Toolgrinding: Resharpening a gear cutter
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- čas přidán 6. 09. 2024
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I am a simple man, I see a Stefan Gotteswinter video; I smash the like button.
I look closely at the tooth pick pointer and nod in agreement. Trying to pretend I understand everything immediately. Uh huh. Yeah. Okay
A cutter with type of relief is marked on the
side ether offset or rake
and a number. This is how far tooth face was
off center when it was
new. As you said that
offset should be maintained. If the cutter
shows no offset it is 0 degrees rake and should
ground on the center line
of the tool. The offset
marked give usually 5 or
10 degree rake on cutter
face. You are absolutely right about rotating the
cutter for stock removal.
I tool and cutter grind for
a living and working on
my 52nd year in the business.
Ernie Storch
nice work! I really like thin cutoff wheels on the surface grinder but they always scare me.
Is that the best you can do. Didn't he call you out for a dual.
Come on Tony...only the un-reinforced cutoff wheels are scary....tm
Tot, That's cos ur cut off wheel broke if I remember correctly!! Lol
The public acknowledge a man as an artist.
It is his peers that acknowledge him as a master...I hope they are watching!
You are truly a master!
Stefan says dont do that, I dont do that. vielen Dank mein Herr
We are all always learning. Thanks for taking us along.
Fantastic Stephan,
I just gobble up anything you put up on your channel.
I learn stuff every time.
Anything on tool and cutter you care to put out will be apreaciated.
Don't know anyone else sharpening tools...
You have no idea what your doing, but you figure it out so well. Thanks again stefan figuring things out takes time experimenting takes time, sharing like this saves alot of time.
Great explanation on the cutting geometry at the end. Your vacuum nozzle looks like mine with all those battle scars.
I appreciate your time . Good explanation of the cutting angle
What to say! Stefans chanel will be a document and a knowlege library for generations!😀👍
Excellent explanation, thank you! LOL "precision engineered dirt" actually I don't think 3M will care
Minnesota MINING & Manufacturing, whose business began with dirt. :)
3M, manufacturing P.P.E. to the tune of billions of $$$, that's not dirt.
they might take it for their new slogan :)
very smart to use the cutoff wheel in the grinder!
Thanks for circling back and explaining how you turn the gear cutter in before removing material. That wasn't quite clear to me until you took the time at the end to explain.
That was interesting and soothing at the same time. You are a very pleasant narrator.
Best way to social distance is getting in the shop. Stay safe Stefan.
For those interested there are videos on CZcams on relief turning. Ivan Laws book on gear cutting has plans for building one
Bob Reichardt has a number of videos on his back relief lathe:
czcams.com/users/MrRock109
The "Eureka " methinks.
Thanks Stefan, great information! I have a pile of old worn gear cutters that I was hoping to be able to sharpen at a buddys TC grinder some time in the future. Now I'm not scared of trying any more :)
I really love the way you explain how the geometry for cutting tools work. Thank you for the great video.
dammit stafan. you ALWAYS give me food for thought! my head freaking HURTS!!!! poppy says STAY SAFE
G’day Stefan, I must say I was alarmed when you first dived in with that cutoff wheel but I learned something today.
Thanks for sharing, cheers.
Peter
You are an amazing teacher. Thank you for being so patient with me.
Great info. Thanks for making this video😀
Nice job Setfan. Great explanation.
Thanks!
Nicely done Stefan!
ATB, Robin
Thanks Robin!
Awesome! The drawing at the end really shed light on the geometry! Thank you for taking the time to show us!
Thank you, Stefan, for another video. You are a knowledgable man. Always a pleasure to see you teaching us how to be a better professional.
Hi Mr. Stefan, I'm a new(er) subscriber to your channel, and because of the Covid-19 virus and the results of the virus (and I'll leave it at that ;) ) ... and have been catching up on your excellent, well-detailed, and educational videos (about 3/4 of the way to catching up to your latest video). I loved your introduction at the beginning of this video... your modesty is quite admirable and if that's how you think of yourself, i don't think anyone on this plant can be called an "expert" or "master" of engineering and manufacturing!!!
