How to sharpen carbide inserts - TCMT and similar mount
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- Опубликовано: 9 мар 2016
- OK - so I'm cheap. Works on any insert with a hole in it.
Build dimensions for TCMT and similar size mount hole inserts below:
- Length 140 mm
- Diameter 9 mm
- Knurl length 48 mm
- Cross hole 3/8 "
- End thread 4 x 0.7 mm
- Thread depth 15 - 20 mm
For larger form factor inserts the end thread will be 5 x 0.8 mm
Camera: Nikon L820 
Хобби
This is a great idea. I never throw away any of my carbide inserts and have been waiting for an opportunity to regrind some of them. I am going to try your technique. Thanks for the tip!
A good tip I learnt today... if you go to a CNC type workshop, you will find that they do not sharpen any of their inserts. They simply throw them out as soon as they don't perform well. .....OR, if you ask nicely, they will give them away. Many places like this scrap all the very short off cuts of steel etc, but again, if you ask, they will sell at scrap prices.
Good idea. I like how you added a chip breaker in the process!
Re-ground inserts are what you use for all the dodgy, rough and tough jobs which have a good chance of damaging a new insert.
You've got nothing to lose and everything to gain.
These will still go through case hardening and anything else a new tip can handle.
Cheers Rob
+xynudu I use diamong wheel with a small grid for getting perfect surface
+Andrii Podanenko so do I. works great
+Andrii Podanenko It's a tungsten sawblade sharpener
+Paulman50
That's a great tip.
I will check them out.
Cheers Rob
That's a good tip Rob, thanks for sharing. You're right, those inserts are pricey, that's great you can get some extra life out of them. Looks like it cut pretty good, the chips got large when you put that relief on it.
+ShysterLawyer
The Mitsubishi inserts shown are hellish expensive, but excellent.
Grinding is tricky to do without magnification, as shown - plus you need good light and a steady hand.
But, as the insert tip is junk to begin with, you've got nothing to lose if it all goes pear shaped.
Only the bad tip will be affected, and the insert will still mount OK for the other positions.
If you check out previous videos you will see examples of my grinding on inserts that have been flogged to death.
Cheers Rob
G'day mate. Another good idea there. I think I will do that myself. Thanks a million Rob.
Yeah g'day Rob--I do something similar and I also have a couple of small 600 grit hand diamond stones which can be used to touch up as you go along..They all work alright..
Listening to the back ground noise on the video I can here the sound of many doves--its summer time for sure..
+Ian Craig
Hi Ian,
Yes, the inserts scrub up OK, depending on how bad they are. Obviously the chipped ones (as shown) are a pretty extreme case.
We are over run with wild doves and top notch pigeons here.
Some days the racket is incredible. They breed like crazy, and are always territory fighting.
Trying to shoot videos in the morning when they are most active is a real hassle.
Cheers Rob
Hey there Rob,
I read below that you have not honed them before.
It's quite easy, you don't need a power tool either, just a diamond hone/lap.
They are available foe niks on Ebay, and occasionally at Aldi. Just make sure you get a few different grits so you can work your way down to a high finnish.
Matt
+Matthew Gischus
Thanks Matt. I will check out diamond abrasives more closely.
I use diamond burrs in the air die grinders and they are excellent.
I just switched back to my 2600 grit (super fine) green stone, and am getting great mirror finish results again.
It's also more controllable as it doesn't grind anywhere near as aggressively as the coarse stone.
Cheers Rob
Great idea to hold the inserts! I was just thinking how I was gonna hold these TCMT inserts :)
That grinding wheel was not a green wheel used for carbide inserts, That is one reason why you got a rougher finish on your cutting, And you I thought were a little to aggressive sharpening it, Which will have a tendency to fracture the bits,
No. That wheel is definitely for carbide. I have two and they are both (marked and labelled) for carbide. One is coarse and one is fine. Not all carbide grinding wheels are green.
Cheers Rob
Hey Rob me fellow tight-arse. Get the word out! Shops toss their inserts or sell them to recyclers and buying said inserts at scrap price accounts for most of my tooling. Since most of us here do a lot of aluminum and casting, a bit of honing is worthwhile to get that smooth edge aluminum likes.
I've been using diamond coated lapping discs with great results. They are pretty cheap at under $20 for three. They stay flat, don't need dressing, and they cut so well you won't bother with grit wheels and stones even for roughing. I use 6 inch discs to match both my grinder and face sander. Also made an arbor to chuck them in the lathe so I can use the cross slide and compound for precision sharpening. An eBay search for "diamond lap disc" will get you plenty to choose from.
Cheers.
+Eddie the Grouch
Hi Eddie,
Thanks for the heads up on the lapping discs.
Glad to see I'm not the only one doing this.
I must get a diamond wheel to hone the edges - I'm sure they can be improved.
Also in the video I was using my coarse green stone as it was a lot faster than the fine one - swapped over the wheel and hence the obvious run out in the grind stone as I hadn't redressed it.
Thanks again.
Cheers Rob
+Eddie the Grouch
What grit number do you recommend? I suppose finer the better?
Cheers Rob
Nah. I don't shave with mine so I keep it simple :)
200-400 for shaping and general sharpening. I use a 320 because I couldn't decide. Removes carbide surprisingly fast.
