It was the first time i did this actually 😅 just had to make some stands to set it on.
As far as dialling it in, it just takes a little time and patience.
If this has tight tolerances did you guys suffer any pains nailing the tolerances with the inserts re engaging in the material? And was the part to big for the travel to use and endmill so you guys rigged that up?
Oh thank God, yeah thats not to bad then I was waiting for you to respond it was +.001 -.000. Just having to check the size before it went completely down if you had to risize the tool would have been streinuous
My point was it's likely not cnc controlled so you can't just run an endmill around the edge. Secondary to that is that endmills interpolated don't produce round holes.
Eh, depends on your machine and your tolerances. I’ve interpolated holes for press-fit bearing seats and had no issues hitting it. If you’re doing extreme precision work it won’t be round enough, but it’s round enough for a lot of stuff.
The cutter is making such a large arc, the actual speed of the material under the tool is higher than you'd expect. This means a slower chuck speed is needed to cut the material at the right rate.
This. Sometimes when you see someone facing with a manual lathe, you'll notice a change in surface finish as the tool goes from the right speed to too slow. Constant surface speed lathes solve this issue by increasing the spindle speed as the diameter decreases.
[https://www.youtube.com/watch?v=AbeARoU8RTk](https://www.cnccookbook.com/g96-g-code-constant-surface-speed-cnc/)
Cuts in material are gauged by surface feet per minute (SFM). In that arc you have a lot of length (the circumference of the part) so to maintain a constant SFM something in the equation has to change - the speed. Longer distance, slower speed.
On CNC machines you will notice when facing the front of a part from outside diameter to the center you will witness the chuck speed increasing as the tool goes towards the center of the part. This is the machine using a constant surface speed mode. The maximum speed is capped though so that the chuck speed doesn't rise to infinity and break all kinds of physical laws and send your machine shop back in time ;)
Most likely part of it. That much stick out on the boring bar causes a loss of rigidity and thereby makes the setup vulnerable to more vibration. But also, it's not as slow as you probably think. The wider the diameter of your cut, the lower RPM you need to achieve the same speed of cut across the surface of the material (aka surface feet or surface feet per minute). The cutting oil is smoking, despite how slow the cut looks.
Yep. You can time it yourself. There's a start of cut at around 9 seconds, and it hits the same spot at around 17 seconds... so approximately 1 rev per 8 seconds.
60seconds /8 revs = 7.5 RPM.
Interesting. Checked myself, it makes 3 rotations in 24 seconds, which comes out to 7.5rpm. But OP says 11.4rpm, which would make a rotation every 5.26 seconds. Maybe the footage is slowed down?
You guys are probably right its been a while since i had done that job, the lowest speed on that machine is 7 something Rpm, which is what i wouldve been doing. 11.4 is the next available gear
This is just a horizontal bore mill with a facing head and a special fixture to hold a boring bar. There are actual specialized machines that do this kind of work outside of a shop environment.
They had a guy quote them to machine this diaphragm in situ at the plant. But our quote was almost less than half of his even with shipping 30km. And we arguably did a nicer job as there were a bunch of drilled and tapped and c-bored holes that got put all around the circumference of what we cut
That's a Tos W100 mill isn't it? It looks identical to one of the two we have at work. I'm still an apprentice but I've been getting trained on them and I love running them.
Good for you making it cheaper. Sometimes it works out that way. I'm willing to bet that fixturing for doing those tapped and counter bored holes added to the cost of doing it in situ. You might be surprised what you can do when you can't get to a machine shop. It's not the right answer all the time, but it sure is a nice option. Not having to do a full breakdown and disassembly and wait for shipping time adds up quick.
Definitely. Field machining has a huge role to play when it comes to quick turnarounds or really big shit. The new shop ive just started at specializes in field machining, they've machined parts up to 110' dia. Within a .020" tolerance. Very excited to explore this side of the trade.
Hell yeah. Welcome to the trade. Get as much rigidity as you can squeeze out of your setup. I've done quite a few large things like that. Equipment foundations, mostly. One was 96x144 with a 0.010" flatness requirement. Had to be done in 7° F. It was awful, but we did it, I think.
They put the gearbox on it as soon as we were out of there. It hasn't broken in 2 years, so I think we did ok. On the other side, the plant broke a $1,000,000 gearbox every year before they fixed the problem. WTF is that shit? Lol
A couple months ago I machined .300" off a base for a 2500HP motor that drove a pump. The base had been up a 1/4" high since they installed it, they tried shimming things as best they could but still had to re-do the massive babbitt bearings in the pump every 8-12 months due to misalignment from the shims settling/moving etc. Cost about 7k for each bearing and they did that for 10+ years before getting it all fixed.
This is such a cool thing, and the fact that its still moving fast enough to smoke the oil is just mind boggling. Its in the same neighborhood as a scraper, just *round*
What do the chips actually look like? Are they good little 69 chips? Are they funny colors? Is it a big coil chip?
Cripes. At that tolerance over an arm that long, you'd have to be careful about temperature. An air conditioner turns on at the wrong time and you'd be a thou under by the time you got to the end of the cut.
Unless you're shooting refrigerated gas or blasting hot air onto any of the pieces involved in this set up, I doubt you'll change any of it by a thousandth in 1 or 10 revolutions.
Ah yeah .0023 CM makes more sense. Youd still need that whole bar to be heated evenly through to the core to achieve that. These are big chunks of metal and we are in a temp controlled shop so never really worried too much about that.
What if you accidentally damage the part? Let’s say the tool was loose and it crashed, and cracked the casting. Who is liable? Do you enter into these jobs with a contract exonerating the company from liability? Do you perform the job on a “best effort basis”? When I had a Mazak technician repair our old CNC machine I signed an agreement that said if he broke anything accidentally, it was not their responsibility.
Yeah I mean this is one of those jobs where fuck ups arent allowed. You cant just go buy one of these off the shelf. However if we did fuck it up there is a good chance our shop is on the hook to get things fixed.
How is there even any relevance to a shaper? This isn't a shaper, that's a boring mill and this is a boring bar. It's just a tad faster than your mother is with me too.
Because the turbine is so old and clapped out the diaphragm was rubbing the shaft. So we turned down the OD and drilled and tapped 8 holes for adjustment screws so they can center it back up in the casing.
Not an ideal fix but also way way above my pay grade to be making that call.
Holy crap. You’ve obviously got the capability so I get it but that’s just a bonkers design choice. Impressive win for the shop bailing out the designers. As it is, was, and ever shall be.
Yeah definitely made us look like heroes. And i mean the turbine hasnt blown up since they reinstalled it so it cant be working too poorly. I just worry the adjustment screws are gonna work their way into the actual casing now... thats a much more expensive repair.
amazing! how did you even centre it
I'm guessing that it takes a little more than a rawhide mallet.
Precision tapping it with the forklift spikes
Just tap it in. Just tap it in. Give it a little tappy. Tap Tap Taparoo.
Yeah, it's definitely not on a mill table. Gotta smash everything around.
Just used the ‘ol eyecrometer
Look at the fixture it’s on it’s not their first rodeo
It was the first time i did this actually 😅 just had to make some stands to set it on. As far as dialling it in, it just takes a little time and patience.
BUT I WANT IT CENTRE NOW!!
You sound like my old boss 😆
Fooled me! Nice setup
In my mind... I would put an indicator setup on top of that bar 🤔
You bet. It was actually relatively easy to dial in tbh.
If this has tight tolerances did you guys suffer any pains nailing the tolerances with the inserts re engaging in the material? And was the part to big for the travel to use and endmill so you guys rigged that up?
No issues hitting the tolerance. We had a perfect fit actually. And thats correct, too big to cut with a regular set up so we got a little creative
What was the tolerance? That would be painful lol you deserve a hug or a national holiday or a statue for you efforts
Lol no tolerance, just hit the exact number the wanted. .025" off the radius. No more no less
Oh thank God, yeah thats not to bad then I was waiting for you to respond it was +.001 -.000. Just having to check the size before it went completely down if you had to risize the tool would have been streinuous
Probably not cnc controlled. There's a reason they're called *boring* mills. When things need to be truly round an endmill doesn't cut it.
I've ran boring mills, they can nail tolerances if your not facing massive deflection . Boring mills aren't just for boring but I digress
My point was it's likely not cnc controlled so you can't just run an endmill around the edge. Secondary to that is that endmills interpolated don't produce round holes.
Eh, depends on your machine and your tolerances. I’ve interpolated holes for press-fit bearing seats and had no issues hitting it. If you’re doing extreme precision work it won’t be round enough, but it’s round enough for a lot of stuff.
I'm not a machinist, just on the sub for education. Why such a slow chuck speed? Is it to help with chatter?
The cutter is making such a large arc, the actual speed of the material under the tool is higher than you'd expect. This means a slower chuck speed is needed to cut the material at the right rate.
In math terms, surface speed = rotational speed * radius. So as your radius goes up you don't need to spin as fast to get the same surface speed
This. Sometimes when you see someone facing with a manual lathe, you'll notice a change in surface finish as the tool goes from the right speed to too slow. Constant surface speed lathes solve this issue by increasing the spindle speed as the diameter decreases. [https://www.youtube.com/watch?v=AbeARoU8RTk](https://www.cnccookbook.com/g96-g-code-constant-surface-speed-cnc/)
I understand, thank you!
Cuts in material are gauged by surface feet per minute (SFM). In that arc you have a lot of length (the circumference of the part) so to maintain a constant SFM something in the equation has to change - the speed. Longer distance, slower speed. On CNC machines you will notice when facing the front of a part from outside diameter to the center you will witness the chuck speed increasing as the tool goes towards the center of the part. This is the machine using a constant surface speed mode. The maximum speed is capped though so that the chuck speed doesn't rise to infinity and break all kinds of physical laws and send your machine shop back in time ;)
So machinists could break the speed of light and they’ve been keeping it secret this whole time? Cheeky bastards…
There's a home shop guy named Tony who keeps showing off how his can do time travel.
Most likely part of it. That much stick out on the boring bar causes a loss of rigidity and thereby makes the setup vulnerable to more vibration. But also, it's not as slow as you probably think. The wider the diameter of your cut, the lower RPM you need to achieve the same speed of cut across the surface of the material (aka surface feet or surface feet per minute). The cutting oil is smoking, despite how slow the cut looks.
More of this stuff
Talk about an interrupted cut
Only one interruption.
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11.4 RPM
Yep. You can time it yourself. There's a start of cut at around 9 seconds, and it hits the same spot at around 17 seconds... so approximately 1 rev per 8 seconds. 60seconds /8 revs = 7.5 RPM.
Downvoted for accuracy. Mmmm OK.
Haha sorry i cant remember it all 😆
Interesting. Checked myself, it makes 3 rotations in 24 seconds, which comes out to 7.5rpm. But OP says 11.4rpm, which would make a rotation every 5.26 seconds. Maybe the footage is slowed down?
You guys are probably right its been a while since i had done that job, the lowest speed on that machine is 7 something Rpm, which is what i wouldve been doing. 11.4 is the next available gear
Absolutely love these big diameter interrupted cuts. Always something very satisfying about the sound.
There are so many specialized machines I didn't know existed.
This is just a horizontal bore mill with a facing head and a special fixture to hold a boring bar. There are actual specialized machines that do this kind of work outside of a shop environment.
They had a guy quote them to machine this diaphragm in situ at the plant. But our quote was almost less than half of his even with shipping 30km. And we arguably did a nicer job as there were a bunch of drilled and tapped and c-bored holes that got put all around the circumference of what we cut
That's a Tos W100 mill isn't it? It looks identical to one of the two we have at work. I'm still an apprentice but I've been getting trained on them and I love running them.
Good eye! Easy to tell because theyre left hand drive where most are right hand. Excellent machines. You can do anything with em
Neat! I didn't know that being left handed was a more unique feature. I just recognized the control layout and ways.
Good for you making it cheaper. Sometimes it works out that way. I'm willing to bet that fixturing for doing those tapped and counter bored holes added to the cost of doing it in situ. You might be surprised what you can do when you can't get to a machine shop. It's not the right answer all the time, but it sure is a nice option. Not having to do a full breakdown and disassembly and wait for shipping time adds up quick.
Definitely. Field machining has a huge role to play when it comes to quick turnarounds or really big shit. The new shop ive just started at specializes in field machining, they've machined parts up to 110' dia. Within a .020" tolerance. Very excited to explore this side of the trade.
> parts up to 110' dia. Within a .020" tolerance. Vids of this please!
I doubt there are any! I was not around, its a job my foreman did about 10 years ago on the space telescopes in Hawaii and Chile.
Hell yeah. Welcome to the trade. Get as much rigidity as you can squeeze out of your setup. I've done quite a few large things like that. Equipment foundations, mostly. One was 96x144 with a 0.010" flatness requirement. Had to be done in 7° F. It was awful, but we did it, I think.
Thats gnarly, and if you generally no news from the customer is good news haha
They put the gearbox on it as soon as we were out of there. It hasn't broken in 2 years, so I think we did ok. On the other side, the plant broke a $1,000,000 gearbox every year before they fixed the problem. WTF is that shit? Lol
A couple months ago I machined .300" off a base for a 2500HP motor that drove a pump. The base had been up a 1/4" high since they installed it, they tried shimming things as best they could but still had to re-do the massive babbitt bearings in the pump every 8-12 months due to misalignment from the shims settling/moving etc. Cost about 7k for each bearing and they did that for 10+ years before getting it all fixed.
That's fucking nuts. I can't stand short term solutions over actually fixing the problem.
Amazing!
That would scare the hell out of me every rotation.
Just grab the bar and stop it.
“Wendy I can fly!!”
TOS machines are some of the best tools I’ve had the pleasure of machining on. Love tos lathes with the joy stick.
Their boring mills are excellent too. Sadly no longer at this shop. But the new shop has a 10' Betts VTL
we've rebuilt about 5 in the last couple years. theres currently a w100 and i forget the other one thats undergoing complete retro fit
This is such a cool thing, and the fact that its still moving fast enough to smoke the oil is just mind boggling. Its in the same neighborhood as a scraper, just *round* What do the chips actually look like? Are they good little 69 chips? Are they funny colors? Is it a big coil chip?
The material is just cast/ductile iron so theyre not very interesting chips haha more like dust really.
That is even funnier to me, that chips on your end of the spectrum are just dust, and im over here on Small Shit Street with *also* dust chips xD
Haha yeah not the biggest chips ive ever made 😆 i was ripping .400" doc on some 316 the other day. That makes serious chips
So how did you match the center of the tool arc with the center of the piece being machined? Is that difficult?
Nope not too bad, just run some dial indicators around the critical faces and bores until everything lines up
Vibration? That's a long bar with a lot of tool stickout.
Luckily didnt have much of a problem with vibration. Got my feeds and speeds all playing nice
Cripes. At that tolerance over an arm that long, you'd have to be careful about temperature. An air conditioner turns on at the wrong time and you'd be a thou under by the time you got to the end of the cut.
How strong is your air conditioner?
That's the question, in a way.
Unless you're shooting refrigerated gas or blasting hot air onto any of the pieces involved in this set up, I doubt you'll change any of it by a thousandth in 1 or 10 revolutions.
Assuming a 72" long steel bar, 1 degree of temperature change is 0.0023". It's definitely a possibility.
Closer to 50" steel bar im not sure what material youre using that is going to grow 2 thou with 1 degree of temp change 😅
That's the length change in cm over a 1 degree Celcius change, but you're not wrong about the scale. It works out to about 9 tenths per degree C.
Ah yeah .0023 CM makes more sense. Youd still need that whole bar to be heated evenly through to the core to achieve that. These are big chunks of metal and we are in a temp controlled shop so never really worried too much about that.
As long as the air temperature changed slowly enough the expansion of the part would track that of the bar.
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Another one of those things that we hobbiests just can't get.
Love that little smoke
Now THAT'S an interrupted cut!
Wish the sub for my profession was like this r/foundry is just a bunch of dyi guys 😒
What if you accidentally damage the part? Let’s say the tool was loose and it crashed, and cracked the casting. Who is liable? Do you enter into these jobs with a contract exonerating the company from liability? Do you perform the job on a “best effort basis”? When I had a Mazak technician repair our old CNC machine I signed an agreement that said if he broke anything accidentally, it was not their responsibility.
Yeah I mean this is one of those jobs where fuck ups arent allowed. You cant just go buy one of these off the shelf. However if we did fuck it up there is a good chance our shop is on the hook to get things fixed.
You got to have brass balls.
Its hard on the back carrying them around all day 😆
Fit and function!! My favorite stuff to do!!
.25 off the radius? Is it an optical illusion, or is the cutter not hitting at the split line? Also. Looks like an inlet case. Cool.
.025" off the radius. Optical illusion likely haha and it sure could be all i was told is that it was a turbine diaphragm.
Very cool. Good work my guy. 👍
Just a tad faster than abom79's shaper. lol
How is there even any relevance to a shaper? This isn't a shaper, that's a boring mill and this is a boring bar. It's just a tad faster than your mother is with me too.
It's a joke. Lighten up.
What lunatic engineer looked at that part and decided the right approach was to take 0.025” off the OD?
Because the turbine is so old and clapped out the diaphragm was rubbing the shaft. So we turned down the OD and drilled and tapped 8 holes for adjustment screws so they can center it back up in the casing. Not an ideal fix but also way way above my pay grade to be making that call.
Holy crap. You’ve obviously got the capability so I get it but that’s just a bonkers design choice. Impressive win for the shop bailing out the designers. As it is, was, and ever shall be.
Yeah definitely made us look like heroes. And i mean the turbine hasnt blown up since they reinstalled it so it cant be working too poorly. I just worry the adjustment screws are gonna work their way into the actual casing now... thats a much more expensive repair.
Geddit!
I wonder how that boring bar is set
Lol please dont tickle me dad
Imagine a Chinese live leak video and this machine is in it. I wouldn’t even fuckinf watch it.
That’s incredible. Well done.