Slitting rule: Slow feed; More speed. That gives less tooth pressure on the saw & a finer finish on the cut. Good to see you back machining again Paul. Wife & I are well after going through breast cancer surgery and having both her hips replaced with titanium & ceramic do-dads. Worst 2 years of my life, but the sun is shining & I'm back in the shop,too.
Hi Bob, I thought you had been quiet for a while and I was beginning to wonder. Yes I'm back in the workshop for a while but I've still some outdoor jobs to do before the winter comes which will need some priority. This week has seen my son move house and another granddaughter arrived so it's all go here. Regards to Mrs G. Good health is not guaranteed as we get older. Cheers.
It took a while to get used to the cutters spinning with the strobe effect. It got worse when I thought you were climb milling, luckily you had the cutters spinning CCW in the opposite direction to the traditional way. This meant instead of milling traditionally from the right side of the workpiece finishing on the left your traverse was in the opposite direction. Maybe starting the slitting saw centrally above the workpiece and feeding the table up was the way to go. Sometimes when starting on a corner the slitting saw does not precisely align itself when clattering on a corner. Starting smoothly in the middle of the part often helps. When using the depth micrometer it is far easier to read if you have the scale facing you instead of at the back. If you left the bar at the original length you could have cut them off on your saw.😉
Hi Paul. My own adventures with slitting saws has been confined to brass. Thankfully brass has caused no problems, though as others have said, I also don’t use keys in the arbor. Every day is a learning day. 👏👏👍😀
Hi Paul, I have taught quite a few apprentices over the years. My advice to them has always been its how it sounds,and looks. Big cutters slow, smaĺl cutters fast, but experiment. I agree with the other comments make an arbour, faster speed no key and hand feed
I had to commit the broken shards of an expired slitting saw to the scrap bin myself this week. They work great, until they don't. I wouldn't have been brave enough to attempt 18mm in steel in one bite though! Have a good weekend, Matt
That was a great video Paul. A few years ago now I made a simple arbour for my slitting saws. It drives by friction with no key. If the saw jams it just slips. For feed rate on the job I was doing I consulted Chapman. He gives a figure of 0.05 - 0.08mm per tooth. Assuming a cutting speed of 20 metres per minute for mild steel and a saw of 70mm dia with 72 teeth:- RPM = (Cutting speed/pi) x cutter dia... = 90 RPM for the above saw. At 0.05mm feed per tooth, 72 teeth gives 3.6mm per rev. This gives 0.0036 x 90 RPM which is 0.3 metres per minute feed. Obviously this is a bit open to experimentation and depends on the size and rigidity of the machine. It worked well for me on my Taiwan mill drill. I'd imagine the Harrison mill to be even better. Thanks again for posting. I wish I had so much horizontal gear for my Harrison mill!
Thanks for the calcs Carl. A foot per minute I'd be nervous of that, I'm still picking up shrapnel from around the workshop. What depth of cut would you set? Cheers Paul
@HaxbyShed Hi Paul. I had to make something like a 10mm deep slot about 1mm wide in a steel part. In fact it was the slotted knurled nuts I made for securing the change wheels on the Harrison mill feed box, which were missing on my machine. I took that cut in one go, feeding the saw at about half of the feed rate I calculated. The speed worked fine. I just use Chapman as a guide and then experiment from there.
Slitting saws are hiding in fear worldwide… No worries, it’s all part of learning I only hand feed when slitting, been pretty lucky so far. I always enjoy horizontal milling, those keys came out nice 👍 👍
Hi Paul, I am back home and in the loop again! I have inherited a number of variously abused slitting saws. If you think about feed and speed together the slower the saw turns, the more metal each tooth has to remove to allow for the feed rate, so the slower the saw spins the greater the individual tooth load. With a low rpm on the spindle, you think you are going steady but you are actually doing the opposite! Keep rpm high and feed low with slitting saws, doesn’t make for spectacular video, bur saves on cost in the long run! Phil, (moving gently around the house)
Hi Phil, glad you are making progress. Autojumble tomorrow morning so I'll be buying any slitting saws I can find. Usually £2 a saw there and often unused. Online it could be £20 a saw. Cheers Paul
Rather than cringing at your slitting saw, I was surprised you didn't get away with it. I've always been lucky with them and I'm not normally a lucky person 🙂
One thing I never came across when I was an engineering trainee 45 years ago (at York College of Arts & Technology when was on the old site on Tadcaster Road) was a slitting saw. So the first time I ever used them was in my home workshop maybe ten years ago. The vertical arbor I have is the clamp type without a key so it would probably slip when pushed too hard. I was only making controlled cuts of maybe 3/8”. So I just wound the speed right up to about 1500rpm on my Seig X3, took a shallow depth of cut, lots of cutting oil and hand fed because I’ve not yet go around to making an electric table traverse. I had a few slippages but surprisingly no breakages…not that I can’t break a fresh out the box brand named carbide end mill within a few seconds given the ‘right’ circumstances.
