Problems with Engraving Pen Blanks with Neje and Rotary Jig

[Larryreitz]

I have my new Neje 1500 up and running and would like to thank all those whose generous help got me around a couple of obstacles.

Now I would like to enlist some more help this time for engraving pen blanks with the rotary jig from T. Shadow. I have been trying to burn the 2nd Amendment as show in the first picture. It burns fine on flat stock, again pic #1. When burning a blank on the rotary jig not so much. The subsequent picture illustrate the problem. Some lines burn correctly and some burn thinner and smaller than they should. The picture was made in Photoshop and imported to the Neje software as a jpeg file. It is as if the font is changed, when it has not. Also the flat stock burn is the correct size. When the same file is burned on the pen blank it should go nearly completely around the circumference. Coverage varies from burn to burn but usually covers only half the circumference. The problem is illustrated on subsequent pictures. A few pictures of the set up are also include. Please pardon my messy desk. One thing of note (I don't know how important it is) is the laser beam hits the pen blank at about 11:00 rather than 12:00. Any suggestions would be greatly appreciated.

Larry

 

[Sylvanite]

Your rotary jig is not turning the piece at a consistent rate.

 

[SteveJ]

Although i don't have the 3500, you should be able to adjust where the beam starts to have it center on the blank, you can do that with the Neje 1500. It also won't rotate at the same speed of the "belt"isn't tight enough.

 

[MillerTurnings]

I have the same problem and have pretty much given up on it. Check the outer diameter of the bushings to make sure they are smooth, mine had ridges. After trying to smooth them out a little, the bushing then was sloppy in the upright. This allowed the blank to move slightly sideways instead of turning. I couldn't get consistent results, and have moved on.

 

[Larryreitz]

Your rotary jig is not turning the piece at a consistent rate.

I wonder what would cause it not to turn at a consistent rate. I have tried different tension by tightening the belt on the jig and the results are the same. the jig turns smoothly by hand, but that is probably more force than the Neje provides.

 

[Larryreitz]

I have the same problem and have pretty much given up on it. Check the outer diameter of the bushings to make sure they are smooth, mine had ridges. After trying to smooth them out a little, the bushing then was sloppy in the upright. This allowed the blank to move slightly sideways instead of turning. I couldn't get consistent results, and have moved on.

The bushings supplied are less than smooth. I have used a pen bushing in place of them which is very smooth and it turns about the same. I'm wondering if the mechanism that hold the jig in position may have a slight defect which causes it to hold up. I'm tempted to put a drop of oil in the bearings (or whatever you call them) and see if that solves the problem.

 

[MRDucks2]

Appear to be either slightly slipping or slightly binding. I have a different laser but in mechanical rotary jig trials, slipping/binding produced a very similar effect.

 

[Larryreitz]

Although i don't have the 3500, you should be able to adjust where the beam starts to have it center on the blank, you can do that with the Neje 1500. It also won't rotate at the same speed of the "belt"isn't tight enough.

I'm not familiar with the 1500. On the 3500 there is a fixture which holds the rotating part of the jig in place. It its pushed onto the plate on the bottom part of the Neje carriage. To get the laser beam at 12:00 the fixture has to be backed out and then it can move around and doesn't hold as well. To me it appears to be a design flaw.

 

[larryc]

I used the NEJE 1000mw quite successfully until it started compressing the top line. I quit using it for a while and when I tried it again it caused my Mac to crash. I saw somewhere that the compression can be cured by lubricating the rails that are driven by the stepping motors. I'll have to give that a try.