"This Old Toolgrindingshop" 😂
"This old Toolgrindingshop" or otherwise known as "i have no idea what i am doing" hahaha, get your weapons out!
Mace Br He’s got to dry off his hokey gloves somehow!
Was that pulling This Old Tony's leg?!
As usual........................saviour, Cheers, Davo from "Downunder"
That looks like someone turned it in reverse and rammed into the work trying to make it cut.
Exactly what I was thinking also, with the burr coming forwards over the face it is definitely a case of incorrect direction in the cutting.
I thought so too, but what do I know?
Stefan you continue to amaze me with your knowledge of using and sharpening tools. University of SG!
I went much further in gear cutter sharpening. I ran a gear manufacturing shop for 30 years. The multiple flute gear cutters (hobbing cutters). We used a Barber Colman or ITW cutter grinder. Totally automatic and it was made in the 50s. We now use diamond sharpening tools with no coolant. A typical cutter takes 30 minutes or less to sharpen. Also we never remove more than .015" per surface to sharpen. If you have to exceed that you left the cutter in production too long.
Stefan: I never fail to learn something of interest when I watch your video's, thanks for posting
Terrific! A real nice look at these specially formed cutters. Interesting to note that you can cut off the cutting face like that and not lose the profile.
Great explanation Stefan. Is there a method for determining how far back from the centre line the wheel face should be positioned? In other words how do you determine the gap between the two lines. Cheers
I'm currently reading A Treatise on Milling and Milling Machines by the Cincinatti Milling Machine Company. This is a perfect companion video to the chapter where they cover sharpening milling machine cutters.
Thanks for taking the time to share this, Stefan! 👍
That tomb on Cincinatti wouldn't happen to be a PDF would it? Would you have a link if it is.
I seem to have some time on my hands ATM..
@@captcarlosarchive.org/details/treatiseonmillin00cincrich/page/18/mode/2up
An excellent and extremely informative video, thanks once again Stefan.
Nice job rescuing the cutter Stefan. Stay well stay safe. regards from the UK
very good video..thanks for your time
That was very interesting for me - don't have a tool cutter grinder here but I appreciate how you explained this. Would be a shame to chuck expensive (even the cheap ones are spendy) gear cutters because of a few chipped teeth. Thanks for sharing the thought process behind this!
The shot at 10:15 gave me the thought for a 'side hustle' business for you, Stefan: precision shuriken production.
With the damage on that cutter I would say they ran that cutter backwards and took a cut , bet that sounded good (plenty of base tone). There are relieve grinding attachments such as the Alston universal relieving unit, one appeared on eBay a few weeks ago.
Thanks for uploading another video that makes me lust for a tool and cutter grinder, much appreciated.
I'd be a better man if I spent more time watching this gentleman's work.
Will stick a grinder blade on the horizontal attachment of the BP and put my spindexer to work sharpening mine👍
Noooooooooooo! think of your ways! The grinding dust won't do them any favours.
Thanks for your videos,love your style,one of my favorite CZcams channels.Again thankyou ❤️❤️🇩🇰
This old toolgrinder shop aka i dont know what i am doing... was that a litle pointer to "TOT" :)
That's what I thought!! But I know TOT has respect for Stefan!
Another EXCELLENT production by Stefan! Thank you for all of your content.. I enjoy your videos.
Thumbs Up! Now I'll watch the video.
Very clear explanation.
Thanks for the lesson. I will pick up a Cubitron wheel!
They are the ducks guts! Also on the angle grinder, just a joy to use.
Stefan Gotteswinter ducks guts, yuck 😆
@@StefanGotteswinter kick it in the guts Barry!😉
Great discussion/demonstration and for 5 cents what a bargain!!!!
WHY NOT????...Make a 2 flute end mill ground to form a particular gear tooth geometry. Cut the gear in a 2 step process in the same way T-slots are a 2 step process. Regular end mill to the root of the cut for all the teeth. Than use the "form end mill" to clean up the sides. Machine clearances could be much tighter, more rigid, simpler process....( i can hear you say "yea, ok, go do it "Tuffy"...because i am not you or have your ability Stefan )....I enjoy all you do & look forward to future projects....TM
Thanks for the information - very well presented sir.
