Novice considering tackling chunkier pieces...advice please

[Keithie]

Sorry about seeking attention so much .. but I've bottled out of today's project pending some advice/suggestions if poss please.

Project : Shaped lamp, max diam 140mm ish, height 280mm ish, in cheap (<£4/piece) Western Cedar (4.5kg)
Objective : build skills on largest diam piece lathe can reasonably take between centres with tool rest in place

Pic of piece on lathe and spinning are the last two in blog (see below for link)

To start I set speed at lowest (550rpm) on middle belt and have carefully cranked it up to 1000 to see if secure ..it is.
Dont fancy getting very close to it at 1000rpm ..lol..that might just be lack of confidence though!

My nervousness is just approaching it with the roughing gouge...once in the round I think I'll be ok

Questions :

- What speed for roughing a 6x6x12 block (4.5kg)with all corners on? (is 550 ok ? ..I could shift belt ...pfft.. and go to lower to 250rpm ish)
- Would it be massively better to hand cut each of the 4 corners down to octagon shape or, with care, should it be ok?
- Any other tips welcome!

cheers
Keith

 

[Phil Pascoe]

You have a purpose made machine for taking corners off - it's known as a "lathe" - unless you have a use for the offcuts - for some post blocking, maybe. Lowest speed first. Make sure your centres are in deep enough and set the rest as close as possible whilst ensuring the blank goes around without fouling the rest or the banjo. Grind your roughing gouge and away you go. Get the hole bored as soon as your blank is something like round and turn it with the nipple in situ. Holes have a mind of their own and often go wandering, this way you ensure the hole finishes on centre.

 

[donwatson]

I would use a ¼" spindle gouge, carefully, to rough it down. Otherwise the same as phil.p said.

 

[Phil Pascoe]

A quarter inch spindle gouge to rough a 6" x 6"? :shock:

 

[Dalboy]

If the piece is running at 1,000rpm or just above and it is safe then rough it down at that speed. You will find it is easier to rough down at a higher speed than the slowest as it does not give the tool time to enter the lower points while doing so. If you have the ability/equipment to take the corners off first do so.

 

[CHJ]

When tackling large turnings the two most important things are security of fixing and Balance.

From This old thread from my early days.

With square stock always remember to start knocking off the corners by working towards an end never approach from the end as you are likely to get a dig in and shatter a splinter along the length of the piece.

 

[duncanh]

Speed: as long as the piece is secure I tend to turn as fast as possible. If it's not secure then stop and find a better way to hold it. If you're worried about a secure hold you can always hold it as best you can between centres, turn a chucking point at the end, reverse it and hold it in the chuck with the tailstock brought in.

I haven't bothered removing corners on square timber before putting on the lathe since I finished the first few sessions of night class. It's easy enough on the lathe.
If the timber is rough/uneven (from a home made blank converted from a log) then I usually use my biggest bowl gouge (3/4" I think) with a swept back grind. For a square like this I'd probably use the roughing gouge as it's a bit faster. The thing to remember when taking corners off is to move the rest in regularly or you'll quickly get a large overhang.
Also, you tool rest in those photos looks too high for that blank.

 

[AJB Temple]

I have only been turning for about a year so I get where you are coming from. Turning is largely about confidence. I got that by going on a 3 day axminster course. If it makes you fee more confident to take the corners off on (say) a bandsaw first, then do that. Personally I would do what Duncan suggests above but if for some reason I felt insecure I would haev no problem getting the wood balanced with other tools first.

Take it slowly. Wear eye protection.

 

[kevinlightfoot]

Use the lathe,set the speed as high as it will go without the piece vibrating the lathe to bits ,use the largest spindle roughing gouge you own make sure it is sharp ,work gradually from about an inch in from the end towards the end and then keep working back from each end until the middle is reached ,as has already been said keep moving the rest closer to the workpiece if you are lacking the confidence to work with ecxessive tool overhang,the larger gouge will give you more stability and heft when roughing large diameter spindle work.Remember just because you use a large gouge it doesn't mean you have to take heavy cuts a 1 1/2 gouge is capable of taking the lightest of cuts,hope this helps.

 

[SVB]

I would use a ¼" spindle gouge, carefully, to rough it down. Otherwise the same as phil.p said.

No! I don't normally post on Internet forums to say someone is wrong a often it is all opinion / perspective which is fine but this is both wrong and dangerous.

Toolwise, a spindle roughing gouge is fine or a stout bowl gouge with swept wings but for someone who is starting out I'd suggest the former.

Speed, less than 1000 but as fast as you feel comfortable with up to that and the lathe is stable.

Technique, keep the tool handle into your side and move left right by moving your weight between feet, not all arms away from your body. As Chas says, go from centre out, not edge in.

Stay relaxed, don't strangle the tools and you'll be fine.

Brgds

Simon

 

[selectortone]

When I started out wood turning I found roughing down a large spindle blank quite intimidating. I actually built a jig so that I could knock off the corners on my bandsaw so that I started roughing with a blank of octagonal, rather than square, section.

Now that I'm a bit more experienced I don't bother with the jig any more as I find it is more time consuming than just having at the blank with a roughing gouge.

