Is there a Downside to this idea?

[William C Rogers]

I am selling my Powermatic 90. I had bought 5 Robust tool rest with a 1-1/8 post that will not fit the new lathe banjo with a 1" post requirement. However looking at the offset banjo I had for the PM 90, the post is removable an it could be turned down to fit the 1" banjo. I could then use my 1-1/8" Robust tool rest. Kind of an articulating arm banjo that would allow multiple positioning. I can't see any negative to this, but want to make sure I'm not missing something. I don't believe there would be any undue stress on the lathe or banjo. It's kind of a no value gained trade as the offset and tool rest are worth about $400 and new Robust with 1" post are about $400. What would you recommend, keep the offset with added flexibility or just get new tool rest? If I keep them I could also drop the price of the PM 90.

here is a picture of the offset banjo.

IMG_0971.JPG

[Mike Goetzke]

Someone had a similar issue recently and a Creeker suggested using a Robust "dog-leg." Maybe give Robust a call because I can't see the shaft size of it on their web page.

Mike

[William C Rogers]

The Robust dog leg is 1" to 1" and does provide an offset. It basically helps someone who has 1" post, but their post is a little short, the dogleg provides some added length. I'm the same with what I am thinking, but my offset will be about 6".

[Mike Goetzke]

The Robust dog leg is 1" to 1" and does provide an offset. It basically helps someone who has 1" post, but their post is a little short, the dogleg provides some added length. I'm the same with what I am thinking, but my offset will be about 6".

Might be worth a call - they have made non-standard components for customers in the past.

[John Keeton]

Bill, because of the design of the Revo banjo, I am afraid using the dogleg offset you propose would make it difficult to gain clearance of the work in certain situations. It would be a shame to create a cumbersome situation for your new lathe setup. I would suggest reducing the price on the PM, and selling the rests you have. Use the funds to purchase 2-3 new Robust rests. Not sure why you had 5 rests as I have never needed more than 3 at the most, but your needs may differ.

[William C Rogers]

Bill, because of the design of the Revo banjo, I am afraid using the dogleg offset you propose would make it difficult to gain clearance of the work in certain situations. It would be a shame to create a cumbersome situation for your new lathe setup. I would suggest reducing the price on the PM, and selling the rests you have. Use the funds to purchase 2-3 new Robust rests. Not sure why you had 5 rests as I have never needed more than 3 at the most, but your needs may differ.

Well it was a thought. I guess Mickey Mouse popped into my thoughts. The 5 rest I had was the 4" straight, 12" Straight, inside bowl, outside bowl, and J rest. Looking forward I would only get the inside bowl, outside bowl, and 4" straight. Supposedly the 12" Laguna has a hardened tool bar, but may not be as good as the Robust. I'll use it to see how it works.

[Reed Gray]

My main worry about that set up would be vibration issues. Makes me think of the 'extended arm tool rests' for the first pivoting head lathes years ago. They were slightly more rigid/stiff than a slinky, but not much. Vibration is one issue, another would be a catch as cast iron is a bit brittle, and could break if you have a 12 inch rest on an 8 inch extension.

robo hippy

[Brice Rogers]

Some out of the box thoughts:

You said: "I had ...5 Robust tool rest with a 1-1/8 post that will not fit the new lathe banjo with a 1" post requirement. " Idea 1: If there is enough "meat" on your new tool rest, perhaps you could enlarge it to 1-1/8" opening. That is only 1/16" all the way around. I realize that it may be psychologically painful to do this with a new lathe. Many banjos are cast iron and it drills pretty easily. Many Grizzly G0766 owners have drilled out their banjos. But you really need to do this on a drillpress with the banjo clamped down. You can buy 1-1/8" Silver and Deming drills that are necked down to 1/2" at the butt end.

Idea 2 (requires you to either weld or know a friend who can weld): Cut off the bottom of the tool rest by an amount about 1" longer than the amount of insertion of the post. Then cut up some 1" diameter steel the same length and butt weld. You'll end up with a tool rest whose shaft is 1" at the bottom and 1-1/8" at the top. (BTW, before you butt weld them, make sure that the 1" diameter new shaft fits into the banjo. If not, chuck up the not-yet-welded 1" shaft on your wood lathe and live center and carefully use a file and/or sand paper with slow strokes and occasional clearing of filings. It is a decent way to take off a few thou and shines up the shaft).

[John Keeton]

I would not think it wise to drill out the banjo. While it doesn't sound like a lot, it is 8 times the amount of material removed by Grizzly owners. That banjo was presumably engineered for it's intended purpose. Should it thereafter fail, not only could there be a risk of injury, but you would have materially altered a critical part of the lathe. I suspect any manufacturer would take the position doing so would invalidate the warranty.

Putting new posts on the old rests might be a workable and affordable option.

[William C Rogers]

Functionally it would work, but it would not be as good as getting the right tool rest in the first place. And really no savings if I sell the tool rest. I am going to sell the tool rest and buy new rest from Robust.

Reed, I used the setup occasionally on the PM 90. There are no vibration issues on the PM 90, but it is more mass then the Laguna. It's about 1-1/2" thick, so a cast tool rest would break first. These were designed for outboard turning and would see a lot of abuse.

Brice, appreciate your thoughts, but I could sell the tool rest and offset banjo and just get the right size. I measured my stock tool post and it is 0.999". A 1" post should fit fine.

John, I'm not going to break my new rule and modify things to work. I did enough of that with the PM 90. I am going to buy the right tools necessary to do the kind of turning I want to do. The only thing I will do is make my vacuum chucks and adapter.

[Rich Colvin]

I must say, any post that starts with "is there a downside to..." sounds like something that will be a great story later. It's like the ones that start with, "hold my beer ...".

[Dennis Ford]

Personally, I would not be worried about weakening most banjos by drilling it out from 1" to 1-1/8" BUT would be concerned that I had then created a need for custom accessories in the future. IMO the best choices would be selling the custom tool rests or having them cut down to 1" (this can be done with a milling machine and boring head turning in reverse).

[John Keeton]

This might otherwise be a moot point since Bill has already made his decision regarding the toolrests.

However, hundreds and often thousands of folks view Sawmill Creek and some rely on the information posted here. For that reason, I think it is relevant to distinguish the Laguna banjo from "other banjos."

Most banjos consist of a hole in cast iron through which the toolrest post is inserted. A turnbolt is tightened against the post of the toolrest in order to hold it in place.

The Laguna banjo is actually "split" and when the post is inserted, the "hole" is squeezed tight by the turnbolt. Because of this there are stress factors on the cast iron surrounding the toolrest post that would different from those in a "standard" design banjo and perhaps not even present.
IMG_4279.jpg

Aside from the issues of modifying a brand new lathe to fit an odd size toolrest, and the obvious warranty issue, I still think it unwise to remove material from the Laguna banjo. I would not want folks viewing this thread walking away thinking the Laguna banjo is the same as "most banjos" that are similar in design to the Powermatic banjo.

[Ted Reischl]

The Laguna banjo may well NOT be cast iron. It could very well be ductile iron. Most designers I know would not use regular cast iron and then try to squeeze it around something, just asking for a crack. Ductile iron is a different story.

[John Keeton]

Ted, you may be correct. I honestly don't know, but that may or may not change my thoughts on such a modification.