Could you do a video showing how you did the initial set up? Thanks
I doesn't take that much effort to do this much damage. ;-) I just did it to a gear cutter today in 1018 mild steel. My cutter looks pretty much the same as the one in this video. I'm ordering a tool and cutter grinder, the cut-off wheel, and the cup wheel. Compared to me, you know exactly what you are doing! LOL
I guess that having un-regularly spaced teeth might reduce the risk of chatter, and is therefore desirable. Excellent video, I learned a lot - thanks Stefan.
You are right but the cutter has to have unequal spaced teeth in the first place. If you try to grind an unequal spacing on an equally spaced cutter you change the radius (distance form tool centerline to the cutting edge) of each tooth individually.
Can't believe you didn't touch up those gullets. :)
High RPMs, gives a great result. Nice grinder..
Very informative, thank you sir.
Thanks Stefan. A very informative video
Excellent!
Excellent video, thanks Stefan!
if you get a minute stefan to have a look at Pearce machine shop he could do with your advice on tools to use for accuracy. please look.
Darn, only 15 mins. I could watch hours. 😊 BTW I already bindged all the others. Thx Steph, auto-like as usual .👌
Great video Stefan maybe think about making a video how to skeff a gear not sure about spelling new exciting wear to form a g
Very interesting, thanks.
Hello Stefan, interesting video. Thank you for sharing.
I don´t even own as much as a angle grinder, but still enjoy seen your videos Stefan :)
Did tool and cutter grinding for over 30 years you know what your doing
So taking the cutter a millimeter back will inevitably make the whole gear profile smaller due to the relief of the tooth. Wouldn't this mess up the finished product? Unless you did the same for the mating gears? So let's say the tooth has a relief of 5° at 1mm would make the entire profile almost 1/4 mm smaller correct? I am probably off, I did it in my head and not used to metric. But I dont see how this would be effective as it would change the diameter, pitch diameter, and meshing of the gears.
No, the profile stays the same all the way back, thats the whole idea behind a backrelief-turned cutter. The cutter itself will get smaller in diameter, yes, but the profile is always the same and always the same size/dimension.
@@StefanGotteswinter Oh okay cool, I didn't realize it didn't have relief to it. Is that why when you showed the wear due to excessive speed that it rubbed so far back on the tooth? And does this style generate more heat with no relief? Pardon my ignorance, I have moderate milling experience but most of my experience is in mill/turn and cardiovascular swiss machining as well as precision cutter grinding. Have you ever heard of/used Agathon grinders? I believe they are swiss made. If you ever get a chance to get your hands on one they are amazing. I regularly make .035" boring bars and .010 grooving tools with them. I notice in another comment on a different video you mentioned using molybdenum for facing your diamond wheels, do you use this in conjunction with a silicate stick to open the pores? The best way I have found is to use the silicate to knock back the binding material and then dress with molybednum to create a plane with pores still open. I have great respect for you and your videos. You possess alot of intelligence and talent shared with many people. I wish I was allowed to film what we do at work. I actually make parts for a German company called Biotronik. Pacemakers, ablation tips, endoscopic cardiovascular components, etc. But since we machine exclusively platinum alloys no cameras or metals are allowed in the shop sadly. But most of the micro drills, reams, boring bars, etc are pcd. Which is amazing to work with as long as rigidity is maintained. If you ever have any swiss turning/micro machining questions feel free to ask. It is always a pleasure to hear from talented individuals such as yourself. Take care.
With your regrinding knowledge you're really able to squeeze every last ml (0.033814 fl oz) out of your tooling.
Thanks for the lesson, well appreciated.
There’s something very wrong with your mill spindle Stefan. One bit spins backwards whilst the gear cutter spins forwards. I suggest running it always at x 4 speed as then it does not happen .......BobUK. (.... and waits for the comments on this one!)
thanks for sharing great information. keep up the good work
I think you just saved a lot of used cutters out there from being rendered useless. Good job!
On an unrelated topic... any chance of a video on hard turning (in a small shop)?
video has been done , search his vids....
I use a copper penny to rub the burr off the grind edge.
