Toolgrinding: Machine Reamer Sharpening

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[@raindeergames6104]

Life is better with a Stefan video.

[@behold.the.flux.switzerlan3536]

It sure is man

[@firstmkb]

You have a gift for teaching, backed up by a mountain of knowledge & experience. This answered questions I didn’t even know I had about reamers. The tips on how to grind if you don’t have a surface grinder are gold, and the additional ones on tuning holes a bonus. For a “quick one,” you packed a lot of value into this!

[@jdmccorful]

Ditto! Thanks!!

[@Joelsfilmer]

Stefan, this is going to be one of those misplaced and slightly cringy comment, but it can't be helped. My much loved dog passed away less than an hour ago and I'm a hollow husk slumped on the couch. During his sickness I've watched some of your old videos to get the clockwork in my head turning in a different direction. This new video couldn't have come at a better time. Thanks.

[@StefanGotteswinter]

Sorry to hear about your dog :-\

[@paulpipitone8357]

Stefan…hmm a challenge hold my micrometer lol

[@Steve_1401]

Feel for you my man.

[@snatchie715]

I can feel Stefan's Brain melting as he was trying to accurately draw the reamer face geometry, Awesome video as always.

[@StefanGotteswinter]

LOL! Yes, 100% meltdown.

[@docostler]

Stefan, the human x-y plotter. I'd check the shielding on the cable connection.

[@kastrup2dk]

Als dänischer Feinmechaniker ist es immer eine Freude, andere in diesem Beruf zu sehen. Und die Funktionen, die Sie machen. Es ist immer ein Vergnügen, ihm zu folgen. Ich hoffe, Sie fahren mit den guten Funktionen fort.

[@jameskilpatrick7790]

This kind of in-depth explanation of the tools and how to maintain them is amazingly interesting. I find that I was nearly ignorant about how reamers function. Thanks for the video!

[@hurricanehardey]

Frequently sharpening reamers this way makes sense, because the cylindrical part will start wearing a lot when the cutting edge on the front gets dull. Wear on the cylindrical part will produce a lot of friction and bad surface finishes. Same with drills. Neat trick: cylindrical grinding an end-mill produces a nice end-cutting reamer for short holes. You can get great surface finishes and positional accuracy with these things.

[@sky173]

This video answered so many questions I have about reamers. I may actually be able to sharpen some of my old ones now. Thank you for sharing.

[@HP_rep_mek]

Thanks Stefan, another great piece of information from you👏

[@2lefThumbs]

Fascinating insight, I totally misunderstood reamer geometry it seems👍👍

[@kwk8363]

Same here, turn outs they are more like drills than end mills, crazy

[@williammills5111]

Thank you, Stefan. Still more gold!

[@TrPrecisionMachining]

very good job stefan,,thanks for your time

[@wrstew1272]

Always informative, thanks Stefan!

[@angelramos-2005]

Lots of good info.Thank you,Stefan

[@paulbadger6336]

As always, well done 👍

[@OstapHelDesigns]

Well done! It’s always very interesting to learn new things, thank you! 😊

[@warrenjones744]

End Reamers, Moore talks about them in the book Holes, Contours and Surfaces. I have never seen one or at least seen one and knew what it was anyway. Anyway nice explication of things Stefan. Cheers

[@MichaelMoranGearHead]

I did the reverse. I bought a magnetic chuck to mount on my tool and cutter grinder. That way I can use it as a surface grinder. 😊

[@garysgarage101]

Thank you so much for putting together another great video, especially one that doesn’t require NASA level skills.

[@jimsvideos7201]

Thank you as always for sharing your knowledge; it helps.

[@adhawk5632]

I'm literally making an arbor right now, for a diamond wheel for grinding inserts on my mill. And i just got my first set of h7 straight machine reamers. My 10mm holes are coming out oversize. I'm using oil....(and 9.5mm drill, not 9.9)Stoked on the vid.👍👌🇦🇺

[@hansbjaeke3414]

😊 A new video from Stefan 🤗🍀😍

[@bkoholliston]

I have days where I don't feel very focused either. 😂

[@VanillahGarillah]

"If you don't have a set like this, well.....build a set" 😂

[@ryanvanderpol7962]

Great video, thanks for sharing!

[@624Dudley]

Stefan, you think up 🤔 terrific stuff. Keep on being you! 👍

[@mrcpu9999]

would've really liked to see that whole reamed again with the oil just to really prove the point. Not that I don't believe you, but seeing it would've been really cool.

