Thread: WIP: deep hollowing

Great thread Ern I want to try deep hollowing but wasn't sure about the cost of the hollowing jigs and chisels. How deep can you safely hollow using gouges and scrapers?

HH.

HH, not far in my experience with gear with std handles. 100 - 125mm depending. The prob is flex in the tool with a long overhang.

With a pencil jar tapering out towards the bottom and a straight side, 100 mm is possible, 125 maybe with a 3/8" thick scraper if you have a taste for excitement. With a vase shaped form tapering towards the bottom I've done the same depths with a 17mm P&N Supagouge.

A custom rest inserted into the work as far is possible makes it easier

Hollowers like the Munro and Proforme cut rather than scrape, have caps which prevent catches, and have long shafts and handles which all help with tool control and improve the odds.

But you can make your own Oland style tool - a tip with shaft and solid handle that is a good way into this game and costs peanuts. (Plenty of posts on this in the forum.)

Hope this helps.

This might be a good time for others to chip in with their experience with bought and home-made tools for deep hollowing (as if any invite was needed!). Esp. Jim Carroll who sells both the Munro and Proforme tools.

There are other makers too: Sorby, Kelton etc.

There's some very good articles by Lyn Mangiamelli on this matter at Fred Holder's website.

I was thinking of buying a Hamlet 1" round nose scraper with a 10" (254mm) handle. What do you think is the max depth you can safely use this for hollowing?

I'd be interested in views on the hollowing tools out there as, after searching the forum and having a read, I don't think I'm up to making an Oland style tool. I also want to be confident with a tool if I'm going deep as I'm a beginner, so I might have to buy one.

HH.

I made my own from bent bits of square bar in about '93 I think.
They weren't flash & couldn't go very deep but I did win 2 prizes at the Townsville show with pieces made with them.
Allan at Wallan now owns them & to show that they worked, I did an under cut rim on the big bowl we made at Ern's place last year.

I now own & use the Vermec hollowing set.

well here goes I have been holding off just watching the progress.

I use a Porforme on a custom 20mm shaft for most of the deep hollowing. Getting around the corner or reverse hollowing I use a Oland type.

The additional handle gives very good control and with it rapid removal. Its from an old hammer drill and is very comfortable.

Originally Posted by rsser

LOL.

Have put some coffee tinted epoxy in a couple of the holes; more tomorrow. Will see how they hold during hollowing. I think (hope) they'll give notice before vacating.

Which club btw?

Northern Woodturners Club in High St, Thornbury
located in a hall behind the Salvation Army Church
cnr High and Gooch. We will shortly be relocating
into the hall that was the Opportunity Shop.

Great bunch of blokes.

Allan

_____________________________________

I once stole a calendar - and got 12 months.

I regularly go to 200mm deep but have gone to 275mm before the jocks are in danger. Most often used tool is one of the early Sorby/Stewart tool, but i also have tools made from 35 x 12mm mild steel bar with heavy duty hacksaw blade pieces silver soldered to the end. The recently posted cedar vase was done with the Stewart tool.
Jim

Originally Posted by rsser

This might be a good time for others to chip in with their experience with bought and home-made tools for deep hollowing (as if any invite was needed!). Esp. Jim Carroll who sells both the Munro and Proforme tools.

There are other makers too: Sorby, Kelton etc.

There's some very good articles by Lyn Mangiamelli on this matter at Fred Holder's website.

1/8-inch (3mm) HSS cutter in 1/2-inch (13mm) shank of my shop-built Oland tool. Deepest I've gone is about 170mm, where chatter became too much of an adventure. This was with the tool rest very very near the mouth of the piece.

Joe

Originally Posted by HappyHammer

I was thinking of buying a Hamlet 1" round nose scraper with a 10" (254mm) handle. What do you think is the max depth you can safely use this for hollowing? HH.

As I'd posted HH, using this kind of tool (assuming 1/4" thick shaft), best I've done is around 100 mm. If you can get a rest into the work you can go further. (Eg. Sorby make a modular rest system inc. a box hollowing rest which is intended to do this but I've never used it or heard reports of how solid it is).

I have a Black Walnut vase that is 13.5" (over 330mm) tall x 6" dia at the wides point. I hollowed this before I had any other tools, with an Oland tool... 3/16" cutter in 3/4" x 12" round tool shaft, in a 3/4"id x 16" black pipe, adapted to a 1"id x 24" black pipe handle filled with BBs. The 1" handle is wrapped with foam pipe insulation, so I can stick it under my arm to add my body weight to the BB ballast. I had very little chatter with this system, but it took light cuts and good rpms, and a steady rest near the top of the piece.

Ern, this makes a really efficient steady rest... Pic
It's made with 3/4" x 1/2" T-Track and rollerblade wheels.

Nice steady Al. I like the T-track idea. Slotted ply tends to bind when you go to adjust it.

Thanks for the post.

Added: here's one account of deep hollowing; I've been thinking of Herman's kind of steady rest - www.hdv.net/2004/<WBR>turning%20a%20large%20vase%20-%20freehand.pdf
and here's his design: http://www.hdv.net/tips/Making%20a%20Steady%20Rest.htm

I need to have clearance over the top for the laser arm.

Originally Posted by OGYT

...

Ern, this makes a really efficient steady rest... Pic
It's made with 3/4" x 1/2" T-Track and rollerblade wheels.

OGYT

Can you please give us a couple of more photos of the steady rest ie from the other side. I'm interested in how you've used the T-track
pretty please

rssr

thanks for the links, the rest looks simple enough
cheers


SM

The scrapers are used only for cleaning up not for hollowing.

If you want to to any hollowing you need a minimum of 3/8" thick by 1-1/2" wide to avoid flex.

I have used both the Munro mini, mega and the new proforme tools and find they all work just as good as each other in the different size hollow forms you try to do. Obviously you would not use the mini on the one ern is doing as it does not have enough reach. The main thing is to try and get the toolrest as close as you can to eliminate too much over hang but far enough away to be able to get the tool back out without catching.

The new proforme has a better gate compared to the older model so there is not as much gap between the guard and the cutter.

This helps when you roll the tool of the guard and then the cutter starts cutting, with the older version you felt you were in no mans land waiting for it to catch.

I am more of a feel turner so do not like the gate type as it does not give you the feed back needed. Others like them as they do take out some of the jarring that can happen on the deeper forms.

Each tool has its place.