While most of us G0766 owners have long since made these two mods to our lathes, there seems to be newer owners that are having to chase information from all over the place, so I thought it advisable to put the two things we owners have done and how to do them........please note: Spindle boss modification - the spindle boss is the raised area that is behind the flat directly behind the threads on the spindle. That area is made to 1.260" diameter, and most aftermarket chucks have a 1.250" inside diameter, which makes the chuck not seat all the way back to the shoulder of the spindle face. The correction is to take a flat file, and hold it against the spindle boss, take off a bit, check the fit, several times until your inserts fit flush against the face of the spindle. You want to have the lathe running at about 500 rpm, and when your inserts fit all the way back, polish it up with 400 grit and 600 grit, and it will look new.
part 2 - Banjo hole enlargement - The banjo comes with a 25mm hole for the toolrest post. Most aftermarket toolrests, and hollowing jigs, threading jigs, etc have a 1" post. Easy to enlarge and only needs to be bored out by 1/64th" to make the 1" fit. Best to use a drill press, with a 1" twist drill bit, and use some oil to lubricate the cut. Make sure you have the banjo clamped down on your drill press, and the bit spinning slowly at about 300 or so rpm. If you need to use a hand drill, then clamp your banjo on the bed of the lathe, use oil, and have your bit spinning slowly as you enter the cut. Going too fast can break your wrist! Disclaimer: I did my former G0698 banjo with a corded hand drill with this technique, but each person is responsible for their own safety and I assume no responsibility for what you do.
Part 3 - Also note: Robust makes custom tool rests with a 25mm post, so they are available if you want to go that route, but most aftermarket accessories use a 1" post, so in my opinion the 1" hole is the way to go. Robust rests for the G0766 - If you want Robust toolrests for your G0766, then order custom rests that have a total height of 8-3/4" [8.75"] top of the rest where the gouge sits to the bottom of the post, as this will allow you plenty of post down into the banjo. 8.5 can be used, but that extra 1/4" is the best and gives more stability. owners - if you have what you believe is important other information, feel free to add to this thread, but I wanted to focus on the mods that most of us have done. Things like potentiometers, etc can be added here so as to consolidate information in one easy to access thread.
I have a Robust 6" tool rest with a 1" shaft. I have bored out my banjo with a 1" bit on a drill press. The Robust tool rest won't fit in the banjo. I have read that some after drilling polishing or sanding might be necessary. What is your experience?
Jeff...at times some bits may be just a hair under the 1" size, like the silver & deming bit from DeWalt that I used. The fit was just a hair too tight, so I took the bit, put into my hand drill and did a little side to side action with the side of the bit, in a circular motion...that gives just enough relief that my 1" Robust rests are perfect. Now, please know also, that they use 1" bar stock, which is not always exactly 1" diameter... that can vary from vendor to vendor, run to run from the steel factories!
I have purchased the bit to drill my banjo hole, just haven't found time to actually do it yet. Any tips on getting the bit perfectly centered over the existing hole? I'll be using a drill press as well.
With the drill press off, just lower your bit into the top of the hole. Center as well as you can [the taper of the bit on the end should just about go in]. Once happy, clamp down the banjo, then put oil around the hole, and on the bit sides, then drill at 300-400 rpm slowly advancing the bit through the hole. It would be good to not hit the lock down bar inside the banjo. I diassembled my banjo, taking the inner parts out, then reassembled once completed.
Good advice, Roger.
Bump. ... this needs to be at the top of the list for new G0766 owners.
On the spindle boss mod, does anyone have photos of this?
