[4]

[Newbie] Feeds and Speeds not going well & Pecking?

[3]
[10] Like what you see?
Click here to donate to this forum and upgrade your account!

awaqa909

Active Member
Registered
Joined
Jan 28, 2017
Messages
47
Likes
9
#1
I've learned how to turn SFM into RPM and find a Feed speed in inches. However it seems the Speeds and Feeds I'm using are not doing too well in tool longevity/noise/smell. I wonder what people use 30k spindles for when any speed I've come up with are less than 3000rpm. I've been working with AW36 steel and 304 Stainless steel and now some other type of steel. For now I want to talk about drilling and pecking. The machine I've been using at this time is a Haas VF-0 7.5k spindle, 20 tools, auto coolant aim. We seem to have a fair amount of YG drills in Gold-P and HSS. At the time I was using a .25" Gold-P drill which is a gold coating maybe TIN? Not too sure at the moment. Despite looking on their website and googling, I can't find any speeds and feeds for them.

I was drilling a through hole in 304 SS about .312" thick with .25" drill. I was trying out 100SFM which was 1528 RPM and F6.112 which comes out to .004IPR. The program has a centerdrill (still learning about centerdrills and stub drills) that dimples the part and then the drill comes. I changed the drill's Q value to peck a total of 4 times vs 18 times Q0.1125 Think it was about Q0.025" Z-0.45" (0.10" shim when measuring tool offset, we make the program +0.10" the depth we need to go, not sure if that's something that needs to change too or what) With these settings it sounded good and was fast, but after about 20 holes, the corners of the drill were well worn and pushing a balloon on the bottom side of the part. Although, the hole accuracy didn't seem to change.

Now we've got a .5" steel plate that gets about 8, .312" (5/16) though holes. Z-0.75 Q0.1 F9 (Drill depth, Peck amount, Feed) 1500RPM It's just under 130SFM (Don't know how to convert the other way around) This setup seems to run stable, but not as fast as the internet makes me think it could be.

On youtube and reading I see things like you can peck x4 the diameter of your drill, 1/2" depth is 0 peck I'm trying to google other brand S&F charts for these YG drills and I get too big of a range. What is worse, too much RPM or too much Feed? We've got some carbide insert endmills (cutters?) and I've looked up the S&F for those inserts and can't get near it without the machine sounding/vibrating like it's going to fall apart. I was wondering if you're supposed to ignore the noise and go off of load meter and smell? (Been cooking up coolant these last few days)

What am I doing wrong with my Speeds and Feeds? Does that amount of pecking sound realistic? Is it supposed to sound and vibrate like that? Pretty much have to yell at someone 1 ft away for them to understand what you're saying. I've been trying to watch Haas machining videos on youtube.

Thanks,
Awaqa909
 

Bob Korves

H-M Supporter - Sustaining Member
H-M Platinum Supporter ($50)
Joined
Jul 2, 2014
Messages
5,848
Likes
6,159
#2
Are you making parts commercially or are you doing hobby work? When your costs for employees and other stuff are a big part of your overhead, then you need to get it done. Also if you you have back orders and customers who want their parts yesterday. In a hobby shop, it is about enjoying the ride. Why do your work so you are damaging tools and messing up parts when there is no foreman on your butt telling you to get it done faster?

I am a home shop guy, and I am interested in my machines and tools lasting as close to forever as possible while still getting the work done at some point, no deadlines, and the overriding goal is only MY happiness.

I am not a CNC guy, but I sure see a lot of them trying to match the bushels of chips flying off machines in videos posted by machine builders, tool makers, and hobbyists who like to brag about how many carbide tools they break. Even if I was working commercially, I would start on the slow side and gradually work it up to a point where tools still last for a reasonable period, things don't crash, and good parts keep coming out. I usually find that the faster I try, the slower I succeed. To hell with bragging rights, a commercial business is about making a profit...

Many of the speed/feed charts out there show settings for highly rigid machines, excellent flood coolant strategies, and best quality cutting tools. Not a great place to start, but rather to try to work up to if possible, watching closely for problems starting to develop. Tool and machine sellers have a vested interest in selling more machines and more tooling, don't feed the monsters...
 

T Bredehoft

Active User
H-M Supporter - Gold Member ($25)
Joined
Dec 27, 2014
Messages
2,726
Likes
2,099
#3
I always figger'd that 900 was the ideal/max rpm for 1/4" HSS drills. never mind the coating, it's still HSS underneath that. If any coating was really good, they'd put it on CRS. Granted, carbide's another material.
 

Glenn Goodlett

Active Member
Registered
Joined
May 22, 2017
Messages
40
Likes
20
#4
Maybe have a look at GWizzard to calculate F&S. I was having the opposite problem and going too slow, but, I have come to trust GWizzard.

I'm not associated with them in any way except as a customer.
 

awaqa909

Active Member
Registered
Joined
Jan 28, 2017
Messages
47
Likes
9
#5
Maybe have a look at GWizzard to calculate F&S. I was having the opposite problem and going too slow, but, I have come to trust GWizzard.

I'm not associated with them in any way except as a customer.
I've looked at that before and now that I have some money and am actually getting into programming a little bit, I was thinking about getting it. I thought it used to be way cheaper though. It's $80 year and $270 to buy out. I thought it used to be something like $50... maybe it was something else?
 

JimDawson

Global Moderator
Staff member
H-M Platinum Supporter ($50)
Joined
Feb 8, 2014
Messages
7,255
Likes
5,550
#6
I've learned how to turn SFM into RPM and find a Feed speed in inches. However it seems the Speeds and Feeds I'm using are not doing too well in tool longevity/noise/smell. I wonder what people use 30k spindles for when any speed I've come up with are less than 3000rpm. I've been working with AW36 steel and 304 Stainless steel and now some other type of steel. For now I want to talk about drilling and pecking. The machine I've been using at this time is a Haas VF-0 7.5k spindle, 20 tools, auto coolant aim. We seem to have a fair amount of YG drills in Gold-P and HSS. At the time I was using a .25" Gold-P drill which is a gold coating maybe TIN? Not too sure at the moment. Despite looking on their website and googling, I can't find any speeds and feeds for them.
30K spindles are great for aluminum and plastics, using a trochoidal cutting pattern. We are wishing that our TM-2P had a bit more than 6K spindle speed, we run mostly aluminum and plastics. When drilling, your spindle speed requirement is limited by the tool and material so a high speed spindle is not useful in that regard.

I was drilling a through hole in 304 SS about .312" thick with .25" drill. I was trying out 100SFM which was 1528 RPM and F6.112 which comes out to .004IPR. The program has a centerdrill (still learning about centerdrills and stub drills) that dimples the part and then the drill comes. I changed the drill's Q value to peck a total of 4 times vs 18 times Q0.1125 Think it was about Q0.025" Z-0.45" (0.10" shim when measuring tool offset, we make the program +0.10" the depth we need to go, not sure if that's something that needs to change too or what) With these settings it sounded good and was fast, but after about 20 holes, the corners of the drill were well worn and pushing a balloon on the bottom side of the part. Although, the hole accuracy didn't seem to change.
304 is a PITA to machine. 100 SFM is maybe a bit fast for a HSS drill, maybe try 80 SFM , normally I like cobalt drills for stainless, which should run at 100. I haven't run carbide drills in 304, so I don't have a good feel for that. At 0.312 deep I would do that in one pass with at about 6 IPM. 304 likes to work harden if you look at it wrong. Sharp tools are required, and don't allow the tool to rub. Tool life is not going to be very good in any case.

Now we've got a .5" steel plate that gets about 8, .312" (5/16) though holes. Z-0.75 Q0.1 F9 (Drill depth, Peck amount, Feed) 1500RPM It's just under 130SFM (Don't know how to convert the other way around) This setup seems to run stable, but not as fast as the internet makes me think it could be.
RPM = (SFM * 3.82) / Cutter DIA
SFM = (RPM * Cutter DIA) / 3.82
Tooth Load = IPM / (RPM * Flutes)

On youtube and reading I see things like you can peck x4 the diameter of your drill, 1/2" depth is 0 peck I'm trying to google other brand S&F charts for these YG drills and I get too big of a range. What is worse, too much RPM or too much Feed? We've got some carbide insert endmills (cutters?) and I've looked up the S&F for those inserts and can't get near it without the machine sounding/vibrating like it's going to fall apart. I was wondering if you're supposed to ignore the noise and go off of load meter and smell? (Been cooking up coolant these last few days)
Too much RPM will burn up cutters, too much feed will overload the spindle or just break the tool. You have to find the happy medium.

If you are cooking coolant it sounds like you have dull cutters or are turning too fast. First check the inserts, then back off the SFM, Feed, and DOC. Then increase them until the machine is happy.


What am I doing wrong with my Speeds and Feeds? Does that amount of pecking sound realistic? Is it supposed to sound and vibrate like that? Pretty much have to yell at someone 1 ft away for them to understand what you're saying. I've been trying to watch Haas machining videos on youtube.

Thanks,
Awaqa909
No, it shouldn't vibrate like that. Something is drastically wrong, speed & feed, cutters, or the machine.
 

Bob Korves

H-M Supporter - Sustaining Member
H-M Platinum Supporter ($50)
Joined
Jul 2, 2014
Messages
5,848
Likes
6,159
#8
Unless I have previous experience with a material and cutting tool combination, I always start well below what the various charts suggest for a cutting speed and feed. Then I move the speed and feed up (or down!) as indicated by the results I am getting. Starting low often requires a increase of speed or two, but there are few surprises, broken tools, or other drama. With experience over time, we get better at guessing what will work and what will not for more common tasks. For the oddball jobs, I start by studying the feed and speeds calculators, and then test carefully. Sometimes there are big surprises in what happens, but not often, and less and less with more experience.
 

BaronJ

Brass
Registered
Joined
Aug 7, 2018
Messages
660
Likes
334
#9
Hi Guys,

Probably not directly relevant, more of an example !

Some time ago I built John Moran's "Four Facet" drill grinder,

https://www.gadgetbuilder.com/DrillSharp.html#Facet4

and started to sharpen my old drills. I was surprised by how much better drilling holes became, even better than brand new German made drills.
I found that I could spin the drills faster and the holes were much cleaner, and no chatter. One advantage of four facet drill grinds is I could, more often than not, get away without using a pop mark. The drill not wandering as they normally seemed to do.

The point is that its always a learning curve ! In this case simply drilling a hole.
 

awaqa909

Active Member
Registered
Joined
Jan 28, 2017
Messages
47
Likes
9
#10
My work has a drill sharpening machine... but it has seen better days... Then there is only one guy that I know of, that actually knows how to use it. I do work in a shop. We have time quotas per part and we don't want to be swapping tools too much either. I get put on different machines and that particular machine will spike my interest in wanting to learn it. But haven't gotten very far at all. The one thing I see the most that always makes me question things is the pecking they do when drilling. I used the G Wizard calculator and found speeds and feeds for the parts that were being made before. G Wizard was telling me a lower feed and rpm, but telling me 0 peck. I think this was a .312" drill going .75" deep. Not sure if it thinks it was centerdrilled or stub drilled already. What are conditions that you would start to peck?

I can say the enclosure of the machine was definitely vibrating. There is a little shelf under the controlpanel and you can't put things on it because it will slowly vibrate off. Thoese jobs were .5"~ thick steel plates, 6" Kurt vise and aluminum soft jaws. The parts were only supported on the edges, so unsupported in the middle. That would be a big cause for vibration?
 
[6]
[5] [7]
Top