Hi again I really appreciate all your videos question for you I have a very small shop 12’ x 12’ do you think a regular shop vac would be good to collect the dust from Tool Grinding using a diamond wheel
If each tooth on the cutter is relieved and falls off, and you grind the leading edge back, isn't the new leading edge shorter than before? I guess maybe the radius of the whole cutter doesn't matter, just the profile, and as long as that stays the same, everything's good? Also curious how much you paid for that grinder? I think there was one just like that at an auction I was watching today. It went for the opening bid of $500 USD Is that an ENCO Tool and Cutter grinder 450A?
Yes, the cutter in general gets a bit smaller when you do a regrind, but the profile stays constant,
The grinder was about 1keur - Its a Knuth KSW200. A good base, but you have to put a lot of work into it, to make it a every useable grinder.
Better start giving yourself a bit more credit Stefan. For having no idea of what your doing that was really well explained (as always) and the test cut speaks for itself.
I prefer to take myself not to serious on public record ;-)
@@StefanGotteswinter That also gives a bit of room for a few semi believable excuses if ever a mistake is made as well. :-)
@@StefanGotteswinter High Fives!!!!!!!!!!
Nice video thank you
Stay safe and well👍👍🏴
Bloody brilliant, pardon my French.
It looks like it was run in reverse.
Thanks,
John
Thanks, another very interesting topic :)
Just to clarify my understanding, as you sharpen the cutter, the OD gets smaller. In use, the depth of cut would be the same, but the offset for the cutter needs to be adjusted after grinding?
Very informative video! Do you know if this sharpening principle holds also for cycloidal cutters (for example Thornton)?
Lovely... thanks for the interesting "relief" from day2day... :)
I have a feeling that even with what you paid for it and the time you put into it that you're quite a ways ahead compared to buying one new. Stay healthy over there.
It was like 30min of actuall work, without the filming - So I guess its not to bad. Module gear cutters are seriosly expensive and these days quite hard to source new. Emuge Franken still has them in the catalogue, but I dont dare to ask for the price ;)
@@StefanGotteswinter aliexpress has chinesium ones for about 8€ a piece or 70 for full set on small sizes I think but I don't know what quality they are.
Very interesting. Can you please clarify the 3M wheel name as I can't catch it in your narrative.
3m Cubitron II
125mm, 1mm thick
Judging by some things I've seen done to hobs were somebody is doing a repair on a gear with welded teeth it looks like that's what happened here. Somebody welded one or more busted teeth and tried to recut them.
highspeed steel is probably not to good at hardmilling ;)
@@StefanGotteswinter
The advantage of hobbing of course is the load is spread out across more teeth. But still trying to cut stuff hard with high speed jobs just doesnt work. I know Barber-Coleman in the US built special grinders just for sharpening hobs
well learnt lots as always. Спасибо
Thank! - Russian collusion?
Nice
I was looking for a great way to draw up one of those in AutoCAD or Fusion360 recently just as an exercise. That would be a great lesson.
gbowne1 Much simpler ways to do that. I recommend picking up the latest Machinery’s Handbook.
Hi, Stefan, I often see you pick up second hand tools and equipment and wonder if you are specifically looking for items or just scanning for potential bargins. I use ebay but struggle to find equipment. I would be interested to know what search or sites you use, is it more than just typing in "second hand gear cutter location Germany"?
Almost all of my used stuff comes from Ebay - I search mostly for auctions.
I use fixed price offers only, if I need something for an particular project right away and quick.
The rest of the used things come from a used machinery dealer close to me, its one of those places who bid on places that go out of business.
So keep cutter on center line of tool and radialy turn it into cutter gotcha, a question i had on the tip of my tongue
You touch off on the cutting surface when its vertical and then turn it into the wheel.
@@StefanGotteswinter Great video Stephan as usual, thanks for sharing and be safe.
Cheers from John, Australia.
Oh ah haha I was thinking of your drawing when you said don't move cutting wheel in. So I assume that when setting up your cutting wheel is on centre of the tool to be cut, then turn into cutting wheel to dress
Impressive.
wasn't that more like 0°02.5' that you rotated the cutter into the grinding wheel at 06:20?