Lathe Trepanning - 99.9% Not Brain Surgery
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- čas přidán 9. 06. 2024
- G'day everyone,
As the title suggest, today we will not be delving into the subject of archaic medicine (also called trepanning), but instead we will be looking at a more efficient way of creating large holes in workpieces. I am looking to create a few mounts for some nema 23 stepper motors (for a project that may or may not materialize). The holes I need are roughly 38mm. That is a relatively large hole. A hole saw is not great in steel and boring it to size would take a long time and would waste a lot of steel (although it is the method I was planning on using).
Trepanning seems like a good method to try out here. Trepanning is like parting, expect we are parting on the face of the workpiece. Because the only cut we need to complete is a thin groove, the cut can be done quicker with less material wasted. I will grind up a tool and attempt to cut aluminium and steel.
I also want to take a look at annular cutters for cutting smaller holes, roughly 18 mm and up. I have been recommended them for quite some time and given that I am going to be making a few extra die holders, I though that annular cutters would be the perfect tool for the job. In addition to testing them I will also make up a basic tool holder to use them with. I hope you enjoy the video.
#machining #annularcutters
Annular cutters
Annular cutter holder
Making an annular cutter holder
Trepanning
Lathe Trepanning
Timestamps
0:00 - Introduction
1:57 - Tool Grinding
3:04 - Lathe Trepanning
7:41 - Making an Annular Cutter Holder
15:16 - Testing The annular Cutters - Věda a technologie
Proud graduate of Hollywood Upstairs Medical College
Call your accountant and tell him you've finally discovered annular cutters. There's no way back now 👍
Congrats! 🤕🤣
Hollywood Upstairs Medical College gotta say hahahaha nice Do you also provide Imitation Botox injections ?
Now I don't have the knowledge or tolls to test the claims--
I've heard a good source of rods is Photocopy - printers - fax machines
Suppose to be quality ground rods
artisanmakes, AKA Dr Nick!!
The trick for the brain surgery version is getting the workpiece chucked up in the lathe.
best comment so far......hah
One thing you could try: instead of the positive rake you ground on the tool, try neutral or maybe even negative rake.
The cutting edge will not only be stronger, but will also be less prone to be pulled into the material, thus be less likely to chatter or snap. Also, if anyhow possible, try making your clearances only as big as they need to be. Towards the inside of the hole your cutting, your tool goes straight down, right? If you'd grind it so that the inside would also follow the curve you're cutting, you'd get more cross secrion, and therefore a stronger tool. And every square millimeter helps, so even dishing it out just a little will improve your tool.
Just to put the price into perspective - let's assume you need to drill 100 holes.
73 seconds per hole for the annular cutter. 7,300 seconds in total, which is 2 hours and 2 minutes. ~300 seconds per hole for the deming bit. 30,000 seconds in total, which is 8 hours and 20 minutes. That's saving you 6 hours and 18 minutes.
You paid $70 for one annular cut. That puts an estimated hourly value for those 100 holes made with the annular cutter at ~$11.10/hour, if we assume that the deming bit were free of charge. If you put the value of your own time at more than $11.10/hour, the annular cutter is worth it.
This doesn't take the amount of material saved into account (as the pucks can be used for other things, and the cut-off point also depends on the number of holes you expect to cut. It also ignores opportunity cost, because if you have a project in mind where you'd need to make just 12 holes, the hour you'd need to spend making them with the deming bits might just make you forego the project entirely.
I use anular cutter all the time use water to cool your bit it will last longer than oil
Whoop, it's This Young Tony again with a gem!
Not to mention trapnning is also used for ‘o’ ring grooves in faces
what aboout ahh rings...or boxing rings?
@@TalRohanAhh rings are done with a large tool, prefferabley an extremely expensive bench tool, simply drop it on the floor and the groves will appear permently on your face.
As for the boxing rings, well those appear spontainously in the presence of an cartoon protaganist after a challenger appears, for best results spend a season building up the match.
@@AnonymousAnarchist2 ROFLOL love it, the last Ah ring I made was when I lifted an anvil with an engine crane and mistakenly thought hitting it with a hammer was a good idea...my ears were ringing for several minutes ...something of an AHHHH the ringing....🤣
Awesome video.
I will note; I believe that the hole in the end of annular cutters is usually used for flood coolant; which will Also push the puck out.
Any kind of center or pin or drill bit should allow you to center the hole location before you swap the annular cutter into your tailstock or mill.
Cutting Edge Engineering had a video on an aftermarket tailstock flood cooling attachment he found; tgo for a mini lathe, you'll probably need to adapt that & make it yourself.