600-800 for fine tuning and renewing. Okay for final on bits for steel.
1200-2000 for touch-up / final on polished bits for aluminum. Any higher is just getting fiddly for me.
While I still rough shape HSS/M2/Cobalt on a wheel, these discs are fine for the final edge. Don't use with mild steel as it will smear into the diamond matrix and oxidize it. For brazed tools and boring bars I undercut with a Dremel or cut-off wheel to clear the softer steel and brazing away from the edges before using the diamonds.
Cheers, Grouch
This is a good way to use those chipped tips, and we must all have draws full of them as they chip off at the slightest chance, (especially the screwcutting ones), however, it does make me wonder why we use them at all, unless we are turning a very hard material, the HSS tools are so much better for everyday use, and we can grind them to get a much better finish, the tips are OK for production line work when we need to change a tip and not loose position, but for home workshop they are more trouble than they are worth.
+Englishman French
I suppose we use carbide because we don't have to sharpen it so often, and we can cut dry. Laziness.
But I totally agree, except for hard metals (facing etc) I much prefer HSS, and where possible finish off with HSS.
Carbide is so finicky on cutting depth and feed rate to get a good finish.
But it is convenient having indexable cutters for sure.
Cheers Rob
+xynudu : I think the home workshop operator sees these carbide tools being use in industry, and thinks that is the modern way to go, but the reason industry use these things is because they are all, (most) using CNC, there is nothing worst than using carbide inserts when screwcutting and not having a deep enough groove on your stop, a chipped cutter is guaranteed !
+Englishman French
I know what you mean. I have a pack of threading inserts almost unused, as I just couldn't get any sense out of them for home use.
Very brittle to use.
Might re-sell them.
Cheers Rob
Rob I keep a flat 5" diamond wheel ($8 from the orient) handy just for touching up carbide. Great for brazed carbide cutters when you want to get a nice radius on the corner.
Colin :-)
+CompEdgeX
Thanks for the tip Colin.
I will get one.
Cheers Rob
I have always used a diamond stone Wittrock there's less chance of destroying it one little wobble on a grinder you've destroyed what you've already accomplished plus it's just not necessary to use a grinder
ruclips.net/video/zBND6emsSE4/видео.html
muito legal a sua idéia.
+Carlos Roberto Monteiro
Obrigado. Ainda bem que você achou útil. Saudações Rob
g`day cobber hope to see you again at trash & treasure i talked to you about a hercus lathe i like your shows i wish i could
How do you think of these Ideas, Rob?, of course I will be making one of them in the morning. Cheers
Hi Rob, any idea how you go about sharpening the carbide parting off insert? They are a different shape and don't have an hole to start with.
Hi Steve,
I don't have one of those, so no experience. My only suggestion would be to grip the insert with a small pair of locking pliers (multigrips).
Cheers Rob
ruclips.net/video/zBND6emsSE4/видео.html
I'll give it ago thanks Rob
good idea the holder, breathing in the cobalt not a good idea put some wax or oil on it to cut down on killer dust particles.
The dust is classified as toxic, so a good quality dust mask is advisable when grinding inserts.
isn't there an issue where regrinding means it's no longer all the same on each face? New indexable cutter inserts should be able to be switched or rotated to a new edge without setting up the cutter again right?
Just clarifying as someone who hasn't use indexable cutters much that you need to use new/mostly pristine inserts to get all the benefits of the indexing, right?
+Robert Szasz
Yes, that's correct. The face angles will change.
Rob
+Robert Szasz
If you want to swap cutters on a toolpost without checking the cutter height each time, then you use undamaged inserts - that's why they make indexable tooling.
The carbide in the video actually was still within the vertical index level, but the face angles were totally different (obviously).
Cheers Rob
xynudu Thanks for the reply.
I have honed them before, but haven't tried to grind them... maybe both would be a good idea for roughing bits?
+DSCKy
How do you hone them?
My belt sander won't look at them.
Cheers Rob
+DSCKy
I suppose a diamond cup wheel on my angle head pencil die grinder would be the way to dress them.
Does it make much difference ?
Cheers Rob
+Donner PartySupplies
Thanks Jim. Looks like this is a popular method by other viewers.
I've never looked any further than a green stone, because they are made for carbide, and I thought I was the only cheap bastard doing this :)
Cheers rob
Hi great vid. Got 1 question for you. Can this same bit be used ed to turn down plastic..ty
I expect so. Basically you can grind a very fine/sharp edge (which you need for poly) on any carbide with a green stone or diamond abrasive.
@@Xynudu ty Sir
@@Xynudu where do I get those kinda grinding stones
Green grinding stones are available from companies that sell abrasives, but will be expensive (and usually only available in larger sizes). I bought both of mine at garage sales very cheaply, but that's pretty unlikely to happen. The cheapest option would be to buy a diamond coated cup disc or whatever fits your power tool from Ebay or Banggood - they are not overly expensive. Cheers Rob
Hello what grit would I need for this diamond cup disc you talk about. I am looking on ebay right now.
Excellent. BUT: WEAR A MASK. As said before, carbide dust is very dangerous for your dear and loved lungs.
ouch....my ears!!!! You could use some new bearings on that grinder.........
😂