[@billshiff2060]

When pressed for time and lack of tooling I just use a stone and a🍀combined with a U (horse shoe) and stone each edge as carefully as I can and 🙏 for the best. .... so far.... it has worked.... 💣

[@outsidescrewball]

Enjoyed….great mentoring

[@toddcumberland132]

I love that grinder. Again fantastic processes and advice. If only that form of surface criner was a available in the states. What a nice form factor.

[@daveharriman2756]

Thankyou Stefan, very informative, I knew about the trick of raising a burr to cut bigger, albeit bad for the reamer, and a great tip using a lap to reduce the size slightly. An old engineer when I was an apprentice here in England, like you, used to say: "Well what if you were in the desert?" lol.

[@euroman12000]

Very useful to know!

[@perrypark8485]

By the way, the low profile DTI was fantastic

[@richardjones2151]

SUPERB (again!) thank you :-)

[@rootvalue]

Using the directional flexibility of the scale is so clever.

[@MarkW321]

Cool!

[@jorgeconcheyro]

Wow,I just learnt something new about how the reamer cuts material. Never thought about the 45° from. Thanks mate!!!!

[@mce1919A4]

Thank you.

[@ErikBongers]

I'm sorry, so much information in one video...things got blurry at the end.

[@emiliog.4432]

Good stuff. Ty

[@adam19890911]

Really informativve, how about if you cut with the reamer dry, would it cut plus or minus?

[@thanos_vgenis]

Before the elaboration on reamer geometry and the 'grind only the front' I was feeling very stupid thinking that you would use your indexing fixture to grind flutes in a manner incomprehensible to me.... Thanks for the explanation!

[@campbellmorrison8540]

I didnt realise it was only the leading edge that was sharpened, that explains how you can sharpen a reamer without affecting its diameter. So what I'm wondering is how do you know the leading edge is blunt? and how do you know when the flutes are warn? ( Im guessing when the hole doesn't ream the right size but that would mean having to check each hole wouldn't it? )

[@djizomdjinn]

"Now that you know it's possible, never use it." 🤣

[@Andrew_Fernie]

I ground up a set of flat stones in the mill using a diamond cup wheel. The only downside is the million turns of the crank

[@MrZX1206]

That cut on the second flute sounded like it took a big bite, bigger than the others.

[@TheDaumen]

I thought I might like to have a Kopal clamp after seeing you use them a few times. I just looked them up on Hoffmann. About 450€ for the base clamp. Ouch.

[@StefanGotteswinter]

Oh boy, they are expensive, yes. Definetly try to get them at the used market if you want one - I would never spring for the money to buy one new.

[@alungiggs]

Hello Stefan. I didn’t mean to be rude by not contacting you sorry. I don’t have telegraph unfortunately and I wasn’t sure what to do. Just wanted to clear that up. Now back to enjoying this video.

[@2lefThumbs]

🤣

[@markmuranyi9289]

Same here.

[@StefanGotteswinter]

All good :-)

[@lesenundverstehen8831]

So grundsätzlich hast du das echt gut gemacht 👍🏻. Wenn man sowas professionell und manuell nachschleift nutzt man ebenfalls einen stützfinger während man es zwischen spitzen spannt. Das einzige: dein stützfinger ist ziemlich breit. Es sollte so nahe wie möglich an dem zu schleifenden Zahn liegen und dann relativ dünn. Quasi die Hälfte von dem stahmaßstab nochmal weggeknipst

[@StefanGotteswinter]

Danke! Guter Hinweis mit dem Stützfinger, dankeschön.

[@MI-vf5zs]

For some reason I have terrible luck with reamers, it seems that an H7 reamer will barely produce an H9 hole in my use. I suspect it's due to machine rigidity, they seem to work better in our drill press and manual lathe, but whenever i put one in one of the VMCs I get terrible results. But sometimes an H9 is fine and a reamer works for that.

[@Der_Edelpfuscher]

Ich dachte eigentlich immer Reibahlen nachschleifen, geht ja nicht, dann wird die Bohrung ja kleiner. Aber jetzt bin ich schlauer. Weißt du zufällig auch warum Öl oder KSM die Toleranz verändern, das würde mich noch interessieren. Danke fürs Wissen teilen🖖

[@peachmunich]

I have no luck with reamed bores. They are always 1 or 2 hundreds of a mm to big. I use good new reamers, the proper RPM and water soluble coolant. Thendrill chuck is also a good brand, but a little old. Is the chuck spinning out of center axis?? How important is the predrilled bore diameter? Should it be as close as possible to the final diameter? I'm a hobbyist. Thx for any advise 😊

[@MegaRiffraff]

👍🏻

[@johnsmith-zs9jq]

Guy Lautard's Machinist's Bedside Reader #3 has some info on sharpening reamers by hand. Kind of like a knife sharpening jig.