Hi Paul, Well that made me jump!! Lots of sage advice on feeds and speeds in the comments. Well done you got there in the end. Good idea to mark the side It's been a wet few days down here we haven't been affected. The worst affected zone is Valencia where my sister-in-law lives fortunately she is ok. All the best!!
I've only used a slitting saw once, in a vertical head. My work moved a little in the vice with the same result you had. I ended up in the Record vice with a hacksaw. When I finally get the new to me mill working correctly, I'll try it again with the horizontal. I think I will take on the comments of the contributors here.
Hi Bill, my slitting saw experience seems to have started quite a conversation hasn't it. But all good info I can use. I could have edited that stuff out - but what's the point in that...... Cheers
Hi Paul Thin blade's avoid , Hack saw blade's run teeth cut on the back stroke. I stopped making square bar keys . I turn them to size. Far easier harden temper if want. Steve
A quick tip about slitting saws from a retired machinist. Firstly they inevitably don't run true so you'll find you are really only using 3 or 4 teeth to do all the work. So hand feed only, *don't* put a key in the arbour, don't over tighten the arbour nut as you actually want the saw to slip on the arbour rather than break. If the saw slips just back off the table hand wheel before the saw scores a ring on the arbour and feed in again slowly. Hope it helps.
I've made the same mistake with the slitting saw as you did. The saw teeth are too fine for that depth of cut, the few teeth that are cutting fill up the gullets, stop cutting and the pressure snaps the blade. A blade with far fewer teeth (20 ish?) would work much better and dont use a key! The gang milling setup was good. I've never had a matched pair of cutters to try it. You'll find that a horizontal cutter is much noisier at the start of a cut as the teeth are approaching a vertical surface. Once the cut is underway the teeth start cutting on a horizontal surface and the chip gradually thickens. A vfd on the feed motor works well, slow at the start, speed up when the cutter is in the work.
Hello Sir, I bought a new batch of slitting saws from the autojumble at the weekend and a few have quite large teeth more like a rip saw than a panel saw (if we were talking wood saws). I have a VFD on the x-feed and I have set the adjustment range 2:1 so it would run 22 to 44 mm / min in that example. Next time I will try a less-fine saw and cut by hand - and no key. Cheers Paul
Good to see a horizontal mill working. I like your digital height guage, great idea. Hope you havent done any unseen damage internally to your mill. I did similar on my Rapidor hacksaw (to post yet, lol). Sometimes you can't see the wood for the trees concentrating too hard. Good learning curve Paul. Enjoyed cheers..... Tony
The slitting saws I've used went well. But I always hand fed them with a keen eye and ear looking and listening for anything. The mystery was that I didn't hear anything untoward right up to the KABOOM! No idea really. But I think Robert Ginther hit the nail on the head with more speed. Not a whole lot more. Check the SFPM or circumferential meters per minute I guess. But yeah, somewhat faster would have avoided a dig in. The slitting saws do tend to only cut on one part. And the next time on some other segment. With the low RPM and power feed I suspect it simply dug in and the thin nature of that blade just couldn't dig deep before it hit the last straw.
I’m surprised at the amount of runout the saw exhibited. Generally, it’s best to cut deeper rather than shallower cuts. I rarely make shallow cuts unless that’s specifically needed. But if the blade isn’t pretty concentric, and they’re never as good as a mill bit in that, all the cutting is being done with just a few teeth, which puts a lot of stress and wear on those teeth. I’m surprised that a saw would explode unless it’s stressed or cutting is much too fast. If cutting is too slow, the teeth dull rapidly.
