Tool support (banjo) not staying tight

[David Muehlbauer]

I have a new Jet 1640 lathe and it is great, but occasionally the tool support (banjo) lever refuses to stay down and tight. Seems to happen more when the support is closer to the bed. I have tried loosening the nut, but that hasn't helped.

Any ideas?

 

[Ed Ward]

maybe I am not understanding tbe question but if it is not staying tight I would tighten the nut.

 

[hockenbery]

The locking mechanism on jet like most banjos consists of a curved bar that goes through sort of an eye bolt the goes though a clamping plate. The nut on the eyebolt adjusts where the clamping.

The issue with this mechanism is that the curve of the bar will rise higher in the middle than on the ends.
When adjusting the nut. Test on each end and in the middle.
If you just adjust in the middle it may not clamp on either end and vice versa.

 

[GRJensen]

There was a recent post that sounds like the problem you are having ... I tried the procedure for cleaning/lubricating the support rod on my PM2014 and it seems to have worked. Here is a link to the post ... https://www.aawforum.org/community/threads/spongy-banjo-lock-on-pm2014.18830/

 

[Doug Freeman]

The locking mechanism on jet like most banjos consists of a curved bar that goes through sort of an eye bolt the goes though a clamping plate. The nut on the eyebolt adjusts where the clamping.

The issue with this mechanism is that the curve of the bar will rise higher in the middle than on the ends.
When adjusting the nut. Test on each end and in the middle.
If you just adjust in the middle it may not clamp on either end and vice versa.

Well, its only curved after you use it for a while and it bends. The design is a shaft set eccentrically (off-center) of the pivot/rotating ends in each end of the banjo. Like a short stroke crank in an engine. This is how the clamp bolt, #10 in the drawing, is moved vertically.

The weakness in the design is the shaft will bend when the banjo is centered on the bed and really clamped down. This then makes it difficult to adjust for good clamping everywhere along the length of the banjo. Cleaning certainly cant hurt.

If you cant get it to work for you, check out Oneway’s banjos. They have a unique design that wont bend etc. they sell them separately (you dont have to buy a whole lathe).

 

[David Muehlbauer]

I found that cleaning it helped a lot. Since it was new, it was still coated with a light film of oil from shipping. The combination of cleaning the shaft and loosening the nut seems to have done the trick.

 

[Jim Woods]

I think my 1624-44 has the same banjo. It seems I often have to reach to the nut on the back and turn it a quarter turn to get the banjo to hold.