looking for help with faceplate

[sjBrian]

i just started turning last week i have a delta LA200 with 3in faceplate. i've noticed that when i try cutting on the face of the wood, it tends to become offcenter(thick rim on one side thin rim on the other). not sure why this is happening. am i just going too fast? does the blank need to be perfectly round?

thanks

 

[Jim Stoppleworth]

What are you trying to make?

How fast are you trying turn at the start? 200,300, 500RPM's?

The blank doesn't have to be perfectly round to start but you do want the faceplate as close to the center as possible.

Jim

 

[hockenbery]

Brian,

When the blank is turning with minimal vibration and the turning tool is working properly a circle of wood is removed from the blank every revolution.

if wood is vibrating and/or the tool is bouncing
the continuous circle cut can get distorted and the tool can follow the uneven surface and never get it true.

In my opinion, using a faceplate properly requires a bit more technique than using a chuck. I usually stark my bowl students with a chuck and then introduce them to the faceplate when they have the tool control and skill to make a surface to mount the faceplate on.

I encourage you to find a local AAW chapter. They many have help sessions and will know about classes in your area.
happy turning
Al

 

[john lucas]

I'm confused. Why is a faceplate more difficult to use than a chuck? Both spin the wood. I've use faceplates for years and don't see any difference other than the wood is more secure with the faceplate if the right screws are in. I'm not doubting you, we may be talking about a different technique or other problems that beginners have.
Problems you can have with a faceplate. If you don't true up the end where the faceplate goes it won't sit flat and will rock or cause vibration. Along those same lines I find that it helps to make the area inside the faceplate slightly concave so the edges of the faceplate will sit perfectly flat.
If the screws are too short or too small you may not have a very positive hold, or if the wood is rotten where the screws attach.
You might get the faceplate way off center to begin with which causes excessive vibration, expecially if the lathe won't go below 500 rpm.

Early on I learned to turn a slight recess in the bottom of the blank to fit the faceplate. I usually did this with the wood between centers and after I trued up the end with a parting tool. I have a tool I made by regrinding an allen wrench. It lets me turn a recess so the faceplate is perfectly centered.

 

[sjBrian]

so far i've been using the lowest speed. from the replies, i'd say maybe i'm trying to learn too quickly. maybe i need to go slow and get the basics down.

my faceplate has been centered and flush with the wood. i think maybe it is the way i hold my gouge. the first piece i turned was a small spalted maple blank. it came out fairly nice. my second piece was a large spalted apple blank. that one became off center.

my tools came with a small pen turning lathe i got a few years ago. would bigger tools make any difference?

 

[odie]

so far i've been using the lowest speed. from the replies, i'd say maybe i'm trying to learn too quickly. maybe i need to go slow and get the basics down.

my faceplate has been centered and flush with the wood. i think maybe it is the way i hold my gouge. the first piece i turned was a small spalted maple blank. it came out fairly nice. my second piece was a large spalted apple blank. that one became off center.

my tools came with a small pen turning lathe i got a few years ago. would bigger tools make any difference?

Hi Brian.....

Has the bowl actually shifted on the faceplate itself, or has the base of the bowl remained in the same place, but the bowl rim/walls become off center?

Bowls naturally do warp. Could this warping be what you are experiencing?

....odie

 

[hockenbery]

I'm confused. ........
Problems you can have with a faceplate. If you don't true up the end where the faceplate goes it won't sit flat and will rock or cause vibration. Along those same lines I find that it helps to make the area inside the faceplate slightly concave so the edges of the faceplate will sit perfectly flat.

Early on I learned to turn a slight recess in the bottom of the blank to fit the faceplate. I usually did this with the wood between centers and after I trued up the end with a

john,
all that plus the centering of the chuck when you screw it on added to the other basics for beginners is why I start them with a screw mount on the chuck to begin and a tenon to open the bowl.
I use a chuck for 90% of my face grain hollow forms stronger mount and more room to work close to the bottom.

happy turning
-Al

 

[George Guadiane]

Apple!

my faceplate has been centered and flush with the wood. i think maybe it is the way i hold my gouge. the first piece i turned was a small spalted maple blank. it came out fairly nice. my second piece was a large spalted apple blank. that one became off center.

my tools came with a small pen turning lathe i got a few years ago. would bigger tools make any difference?

