Taper Ball Mills

Re: Taper Ball Mills

Postby Leo » Fri Feb 10, 2017 9:47 pm

Martin, I agree. If I were a production shop, I would buy from a known domestic vendor.

In a hobby shop, I can stock 6 cutters and be set for years. Currently, I am doing just that, stocking for years. A little at a time I am stocking up cutters and materials for retirement. Hopefully all goes well and I will have a nice little nest egg in my shop.

When I get the cutters I will do a nice 3D profile in Cherry to test them out. I may even cut a little corian.
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Re: Taper Ball Mills

Postby Rcnewcomb » Fri Feb 10, 2017 11:16 pm

Don't think I would seriously look at buying any of these bits if I ran a production shop where time is more important from a financial point of view but as I am more of a hobby type person despite being registered as a business time is not quite so important to me :lol: :lol:


I concur. When I was running a production shop the cost of a new Beckwith bit was factored into each 3D job. If the bit lasted for more than one job then that improved our margins.

Doing more hobby work I can mess around with an $18 experiment.
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Re: Taper Ball Mills

Postby Mogal » Mon Feb 13, 2017 11:13 pm

Got mine today:
Seem to be nice and sharp. Only time will tell though.

P_20170213_135036_vHDR_Auto.jpg
2.jpg
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Re: Taper Ball Mills

Postby martin54 » Tue Feb 14, 2017 12:18 am

Mogal wrote:Got mine today:
Seem to be nice and sharp. Only time will tell though.

P_20170213_135036_vHDR_Auto.jpg
2.jpg



Are those from the same seller as the others have bought from or someone different? Would be good to know who people bought them from as well as if they are good or bad lol
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Re: Taper Ball Mills

Postby Leo » Tue Feb 14, 2017 12:33 am

martin54 wrote:
Mogal wrote:Got mine today:
Seem to be nice and sharp. Only time will tell though.

P_20170213_135036_vHDR_Auto.jpg
2.jpg



Are those from the same seller as the others have bought from or someone different? Would be good to know who people bought them from as well as if they are good or bad lol


I plan to do a full write up when I get mine.
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Re: Taper Ball Mills

Postby dwilli9013 » Tue Feb 14, 2017 3:12 am

I plan to do a full write up when I get mine.

It is so hard for me to resist going into full on Enginerd mode on this site. :lol: :lol: :lol:
Most times I have had enough of it at work for 9 or 10 hours that I am glad to drop the modality in my off hours.
I will occasionally get on a rant and go all full blown. Although I have not seen the need to do that on this forum.
Everyone speaks in friendly tones and no one is made to look the fool. Thats tough to do these days especially with a bunch of guys and gals that are passionate about their hobbies and businesses.
Many times I find myself wanting to over engineer some of the pieces that I work on. Many times I have to remind myself that fine furniture and cabinets is not my gig. I actually like the wide open tolerances and datum points that I am allowed in my craft.

I do however appreciate the write ups that you do Leo as well as some others. Clear concise and deliberate instuctions so that masterpieces can be reproduced to the creators specifications.
:lol: :lol: :lol:
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Re: Taper Ball Mills

Postby Mogal » Tue Feb 14, 2017 5:00 pm

The seller is: sign_store at http://www.ebay.ca/usr/sign_store?_trks ... 7675.l2559

2p R0.5*D6*5​0 Solid 2Flute HRC55 taper ball nose endmill CNC bit milling cutter
http://www.ebay.ca/itm/172386399197?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT

I'll post back when I get a chance to use them.
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Re: Taper Ball Mills

Postby martin54 » Tue Feb 14, 2017 9:37 pm

I actually looked at them a while ago, the prices are a little more than some of the other sellers even though they are still cheap compared to me buying from a UK Company, I thing I do remember was that their pictures looked to be different from all the other sellers so maybe they are sourcing these from a different manufacturer to some of the other sellers.
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Re: Taper Ball Mills

Postby Kayvon » Wed Feb 15, 2017 6:22 pm

I've been using cheap Chinese router bits for a while now. You get what you pay for, of course. I generally purchase cheap HSS bits that I won't feel bad about tossing when they go dull. It'll help to have a 6mm collet as most cheap bits aren't true 1/4" (6.35mm). Maybe one bit in five I receive doesn't fit well in the collet and has to be tossed without using it, so factor that into your costs.