I invested in a big, heavy 1½" roughing gouge and that in itself instills confidence. A small roughing gouge and a large uneven spindle blank are not a marriage made in heaven. Taking light cuts to start with is the key I've found. As with all turning, ride the bevel and then gently lift the handle until the tool starts to cut. As others have said, run up the speed until you get vibration and back it off. You can always increase the speed once the blank starts getting into round. I put my face mask on when I'm starting out with big lumps of wood. Better safe than sorry!

You might consider a lesson or two at Yandles (I see you are in their area) - I've heard they are good VFM. I'm very lucky that I found a club local to me and took some lessons from a pro there when I started out. Looking back I could have done myself some serious damage otherwise.

 

[CHJ]

...... I put my face mask on when I'm starting out with big lumps of wood. Better safe than sorry!
.....

I would say in the interests of not loosing an eye or having other severe facial injury an impact resistant mask should always be worn regardless of size of work piece if working it with tooling.
Smaller pieces are usually rotated at higher speeds and the centrifugal forces just project the smaller lighter item at higher velocity.

If you have experienced a cracked facial shield from a recalcitrant lump of wood or prised a piece out of the plasterboard ceiling you would appreciate that you never know when it's going to happen despite all the precautions.

 

[Keithie]

Thank you very much (again) everyone.

I found Chas's safe turning speed bydiameter pdf guide in the novices health & safety guide here. The diameter is 150-160mm across the side, but 220mm ish on the diagonal. So I'm going to start at about 700rpm and work up to 1000as I get to a cylinder

The lathe only has tiny8mm securing bolts to the bench so I've locked them down as tight as you like. Dont fancy drilling the cast iron to get 10mm or more on a brand new machine with 5yr gtee!
I only have a long handle 3/8" roughing gouge so I'm just going to have to take it slow...its remarkably sharp right now!
(I got 12 of these blocks from the sawmill for £45 total so will buy a bigger gouge)
The lump is centred up with a slight bias to try and compensate for damp wood on one side...at 1000rpm the lathe vibrates a little bit but its steady enough by the look of it
4 prong drive is less than two weeks old, so not worn, and I've knocked it fully in to the hilt with a pvc mallet
Tool rest is now a bit lower
I am a safety freak ...so have a full p3 face mask with a visor sitting on top of that plus heavy duty old leather hiking boots for when the gouge tries to jump into my foot

I def gonna go for it tomorrow (never had any trouble with 4" squares so 6" shd be ok) by nibbling from centre out to side then centre out to other side, then moving rest in and repeat till it feels easier. No bandsaw yet anyway!

After rounding it'll be interesting to see whether the Axminster 100mm clubman chuck and 'mega jaws' can hold the full weight with my augur bit in Jacobs chuck in tailstock. Failing that boring will be in drill press (not bought long hole kit yet..I should!)

Thanks again everyone for the support and advice .. should be a fun Sunday morning project!

cheers
Keith

 

[woodfarmer]

I would use the biggest rough gouge you have, or a really big bowl gouge. Big lumpy wood = big lumpy tool.
Have the rest close to the highest point and work on that.

Once the lumps have mostly gone you can use smaller tools.

a really nasty lump like stub end of a branch, cheat and use an angle grinder with 24 or 36 grit sanding paper with a backing disk.

Use filter to breathe.

 

[CHJ]

..The lathe only has tiny8mm securing bolts to the bench so I've locked them down as tight as you like. Dont fancy drilling the cast iron to get 10mm or more on a brand new machine with 5yr gtee!
...

8mm Bolts are more than adequate they are only taking any out of balance loads and dampening subsequent vibration, they should hold a couple of ton each.

 

[Phil Pascoe]

Keith - don't attempt to drill using an auger in the tailstock. It is an accident waiting to happen as the draw on the auger will be to fast for the lathe. If you have any metal working facilities you can make a cheap long borer with an 8mm bms bar and an 8mm hss drill bit.

 

[mayo.mick]

Would definitly recommend a large roughing gouge, as a poster above said, that instills confidence in itself! I certainly did for me when I first bought mine. I used rough plane the corners off blanks when I started first. Don't bother now! ++1 on the facemask too!!

You might upload a few pics of your progress?

 

[Keithie]

Thanks again....

- Good to know the 8mm bolts are up to the job...my old coronet was a bit meatier ...hence my surprise.
- I think I'm resigned to the drill press for the boring (unless I make a trip tomorrow for the long hole kit from Axi / Yandles) my experience with the 230mm x 16mm augur in drill chuck on tailstock onto a 4 inch long 30mm round of pine wasnt very constructive ...I assumed winding the tailstock slowly into the wood might be ok ...not great tho... a bit splintery! On a piece this size I'll take your advice and not even try!

I'll take some pics as I go & post

thanks again

 

[Phil Pascoe]

It doesn't much matter how slowly you wind it, the screw will go at its own speed once it grabs.

 

[Keithie]

Good progress made today ... rounded up the little spindle blank a put a 5/16" hole though the middle with the Record long hole boring kit ...remarkably easy to use.

Pics so far are in the blog (link below)

Thanks again for the adviice...definitely kept me on track. I was nervous the hollow tailstock centre might not hold the piece, but no trouble at all. Upgraded to a 1 1/4" roughing gouge as well, which makes a big difference on a bigger piece.

Will try to shape lamp tomorrow and post pic.