Router bit wear...

[adam_m]

I was milling some aluminum this morning and wanted to post a picture of my bit after the job was complete and get you input into what causes the buildup on the bit.

So here are the specifics:

.375 oFlute
Rpm 18k
Feed 70ipm
DOC .016
1/4 6061
Using light wd-40 and air for chip clearance

Does the buildup on the bit come from to slow of a feed rate because I think it's heat and chip welding.

Can the bit be saved?

Adam,

Similar Threads:

• Wear of ballscrews
• Bit wear?
• Does a CNC wear out?
• Nut wear

[nlancaster]

That looks like reweld. Take a deeper cut, I routinely cut .04-.07 in 6061 at 24k RPM and 60-80ipm.

I only use pledge furniture polish for lube. No reweld occurs.

The bigger chip from going .04-.07 will get the heat out in the chip, not into the tool and work.

Also, what material were you cutting? Was it hardware store aluminum, because that is often 50 series wish is gummy as all hell.

[plcamp]

I believe nlancaster has made a valid point in both feed and speeds and material composition. Chip load is critical to heat removal thus reducing welding. You should probably target a chip load in the range of .006-.008 and should not be confused with depth of cut.

Cutter Chip Load (CL) = Feed Rate (Inches Per Minute) / RPM / Number of Teeth

6061 Aluminium T4 or T6 is a good all around choice

[adam_m]

Thanks for the posts.

NLLancaster, this was 6061 purchased from a metal works company online.

My setup is based around a wood router for the moment M12V and I wonder if that has some impact on things as well. I initially tried a larger DOC based on the outputs from both (FSWizard and G-Wizard) but was cutting a number of pockets and it seemed to stress over the additional material removal. At the recommended numbers from the calculators the machine choked on the initial plunge and practically came to a halt, I assumed the DOC was too much reduced it and away we went.

The feeds aren't an issue with the machine it seems to be more problematic around the DOC setting.

Anyway, Pledge is a good idea.. does it work better than WD-40? It seems like the chips just hang around with WD-40 and do not disperse from the cutting path.

With the chip welding can the bit be saved, meaning cleaned up and re-used or has it began its down ward spiral and needs to be replaced?

Adam,

[nlancaster]

Pledge does not evaporate as fast as WD40, and has a higher wax content. With just lubricant the chips are going to stay near the cutting area, you also need air blast to clear chips. Fogbuster is a great coolant and air blast system many people use, I want one.

I have no idea if the rewelded material can be removed from that bit.

[zeeflyboy]

as long as the cutting edge is still sharp the bit will be fine...

If you can't scrape the welded chips off them just grab some.... I think you call it lye over there... just bog standard stuff rather than drain cleaner with lots of other additives, and it'll dissolve the alu but leave the tool intact.

[adam_m]

OK, thanks for the input.

Adam,

[wizard]

One question about that end mill, what is the coating? I ask because some coatings are not suggested at all for aluminum. Your supplier should have info specific to the coating but it is always worth checking on.

As for aluminum welding, it does vary with the alloy significantly. Also as others have mentioned you need good chip loading and a fast spindle creates a problem there if you can't feed fast enough.

[adam_m]

This is an un-coated bit.

Yes, Feeds/speeds are definitely dependent upon one another... I'm thinking in this case I may try to pick up the feed and see how that works, also to try Pledge, good idea there.

I'm at somewhat of a disadvantage as I've never worked in a shop so my curiosity is finding out what others have experienced in relation to running a wood router vs running a spindle to cut aluminum.

Adam,

[wizard]

This is an un-coated bit.

Never would have guessed form the picture.

Yes, Feeds/speeds are definitely dependent upon one another... I'm thinking in this case I may try to pick up the feed and see how that works, also to try Pledge, good idea there.

I don't know about pledge. Often the recommendation for Aluminum is kerosene but that stuff smells bad. This is one reason why WD40 works so well as it is like 50% kerosene along with some of the oils and some surfactants. You need to use it liberally.

I'm at somewhat of a disadvantage as I've never worked in a shop so my curiosity is finding out what others have experienced in relation to running a wood router vs running a spindle to cut aluminum.

Adam,

My experience comes primarily form automation maintenance work and here we just have clap out milling machines and lathes. One thing with aluminum is that even on a manual mill with a low spindle it is possible to go too slow with your feed rate. Beyond that you need to be careful with coated mills as some coatings don't work well at all with aluminum even on a slow spindle. There are coatings suitable for aluminum, designed for even, but I've not used them on a high speed spindle. The reality is there is a lot of difference in the way that the various grades of aluminum machine so their is a learning curve for each grade that you try to machine.

Being the medical industry we work either with aluminum or stainless steel for the most part. So we are either going real fast or real slow when making parts for the machinery. Real fast here being what can be accomplished on a light weight Bridgeport type mill.

The biggest advantage you get with a real spindle as opposed to a wood router is the ability to match the spindle speeds the work via a three phase drive. you also benefit form a stiffer spindle and lower noise. When it comes to spindle speeds and feed rates you should first look at manufacture recommendations or buy a good feeds and speeds calculator or use an online version. Or write your own speeds and feeds calculator. Getting these right is important as you have no tactical feedback like you get on a manual mill. In the end getting the right feeds and speeds takes a bit of experience (which may cost you tooling getting there). There are a lot of variable when it comes down to the complete science of automated cutting.

As for hand held verses a router spindle I've used an handheld router to machine steel. It can be done but I'm not suggesting that anybody go out an do it. The point is with the right tool and cutter you can accomplish a lot with limited tooling if willing to expend tooling at a high rate.

[adam_m]

Thanks wizard for the insight, its great to hear from those working in the industry and their experiences, it certainly helps me understand what I'm up against and how to tackle it.

The actual bit number not that it matters much is a 63-625 Onsrud, I'm pretty sure they are uncoated, this one was, at least it was when I started... ha.

Adam,