Reverse Turning Grubscrew - Talon/VM120 - Direct Thread/Insert

[Michael Ogden]

I am about to purchase (most likely) a Laguna 1836. Ideally, I'd like a VM120 direct thread, but those seem to be hard to come by in the US.

In any case, I'm having difficulty determining if either of these chucks, with or without inserts, have some method to keep the chuck from unscrewing when sanding in reverse.

I'm not a machinist - so do I need to find one regardless of which chuck I order?

Thanks!

 

[Marc Banka]

They don’t. Neither direct thread or with an insert.
It worried me a bit, at first. I give my chucks a nice ‘snap’ when installing to make sure they don‘t back off in reverse.

 

[Michael Ogden]

I "snapped" my Nova/Record Power chucks onto my little JET 1221. I never had a chuck come off, but I've had them wobble loose as I was sanding if I forgot to tighten the grub screw. Of course these chucks are about twice as heavy as the dinky Nova, so a snap may mean more.

 

[Michael Ogden]

They don’t. Neither direct thread or with an insert.
It worried me a bit, at first. I give my chucks a nice ‘snap’ when installing to make sure they don‘t back off in reverse.

Oh, and thank you for replying!

 

[Michael Anderson]

I have an Axminster chuck. I occasionally turn in reverse, and always sand in reverse. I don’t use the grub screws, and have never had an issue. I wouldn’t trust sans screw if I was hogging out material in reverse (or if I had a bad catch), but for normal operations the “snap” does the trick very well.

 

[Gabriel Hoff]

I have a VM120 and don't use the grub screw. Once it's on there it doesn't come off easily.

 

[Leo Van Der Loo]

I do use the OnewayTalon and Stronghold chucks, and with just sanding in reverse I never use a screw to keep it from coming loose, just snap them onto the shoulder.

If turning in reverse I would use a setscrew, but that would be seldom.

On my large lathe I use a taper to hold the chuck on the lathe, so there the chuck can not unscrew.

 

[Dave Landers]

The VM chuck inserts do have a set screw to hold the insert in place. One or two of my chucks wouldn't stay put so I drilled a shallow countersink for the set screw to grip.

But there's not a screw for bunging up your spindle threads.

I sand in reverse - several times for every piece I make. If it loosens your chuck then you either didn't put the chuck on all the way or you are leaning way too hard on the sandpaper.

Just make sure the mating surface on your chuck and on the lathe spindle are clean and flat and free of nicks/scrapes.

 

[Tom Albrecht]

Keep in mind that the larger the diameter and the heavier the workpiece, the more likely it will act like a flywheel and want to keep spinning after you turn off the power-- that's when you may run into problems.

 

[Kevin Jesequel]

Since no one has replied about the Talon, I will. The Oneway taper lock inserts are all drilled and tapped for set screws, but only the m33 inserts come with the screws. I think Oneway says something about only using them on hardened spindles (which theirs is, but most others are not). The screws can be purchased at the hardware store. I used to never use them, but had a couple chucks come slightly loose (probably due to breaking) and decided to start using them. I don’t like snapping the chuck on because of the force then needed to remove the chuck. I also find it a good way to make sure the spindle lock is disengaged before starting the lathe since you need to rotate the chuck to tighten the 2nd screw.

 

[Tom Lucas]

I have a VM120. It will come loose when sanding large diameter items with coarse paper. Mine even comes off if the object is large and I just cut the power, I have to turn the rpms down first.

Mine is direct thread. If I had it to do again, I'd get the insert type and use a grub screw. Mostly it's not a big concern. When sanding, you'll know with time to react if it starts to come loose.

My VM is my favorite chuck though. It grips like crazy.

 

[Owen Lowe]

I think Oneway says something about only using them on hardened spindles (which theirs is, but most others are not). The screws can be purchased at the hardware store.

For non-hardened spindles or those without the machined set screw groove, there are nylon-tipped and brass allen screws available. These won't damage the steel threads.

I've had chucks come loose and the scramble to get control again is no fun. My issue is that I forget I snugged the set screws and then can't figure out for a second or two why the chuck won't come off!

 

[William Rogers]

I also have the Axminster direct thread chucks. I use to give my chucks a snap, but on occasion had a stuck chuck. The late John Jordan did a demo at our club. One of John’s “rules” was to never snap a chuck. He said just bring it up hand tight then snug it tight and it will never take more force to remove it. I have been doing this for about 4 years and have never had a chuck come loose reverse sanding or get stuck.

 

[Doug Freeman]

I have set screws in all my chucks. If the chuck or insert did not come with a tapped hole I put one in.

2 reasons 1) deceleration on the Galaxi lathe is enough to loosen a chuck with a heavier piece, 2) I hollow in reverse. Sand in reverse as well, but that doesnt cause a problem. Its best to follow the same process to prevent “I forgot on this one”, so I always use the set screw, even for small stuff.

Several ways to deal with set screws that mar threads, main thing to remember is the marring can be easily filed down and not be an issue, if it happens. You might not like the look but it doesnt affect functionality.

 

[Leo Van Der Loo]

I do have the taper lock inserts in all my chucks, they are secure and more accurate than the screw type inserts.

The other reason is if I get a lathe with a different spindle thread, I can change the inserts for $20-- or so, rather than having to buy a new chuck.

As for the set screw to hold the chuck onto the spindle, grind a flat spot on a non hardened spindle where the set screw will tighten down onto, a Dremel will do this easily.

OK, so I was told that other chucks had the insert setscrew at a different spot, so it would not work, well it is easy to drill and tap those at the spot the setscrew should sit to tighten at the same spot.

This is the setup on my large lathe where I turn outboard, the Stronghold is mounted on a no 4 morse taper that is held in with a drawbar, so I can and do often turn in reverse.

this picture shows the pieces I mad and machined so I can turn outboard, faceplates, banjo and tool rests, the stronghold chuck and a stub for vacuum holding (never use it)


Here is the vacuum stub that I made with a quick connect, also the power switch that I do use, the airpowered switch bulb I can place anywhere close, has a magnet to hold it in place.

 

[Mick Fagan]

Vicmarc do have a chuck retaining feature on their VM100 and VM120 chucks, which unfortunately only works on Vicmarc lathes; mostly.

Basically on the reverse of the chuck, if it is a non-insert chuck, there is a V groove almost at the end where the metal meets up with the flat face of the spindle. On Vicmarc lathes there is a mirror V on their spindle, these two V grooves can be locked by using the Vicmarc Safety Collar; part number V00975.

If you purchase any Vicmarc chuck using an insert, then if you have a genuine Vicmarc insert, not an aftermarket insert, that insert will have the Safety Collar groove

This is the link to their site and the item in question.

Safety Collars | Vicmarc

All the Vicmarc lathe models are equipped with this unique locking system to stop face plates and chucks from coming undone while inboard or outboard turning, making turning safer. An additional safety collar can be purchased for reverse turning on the inboard side

www.vicmarc.com

To your issue with a Laguna 1836, it should be possible to get some machining done to the spindle of your proposed lathe. I have the Revo 2436 lathe and as far as I know the spindle end is the same for both units, 1836 and 2436 that is.

My 2436 spindle below, which is around 500mm long.



There is enough meat to allow one to cut a V groove to enable one to use Vicmarc's Safety Collar.

The next picture shows a reasonably heavy/large piece of wood being held with a VM120 chuck with Vicmarc's largest face plate ring, where you can see the groove on the chuck and directly behind it on the spindle, you can see that there is enough room to cut a mirror image groove to the one on the chuck.