Bigger tools WILL probably help, the mass makes them bounce less on the tool rest, BUT...
The probable culprit here is the wood itself: Unlike metal, which when properly mixed, is of an even consistency and weight, wood density (weight) OFTEN varies from one part to another...
Wet wood has the most chance to travel. I have seen a 5 inch thick slab from many straight logs bow up MANY inches when cut. They can look like rocking chair bases. That indicates a lot of stress in the wood, so when you try to turn it, the stress is released and "reshapes" the turning.
Also, sap wood usually being lighter and softer than heart wood, for instance can cause pieces to shift if the wood is not all one or the other. Branches and crotches also change the density of the area that they are in, so - even what appears to be an "ordinary" piece of wood can hold significant surprise.
Then you add in the spalting factor, which is yet another opportunity for the wood to work against you. More decay in one area than another can make things out of balance too. The wood itself could be unbalanced and fighting to find it's own center, which could cause the lathe to "vibrate" and cause the light tools to skip which would cause the piece to go off round.
AND, as the edges get thinner, the stress in the wood might be strong enough to push the edges out of round. Unlike a block of metal, the stress of growth is inherent in the wood. That stress could work against you as well.

FURTHER (and most probably in this case), apple distorts like CRAZY, almost all of the time.
So, you might have a perfectly round piece, go in for lunch and come back to an oval... and the thinner the turning gets, the faster the water comes out and the faster it distorts.
Always coat or cover a piece you are working on when you leave it, otherwise you could come back to BIG cracks (I learned that lesson the hard way, and it ain't pretty).

 

[MichaelMouse]

i just started turning last week i have a delta LA200 with 3in faceplate. i've noticed that when i try cutting on the face of the wood, it tends to become offcenter(thick rim on one side thin rim on the other). not sure why this is happening. am i just going too fast? does the blank need to be perfectly round?

thanks

Lots of advice so far, some a bit strange to my ears. First, when you say one side, do you really mean one as in 180 degrees of the circumference, or do you mean two shorter places 180 degrees apart are thicker? If it's just one side, has to be attachment. The blank will spin around a constant point if you have it attached tightly, so if you keep your tool steady it must turn out round. Make sure your out and in sides are referenced to the same center. Couple of things that can lead to thick short grain and thinner long grain are the natural drying stress on a wet piece of some thickness, and the natural weakness of shorter contiguous grain on thinner.

Wood shrinks almost not at all along the grain, and an average of 5-7.5 % across on a cross-grain bowl. This from the FSP (Fiber Saturation Point) to equilibrium with ~10% moisture (EMC). So if you get drying, and you will over time with a wet piece, it'll shrink across the grain, and re-truing will make two thinner spots. One thinner is possible with some really odd grain orientation, but not too likely.

The weakness of shorter wood comes into play if you press on the bevel rather than just guide it. Press the tool to the rest with an overhand grip, and keep the rest close to minimize any actual tool flex. Arc the tool through and nibble to round until you get a continuous place to steady on the wood itself. The wood will still flex a bit, and when you get below 1/4, it can get downright floppy if it's wet. Use a steady or wrap with tape on a continuous edge bowl, and just let it happen on a bark up or non-continuous. Nobody'll notice as long as you take a few extra passes with the paper after drying.

You can also sand your way into trouble of the two-spot variety if you press the paper. It'll have a tendency to ride over the tougher end-grain and abrade the softer face. Why I steady my sander as I would a lathe tool.

 

[Sky]

I "cone" out the screw holes on my face plates slightly by using a much larger drill bit on the face (side that touches the wood) to give room for the wood that always raises around the screw, which can push the face plate off the wood blank weakening the hold causing vibration or movement.

 

[Wilson Williams]

dont forget to draw in the tailstock to the opposite end of the faceplate. drive it into the other end and clamp it down. then true up your block. maybe one of the raffan turning books would clarify. i have been turning for 20 odd years off and on, and re reading them helps me re remember techniques i had pushed off the brainwaves when not doing every day.