Hollow Forms beginners guide

[Prashun Patel]

I'm venturing into the world of HF's after having rec'd my Monster Hollowing system last week (stealth gloat). I'm glad I got it bkz I'm having back and shoulder problems, and this really takes the strain off.

Three questions:
1) How do you get a smooth interior surface? I find it's trial and error when working blindly under the lip. Is this just a matter of feel that develops over time?

2) How do you sharpen the cutters? I just free hand it on the grinder - no jig. How are you all sharpening your cutters?

3) Can anyone recommend a beginners guide to hollow forms - both technique and design.

[Tim Rinehart]

I'm venturing into the world of HF's after having rec'd my Monster Hollowing system last week (stealth gloat). I'm glad I got it bkz I'm having back and shoulder problems, and this really takes the strain off.

Three questions:
1) How do you get a smooth interior surface? I find it's trial and error when working blindly under the lip. Is this just a matter of feel that develops over time? My feel has gotten better...but with some practical advice, you can accelerate the process. Make sure the rig is SMOOTH, any sticky areas use paste wax or other lubricants so it is fluid. Can't over-emphasize that. I use my laser and leave a good 1/16 extra of wall thickness after getting an ok surface using my 3/16" rounded tool (fairly smooth, but lines remain visible to eye and touch), I then take LIGHT sweeping cuts using a scraper and maintain use of laser to make sure you're not spending too much time in any one area. Be sure to get rid of the point from forstner at bottom of vessel. This requires the scraper (my choice) to be EXACTLY at center line where it hits the point at the bottom of vessel. You can't rely on center at top of vessel, as the slightest slope will throw things off. Use a flex light to look into the bottom with the tool inside. Difficult, but absolutely necessary in my opinion.

2) How do you sharpen the cutters? I just free hand it on the grinder - no jig. How are you all sharpening your cutters?
Free hand sitting on a platform 1/16" away from wheel. If you have much more space than that to the wheel...you could have the tool get sucked in to the gap between the platform and wheel...and well...we don't want to go there. Be safe and smart about this!

3) Can anyone recommend a beginners guide to hollow forms - both technique and design.
SMC is a good start! One thing I'd caution you on, don't start with forms that have a defined shoulder at the top, as this is one of the more difficult cuts to make well. Do forms that require only the straight tool for your initial forms so you can see what is happening. Try to visualize the part of the cutting tool that is doing the work when you line up your laser, assuming using a laser.

Lastly...visit someone who hollows well in your opinion and spend an afternoon together.

[David E Keller]

Congrats on the new system! I think 'practice' is probably the best answer for getting smooth walls... I generally use one of the scraper tips for a final smoothing pass.I sharpen my cutters upside down on the platform attachment of the wolverine setup... No other jigs needed.I like Mahoney's Hollowforms and Urns DVD better than the others I've seen. John Jordan's would be a close second with Ellsworth finishing third.Looking forward to seeing what you crank out!

[Jim Burr]

Gratz!!! You're gonna be a busy guy! The ring cutter does a great job of smoothing the way Vaughn taught me. I sharpen the cutters on my 80 grit with the table set at whateer angle Randy ships them ground at...dunno what it is. I was taught that the burr on the top of the cutter is what cuts so when I don't feel the burr anymore, it's time to sharpen. I also grind both ends so I flip and keep going. Hope that helps!!

[Greg Bender]

Prashun,
I made an arbor that has a threaded end so I put the cutter on it and thread a nut to jam it .Then I chuck it up in a cordless drill hold it at the appropriate angle and spin it slow while kissing the wheel.Gives you a real sharp edge and allows you to control how much force/heat the cutter see's.Enjoy that hollowing rig ,I love mine.BTW,you will get the feel for it with alittle practice.
Greg

[Bernie Weishapl]

I do free hand my cutters and scrapers for the monster system. I agree with David that Mahoney's DVD on HF and Urns has probably helped me the most. I agree practice and light cuts are probably the best advice.

[Jim Burr]

I do free hand my cutters and scrapers for the monster system. I agree with David that Mahoney's DVD on HF and Urns has probably helped me the most. I agree practice and light cuts are probably the best advice.

Remember that at the end of the HF segment Mahoney says that the up coming lasers are close to cheating...hope you don't agree with that!

[Harry Robinette]

Prashun
Something about your back and shoulder if it bothers you after turning you may want to look at raising your lathe just a little. I raised my lathe only 1 1/2" and made a world of difference. Back and right shoulder pain GONE. Not a doctor just someone that had the problem.
Your HF question practice,practice,practice but like the others are saying find someone to show you a little about it.

[Kathy Marshall]

Prashun, try practicing by hollowing out some closed bowl forms. You'll be able to clearly see what the cutter is doing and find the angle/cut/method that gives the best result, it will also let you get a feel for working on a shoulder and again be able to see what the cutter is doing.
Not sure what cutters the Monster system uses, but I use a jig that Lyle Jamieson sells to sharpen the 3/16" square cutters used on my Jamieson system. I also was able to find a metal tool shop that was able to order in some cutters for me at about 1/2 the cost. I ordered 10 blanks, they come in 2 1/2" lengths, so cut in half it gives me 20 cutters. I sharpen up about 5 or 6 before I start a hf and then I can quickly change the cutter when it loses its edge without having to make a trip to the grinder.

[Prashun Patel]

Thanks, Harry. I actually have raised my lathe considerably. It has helped. However, I had not realized how tense I was when hand hollowing. Using the Monster has really been a joy.

[Richard Jones]

I have not seen John Jordan's video, but I really like Mike Mahoney's HF's and Urns as well. Very clear, concise, and great views of the work.

After you do a million HF's like he has, maybe you can think about not using the laser...............:)

I sharpen on the Oneway platform, same angle as I do my other scrapers, works fine. Just kiss it, don't grind it hard.

Smooth inside is practice, a sharp tool, and a light touch. I have started using the round carbide cutter, turned up at 45 deg (way too aggressive when flat!!
), seems to make a huge difference.

Good luck, just wade in!!!

Rich

[Faust M. Ruggiero]

Kathy gave you good advice. Instead of jumping right into hollow forms, sneak up on them with closed bowls. The opening will be large enough to let you see what you are doing and experiment. Close your eyes when you hollow them and get the feel. Then do dry runs. Move the tool across the inside with the lathe shut off. Feel the surface. Stop aside a high spot and with your eyes closed and try to lightly remove the high spot. The problem with starting out with the laser is you may not learn to measure thickness without it. I am not saying it is not wonderful but it never hurts to learn to hear and feel the thickness as well as see it.
faust

[Prashun Patel]

Here's my first attempt.

http://www.sawmillcreek.org/showthread.php?174644-First-HF-Spalted-Box-Elder&p=1795761#post1795761 (http://www.sawmillcreek.org/showthread.php?174644-First-HF-Spalted-Box-Elder&p=1795761#post1795761)