If anyone wants to dive a bit deeper into how trepanning is implemented, look up David Wilks and his videos.
He used to trepann Inconel and other difficult high value materials and made it look easy.
These days Trepanning isn't as common as it used to be, since machines are so powerful that you an easily drill big holes and bore to size and you can't easily automate the process. You also need to find use for the material that is left over, which usually isn't economic unless the material is really expensive.
Dave's videos are a big miss, he certainly was the master of trepanning and of making the tools.
Just as an aside, if you're ever single point trepanning through a piece of steel plate, stop the process just before you break through and tap the slug out with a hammer. This stops the slug binding up and snapping the tool, BTGTTS !
You are so right
@@graemewhite5029 Hello, do you know what happened to David Wilks, hope hes ok ?.
@@rogerwilliams2902 Hi Roger, I'm not sure but heard a rumour that he hadn't hit it off with the people he went to work for after he shut up his own business and the only comment I've seen from him was on a Haxby Shed treppaning video about two years ago where he said he was unwell, but hoped to be picking up soon ?
Whatever the case, I hope he's doing well and sinking a few John Smith's !
In a professional setting, I would agree, but for a hobby machinist, those little pucks and cylinders are going to be quite useful and often money is more valuable than time, compared to a professional setting where time is what your selling.
I think I learn more from these experimental videos.
I use angular cutters a lot in mag drills i my line of work
and they are magic
To help with the birds nest i tend to peck at the part it seems to have no negative affects on the part or bits
Scrolled down to look before suggesting peck drilling. I find it very helpful too.
As a data point I made some simple holders for my annular cutters - basically just a close fitting socket with a locking screw to bear on the annular cutter flat. Then a 18mm round shank with three shallow flats to prevent twisting in the tailstock chuck. Runout is minimal. I don’t use a plunger either as plugs tend to fall out due to the relief ground on the inside of the cutters. Clearly yours is far more video-worthy however! Interesting findings.
For using hole saws on anything thicker than it's own teeth, wood and steel.
Start cutting then when you have the circle drill one or more chip evacuation holes in the circular trail and keep the big side of the hole innside then the chips will fall nicely down through the hole without blocking the cutter and you won't need to lift it all the time to get away the chips
Great tip. Works especially well on wood because cutting oil can make the chips stick to the teeth and fail to evacuate through a small hole, but still worth a try. Small correction, the critical thickness is less than the depth of the teeth - it's the depth of cut that starts to lead to chips packing in the gullets, which is typically about half the tooth height but depends on the tooth geometry. It isn't much, anyway!
For hole saws on thicker plate, first of all you need an absolute flood of coolant, as well as dropping your rpm a lot. For chip evacuation, you can drill a small hole in the path of the cutter, so the stuff that usuallly gums up the teeth has somewhere to go. You will still need to clear up the channel when it gets too clogged, but its far less frequent than without the hole.
Source: have had the displeasure of using hole saws far too often on 316L plate
Agreed. The tangential evacuation hole makes a world of difference--in both wood and metal!
You are that’s what I can’t do on my mill. Once it drops below 4-500 rpm the torque takes a real nose dive and it’s very easy to stall it
@@artisanmakes so first job shoud be to make additional set of pulleys, that will drop rpm and increase torque :)
That’ll be the way to go. The top end of the spindle uses a custom spline profile to connect to the pulley/drive belt and I have to gotten around to making the broaches for it yet. Cheers
@@artisanmakes Can you fix new pulleys to existing ones?
So you escape spindle and it's profile...
Here are two tips for drilling holes accurate to size and clean finish, without resorting to boring or spending good money on reamers:-
1. Feed the drill bit in until reasonable size chips come out. Then back the drill out briefly and allow the hole to be reasonably chip-free, then feed the drill in again. Repeat as required for the depth of hole.
2. I have a set of drill bits in 0.1 mm increments. If I need, say, an accurate clean finish hole of 23 mm diameter, I first drill with a 22.9 mm drill bit, then take the hole to size with a 23 mm drill bit. This gives a reamer-like clean hole and spreads the wear in drill bits you wouldn't otherwise use much.
Love this young Tony
Ha. Before the video turned to them, I was gonna suggest those (annular cutters). I got some "cheap" ones from "Vevor", which turned out to be quite good (even up to 2 inch). I just put them in a collet, since I feel the pin hurts more than it helps. Great job!
I have looked at them many times, but have not pulle dthe trigger yet, how long do they last before they get dull, is it something like a big drill bit, or do they last longer?
I can see there are both HSS and carbide models to choose from.