Hi it was my first ever attempt with a slitting saw (so lots to learn) and I probably had far too much feed on and maybe a bit slow speed also. I know that arbor is good so the runout surprised me also. Anyway, I've bought 7 fine slitting saws today at the flea market. Cheers
Never seen cutters running in reverse before, what was the benefit? You have a shaper, surface grinder, universal mill and center lathe, but no counterbores or any idea how to grind a flat bottom drill. I strongly suggest you research how to use a surface grinder safely before you use it again. ATGNI
Hi Marley, the cutters look like they are going backwards but it is camera strobe 50Hz video and about 65 rpm on the arbour. Just like the wagon wheels seemed to run backwards on the old cowboy movies. I've bought the counterbores now, and I'd be very pleased to receive your advice on surface grinding safety if you would be willing to share it? Cheers
@@HaxbyShed The strobe effect did throw a spanner in the works. I expected them to rotate clockwise and conventional milling right to left. The confusion started when the cutters were put on the arbor backwards. The consequences of this led to the spindle having to be run in reverse and fed in the opposite direction. Coupling this with the strobe effect was baffling:) It's worth checking a few things with the counterbores. Check the shaft is soft so it does not spin in the drill chuck. Make sure they have 4 flutes to minimize the risk of snatching that you get with 2 flutes. See if there are gashes in the pilot. This confirms they will cut beyond the pilot circumference. Measure the pilot diameters. Some specifications need large clearance holes for the pilot to fit. This removes the advantage of the larger head diameter that metric cap head screws have. If the flute depth allows, you can reduce the pilot diameter to suit your preferred clearance hole sizes. There is far too much grinding info to include in a comment, but I can shed some light on your setup. Heat is the enemy of grinding; your setup needs to pay attention to this. You have a manual traverse, this is often far too slow over long parts. Having the wheel dwelling over a part will heat it up, this leads to the part growing thus increasing the depth of cut and helping to generate more heat, and on it goes. On your part, this consequence is exaggerated because it has a small mass so it will heat up quickly. There are ways to minimize this, pop the part diagonally on the chuck. Then each pass is much shorter and won't build up so much heat in the middle. Another thing to avoid is plunging down on a long low mass part as you did. This is probably the fastest way to heat the part up and have it grabbed by the wheel. Don't rely on the flat dress of the wheel to produce a flat surface. Put the cut on with the wheel off the part then traverse across using the Y feed to index over the part incrementally. Hopefully, this sheds a bit of light on your setup and helps keep you safe in the future. No more parts with a dip in the middle where it has got hot.
Slitting rule: Slow feed; More speed. That gives less tooth pressure on the saw & a finer finish on the cut. Good to see you back machining again Paul. Wife & I are well after going through breast cancer surgery and having both her hips replaced with titanium & ceramic do-dads. Worst 2 years of my life, but the sun is shining & I'm back in the shop,too.
Hi Bob, I thought you had been quiet for a while and I was beginning to wonder. Yes I'm back in the workshop for a while but I've still some outdoor jobs to do before the winter comes which will need some priority. This week has seen my son move house and another granddaughter arrived so it's all go here. Regards to Mrs G. Good health is not guaranteed as we get older. Cheers.
Looked too slow to me. I dont know also how a fragile saw would be affected by the audible run-out of the spindle
Worst two years of her life.
It took a while to get used to the cutters spinning with the strobe effect. It got worse when I thought you were climb milling, luckily you had the cutters spinning CCW in the opposite direction to the traditional way. This meant instead of milling traditionally from the right side of the workpiece finishing on the left your traverse was in the opposite direction.
Maybe starting the slitting saw centrally above the workpiece and feeding the table up was the way to go. Sometimes when starting on a corner the slitting saw does not precisely align itself when clattering on a corner. Starting smoothly in the middle of the part often helps.
When using the depth micrometer it is far easier to read if you have the scale facing you instead of at the back.
