 degree corners ] I’ve had to slow my feed rate right down to about 80 or 90 ipm to avoid the machine jumping off course. Not sure if it’s incorrect jerk setting or what I should be looking at, but on short toolpaths with high feed Rate, my machine goes completely off path. Are the default jerk settings on the 1f working for most people?

Have been told to run my 1/4 em at 200imp through Birch plywood by onefinitycnc themselves. Worked great for bigger cuts with long straight edges, but small shapes with sharp corners at that speed was a disaster. Machine was pushed off course and then tried to continue the cut in the wrong place.

Will be running tests , but as a starting point. What would you suggest for feed, speed and DOC for a 1/4 endmill to hog out these pockets in a reasonable about of time?

Was thinking of time saving. Don’t think I’m running my 1/4 em fast or deep enough so this type of clearance is taking a bit too long for me. Have definitely seen it done online somewhere so thought I’d give it a go.

I have been wanting to do some detailed 3d carves recently where the 3d object sits proud of the surface.

fish sushi tray as an example.
image

What sort of bit would you use as a clearance tool here?

I guess I’m struggling to see the difference between surfacing with the bit and doing pocket clearances.
The feed and speed is the same, I’m taking shallow passes as I would with surfacing and the cut duration is also similar. How is it that a makita router can handle this bit only for that?

Never seen an 8mm bit- especially not for a 1/4 inch shank. Please send a link if you have (although I’m in South Africa).

Also don’t really understand your comment about the motor not handling this bit at all. Hundreds of users on here surfacing their wood with a makita trimmer and surfacing bit? You saying surfacing should only be done if you have a spindle and not the makita?

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Hey Kyle,

What I meant is approximately 8 mm. You could also use 1/4″ (6.35 mm) or 3/8″ (9.525 mm). What I meant is that for milling pockets, I would consider a 1.125″ (29 mm) bit as much too large.


Goran tek-en, CC BY-SA 4.0, via Wikimedia Commons

Milling bits in Imperial/U.S. Customary units are uncommon in Europe, and at least as far as I know, elsewhere too (except USA and Canada). Here we commonly use bits with 6, 8, 10 or 12 mm shanks on ER collets (that I buy from spindle manufacturer), and the Makita hand trim router is sold outside U.S. with 6 and 8 mm collet:

Makita.co.jp__Routers__Catalog_page
www.makita.co.jp: Routers – Catalog page

Makita.de__RT700C
www.makita.de: RT0700C

You are used to use metric units in South Africa I assume? Maybe because you have imperial history and also many goods are imported from the U.S., you use imperial units too?

Economy_South_Africa

We mainly sell to U.S. rather than to buy there:

Economy_Germany

Of course here inch collets are also available (for both trim router (UK version) and ER spindles) for those who want to use milling bits from the USA, but it’s not that common.

I think you can achieve surfacing the wasteboard with such a large bit in the hand trim router, and sure, many do, but surfacing the wasteboard means removal of only shallow depth. I would not use such a bit for milling pockets, especially not with high plunge rate. I would use an end mill (which is good for plunging) and a high speed.

Also keep in mind that the hand router has only approx 0.75 kW power (which due to poorer efficiency of universal motor in comparison to spindle induction motor only corresponds to 0.5 kW spindle) and a 1.125″ (29 mm) surfacing bit is a very large diameter. Usually in normal use of a hand trim router you don’t use bits larger than 1/2″ (12.7 mm). It’s simply too much couterforce with such a large diameter bit for the weak motor, at least when you try to do deep pockets.

Also what I meant is that the trim router is not made for longer and/or stationary use. I did not buy one for use in the Onefinity.

My comments about the motor not being strong enough is from 2 years of observation and experience burning up the router using a surfacing bit. The router can use the bit it just does not handle the mass well. The hp of the makitia will not handle long uses of the weights of these bits and will burn the windings out trying to do it. I would suspect that any bit larger than 1/4 at the head is going to give the makita issues in the long run. This would include large vbits and bowl bits.