@@christiantrab6160 You can resharpen or get them resharpened once they get dull. Only used mine twice on aluminium and they are still sharp as is so can't really give you an answer as to how long they take before they get dull.
Nicely shot video. It took me back a ways. Trepanning can be an education in the causes of chatter. Retired prototype machinist here.
Chatter always have just 3 "To" reasons...
To high speed
To low feed
To wide tool
The trick is just to find right corelation for your specific machine.
And in this case.. 4-th rider is low rigidity of the machine.
But.. poking around with first 3, and not be too greedy, should give you a good result.
Been there, done that, with even smaller lathe.
i havent adopted a lathe yet, and at the time neither had i a milling machine.
but i remember buying two of those with carbide inserts brazed to them, because i had to drill 25mm and 26mm holes in a 20mm thick aluminum plate..
and i have to say they worked perfectly. not only can i say that the price was alright compared to the one time use hole bores, but also was the diameter so much more accurate. they fit perfectly and snugly, not oversized in the slightest.
I like them
Great video and great demo. Trepanning takes nerves of steel, the annular cutter just melts that anxiety away, cheers!
Really well produced video, and really nice lathe/mill work.
Tip for hole saws on deeper holes, drill a small hole along the circumference of the cut on the side that is the waste part. Main trouble hole saws have is clearing chips, so a few holes allows for better evacuation
Think I watched a trepanning video where the tool was used to cut inside clearance. It makes a wider groove but it worked. The method was... cut some of the outer dia. then move inward to cut the clearance area. Then you can move out and repeat. Wonder if it would work for you.
Thanks for this! It was very painful to turn brass into chips a few days ago. I had to make a bushing that had an OD of 2.300"/58.42mm, an ID of 1.885"/47.88mm and a depth of .875"/22.23mm. I hated to scrap that much brass. The workpiece was 2.5" x 6" (63.5 x 152 mm) and cost $172 USD. That's $28.67/26.43 EUR per inch (25.4mm) so I converted over half of the value into chips. A 1.5"/75mm x 7/8"/22mm disc is still a very useful chunk of brass.
I am a fan of your experimental videos. Nice work with the annular cutter.
I converted my benchtop milling machine (Sieg SX2P) to CNC, and use that for trepanning a hole for a diffusion pump on a high-vacuum base plate, and for feed-throughs.
Annular cutters are kick ass.
I love that you discovered annular cutters. I have to admit being disappointed that you used an angle grinder instead of the hacksaw with a diamond grit blade on that HSS. Joking of course! Love your content!!!
If you ever have the will and time you can try to put trepanning tool on the other side turned upside down and cut it so that cutter is pushed away from the workpiece when catching. I am really interested to see the result.
I loved this, thanks so much for sharing mate 🤩
I love the project focused videos. Yes a structured dive into the theory is valuable, but application is where the information actually gets retained. I recommend you and Quinn to anybody remotely interested in metalworking.
Nope.. theory is just 2000 years of application :)
If you learn theory, but realy learn it, understand it... you can implement it in any specific application.
If you learn just one application, you have no clue what wiill happen in another one. And then you are stuck.
Practice is everything, theory is nothing... is just excuse for bad and lazy students :)
I was building up a nice bout of trepannation waiting to watch this one.
The annular cutter looks more like the medical tools I've seen btw, the really old ones look more like they were made for pulling teeth.
great video with lots of good information ....yay for annular cutters
Annular cutters have shaved minutes off performing labotomys, thanks for the recommendation 😅
I use those annular cutters any time I can. They out perform any drill by a large margin and need no pilot hole. I even use them on CNC work. The downside as you mentioned is cost. They are spendy and are difficult but not impossible to re sharpen when needed.
I’ve used annular cutters on aluminum tube for a trailer cross bar and they work well.
Very nice work mr. Interesting. Something I haven’t done yet
Nice video.
Thanks for sharing. 👍
Re turning the morse taper holder - you can buy morse taper blank arbors, with ground & case hardened tapers, & soft machinable ends... They're not very expensive, and make the job a lot faster & easier.
Fantastic work, dude! 😃
Really interesting tools indeed!
Stay safe there with your family! 🖖😊
I have a general medical license from Guyana Public Medical Middle School. Class of '99. I do my residency at the local grocery stores.
annular cutters are the best
I'll be recommending to the neurosurgical team on Monday that we purchase a set of annular cutters. Would the heat of the autoclave effect the temper of the cutter?
