Will notches in a tapered seating surface affect performance too much

[TorontoBuilder]

I want to make a D1-3 to stronghold chuck adapter since Oneway only makes adapters for screw mount spindles.

I'm not interested in a debate (too much anyways) on the advisability of turning wood on a metal lathe, I more wish to know if this may be unsafe or lacking good alignment.

The stronghold chucks mount on a 1" long spigot with a 3+ degree taper. The chuck is secured by two opposing M5 screws from the rear of the adapter. These two holes are slightly over sized and unthreaded.

Two M5 threaded holes offset 90 degrees allow screws to be inserted to push the chuck off the spigot for removal.




Sadly, all four holes land right in the D1-3 spindle taper surface. Two of the holes are larger to accommodate the socket screw head. I can use grub screws in the threaded holes to push off the stronghold chuck and therefore have a smaller notch in my tapered seating surface. Still there will be 4 evenly spaced notches in my tapered surface.



Any foreseeable issues that make this a non-starter?

I'll only be using this on the chippie so I cant throw any wide heavy bowls due to the small lathe size. I more want to turn tool handles, small round boxes, and small bowls and decorative wood items

 

[whydontu]

Completely uneducated response. I doubt the notches will have any effect on anything. As long as they are deburred with no projecting bits, so it doesn't scar the lathe spindle nose. Even then, highly unlikely since the nose is probably hardened and your adapter will be soft(er). There's no way you could put enough radial load on a wooden workpieces to deflect the adapter or overload the spindle taper.

 

[TorontoBuilder]

Completely uneducated response. I doubt the notches will have any effect on anything. As long as they are deburred with no projecting bits, so it doesn't scar the lathe spindle nose. Even then, highly unlikely since the nose is probably hardened and your adapter will be soft(er). There's no way you could put enough radial load on a wooden workpieces to deflect the adapter or overload the spindle taper.

Thank you for the reply, and cogent reasoning. I trust your judgement enough to try it.

Yes, I would be sure to eliminate any burrs, and the chuck will me unhardened since I cant see that being necessary.

 

[PeterT]

That's a hefty chunk of iron with a lot of precision surfaces. A standard D1-3 chuck adapter would save some finicky machining work adapting to the metal lathe side (big lump of iron + spindle nose taper + studs + retention screws). That would leave how to encompass the Stronghold spigot, but I would think if you bolted an oversize blank & turned it in-situ, it would be the best approach. You could even make an oops & just bolt on another - much smaller piece of steel.



Maybe another option is just turn a Stronghold matching spigot with a plain cylindrical end (or hex sided if you are worried about torque) so you can hold that side in your 3J (metal) chuck?
<edit> oh I think I see your issue - the bolts are rear to front mounted? <edit-2 so the shank would have to be reduced if feasible>


Not sure if this is the system but maybe another option is buy some soft jaws for your metalworking chuck & drill them to match the bolt pattern of the Stronghold?
(ie turf the Stronghold chuck part & just use their jaws)

 

[TorontoBuilder]

That's a hefty chunk of iron with a lot of precision surfaces. A standard D1-3 chuck adapter would save some finicky machining work adapting to the metal lathe side (big lump of iron + spindle nose taper + studs + retention screws). That would leave how to encompass the Stronghold spigot, but I would think if you bolted an oversize blank & turned it in-situ, it would be the best approach. You could even make an oops & just bolt on another - much smaller piece of steel.

View attachment 53144

Maybe another option is just turn a Stronghold matching spigot with a plain cylindrical end (or hex sided if you are worried about torque) so you can hold that side in your 3J (metal) chuck?
<edit> oh I think I see your issue - the bolts are rear to front mounted?
View attachment 53146

Not sure if this is the system but maybe another option is buy some soft jaws for your metalworking chuck & drill them to match the bolt pattern of the Stronghold?
(ie turf the Stronghold chuck part & just use their jaws)
View attachment 53145

This, this is why I post such things.

I got fixated on my design concept, and never thought of just making an adapter spigot that can clamp in a 3 jaw or better yet in a 5C 1 1/8" collect, since the 5C will be on my lathe most often.

I guess that was just too easy because I was thinking of the learning experience as well as the end product. I have plenty of other things I can learn on.

 

[Stuart Samuel]

I want to make a D1-3 to stronghold chuck adapter since Oneway only makes adapters for screw mount spindles.

I'm not interested in a debate (too much anyways) on the advisability of turning wood on a metal lathe, I more wish to know if this may be unsafe or lacking good alignment.

The stronghold chucks mount on a 1" long spigot with a 3+ degree taper. The chuck is secured by two opposing M5 screws from the rear of the adapter. These two holes are slightly over sized and unthreaded.

Two M5 threaded holes offset 90 degrees allow screws to be inserted to push the chuck off the spigot for removal.

View attachment 53133


Sadly, all four holes land right in the D1-3 spindle taper surface. Two of the holes are larger to accommodate the socket screw head. I can use grub screws in the threaded holes to push off the stronghold chuck and therefore have a smaller notch in my tapered seating surface. Still there will be 4 evenly spaced notches in my tapered surface.

View attachment 53134

Any foreseeable issues that make this a non-starter?

I'll only be using this on the chippie so I cant throw any wide heavy bowls due to the small lathe size. I more want to turn tool handles, small round boxes, and small bowls and decorative wood items

On the advisability of turning wood on a metal lathe, I do it semi-regularly. So if it’s a terrible sin, you’ve got company.

I end up making or modifying spinning chucks to suit dimensioned drawings, and I find it a really convenient way to hit my marks, and then just blend/interpolate between.

 

[Susquatch]

On the advisability of turning wood on a metal lathe, I do it semi-regularly. So if it’s a terrible sin, you’ve got company.

There's no way you could put enough radial load on a wooden workpieces to deflect the adapter or overload the spindle taper.

I'm not interested in a debate (too much anyways) on the advisability of turning wood on a metal lathe, I more wish to know if this may be unsafe or lacking good alignment.

I wouldn't be interested in a debate either. I've done it for 50 years and I'm not about to stop regardless of other opinions.

I routinely use my metal lathe to turn wood. And not just intentional wood projects. I often make steel prototypes out of wood first. Costs less than steel and I don't have a 3D printer. Wood chips vacuum up real easy. If there is a downside, I've never heard it and I wouldn't care.

 

[mbond]

You can count me in on using 'metal' tools for wood too. The reverse is much harder, but carbide and HSS can cut softwood and hardwood quite well. The motion of a machine tool bit through the work is less organic then a hand controlled chisel, but it is equally possible to use those tools with a modified tool post

I have a very small space, so I have no choice. But I wouldn't hesitate no mater what. The biggest risk seems to be that sawdust absorbs more oil than other kinds of chips and the ways need to be oiled more.

 

[TorontoBuilder]

You can count me in on using 'metal' tools for wood too. The reverse is much harder, but carbide and HSS can cut softwood and hardwood quite well. The motion of a machine tool bit through the work is less organic then a hand controlled chisel, but it is equally possible to use those tools with a modified tool post

I have a very small space, so I have no choice. But I wouldn't hesitate no mater what. The biggest risk seems to be that sawdust absorbs more oil than other kinds of chips and the ways need to be oiled more.

I seem to recall that you too are in Toronto? Or am I misremembering?

It is hard to afford any space in Toronto so not surprising. I'm trying to make my shop work for wood and metal as much as possible. Then I have brother's for fall back with greater capacity. If you ever need to use equipment you dont have access to ask if we have it. If we do you're welcome to come use it or borrow it if transportable