For high-end projects, I still stick with my nice carbide bits. Clean cutting edge that doesn't go dull quickly. Usually a longer cutting edge, too.
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Re: Taper Ball Mills

Postby Leo » Thu Feb 23, 2017 5:59 pm

I will consolidate all my erratic notes in the end, but for now I will post my progress even though is will be a little fragmented.

I ordered Feb 9
They arrived Feb 22

I brought one to work with me today.
Now, I work in a machining environment where we KNOW cutters.
Fellow engineers, machinists, toolmakers, machine shop supervisor, and me.
I put the cutter in their hands and said NOTHING, but I asked, How does this cutter look to you.
All good reports on visual.

The grinding looks good. I am skilled at grinding myself and I know what a good grind looks like.

I measured on a ST Industries Digital Optical Comparitor with light wand.
It is tough to measure because of the helix, but I got the included angle OK. It is spot on
The ball end was really difficult to get a good reading because the helix grind follows the ball nose all the way to center.
I can say, the grind looks like is was professionally done.

The coating also looks good. I have no way to test the coating other than to compare to other brand name tools we have and in looks equivalent.

Soo in summary for now, Visually, from a professional perspective, it looks good.

That however is by no means the end of the evaluation.

I am thinking of cutting a 3D pattern in brass and in some hard wood, maybe even an exotic wood.
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Re: Taper Ball Mills

Postby Leo » Sun Feb 26, 2017 5:44 pm

A little more fragmented information.

I decided to do my initial cut test on brass.

The brass is a free machining alloy 360 brass, not leaded.

The round in 2.25 inches.

I used the popular eagle head clip art from Vectric.

Being that I have not yet cut brass on this machine I was VERY conservative with Depth of Cut and feedrate. I kept the spindle at 8,000 RPM.

I tried cutting dry, with WD40, and with Tapmagic. All are the same, no apparent performance difference.

First I faced the top with a 1/4 uncoated 2 flute end mill.
I was cutting at 25-30 IPM @ .012 DOC.

Second I used a 1/8 tapered ball uncoated to rough the dished eagle
Cutter from Burchette Tool. Feed 25-30 IPM DOC .032
Tool chattered a bit. I attribute that to length of tool.
I left .015 for the finish cutter

Third The tool in question
.5mm tapered ball from China.
The cutter is pretty stubby.
DOC .015
Started cutting at 25 IPM - quiet looks good
Increase to 50 IPM - same result
Increase to 75 IMP - same result.
I am confident I could have gone to 100, but I am uncertain the 3 axis motions would not have been good for the machine. I am pretty conservative and I don't like to push the limits.

A short Youtube of the tool cutting at 75 IPM
https://youtu.be/C2eAAD_HU8E


Brass Eagle
Brass Eagle.jpg




My Opinion and summary

Price wise - You could not at this time use words to tell me that it is not work it. Even if I was operating a production shop where I depended on having cutters available I would still use these cutters. I would stock my shelves with cutters, to ensure availability.

Quality wise - I consider myself to be an expert in carbide cutters being that I do work with all of this stuff on an engineering level. I will deem these cutters to be on par with all but the top level most expensive cutters available. Even at that, not all that far below.

Performance wise - What more can I say. I just got done cutting brass at 75 IPM and the cutter didn't fail.

Reliability / Repeatability wise - I don't know, but based on these 5 cutters, visually, they all "look" the same and they all "look" good. They ARE CNC ground and the Chinese ARE learning to do better quality. I have a high level of confidence that they will be repeatable.

Summary - will I do it again - YES
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Re: Taper Ball Mills

Postby Mogal » Sun Feb 26, 2017 5:54 pm

I have never set up a tapered ball nose bit before.
The bits I got also do not mention the tapered angle.
Best guess I have after looking around is 7.13 degrees

Diam: 6mm
Side Angle: 7.13
Tip R: 0.5

Is it that easy?
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Re: Taper Ball Mills

Postby scottp55 » Sun Feb 26, 2017 6:10 pm

Paypal is processing my order for the Tiny set Randall linked to now:)
Based on Leo's recommendation....I hope they're the same quality.
Thanks Leo!
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Re: Taper Ball Mills

Postby dah79 » Sun Feb 26, 2017 6:58 pm

Thanks for the detailed evaluation. I thought it very interesting that you did your finish pass in a circular path. I never would have thought that to be the way to go.
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Re: Taper Ball Mills

Postby dwilli9013 » Sun Feb 26, 2017 8:56 pm

Great write up Leo.
I really like the brass piece as well that came out wonderfully.
I will purchase this set soon.
Thanks for the info. :D :D :D
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