Regarding Trepanning. I had a job once that required 3" dia stock 6" long to be turned into special rollers with a 3" long center portion and 1 1/2 long 1 1/4" diameter hubs on either side. I ended up with a 2 tool trepanning holder with each tool doing half the work mounted in the tailstock. 1 would cut the OD and half the floor and the other would do the ID and the other half of the floor. then part off the remaining rings. Since both tools vibrate at different frequencies they couldn't reinforce each others chatter and damped themselves out. Each tool could be much thinner than the groove so clearance was easy, they could each be angled to ease the clearance problem. So it was really like 2 boring bars operating together. |___|
I love annular cutters in the mill. So satisfying and the finish is awesome. ALthoguh they are not cheap, sfar mine seem to lat a long time
Yap! Great tool.Thank you.
this is really helpful! thanks
I'm way ahead of you because I made a cutter like that out of a big end mill and it worked awesome.
I used it to a 11 1/4" Brake disc out of 1/4 " Stainless Steel and also cut out the 4" center of it.
Fair enough. I don’t think my lathe would be up to that task. Cheers
@@artisanmakes I didn't clarify that the end mill was carbide and I cut down in to a cutter about like yours .
thanx for your opinion, that was great help,
Im somewhat a newbie. If I can, I'd rather buy what works
Than have had wasted money by trying to save
I use annular cutters when drilling truck chassis’s. When they become dull we just send them off to our tool grinder guy in Sydney. A fraction of the cost of replacement and good as new..
Yeah hole saws suck in steel over about 1/2" you really need an annular cutter for that job if drilling is how you want to make a hole. Great video as always! 👍👍
17:06 it is basically trepanning with six tools at the same time ;)
Ever since seeing annular cutters on Adam Savage's Tested channel I've been looking forward to seeing annular cutters used for cutting holes in other heavy-duty machine-based cutting operations. :)
9:34 That's a one, fat ass cut. I love it
At work we use TCT hole saw to core out the bottom of the tanks we make to weld the discharge piping.
These tools are pretty fragile if used incorrectly, but when used correctly they last a lot
I have a project I'm working on that this video created the solution for me. 👍
You should look into a quality diamond grinding wheel. One of my favorite shop tools is a very expensive eyeglass grinder that was damaged, but the motor and grinder were (and are) still running perfectly. Ideal for tool steel or carbide and it only cost me $30. The motor alone would have been hundreds. Used Lapidary equipment is also great for sharpening.
The easiest way i know to get the clearance right is to blue up the end if the tool with dykem and use a radius gage to trace a radius tangent at the corner and slightly smaller than the outer radius you're trying to cut.
Oh, and that bird's nest at the end is terrifying. A giant flail of razor sharp steel ribbons moving at high speed.
You need to peck the cutter to break those chips and stop them from becoming a hazard.
Ive added a hole that Ts into the centering pin hole and run through tool coolant on my lathe. I also use mine for roughing counter bores being as i can remove much more material much faster than a boring bar.
I’ve moved to carbide annular cutters. I’ve found that expensive cutters aren’t any better than some inexpensive brands and that’s something I normally wouldn’t say. I’ve had good luck with the brand ACTOOL. I don’t know if they’re over there as well, but as they come from China, they may be. If you cut stainless, carbide is almost required. Otherwise it’s a real pain and damaging the bits isn’t that difficult.
Minimizing front rake on the tool might also help with strength and rigidity. Only need like 7deg.
I was going to try and find or make an annular cutter arbor about 4 years ago. I started just using them in an ER32 collet temporarily, but for me it works fine even without the pin, so it became the permanent arbor.
Ive been a subscriber for a while now and im stunned you never thought to use annular cutters!
When they start at $70 and up you can probably guess why.
buenicimo
It's time to make an endmill holder for the tailstock. Then you will not have so many folks yelling about an endmill in a drill chuck.🤣
This went so much better than his brain surgery video...
Trepanning on a small lathe is always a challenge but isn't something done particularly often by most people
I was taught on full size 'industrial' machines and even then it wasn't 'easy' to learn feed rates and rpm but chatter was less of a problem.
A few years ago I bought a trim router for a completely different reason, (bit of woodworking) made a 3/4" thick aluminium base plate to mount it on drill press.(plus use instead of a Dremel as it was designed for side loads and has many times the power)
I tried clamping to side of lathe tool-post as an experiment.
With 3mm TiAN coated milling cutter it worked great in 6mm steel plate, cut dozens of disc's even though rpm was a bit high.
I don't think I'll go back to conventional trepanning tool although I may buy a variable speed trim router in the future.
Did the annular cutters come with rpm recommendations?
