Carbide Grinding Service - any recommendations?

["Tommy"]

Hello everyone... I have a question...I am using a 6 wing carbide cutter (drawer slot cutter). It is 2" diameter with a 1/4" shank. I have been getting the dreaded barber pole effect on some shafts. I tried slowing the feed down substantially...it helped a little. Then I ordered DMT Dia-Sharp Credit Card sharpeners. (diamond stone) They worked really well...I got the 325 and 600 mesh stones. It got my carbide blades really sharp. (highly recommend them) So...I just knew I was going to get a smooth cut. NOPE...still had the barber pole after cutting another shaft. (not as bad as before sharpening) After inspecting the blade I noticed that 2 blades had some buildup on them and all other 4 blades are perfectly clean. So I have came to the conclusion that I need to get my carbide bits ground evenly. Does anyone have any suggestions on where to go? I have unsuccessfully tried a local tool sharpener. I would like to find someone who specializes grinding carbide bits true to each other and does good work (for a reasonable price would be great also) I would also like to purchase a couple more of these cutters if anyone could recommend where to purchase them. Any suggestions would be greatly appreciated !!!
Thanks,
Tom

 

[conetip]

Any saw doctor company should be able to sharpen that for you. Price wise I don't. Sometimes new cheap cutters are about the same price as resharpening an existing cutter.
Joey might chime in.
Neil

 

[JoeyInCali]

http://farrstools.com/
Send em there. Tell them you want them OD'd too.
Send with your arbor .


My slot cutters are 1 7/8 .
http://www.magnate.net/ProductDetails.asp?ProductCode=4001

I have Freud too . They are 2" in diam and a little more messy b/c they really sling the chips.

Yours look pretty heavy and too thick for my liking. You will get more push-off with those unless they are really sharp.
Imo, they put too much stress on the woods too.

 

[Dave38]

OK, first thing is to ask what your feed per inch is, plus your rpms of the lathe. Barber pole is usually either too fast of a feedrate compared to the RPMs of the shaft, or there is dull, or uneven blades, or worst, BOTH. If the shaft RPM's are spinning too fast, and the feedrate is fast, it will bounce the shaft as you cut causing this effect even with sharp teeth.
Just for haha's, chuck your cutter in your lathe chuck and use a dial indicator first on the mandrel, make sure it's spins true right where the cutter sits, then mount the cutter and see if there is slop between the shoulder it sits on and the hole in the cutter. It should be a tight fit, if not, that could be the issue or a contributing factor. Next, if it fits tight, use the indicator on the tip of each blade and you may find a .010 to .020" difference between all the blades. If they are all with a .001, .002 of each other, you got a good one, if not, throw it out. Now you may also have bad runout on the router also, which can make everything worst as the accumulated runout on the mandrel, blade, and the router spindle can make it impossible to solve the issue until all is changed. I have tried to remachine the mandrel you show, but finally gave up on these 6 wing types that are sold by a certain vender, and now use a quality 3 wing cutter with a custom made mandrel, and will still occasionally have a blade out of tolerance, but no where near as that 6 winger you show in the first post. I could guess who you got it from, but won't.
Hope all this helps a little bit, good luck,
Dave

 

[scdiveteam]

Take six minutes travel passes. @ .010 and play with your lathe rotation speed. Slower travel put less shock or stress on the wood.

Start with 150 rpm and go up or down from there till you find the goldielocks setting combo. Slower is better but you need to experiment. Also set the elevation of your cutter so it is above the center line of the bullet. This way the edge of the carbide just touches the work and when you wear out the tool on the bottom edge, you can change the elevation so you work the top edge below the centerline.

Good Luck

Rick

PS. If your lathe lowest settings are too fast, you may have a machine that can not do a good job. The best set ups have variable speed set ups with dc motors and controllers or cnc.

