How to cut narrow angles (chamfers) on minlathe?

[matthew-s]

Hello all:

I have a Micromark 7x16. There have been a few times where I've needed to cut a very shallow angle (say 15* or less - such as the chamfer on a bolt head)

I overcame one issue - the fact that the protractor is only graduated to 45*, by using a separate adjustable protractor.

The second issue is that at these angles the cross slide and compound dials crash into each other - you cannot feed the compound direction w/o hitting the cross slide dial.

Is there anyway to overcome this? Am I missing a simple solution? One way I suppose it so grind a tool bit to this angle, but I've found pretty quickly the lathe runs out of rigidity and you get a lot of chatter.

Thanks,

Matt.

 

[markba633csi]

Are you able to swing the compound around so the dial/handle is at the rear?
-Mark

 

[matthew-s]

Are you able to swing the compound around so the dial/handle is at the rear?
-Mark

Only if I remove the chip guard! Not at all difficult (I need to get behind the machine and unscrew it all), but geez, sure seems like it should not be necessary!?

 

[JimDawson]

I normally use a file, or just bring the edge of the tool bit in and touch the edge, then maybe finish with a file. Safety note: Make sure you use a file handle and keep clothing and body parts away from the spinning things when using a file.

 

[markba633csi]

Darn chip guards. Not that I'm against safefy, but they sure get in the way sometimes. I think the majority learn to work safely without them
-Mark

 

[matthew-s]

Darn chip guards. Not that I'm against safefy, but they sure get in the way sometimes. I think the majority learn to work safely without them
-Mark

Sometimes! Although in this case it keeps me from growing a swarf pile behind the machine, so I sort of like this one!

 

[mikey]

I normally use a file, or just bring the edge of the tool bit in and touch the edge, then maybe finish with a file. Safety note: Make sure you use a file handle and keep clothing and body parts away from the spinning things when using a file.

I'm with Jim. Most of the time I just rotate the tool and use the edge of the tool I'm using to turn the work piece and put a quick chamfer on the end. Takes a few seconds.

 

[higgite]

I have a dedicated chamfer tool. It looks sort of like a threading tool except with a 90* included angle. Makes a 45* chamfer. With a QCTP, it’s quicker to change tools than mess with adjusting the angle of the tool post or compound. But, that’s a 45* chamfer. For your 15* chamfer, you could use a similar tool with a 15* face or a tool with whatever angle and turn the tool post as Mikey suggested. Lots of options.

To just knock an edge off, I use a file like Jim suggested.

Tom

 

[savarin]

Only if I remove the chip guard! Not at all difficult (I need to get behind the machine and unscrew it all), but geez, sure seems like it should not be necessary!?

On my 9x20 I extended the rear of the splash guard by around 12" to get more clearance for what I didnt know at the time but since it has been a "temper" saver.
Might be worth a look to see if its a viable option for you.

Do I need a backsplash, if so how big?

Setting up a 1943 Logan 820. Most of my work will be with plastics and ebonite, some metal. Does the 820 actually throw oil behind it? If so how high? My wall is 14" away from the rear of the base tray and 2' from the motor assembly. Many thanks, Tim

www.hobby-machinist.com

Mines at post 14