If you left the bar at the original length you could have cut them off on your saw.😉
Hi Paul. My own adventures with slitting saws has been confined to brass. Thankfully brass has caused no problems, though as others have said, I also don’t use keys in the arbor. Every day is a learning day. 👏👏👍😀
Hi Paul, I have taught quite a few apprentices over the years. My advice to them has always been its how it sounds,and looks. Big cutters slow, smaĺl cutters fast, but experiment. I agree with the other comments make an arbour, faster speed no key and hand feed
Oh very nice. I love the "gang tool" set up on the horizontal mill. Cheers, Aaron.
Hi Aaron there is something very basic and appealing about gang cutters I think. Brings the horizontal mill into it's own class. Cheers
I had to commit the broken shards of an expired slitting saw to the scrap bin myself this week. They work great, until they don't. I wouldn't have been brave enough to attempt 18mm in steel in one bite though! Have a good weekend, Matt
Hi Matt, at the autojumble this morning I bought about 7 of those thin saws plus a range of others up to 1/4 inch. Going rate was £2 per saw.
I haven't quite figured out slitting saws myself. But it was entertaining to see yours explode. 😉
That was a great video Paul. A few years ago now I made a simple arbour for my slitting saws. It drives by friction with no key. If the saw jams it just slips.
For feed rate on the job I was doing I consulted Chapman. He gives a figure of 0.05 - 0.08mm per tooth.
Assuming a cutting speed of 20 metres per minute for mild steel and a saw of 70mm dia with 72 teeth:-
RPM = (Cutting speed/pi) x cutter dia...
= 90 RPM for the above saw.
At 0.05mm feed per tooth, 72 teeth gives 3.6mm per rev.
This gives 0.0036 x 90 RPM which is 0.3 metres per minute feed.
Obviously this is a bit open to experimentation and depends on the size and rigidity of the machine. It worked well for me on my Taiwan mill drill. I'd imagine the Harrison mill to be even better.
Thanks again for posting. I wish I had so much horizontal gear for my Harrison mill!
Thanks for the calcs Carl. A foot per minute I'd be nervous of that, I'm still picking up shrapnel from around the workshop. What depth of cut would you set? Cheers Paul
@HaxbyShed Hi Paul. I had to make something like a 10mm deep slot about 1mm wide in a steel part. In fact it was the slotted knurled nuts I made for securing the change wheels on the Harrison mill feed box, which were missing on my machine. I took that cut in one go, feeding the saw at about half of the feed rate I calculated. The speed worked fine. I just use Chapman as a guide and then experiment from there.
I loved working with apprentices when you thought seen every way of f**King something up they would show you a new way !
Kit from down under
Hi Kit, I'm finding new ways. 🙄😁
"Short on numbers that day?"
Geez Paul... now I have to mop coffee off my screen!
Love it!
Andrew
Great fun! I remain baffled as to why slitting saws always have massive runout, so that only a few teeth cut.
Slitting saws are hiding in fear worldwide…
No worries, it’s all part of learning
I only hand feed when slitting, been pretty lucky so far.
I always enjoy horizontal milling, those keys came out nice 👍 👍
Hi Dean, I bought some replacement thin slitting saws now, ready for next time I need a bit of excitement. 🤣 Cheers
Well, that was exciting! I have blown up a few slitting saws too--only perfect people never make mistakes and there are no perfect people.
Hi Paul, I am back home and in the loop again!
I have inherited a number of variously abused slitting saws. If you think about feed and speed together the slower the saw turns, the more metal each tooth has to remove to allow for the feed rate, so the slower the saw spins the greater the individual tooth load. With a low rpm on the spindle, you think you are going steady but you are actually doing the opposite! Keep rpm high and feed low with slitting saws, doesn’t make for spectacular video, bur saves on cost in the long run!
Phil, (moving gently around the house)
Hi Phil, glad you are making progress. Autojumble tomorrow morning so I'll be buying any slitting saws I can find. Usually £2 a saw there and often unused. Online it could be £20 a saw. Cheers Paul
Well some days just have to be a voyage of discovery with some mishaps thrown in. Even so - dual milling cutters? Now. I want a horizontal mill………..
Indeed, you cannot learn experience from a book. :)
Quite so Michel. Sometimes we have to mess up to step up. Cheers
Rather than cringing at your slitting saw, I was surprised you didn't get away with it. I've always been lucky with them and
I'm not normally a lucky person 🙂
One thing I never came across when I was an engineering trainee 45 years ago (at York College of Arts & Technology when was on the old site on Tadcaster Road) was a slitting saw. So the first time I ever used them was in my home workshop maybe ten years ago.
