PM-1660TL

[Winegrower]

Just by a visual impression, the threads do not seem to be symmetrical. I have seen this when I have set the compound at the wrong angle or had the tool not truly normal to the X axis. Yes, I have done both.

if it’s just something about the photo, disregard.

looked at it again...probably the lighting made me think that. Forget this post. ;-)

 

[ahazi]

Just by a visual impression, the threads do not seem to be symmetrical. I have seen this when I have set the compound at the wrong angle or had the tool not truly normal to the X axis. Yes, I have done both.

The thread looked strange to me too. It happened to me on my first threading attempt... You need to have the compound reading 60 degrees not 30 and it is easy to verify with a nut.

Ariel

 

[AlanB]

I did some further research on using circuit breakers as switches. It's been some years since my NEC electrical safety training.

Here's what I found:

The NEC code allows breakers to be used as switches in several circumstances, with some requirements. The breaker must have the requisite number of poles. It must clearly indicate on and off, and on must be up if mounted vertically. If the load is fluorescent or HID lighting circuits the breaker must be appropriately marked for switch service for these loads. NEC does not require special breaker ratings or markings for other types of loads.

Many sources say using a breaker as a switch is not recommended. Others say they have done it for years, and it is standard practice in many places.

Home circuit breakers under 100 amps are tested for 10,000 cycles, over half of which are at significant current levels. Tripping is much harder on a breaker than switching, and breakers are only rated for a small number of trips, depending on the fault current.

In a home shop where the breaker was switched less than once per day it would likely last a very long time.

Internet searches are hardly exhaustive proof, but unless the NEC prohibits this use, and if the user is willing to replace the breaker when it wears out, it may be a feasible option.

Plugging in a rotary phase converter that instantly starts spinning up the motor seems like a less than ideal situation itself. Starting a VFD has a similar large surge to charge up the bus capacitor bank. These situations place large starting currents on a small section of the partially inserted plug. This may be hard on the plug and jack causing pitting and premature failure. The spring loaded breaker contacts will make up much more quickly than a plug insertion.

Reading back through the thread "mksj" seems to be saying pretty much the same. A circuit breaker is not recommended to be used as a switch but can be used (within NEC rules) and is more acceptable than the plug. Of course for those not under NEC jurisdiction other regulations may apply.

Regards,

 

[erikmannie]

I got the day off (with permission!) to stay home & play with this lathe.

On tap today is turning an 18” long piece of 2” cold rolled steel to see what taper I turn. I had the lathe pretty level, but I am sure that the machinist’s level will come back out to really dial in the leveling.

BTW I am turning this 2” stock at 180 RPM. The feed rate is .004” per revolution. So far my cuts have been between .004” & .007” (off of the radius).

I will also be seeing how nice of a finish I can get with my carbide insert, so I will be making much smaller cuts & turning the feed rate down to .002” per rev.

Here is a picture where I am finishing my roughing cuts:

 

[erikmannie]

So this surface finish looks poor after a pass of .006” with no spring pass. I am blaming this on too much CF.

I measured a change in diameter of .002” over 17”, so I will check the leveling.

 

[Aukai]

With carbide, and looking up 2" 12L14, the calculator says 1500 RPM?

 

[ddickey]

If you're checking taper don't use the tail stock.
Are you sure your tool is on center or just a hair below?
Are you trying to turn that length? If not bury the piece in the chuck. You don't need 18" to check for taper.

 

[mmcmdl]

JMO . Your rpms are very slow as is your feed rate . Take a real cut at 1250 rpms and .005 feed and increase that DOC and see what you come up with . That carbide is rubbing and not cutting .

 

[erikmannie]

I saw that my turning tool was a little too high. That is strange because I thought it was centered the last time I was turning.

I centered the tool & changed the RPM to 250 and the feed rate to .0022” per rev.

This is a pass of .001” with no CF.

 

[erikmannie]

If you're checking taper don't use the tail stock.
Are you sure your tool is on center or just a hair below?
Are you trying to turn that length? If not bury the piece in the chuck. You don't need 18" to check for taper.

JMO . Your rpms are very slow as is your feed rate . Take a real cut at 1250 rpms and .005 feed and increase that DOC and see what you come up with . That carbide is rubbing and not cutting .

How much of a length should I turn to check taper?

Thanks for the input. I will set feed to .005” per rev & increase RPM to 1200.

I have heard that carbide likes a deep cut & high RPM.