Beginner Safety-Related Questions

[Jon Nuckles]

I am fairly new to turning and have a couple of questions that I hope someone can answer.

I bought a PM 3520B, which came with the big yellow cage. I could see leaving it in place to rough big and out of round blanks, but it seems to be in the way (at least visually) for other operations. I have been a woodworker for years and have yet to meet a tablesaw in a home shop that still had its original blade guard in place. Is the cage similar, or do people use it?

I also bought a SuperNova2 chuck, and was surprised to find the size and (especially) speed limitations that are listed in the instructions for the number 2 jaws that came with it. For spigot holding, the instructions suggest a maximum diameter of 4", a maximum length of 6", and a maximum speed of 850 rpm. For a dovetail recess holding, they suggest a maximum diameter of 12", a maximum length of 4", and a maximum speed of 600 rpm. For the woodworm screw, they suggest a maximum diameter of 10", a maximum length of 4", and a maximum speed or 600 rpm. Are these realistic, or are they overly cautious? If they are realistic, are there other jaws that would allow me to turn larger bowls and hollow forms with the SuperNova2? I have some more practicing to do before I will be ready to test the full capacity of my lathe:), but I want to be prepared when I acquire some skills.

Thanks for any candid advice you can give!

[Roger Chandler]

I have several friends who have a 3520b, and not one of them keep the cage on it. You must however, be safe when turning........machine manufacturers probably include things like the cage to cover their ________just in case someone does not use it safely, that way their liability is limited, and they can say that the end user did not follow the instruction manual.

Disclaimer: Take this with a grain of salt and decide for yourself what it is worth to you! ;):D:D

[Gary Max]

Tossed the cage on a shelf from day one--------- but that's just me.
The Nova thing---- lots of folks get hurt turning-----getting hit in the head with a block of wood can take the fun right out of things.

[Wally Dickerman]

I wouldn't buy a chuck that the manufacturer has so little confidence in their product. Those figures are ridiculous IMO.

Wally

[Bill Hensley]

I never mounted the cage on mine. I use the mounting rod to hold the dust collector hose.

[charlie knighton]

uh hu ......uh uh.......uh hu

[Doug Wolf]

Bought a 3520B and took off the cage until I got hit in the face shield by flying bark. Cage is now back on and used when roughing bowls. Otherwise it's swung out of the way but easy to use if the wood looks iffy. It has saved me from flying wood several times since.

I use 3 NOVA chucks (2 SN2's & 1 G3) and just use whatever RPM's are comfortable, but mostly over the NOVA recomended speeds.

[Michael Mills]

Different jaws are rated for different sizes and speeds. Here are some of the specs for the SN2

Recommended for power workholding on lathes from 350mm (14") to 508mm (20") diameter swing.
Up to 736mm/29" diameter bowls (using PowerGrip™ accessory jaws)
Up to 482mm/19" length spigots (using PowerGrip™ accessory jaws)

The highest recommended speed (for jaws) I have found is 1440…but the lathe Nova 1624 lathe goes up to 3600 rpm????? I’ve never had my lathe above about 1100 rpm and usually start at the 200 or 360 rpm. I understand pen turners and other small items may go to the maximum.
I think they may be a little cautious because so much depends on the expertise of the turner, the quality of the wood (punky, etc), and balance of the wood.
Recommended speeds are listed on page 18 here, there is a lot of difference in speeds for General Turning compared to Rough Turning.
http://www.teknatool.com/products/Lathes/1624/Downloads/NOVA1624_manual_Jun_08.pdf

I wonder what Porsch recommendations as a maximum speed. Bet it isn’t 160+ mph.

[David E Keller]

I ditched the cage on mine, but I've taken at least one to the head that I can remember... It's your choice.

As for the chuck, I don't pay any attention to the speed recommendations for the smaller jaws... I let the wood tell me what speed is right for the cuts I'm making. I would heed the max speed recommendation for bowl/cole jaws.

[Doug Wolf]

Jon, You might want to cut the top off of an old crew sock and put it around the chuck so the grease dosen't fly off when it's new. I have done this on all 3 of my chucks when new. Just cut a couple holes for the chuck key to go through. It will save you from having grease from the chuck on your wood and wonder where it's coming from.

[Jon Nuckles]

Thanks to all for your answers, though I'm still trying to figure out #6.

Any suggestions on what jaws to buy for the SN2 to safely hold a piece up to maybe 12" long for hollowing?

[David E Keller]

Thanks to all for your answers, though I'm still trying to figure out #6.

Any suggestions on what jaws to buy for the SN2 to safely hold a piece up to maybe 12" long for hollowing?

If you're considering hollowing a 12" deep piece, you'll likely want a steady rest of some sort. I'm not familiar with the SN2 chuck, but I would think a mid to large sized set of dovetail jaws would be fine. You're gonna need some pretty serious hollowing tools to go 12" deep as well. If you're talking about a 12" wide piece, the same jaws would work.

[Dennis Ford]

For the big (or really deep) pieces, a faceplate is stronger and more safe IF enough adequately sized screws are used. In sound hardwood mounted side grain; a 4" diameter faceplate with 8 screws will hold a big hunk of wood. For large endgrain pieces, I use a 6" faceplate with (12) 1/4" lag bolts

[Bob Haverstock]

Any suggestions on what jaws to buy for the SN2 to safely hold a piece up to maybe 12" long for hollowing?

Hi John,

I like making vases and urns. I usually start with fresh cut green wood and rough turn them and rough bore them. For me, a steadyrest is a must. In the past, I've had too many green project try to escape my lathe. Wet green wood needs to be controlled. BTW, a properly adjusted steadyrest takes a lot of the load off the spindle. As an old machinist, I don't like trying to control a project 10 inches long with only 3/8 inch in the jaws. I scare easily in my old age.

Bob Haverstock

[Michael Mills]

These are the specs from Teknatool for the SN2 with the 100mm PowerGrip jaws.
29" diameter bowls and 19" length using spigots.
The Teknatool web site list recommended sizes for all of the jaws. I believe the 19" length was for a 6" or 8" diameter and the 29" diameter was for 3" length.

The jaws on mine are 1¼ deep so a 1 1/8 long spigot would be fine I would think. That being said I have never done it, I purchased the PowerGrips on ebay for about half the $$ of the standard 100mm bowl jaws in stores. I just wanted the 100mm.
I agree with other posters that I would still use a steady rest.

[Harry Robinette]

Jon
I use a Vega 2600 and the cage is on it almost always,I have removed it to finish cut a couple smaller bowls (14" to 16" ) but man it's saved me numerous times.
It's up to you but be as safe as you fell you need to,we don't wont anyone hurt.
Harry