The vertical arbor I have is the clamp type without a key so it would probably slip when pushed too hard. I was only making controlled cuts of maybe 3/8”. So I just wound the speed right up to about 1500rpm on my Seig X3, took a shallow depth of cut, lots of cutting oil and hand fed because I’ve not yet go around to making an electric table traverse.
I had a few slippages but surprisingly no breakages…not that I can’t break a fresh out the box brand named carbide end mill within a few seconds given the ‘right’ circumstances.
I live by, expect nothing, and you will always get your desire. I'm now throwing your philosophy in my quiver as well. 😊
Hi Paul, Well that made me jump!! Lots of sage advice on feeds and speeds in the comments. Well done you got there in the end. Good idea to mark the side
It's been a wet few days down here we haven't been affected. The worst affected zone is Valencia where my sister-in-law lives fortunately she is ok.
All the best!!
David we have seen it on the news and the King being verbally assaulted. It's tragic. Regards Paul
I've only used a slitting saw once, in a vertical head. My work moved a little in the vice with the same result you had. I ended up in the Record vice with a hacksaw. When I finally get the new to me mill working correctly, I'll try it again with the horizontal. I think I will take on the comments of the contributors here.
Hi Bill, my slitting saw experience seems to have started quite a conversation hasn't it. But all good info I can use. I could have edited that stuff out - but what's the point in that...... Cheers
@@HaxbyShed I'm glad you left it in Paul. It confirmed that I'm not the only one who got it wrong. :-}}
I bet even the best have broken those slitting saws. I love those horizontal mills.
good video paul
Hi Paul Thin blade's avoid , Hack saw blade's run teeth cut on the back stroke. I stopped making square bar keys . I turn them to size. Far easier harden temper if want.
Steve
Good fun! I'm always suspicious if something works, figure I missed something! Cheers
A quick tip about slitting saws from a retired machinist. Firstly they inevitably don't run true so you'll find you are really only using 3 or 4 teeth to do all the work. So hand feed only, *don't* put a key in the arbour, don't over tighten the arbour nut as you actually want the saw to slip on the arbour rather than break. If the saw slips just back off the table hand wheel before the saw scores a ring on the arbour and feed in again slowly. Hope it helps.
That's great advice, thanks Andrew. 👍
Having used a circular cut-off saw for years can empathise with the unpredictability of the exploding HSS blade for no apparent reason.
I've made the same mistake with the slitting saw as you did. The saw teeth are too fine for that depth of cut, the few teeth that are cutting fill up the gullets, stop cutting and the pressure snaps the blade. A blade with far fewer teeth (20 ish?) would work much better and dont use a key!
The gang milling setup was good. I've never had a matched pair of cutters to try it. You'll find that a horizontal cutter is much noisier at the start of a cut as the teeth are approaching a vertical surface. Once the cut is underway the teeth start cutting on a horizontal surface and the chip gradually thickens. A vfd on the feed motor works well, slow at the start, speed up when the cutter is in the work.
Hello Sir, I bought a new batch of slitting saws from the autojumble at the weekend and a few have quite large teeth more like a rip saw than a panel saw (if we were talking wood saws). I have a VFD on the x-feed and I have set the
adjustment range 2:1 so it would run 22 to 44 mm / min in that example. Next time I will try a less-fine saw and cut by hand - and no key. Cheers Paul
Good to see a horizontal mill working. I like your digital height guage, great idea. Hope you havent done any unseen damage internally to your mill. I did similar on my Rapidor hacksaw (to post yet, lol). Sometimes you can't see the wood for the trees concentrating too hard. Good learning curve Paul. Enjoyed cheers..... Tony
The slitting saws I've used went well. But I always hand fed them with a keen eye and ear looking and listening for anything. The mystery was that I didn't hear anything untoward right up to the KABOOM! No idea really. But I think Robert Ginther hit the nail on the head with more speed. Not a whole lot more. Check the SFPM or circumferential meters per minute I guess. But yeah, somewhat faster would have avoided a dig in. The slitting saws do tend to only cut on one part. And the next time on some other segment. With the low RPM and power feed I suspect it simply dug in and the thin nature of that blade just couldn't dig deep before it hit the last straw.
