Fuller CleanUp - Share your tips and tricks

Erin Burke

Erin Burke

KnifeMaker...ish
Joined
May 19, 2003
Messages
1,330
Base on recent post to his instagram feed, I'm fairly sure that Matt Gregory will be of no help with this question :p... but for the rest of you...


... What are your tips/tricks for cleaning up your fullers?... particularly the ends of your fullers.

I occasionally like to throw a fuller onto a knife, but I'm not to proud to admit that they can be a pain in my @$$. With a little help from y'all, I'm hoping I can take some of the sting out.

So how am I currently doing fullers? Right now I mill them using ball nose endmills. My first goal is to get the cleanest finish I can directly off the mill. To my novice machinist's brain, this means a final cleanup pass with slightly higher rpms and SLOW feed. But even my best milled finish leaves tool marks that need to be cleaned up... which I take care of with sandpaper wrapped around a variety of round implements.

In the photo below, I milled the fuller with a 3/4" ball nose, and have started hand sanding. For this example, I'm using a little sanding device made from a chunk of flat bar tacked to piece of round bar of the appropriate diameter. The whole thing is covered in an adhesive-backed cork.


27216859573_b7a0a15d72_z.jpg


As noted in the photo, the real pain is getting the tool marks cleaned up at the ENDS of the fuller.

What do you use for this?

So far, I've managed to live my life without Cratex, but I'm wondering if a nice rubberized abrasive cylinder in my Dremel might be the ticket. Is anyone doing this?
My priority is to keep the fuller crisp, and I'd prefer to avoid anything that washes out the edges.

Thanks in advance.

Erin
 
I have made very few knives with a fuller, but those I have made I have had the same problem you are having. Maybe someone in the know will share how they do it.
 
i'd try cratex and then lapping compound....even a piece of sandpaper on a wood dowel as it were a round nose mill in the milling machine...i'd be desperate!!! LOL :)
I don't know if you could go at burnishing as well
 
I wonder if I can buy myself a 3/4" (or slightly smaller) ball nose Cratex point... or a 3/4" Cratex cylinder that can be shaped. Time for Google-fu.
 
what ball mill are you using? how many flutes? what feed and speed?
are you machining annealed or hardened?
let me plug your info in and get back to you with some adjustment suggestions

you might also try a Weiler nylox end brush , maybe even with some abrasive on the tip
 
Cratex is easy enough to shape. I use either a file or a dressing stone depending on what I'm trying to achieve (or what's within reach). I've not done a fuller but have a new knife design that will have them. I'm wondering about the feasibility of replacing the ball end mill for the final pass and using a single cut ball end burr. I use carbide burrs frequently and find them to be very useful. Another route is what Bob Terzuola does, he uses a abrasive wheel running (in the mill) at relative low speed with a wet cutting setup. It might be difficult to do a 3/4" wide fuller this way but seems to be good for narrower stuff. Another good solution could be to use a surface grinder and dress a radius on the wheel. I think you could set a stop for the back of the fuller but it would have to be open toward the tip. I look forward to hearing what other do.

Bob
 
HSC /// said:
what ball mill are you using? how many flutes? what feed and speed?
are you machining annealed or hardened?
let me plug your info in and get back to you with some adjustment suggestions

you might also try a Weiler nylox end brush , maybe even with some abrasive on the tip
Click to expand...


The W2 is in the condition that it comes from Aldo. I did not spheroidize myself. The grooves were started with a 3/16" flat carbide endmill so I wouldn't have to remove a ton of material with the center of the larger HSS ball nose. The rest of the shaping cuts were done right around 500-600rpm (as set on my mill) with a 4-flute 3/4" HSS ball nose. Based on the depth of the cut, I'm figuring that I had about 0.50" of the diameter engaged in the cut. Shaping cuts were probably about 0.02" per pass... feed was cranked by hand, so I can't really give you an accurate number. Just tried to keep decent chips without the machine bouncing all over. The final light pass was done with a very slow feed at about 1000rpm.
Erin
 
while you are waiting for the cratex to show up, here is a crazy idea. if you cut a 1/8" or thinner strip of 400 grit paper, and use contact cement to glue it over the face of the original mill, with light pressure and slow speed you may be able to get those lines out. if it doesnt work the cement will peel off.
 
I just sand it out. Using redline sandpaper over whatever dowel will fit. Recently, I realized while looking for something the right diameter, that my socket set was actually just a range of sanding backers in different diameters... I run the paper just a little past the end of the "block" and bump my way up out of the fuller end.
You could try some edm stones too, if you get the 5lb. assortment of random and broken stones from Falcon Tool you'll have enough stones to mess with on stuff like this to last a LONG time, for cheap.
A lot of times when faced with finish or fine shaping on detailed surfaces, I forget trying to make a machine work and just do it by hand.
 
I like "N" grade die maker's stones from Falcon Tool. Start with 220 and take it to 600, then briefly hand sand.

That said, it's way better to mill the fuller clean than to clean it up. I no longer do anything to my fullers, I just give them a lot of attention when I mill them.

9.jpg~original


That takes three cutters. I rough in many steps then clean up with a fresh cutter than take a spring pass at the same depth with a new or almost new cutter. If you try to finish with the cutter you roughed with, it will suck. I can cut about 10 fullers with an endmill before moving down the line. This needs a good cutting fluid or oil because the SFM towards the center of the cut approaches zero so BUE and a nasty surface finish can be a problem. Also, it helps to use a good quality carbide cutter. I buy mine from Lake Shore Carbide, they have accurate geometry and a good gash.

It's best to ramp in rather than plunge so I'd wiggle it in towards the center of the cut rather than an end.

Edit to add: Use a two flute, not a four. The 2 flute will gouge the sides of the fuller less when plowing and won't leave a witness mark where two of the flutes are trimmed near the point.
 
Last edited:
Erin Burke said:
The W2 is in the condition that it comes from Aldo. I did not spheroidize myself. The grooves were started with a 3/16" flat carbide endmill so I wouldn't have to remove a ton of material with the center of the larger HSS ball nose. The rest of the shaping cuts were done right around 500-600rpm (as set on my mill) with a 4-flute 3/4" HSS ball nose. Based on the depth of the cut, I'm figuring that I had about 0.50" of the diameter engaged in the cut. Shaping cuts were probably about 0.02" per pass... feed was cranked by hand, so I can't really give you an accurate number. Just tried to keep decent chips without the machine bouncing all over. The final light pass was done with a very slow feed at about 1000rpm.
Erin
Click to expand...

I would try this ...some wood / probably softer is better / in shape of HSS ball nose you use to mill fuller , and little fine Valve Grinding Compound .............
 
Last edited:
Well, I suppose I ought to give my po' boy's take on this, as brother Erin so brutally shouted out that I insist on doing EVERYTHING the hard way... :D

Nathan's methods, I'm quite certain, are the RIGHT way. I state this now, for the record, before I proceed in providing every reason I CAN'T do it his way.

My milling machine, and I suspect Erin's, as well, is tiny. Despite it being high precision and built immensely well, it's still under 250 pounds total. I simply don't have the mass and rigidity necessary to keep a ball endmill from chattering or otherwise doing the squirrelly shit that ball end mills want to do. Think about it - who the heck ever heard of a ROUND cutter!

Anyway, I mill my slot to close to final depth, then cut a single smooth pass @ .002" deep with cutting fluid, clear all the chips, and do a final pass back the other way with cutting fluid at .001".

It's still not smooth. It's never going to be with this mill, but it's what I got, and you use what you brung, bruv.;)

Next step is bead blast. Glass bead. High psi. Not a lot, really, but it chases the tops off the nasty bits a bit, eliminates any burrs that I may not get off without first dragging it through the groove with my sanding stick and wrecking my day further.

After that, it's the work that Erin is so averse to. The fullers I'm working on right now are 3/16", so I've got a piece of 3/16" drill rod which I've mounted in a file handle, and I use 3M Micron rolls as paper. It's the thinnest-backed stuff I've found, cuts aggressively if not long, and provides a great finish. I use 80 micron first, followed by 30 micron, then buff with my big buffer and green chrome rouge.

IT TAKES A LONG TIME TO GET ALL THE MACHINE MARKS OUT. I'm convinced a bigger, more stable mill will reduce this (and I'll be able to answer this firsthand when I get to the bigger blade I'm working on - I cut the fullers for it on my friend's old Bridgeport).


That's my way. As Erin has so graciously pointed out, my way sucks. It is what it is. If you're trying to make money doing this, consider not polishing the fullers, learn to enjoy sandblasted finishes, or perhaps even stonewashed finishes. I promise I won't accuse you of copping out, even though I think you are. :p

Cratex, for me, has done nothing more than create micro-ripples akin to flat grinding on a wheel if you're not perfectly perfect in your passes, and it's too easy to glance the edge of the fuller and screw shit up even more, so I don't use it.

I do things the way that I do them because I'm happy with the results, despite not necessarily being happy with the process. I'm also relentless. It will take me the better part of three hours to polish the fullers pre-HT for a 6" long blade. My hands and forearms hurt like hell afterward. Erin's desire to find an easier path is a wise one. I just haven't managed to find it, yet, so I suck it up and do it the hard way. Go with what you know!!!
 
Salem Straub said:
I just sand it out. Using redline sandpaper over whatever dowel will fit. Recently, I realized while looking for something the right diameter, that my socket set was actually just a range of sanding backers in different diameters... I run the paper just a little past the end of the "block" and bump my way up out of the fuller end.
You could try some edm stones too, if you get the 5lb. assortment of random and broken stones from Falcon Tool you'll have enough stones to mess with on stuff like this to last a LONG time, for cheap.
A lot of times when faced with finish or fine shaping on detailed surfaces, I forget trying to make a machine work and just do it by hand.
Click to expand...

^^^This.
 
You must log in or register to reply here.
Back
Top