Hollowing Second Attempt - Questions

Today was day 2 with the new hollowing rig and i took my lap top to the garage and with the pic Vaughn sent and the directions sent i had it together real fast. The wood i chucked up yesterday was still in the chuck and rough hollowed now. Now on to my first attempt at hollowing with a narrow opening.

I tightened up everything and taped a buss card to the underside of the cutting tip (see pic) and set the laser out just in front of it about 1/8" at a guess and started hollowing with the straight tip. Started in thirds and roughed as much as i could to the bottom. I could tell right off the bat i need get used to the tool and technique. It cut fine and would let me know when i cut at the wrong angle but jumping a bit but as soon as i lined it back up in the form it would cut but it was a bumpy ride (this was a very dry pc of wood and i should have used a green pc to start but i didnt ..........ohhh well)...taking small cuts i did as much as i could to the bottom where it really got bumpy but still cutting my way along (probably technique and very dry wood).

I was going to give up for awhile and go rest my leg (out of work with injured muscle in leg so i cant stand for long periods of time). My wife asked if i could sit on a old wood barstool we had and that way i could keep playing with it............hummmm not sure but i gave it a try.......perfect height so i put together the angle cutting tip and put it on the rig and started in again.

This is where i ran into trouble - cutting in thirds and starting at the rim and going down the first third was not to bad.
I thought that as long as the laser dot was showing on the wood (showing on the top at first) i was fine and that as it starts to drop off the side is when you want to slow down and be careful.....guess i was wrong....the dot still touching the side but i cut thru the wall just a bit. I stopped the lathe and checked the turning and rechecked the laser and cutting tip and all was ok...

Not sure what im doing wrong any ideas ?????

Next i just finihed with the angle cutter and leveled out the inside to about 1/8 inch. Then using my Foredom tool i enhanced the hole and touched up the edges and started sanding. I finished off at 220 for this pc and put a couple coats of antique oil on it and left it on the lathe until tomm.

Pic-8 is the one i turned in the class i took on hollowing that im just now getting around to finish.......

Stay tuned for day three....................LOL thanks Dan

Dan not sure what the problem might be. When I ran into problems when I first start with the unit is I was using the wrong tool for cutting. If I was using the straight cutting tip and put the laser on at say 1/8" and I cut on the side of the HF it gave me a false reading with the laser and I would go thru the side. Normally I set the laser at 1/4" and once the laser drops of the edge then I start refining. I do my roughing with the cutter you show but then switch to the swivel tipped cutter to do my refining. Also rather than a card I put the tip of a ruler on the end or tip of the cutter and set my laser that way. Like I said I will cut the walls to a 1/4" then refine down from there. Keep at it Dan. You will get it. I cut thru the side or at the bottom of 2 or 3 before I got it down. Once there you will know it.

Dan, you likely have already figured this out, but as you move to different parts of the vessel, the laser needs to be adjusted in relation to the cutting tip. In some cases the dot will be in line with the tip, but in others, you're almost cutting more with the side of the cutter, so the laser needs to be moved accordingly. This sketch is a bit exaggerated, but I think you'll get the idea of what I'm talking about:



Just one of the reasons why I recommend starting with a bowl with an undercut rim instead of a blind hollow form.

Bernie - yep i did exactly what your saying when you commented about the false reading.
Im going to try again tomm and im going to set the laser the way you suggested using a ruler to 1/4".

FWIW, I don't actually measure the distance from the laser dot to the tip. I just hold my hand under the tip (like using a card) and eyeball the distance. Most of us here can judge 1/4" or 1/8" pretty accurately just by sight.

Another tip...check periodically to verify the laser is still pointed where you want it. I've had times when I didn't have the laser arm properly tightened, and as I hollowed, the arm moved, sometimes an inch or two. Obviously, this can lead to non-optimum situations.

Vaughn if i understand you correctly from the photo - because the cutter is cutting differently because of the shape the laser is constantly adjusted because of where the tip of the tool is cutting.
Example - set the laser to the left side of the cutting tip as you enter from the rim - then reset the laser because the tool edge is now cutting in a different spot - getting past the first 1/4 lets say you would reset the laser again because the tool is cutting in a different spot again and so as you reach the bottom curve of the bowl......so your setting the laser many different times during the hollowing..........Does this sound right????

Dan Mosley said:

...Does this sound right????

Click to expand...

Yeppers, that's how it works for me. I check (and adjust if necessary) just about every time I pull the cutter out to blow the chips out. On green wood I I might only get 30 to 45 seconds of cutting before I have to shop and clean it out, so it gives me plenty of opportunities to check. I'd say I make the most adjustments as I work around the inner lip and around the shoulder.

However, I'm not using the 1/3 at a time approach, especially for the initial rough hollowing. I drill a pilot hole, and widen it progressively for the whole length (or depth, I guess) of the vessel. When I get down to about 1/2" thick, I start working from the opening to the bottom, working it to (hopefully) finished thickness as I go. Because I'm working pretty much from one end to the other, I probably adjust the laser more than if I was doing things in thirds.

As previously stated, the laser needs to be adjusted as the curve changes.
Also you will have less trouble if you hollow from top to bottom once only (twice if you rough and return when dry). In other words, get your wall thickness the way you want it before going deeper. This will keep your HF stronger until you are nearly finished, reducing vibration of the wood.

Dan - lots of good advice and it will all sink in with time. Easiest way to remember where to place the laser dot - it must be perpendicular to where the cutter meets the wood. As the curve of the wood changes - you need to readjust - or at least be well aware of where the cutting edge is located within the form.

Dennis - Steve - I agree with everything you both said and ill finish cut from top down on my next project that i may finish today and if so ill post a new thread about it. The pc is Walnut and i have already started the shape etc.
Yes adjusting the laser frequently is a lesson i learned on that first turning (shown above) but with Bernies/Vaughns comments about the 1/4" thing, dot v. tip checking...... it was resolved for me on the next turning and his comment about the setting has worked well. One the first turning with a pc of very dry wood i had cut it paper thin - and i serious - paper thin - but i woud not have thought so until i read about setting the laser, turning in sections etc.....the help here has been great and the second turning came out fantastic (see the small mesquite vessel - 2nd turning).........thanks and im sure ill have more questions soon as i move forward with using the rig........