 

[GBCues]

I also use 6 wing 1/4" slot cutters. My experience is I get the best result when I spin my shaft at ~300 rpm and a feed rate of 5 in per min. Roughing cuts I use up to 20 ipm, but the last few passes I take off .005 - .002 at the slowest feed rate.
Hope this helps,
Gary

 

[whammo57]

I spin the shaft at about 300rpm and feed 8 to 10 ipm............ I like a 3/4 in 2 flute straight bit,,,,,,,,,,,

the bit must be razor sharp, gibs tight, router bearings smooth, everything lubed............ you must still tune it on your machine.............

some days I must adj some of these settings for the smoothest cut


Kim

 

[JoeyInCali]

I spin the shaft at about 300rpm and feed 8 to 10 ipm............ I like a 3/4 in 2 flute straight bit,,,,,,,,,,,

the bit must be razor sharp, gibs tight, router bearings smooth, everything lubed............ you must still tune it on your machine.............

some days I must adj some of these settings for the smoothest cut


Kim

I must be getting senile, but I thought you ditched those straight bits for slot cutters.

Tommy, I thought Alex used a thin-kerf 6-winger .
If you insist in using that 6-winger, I suggest Whiteside 6801.
http://www.amazon.com/Whiteside-Router-Bits-6801-Drawer/dp/B0012JI6AY
It's smaller but it's screwed on. Use one arbor. Send the arbor and the bits for sharpening. They will be as consistent as can be that way.
Your arbor has a little slop between the hole of the bit and the shank.
They will have some variance and run-out .
Worse, I think it vibrates too much b/c you have too much weight near the end of that arbor .

Take six minutes travel passes. @ .010 and play with your lathe rotation speed. Slower travel put less shock or stress on the wood.

There will be less stress on that wood in taking a 3-minute pass taking out .010".
Give me a break. You're just massaging that wood with air at that speed.
.005" per side with a six-winger spinning at 25K or more is plenty for a 3-minute pass.

 

["Tommy"]

OK, first thing is to ask what your feed per inch is, plus your rpms of the lathe.

Just for haha's, chuck your cutter in your lathe chuck and use a dial indicator first on the mandrel, make sure it's spins true right where the cutter sits, then mount the cutter and see if there is slop between the shoulder it sits on and the hole in the cutter.
Dave

Not sure what the feed per inch is set at. From what Alex had it programmed for I slowed it down to 60% with not much improvement. I will check into what it is set at. As for the rpm of the lathe it is 450. (slowest it will go) Alex used to do all the cutting so I am learning as far as using his CNC.
Thanks for the advice, I will check mandrel and check for for slop on cutter hole.

 

[JoeyInCali]

Not sure what the feed per inch is set at. From what Alex had it programmed for I slowed it down to 60% with not much improvement. I will check into what it is set at. As for the rpm of the lathe it is 450. (slowest it will go) Alex used to do all the cutting so I am learning as far as using his CNC.
Thanks for the advice, I will check mandrel and check for for slop on cutter hole.

He mentioned he used to cut in less than 2 minutes.
But, the cutter he used was a much thinner one from Lee Valley tools.
Maybe Mason knows.

 

["Tommy"]

Tommy, I thought Alex used a thin-kerf 6-winger .
If you insist in using that 6-winger, I suggest Whiteside 6801.
http://www.amazon.com/Whiteside-Router-Bits-6801-Drawer/dp/B0012JI6AY
It's smaller but it's screwed on. Use one arbor. Send the arbor and the bits for sharpening. They will be as consistent as can be that way.
Your arbor has a little slop between the hole of the bit and the shank.

Alex has used many different types of cutters but the one I pictured seemed to be his favorite and most recently used. He had success with it cutting smooth which baffles me with the uneven blades. Good point with the suggested Whiteside cutter and how it screws on. I think I will try one and send it in with my cutter pictured to the place you recommended getting the cutter "ODed" / sharpened. Do you think the Whiteside cutter being a smaller size would also be too heavy?