I ordered this and should arrive in the next day or two. I just wonder if anyone else has tried something similar? I think only minor issue is it only goes down to 5/16 diameter but I hope it will have very little tear out.
http://www.cmtutensili.com/show_items.asp?pars=RBKHW~651-652~2~2~3
I haven’t used straight flute bits on my Maslow but single flute bits are the way to go with the current max feedrate. Two flute bits are really loud at 900mm/min. Looks like a good tool, though. I didn’t see a price on the inserts, do you know how much they cost? You could save some significant money on tooling if the price is right.
As far the bit size, 3/8" bits are very common in production work and you could get the one with a 1/2" shank to fit most standard routers. Unless you need tight radii or a narrow dado, it could very well be a workhorse.
I checked out the replacement knives and the price is in the $5~6 range.
The tool I bought on Amazon for $48 but when I checked it again the price
was $60 so I guess I timed it right. It should arrive today so I will
report on how well it worked.
For fun I decided to do the costing math. I wanted to compare its cost to other similar bits. I took the base price of the bits and checked how much it would cost with each time you replaced it. With the insert tooling, I took the base price of the tool and then used $6 to pessimistically estimate how much it would cost to “replace” the tool.
Against similar sized tooling, the insert tool is cheaper after the first time you have to replace it. Even with a two flute 3/8" bit, the second time you replace it you’d have saved money with the inserts.
Against 1/4" bits, it takes a little longer, but it provides a pretty large return over time. Compared to a 1/4" single flute bit that has 1" cutting length, you save money after buying 4 bits. The Maslow store bit with 1/4" cut length, however, is pretty economic for quite some time. You would have to have bought 10 of them to get to the point where the insert tool is cheaper.
So long as the cut quality is pretty good, those could prove to be a good workhorse! 
Not to mention with 3/8" cut diameter and a 1/2" shank, they could take a lot of side load and they could probably cut pretty deep into the material.
I was looking at those insert bits and it looks like each insert knife has two cutting edges. So, possible to get twice as much use out of each knife? If so, then the cost to replace gets cut in half!
Here is where my roaming took me…
I have no experience with this type of bit, but have some experience with lathe insert tools, and those can indeed be rotated to a new cutting surface.
I will be interested to see how these bits cut, but if no one gets to it before I need to buy new bits, I will probably just take the plunge. As it is, I am still probably a couple of weeks from making cuts with my Maslow 
I see what you did there 
On a more serious note, yes, you should be able to flip that insert to use the other cutting edge. That would cut all my previous numbers in half, and provide even more significant savings. Now it’s 5 Maslow bits before the insert tool is cheaper. I’ve already bought more Maslow bits than that… >.>
Now I’m really tempted to try these out!
I hadn’t seen bits with replaceable cutting surfaces like that before. What a cool idea! I’m excited to hear how these work…great find!
I went ahead an purchased the replacement knives and including shipping came in at $4.65 each at 20 pc’s.
From what vendor did you end up purchasing? Also, in looking at the replacement blades, there are several lengths listed for the 5/16" bits; do you happen to know if they can all be used? Or does it have to match the one for the specific cutting length (which is what I am figuring, but the way they are listed, it seems like none of the replacement blades are a perfect fit).
I am guessing I will just need to figure it out from the original blade, but being able to order replacement blades at the same time would be nice.
I took a chance on the 1 3/16 (30mm) size. I think you have to order a different wedge to use the different lengths. I think they come with the 30 mm size.
I ordered the tool from Amazon but I think it is the same company I ordered the replacement knives from which is routerbitworld.com.
Cool, thanks. I am looking forward to hearing how they work for you!
You caught me 
Very curious to see how this plays out. Bryan, let us know what inserts end up working with the bits as well. It will help greatly to see your observations.
According to my calculations, the feedrate should be about 2500 mm/min @ 10000 rpm. I based the chipload on a single, straight flute bit at 3/8". That is over the Maslow’s max feedrate, but it doesn’t hurt to start low. When I was testing feedrates on the Maslow bits, I used the ideal feedrate of 1000 mm/min but found that was significantly overloading the bit. Through trial and error I found that half of that actually works much better.
Do you mind posting what you find to be an ideal feedrate?
It looks like it will be here late tomorrow, I was hoping for today. Up will definitely let you know how they work.
Really interested in what you find out.
I received the tool and did my first cuts.
I’m going to try an offset .01" and run a climbing cut and follow up with a conventional cut to take the offset off to see if I rid myself of the fuzz. I’m still a newbie as far as wood routing goes so any suggestions to make cleaner cuts would be appreciated.
Close-up cut of the new tool.
I did order the wrong size it looks like it can only take 20mm knives but I plan on buying the 3/8 size so I can use the 30mm knives on it.
IMO, those cuts look fantastic, especially with that material.
Your material appears to be a pretty inexpensive ply with a very thin face veneer and weak glue. It will be really hard to not get tearout with that material. Tape can help with the tearout, but you’ll just rip the veneer off.
A cleanup pass like that might work very well, You should be able to do that as a full-depth pass with a very light conventional cut.
I’ll second what Mike is saying. Looks like you’re getting less top-face tearout with the new bit. It looks like the old bit is a little dull at this point, but I could be wrong. I was able to get this level of edge quality from a fresh Maslow store upcut bit on CDX ply:
All in all, though, the cuts you’re getting with the new bit are quite nice! If you want to clean up the edges you could do a rough cut like you had suggested, then change over to a compression bit for a full height final pass. That should give you clean edges both top and bottom.
This bodes well for the insert tooling, though! I will have to allocate some funds towards getting myself one.
Also, you’re very brave with the climb cuts. I’ve only conventional cut with my Maslow, I didn’t think that it would be robust enough for climb cutting. Good to know that you’ve had success with it!
Looks awesome! thanks for posting the results so quickly.
I just read the only amazon review for this bit mentioning it snapped after only a few cuts?:
What has been your experience, since it’s been a while since you’ve purchased? Also, it was difficult to really grasp exactly what worked for you, as the technical specifications of what you actually purchased (that worked) was spread throughout the thread. Just to clarify, is this what you found to work well?
Thanks for the useful discussion!
Did you compare this bit:
