Paging ToolMaker

borg
Posts
5717
Joined
12/7/2009
Location
Long Beach, CA US
5/1/2022 2:22pm Edited Date/Time 5/3/2022 2:13pm
Some shoptalk here:
I have always heard that using the compound at 30 d, reduces chipload. I don't think it does. If you make the thread with the same number of passes as a straight plunge, the chipload is the same and it's mostly on one cutting edge. It has to be the same because in the end you are removing the exact same amount of material. To me, the only reason to use the compound is because you don't have to remember any dial positions except 1. It's more foolproof but you don't have to set the compound at 30 degrees. You can set it to anything between 0 and 30.
Does this make sense?
|
Sprew
Posts
387
Joined
4/1/2008
Location
US
5/2/2022 12:55am
Hey Borg. Trying to determine what you are having a problem with. Are you cutting a thread on a conventional lathe or talking about a lead angle?
borg
Posts
5717
Joined
12/7/2009
Location
Long Beach, CA US
5/2/2022 5:44am
Sprew wrote:
Hey Borg. Trying to determine what you are having a problem with. Are you cutting a thread on a conventional lathe or talking about a lead...
Hey Borg. Trying to determine what you are having a problem with. Are you cutting a thread on a conventional lathe or talking about a lead angle?
Not having a problem. I'm challenging the reasoning behind a method that is considered "doing it the right way".
This is an engine lathe forming standard UNC, UNF and metric threads with a single point. The commonly recommended method is to set the compound at or just below 30 degrees and use that to plunge the cutting tool which loads the left face of the cutter with almost all of the chipload.
lestat
Posts
1766
Joined
10/3/2008
Location
Piut RE
5/2/2022 8:16am
Coming from the cnc lathe and working on mostly API threads , I believe it works better because of the smaller contact surface , which is less likely to vibrate . A narrower groove insert will vibrate less than a wider one under the same conditions , which leads me to this conclusion . Having said that , there have been times where I used a straight plunge to get rid of vibration that I was getting when coming in on an angle ….so no hard and fast rules I guess .
borg
Posts
5717
Joined
12/7/2009
Location
Long Beach, CA US
5/2/2022 2:09pm
The angle approach does use less tool surface and sure, sometimes you have change stuff up to get results. With inserts you end up wearing out one side of the cutting surface much faster. If you are using high speed steel and dressing your own tooling it's a non issue Theoretically you could rotate the compound to 30 degrees in the other direction and wear out the other side to get full life from the insert but on a manual lathe, the backlash would be messing with you.

Typical NPT threads are at a taper of 3/4"/ft. I understand that API uses a different taper.


The Shop

lestat
Posts
1766
Joined
10/3/2008
Location
Piut RE
5/2/2022 2:28pm
Yes , API are bigger tapers , different thread profiles , big diameters , small TPI , tight tolerences to certified gauge … oilfield tools mostly …. pain in the ass lol
Jeremy A.K.
Posts
1098
Joined
1/5/2022
Location
North Tonawanda, NY US
5/3/2022 9:02am Edited Date/Time 5/3/2022 9:03am
I don't know about reducing chip load overall , i sett the compound at 29.5 . Feeding on the compound advances the leading edge into the material .
ToolMaker
Posts
5964
Joined
11/19/2011
Location
Escondido, CA US
Fantasy
927th
5/3/2022 12:24pm
Sprew wrote:
Hey Borg. Trying to determine what you are having a problem with. Are you cutting a thread on a conventional lathe or talking about a lead...
Hey Borg. Trying to determine what you are having a problem with. Are you cutting a thread on a conventional lathe or talking about a lead angle?
borg wrote:
Not having a problem. I'm challenging the reasoning behind a method that is considered "doing it the right way". This is an engine lathe forming standard...
Not having a problem. I'm challenging the reasoning behind a method that is considered "doing it the right way".
This is an engine lathe forming standard UNC, UNF and metric threads with a single point. The commonly recommended method is to set the compound at or just below 30 degrees and use that to plunge the cutting tool which loads the left face of the cutter with almost all of the chipload.
So I don't think I've single pointed a thread in close to 40 years. I was taught like everyone else the just under 30deg
and in. We did not have any carbide tools in the shop, all hss tooling in our shop. I don't think the chips would come off the tool as well going straight in. After I started designing the machines I was more valuable doing that then doing the machining. I'm actually starting to learn/relearn some new things. Going to start playing with and older Mori Seiki soon.
Also, finally getting good parts of the router.
TM
borg
Posts
5717
Joined
12/7/2009
Location
Long Beach, CA US
5/3/2022 3:14pm
Sprew wrote:
Hey Borg. Trying to determine what you are having a problem with. Are you cutting a thread on a conventional lathe or talking about a lead...
Hey Borg. Trying to determine what you are having a problem with. Are you cutting a thread on a conventional lathe or talking about a lead angle?
borg wrote:
Not having a problem. I'm challenging the reasoning behind a method that is considered "doing it the right way". This is an engine lathe forming standard...
Not having a problem. I'm challenging the reasoning behind a method that is considered "doing it the right way".
This is an engine lathe forming standard UNC, UNF and metric threads with a single point. The commonly recommended method is to set the compound at or just below 30 degrees and use that to plunge the cutting tool which loads the left face of the cutter with almost all of the chipload.
ToolMaker wrote:
So I don't think I've single pointed a thread in close to 40 years. I was taught like everyone else the just under 30deg and in...
So I don't think I've single pointed a thread in close to 40 years. I was taught like everyone else the just under 30deg
and in. We did not have any carbide tools in the shop, all hss tooling in our shop. I don't think the chips would come off the tool as well going straight in. After I started designing the machines I was more valuable doing that then doing the machining. I'm actually starting to learn/relearn some new things. Going to start playing with and older Mori Seiki soon.
Also, finally getting good parts of the router.
TM
Did you build one?
ToolMaker
Posts
5964
Joined
11/19/2011
Location
Escondido, CA US
Fantasy
927th
5/3/2022 4:24pm
borg wrote:
Not having a problem. I'm challenging the reasoning behind a method that is considered "doing it the right way". This is an engine lathe forming standard...
Not having a problem. I'm challenging the reasoning behind a method that is considered "doing it the right way".
This is an engine lathe forming standard UNC, UNF and metric threads with a single point. The commonly recommended method is to set the compound at or just below 30 degrees and use that to plunge the cutting tool which loads the left face of the cutter with almost all of the chipload.
ToolMaker wrote:
So I don't think I've single pointed a thread in close to 40 years. I was taught like everyone else the just under 30deg and in...
So I don't think I've single pointed a thread in close to 40 years. I was taught like everyone else the just under 30deg
and in. We did not have any carbide tools in the shop, all hss tooling in our shop. I don't think the chips would come off the tool as well going straight in. After I started designing the machines I was more valuable doing that then doing the machining. I'm actually starting to learn/relearn some new things. Going to start playing with and older Mori Seiki soon.
Also, finally getting good parts of the router.
TM
borg wrote:
Did you build one?
No, no time. And it's a good thing because I probably would have done it using belts and smaller steppers.
This thing has some pretty nice linear bearings and large ball screws. Also, I probably would have used a handheld router. This has a spindle that is almost noiseless. Of course the big chip collector vacuum makes a lot of noise.
4ft X 4ft x 5in. I also probably would have made it smaller. The bigger size and better build makes it more versatile.
This is the one we bought. Keep in mind the price doubled since we purchased ours. Pretty sure this will handle
not so demanding aluminum work also.
https://www.elephant-cnc.com/pro/1212-desktop-advertising-cnc-machine/
TM
borg
Posts
5717
Joined
12/7/2009
Location
Long Beach, CA US
5/3/2022 5:33pm
OK so you got a real one. I started with a De Walt router and eventually went to the water cooled spindle. 2.2 kw. Huge difference. Now I have a good spindle mounted to a shitty router frame.
I will check out the link.

Post a reply to: Paging ToolMaker

The Latest