Another great vid - however i'd appreciate if you'd say what steel you're using for these projects - cheers
uee your mill to add some more relief slits into the walls of your hole saw bits it will keep it cooler and helps with chips
i use annular cutters in a mag-drill at work regularly and as long as they're not chipped they just eat through 20mm steel
2 or 3 Nema 24 mounts? Sounds suspiciously like a CNC conversion. Excited to see how you tackle it.
The reason that cutter is doing so well is it's the bit used in a Magnetic Drill that's used to drill large holes in steel plate/I-Beams...
This type of work is EXACTLY what that bit is designed for...
I think you are missing the point of the video a bit but yes, it’s a very good tool for the job
One more suggestion - whenever you are cutting/ shaping high speed Steel always keep it cool, do not let it get too hot, to prevent annealing. Otherwise good video.
Sir, high speed steel is designed to take incredible temperatures without annealing. That’s why it works so well cutting metal.
M2 high speed steel can take the temperatures we were throwing at when grinding. It’s not going to affect the temper a whole lot
Coolant up the middle of the trepanning cutters too with a bit of fiddling about.
Surface Finish - Try pulling out more. You have to clear the chips. You also reduce the heat too.
Also try a reamer at the end.
Yeah but that wasn’t the point of the test, it was more of a as fast as possible comparison. Of course the surface will suffer a bit
When drilling holes, with either a twist drill or annular cutter, release the tension on the drill a bit. So drill line normal until you see the chips are like 100mm long, lift the drill a bit and drill again. This way you keep the chips small enough they don't make a birdsnest and mess up any finishing. Too me too many years to learn that
You're correct. Peck drilling is the way to go 👍🙂
i do my fare share of trepanning , currenly machining some cable wheels (680mm diameter) and the faces of the boss need grooves for a labyrinth dust cover , the lathe is old and needs some tlc to eliminate the chatter wich is whats making the proces hell
HA I’m watching this before taking my adhd meds and I absolutely misheard “a 38-ish mm hole” as “a 38 inch mm hole”
I rewatched those 5 seconds like four times
@artisanmakes - Aout your lathe. I have one the same and haven’t figured out one thing. There are two sight glasses to see how much oil is in the lower and upper gear case. Mine leaks, I think from the top gear case. Filling up the top gear case is easy ; remove the top cover oil hole screw, and fill it up. How do you drain, and fill the lower case? Maybe I’m missing everything! Thanks for any advice.
On a small lathe trepan some distance down then move over trepan alittle then go back to where you stated and go further
This adds some forgiveness when the tool does push away
0:51 often a shallow pocket for location and a much smaller hole will do
For making holes at larger than readily available drill sizes, trepanning will mean much lower tool cost. But you should have a means of capturing the puck - you don't want a lump of steel flying out and whacking you.
I have the same lathe, and it sounds exactly like yours, ,what oil are you using in the gearbox’s?
8:42 Side project #1… (I’m glad I’m not alone!)
Put 60˚ center on both sides. Go half way and flip.
Hold the tool upside down and run spindle backwards. This way it won't bind to the workpiece if any flex in toolpost occurs
I don't know anything about making tools - would it be a good idea to harden and temper any cutter you make?
annular cutter could be a good alternative to a hole saw
Why not use an small end mill mounted on a motor for this purpose? Is it done this way?
Was turning the taper detrepanning?
halfway through typing my comment about Annular cutters, "So i have some Annular cutters"
I use them even on a full sized mill whenever i need to use the manual machines at work, they require so little tool pressure and machine power really helps deal with stress on the body and the machines
Класс!
1:13 - or you are using it wrong )
to cut a thick material with a hole saw you need to drill some holes first (about 3) which will slightly intersect the line of cut.
those holes are needed to clear the chips from a hole saw blade.
And my mill isn’t powerful enough for use it anyway
Mitsibishi tooling makes a Treepan tool with different sizes of id tools
16:09, cant you go in small steps so the chips are shorter and fly away instead of curling on the tool? like you’d do with drilling
If you peck with the annular cutter it breaks the chips and can mitigate the birds nest.
you still have to pull it out with the pliers... on the lathe anyway
When I needed to I shaped hollow tube to outer ,inner dia.slowed feed rate bless you 😊😊
In brain surgery the workpiece does NOT spin, but in metalworking, it does. Other than that, they’re rather similar procedures, with similar hazards (if you go to far, the workpiece is scrapped).
Where was the hacksaw?
Humm. I’d be worried what would happen if the puck jams up between the tool and the chuck/workpiece.
Change the cutting angle to avoid draw-in. There is always a setback when one tries to enhance techniques.
Then it just chatters. That’s the problem with these smaller lathes
If his intro makes you curious google Amanda Feilding trepanation.