[@StefanGotteswinter]

It has been some time since i had that book in my hands - is that a fixture for chambering reamers and hand reamers with a long tapered lead?

[@johnsmith-zs9jq]

Yes it is but, I don't see why you can't use it for straight reamers too.lautard.com/t3.htm

[@David_Best]

Did I miss the "hotdog in a hallway" alignment tolerance somewhere ? LOL

[@jimh2887]

He could make video on how to butter toast and I'd watch it😊

[@Kylemachineworks]

Thanks you for the video, I will never do this.

[@StefanGotteswinter]

like you will never do scraping

[@kylewarren69]

@@StefanGotteswinter I would never do something like that (ignore my dms)

[@TheUncleRuckus]

Nothing really to say, just an obligatory algorithm boost 👍👍

[@SailingYachtDreamcatcher]

💪✅👏👏👏

[@sinisatrlin840]

Highly creative, congratulations. What would be smart (easy) way to make reamer conical by 0,2mm on 50mm lenght (10mm, machine reamer)? Going to professional tool grinder shop, waiting 15 days and paying many $ is something i would like to avoid if possible.

[@BasementEngineer]

What is the taper for? To provide relief behind the cutting edge, or to make a taper hole reamer? If the latter then the tapered portion must be sharpened so as to produce cutting edges, similar to sharpening the helical cutting edges of an end mill. This is a more complex and time consuming operation than sharpening a machine reamer, as described herein.

[@sinisatrlin840]

@@BasementEngineer To make slightly tapered hole. I know that it is complex, othervise resharpening new existing reamer by professionals would not cost almost as same as new factory made on order. 1: 10 and 1: 50 reamers are standard on stock items that are available for reasonable prices, good used ones also. But anything not standard is problematic.

[@BasementEngineer]

@@sinisatrlin840 You could try making your own, if the work material is not too difficult. Look up clock maker's reamers and tool maker's reamers. Drill rod such as W1 or O1 would suffice; the heat treatment thereof not difficult.

[@sinisatrlin840]

@@BasementEngineer Maybe it would be easyest way to regrind existing 1: 10 reamer, it has flutes that are quite deep on thicker side. Will look into it. Good used 1: 10 reamer is 10$, sometimes 5$.

[@cda32]

Why does oil make the hole larger?

[@StefanGotteswinter]

unclear why. Just observation over years and shared experience with other machinists/toolmakers

[@tabaks]

Higher viscosity...higher cutting pressure localized at cutting edge/cylinder as a result?

[@solutionreplays6622]

could you free hand it?

[@TheDr1Acula]

A D-bit grinder with a similar indexing fixture should work as well, shouldn't it? If the flutes are evenly spaced, you might even be able to get away with the built in indexing head.

[@BasementEngineer]

It is not safe to assume that the cutting edges are evenly spaced; some manufacturers deliberately space them unevenly to reduce the likelihood of chattering. It is important to locate the cutting edge off the flute being worked on.

[@TheDr1Acula]

@@BasementEngineer Yeah, which is why you'd need a similar indexing fixture with a finger that snaps into the flute, for unevenly spaced ones. A piece of feeler gauge stock in a magnetic indicator holder could do the trick. The only hassle I can see with a D-bit grinder is indicating the first cutting edge properly.

[@FesixGermany]

Could you please avoid audio only on the left channel during timelapses? As a headphone user this is not very pleasant suddenly no audio on the right and suddenly having audio back. Thank you!

[@StefanGotteswinter]

Whoops, yes - I have to see why davinci does that.

[@BigBoss-rh7zq]

I would expect you grinding the side of the reamer....

[@BasementEngineer]

Only on hand and taper reamers.

[@somebodyelse6673]

Wait, wait, waitwaitwait. A sketch that's not on graph paper? I know it looks and sounds like Stefan...

[@greglaroche1753]

I’ve been receiving texts on your telegram , saying that I won an iPhone. Is there any truth to them. Please let me know, so I an spam them if that is the case

[@StefanGotteswinter]

Absolutely Spam - I will never do something like that. Its spam bots, that I am trying to get rid off. (I do not use telegram)