Ive broken slitting saws on the same mill in the exact same way, they can be a pain!
Anthony we could start a Harrison mill slitting saw destructors club. :-)
Looked pretty scary. Thanks
I’m surprised at the amount of runout the saw exhibited. Generally, it’s best to cut deeper rather than shallower cuts. I rarely make shallow cuts unless that’s specifically needed. But if the blade isn’t pretty concentric, and they’re never as good as a mill bit in that, all the cutting is being done with just a few teeth, which puts a lot of stress and wear on those teeth. I’m surprised that a saw would explode unless it’s stressed or cutting is much too fast. If cutting is too slow, the teeth dull rapidly.
Hi it was my first ever attempt with a slitting saw (so lots to learn) and I probably had far too much feed on and maybe a bit slow speed also. I know that arbor is good so the runout surprised me also. Anyway, I've bought 7 fine slitting saws today at the flea market. Cheers
I run quite fast spindle speed and actually prefer to feed by hand as I can feel how it is cutting. Also I don't fit a key when using a slitting saw.
Thx for the vid.
to know it is to see someone else do it🙂
I have never had much success with slitting saws either & can’t work out why the things never run true, every other milling cutter seems to.
yes i was cringing,, i like to break them too!!! many times.
I always hand feed and no key, a little faster speed as well as the blades are never balanced and only cut on a few teeth. that seems to work for me.
I think that is good advice Paul. Cheers
Dull blades? Only needs the corners of the teeth to be worn a bit & the sides of the blade will rub. Also looked too fine for that depth of cut...
Thanks MidEng, I've noted the point about fine teeth. I think I'll need a fair bit of practical experience to master slitting saws.
Never seen cutters running in reverse before, what was the benefit?
You have a shaper, surface grinder, universal mill and center lathe, but no counterbores or any idea how to grind a flat bottom drill.
I strongly suggest you research how to use a surface grinder safely before you use it again.
ATGNI
Hi Marley, the cutters look like they are going backwards but it is camera strobe 50Hz video and about 65 rpm on the arbour. Just like the wagon wheels seemed to run backwards on the old cowboy movies. I've bought the counterbores now, and I'd be very pleased to receive your advice on surface grinding safety if you would be willing to share it? Cheers
@@HaxbyShed The strobe effect did throw a spanner in the works. I expected them to rotate clockwise and conventional milling right to left. The confusion started when the cutters were put on the arbor backwards. The consequences of this led to the spindle having to be run in reverse and fed in the opposite direction. Coupling this with the strobe effect was baffling:)
It's worth checking a few things with the counterbores.
Check the shaft is soft so it does not spin in the drill chuck.
Make sure they have 4 flutes to minimize the risk of snatching that you get with 2 flutes.
See if there are gashes in the pilot. This confirms they will cut beyond the pilot circumference.
Measure the pilot diameters. Some specifications need large clearance holes for the pilot to fit. This removes the advantage of the larger head diameter that metric cap head screws have. If the flute depth allows, you can reduce the pilot diameter to suit your preferred clearance hole sizes.
There is far too much grinding info to include in a comment, but I can shed some light on your setup.
Heat is the enemy of grinding; your setup needs to pay attention to this. You have a manual traverse, this is often far too slow over long parts. Having the wheel dwelling over a part will heat it up, this leads to the part growing thus increasing the depth of cut and helping to generate more heat, and on it goes. On your part, this consequence is exaggerated because it has a small mass so it will heat up quickly. There are ways to minimize this, pop the part diagonally on the chuck. Then each pass is much shorter and won't build up so much heat in the middle. Another thing to avoid is plunging down on a long low mass part as you did. This is probably the fastest way to heat the part up and have it grabbed by the wheel. Don't rely on the flat dress of the wheel to produce a flat surface. Put the cut on with the wheel off the part then traverse across using the Y feed to index over the part incrementally. Hopefully, this sheds a bit of light on your setup and helps keep you safe in the future. No more parts with a dip in the middle where it has got hot.
I had my eyes squinted, reminded me of watching the darleks from behind the sofa😊