A few basic lathe questions....

[=Adam=]

Hi guys!

So far I must admit, I have been very impressed with the members of this site and how helpful they have been. I am hoping you guys can help me out once again

Right so here we go....

1) The lathe that I have is a three speed model however I tend to be only using the highest speed for everything (roughing down, detailing and sanding etc). Am I right in doing this or am I better off using the slower speeds for different parts and if so then what stages would i do it for?

2) I was trying to part off a piece of work the other day (using a chuck to secure the work) with the parting tool, but when I got to the last 5mm, the piece snapped which ruined the piece. What is the correct way to part off? A YouTube video would be great if there are any!

3) I would like to have a go at pen turning at some point but I am not sure what I actually need to do it. Now I know I need a mandrel to mount the wood and some way to drill the pieces but is there anything else that I need? Also where is the best place to buy the kits? I don't need blanks as I have enough wood to make some

Sorry for the questions but I thought that this is the best place to ask


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I am here: http://maps.google.com/maps?ll=51.669203,-4.055689

 

[Nozzle]

Hi there!!

im a relative newbie to turning aswell and im also wanting answers to the same questions as you are... however on your first question from my little experience and online videos, i tend to use lowest speed to true the peice up and also for sanding, and then speed it up for the rest.
but my lathe is a 5 speed one so it might well behave diffrent to yours....hope this helps and i also hope you get the answers ypur lookin for as do i !!

happy turning

Paul

 

[CHJ]

......1) The lathe that I have is a three speed model however I tend to be only using the highest speed for everything (roughing down, detailing and sanding etc). Am I right in doing this or am I better off using the slower speeds for different parts and if so then what stages would i do it for?

Depends upon the diameter of the turnings and initial balance, if out of balance slow down, although extra speed can be an advantage as the tool workpiece interruptions are shorter on uneven pieces when roughing.
In general slower speeds are desirable for sanding, gives the abrasive time to cut without skating over the surface and reduces the friction heat generated.

......2) I was trying to part off a piece of work the other day (using a chuck to secure the work) with the parting tool, but when I got to the last 5mm, the piece snapped which ruined the piece. What is the correct way to part off?

Only in very controlled , open ended (no tailstock support) is it likely to be safe parting off completely, the workpiece is bound to sag/flex at the final cuts and in the case of tailstock support invariable result in a tool jam in the groove. Standard practice in all but the best controlled conditions is to use a fine bladed saw to sever the final connection, I personally use a japanese style pull saw.

......3) I would like to have a go at pen turning at some point but I am not sure what I actually need to do it. Now I know I need a mandrel to mount the wood and some way to drill the pieces but is there anything else that I need? ...

A browse of this very basic info.may act as a guide to the next set of questions.

 

[jumps]

Speed

There are a number of factors to consider -
1. diameter of piece - the outside of a large piece will be moving a lot faster than the centre, or a small diameter piece
2. task - sanding is done at the slowest speed, burnishing a wax finish at the fastest. other than that it's a function of no 1 and most tools work in a similar fashion at all speeds. Scrapers are the exception and tend to work better at faster speeds, especially cross grain
3. overall, things (except sanding) happen faster at higher speeds; you can rough out faster, smoth quicker, cut faster, shape faster, hollow faster etc - if that matters to you (production turner) you will use higher speeds. Pieces leave the lathe faster, catches happen faster and with more impact, it's suggested that below 1000 a piece leaving the lathe wiii 'fall' - above 1000 it tends to head 'up' and across.
4.unbalanced pieces should be turned at slowest speeds - although small, light, pieces being turned off-centre can benefit from higher speeds
5. bit's with holes and gaps can be easier at high speed

parting off

1. support the pieve lightly in you cupped hand as you complete
2. the last bit has to be 'cut' and with a normal parting tool you will find it difficult to be cutting the last few mm
3. any heavy piece will easily rip off from the last few mm - so you need to be prepared to cut the last bit quickly, but without applying pressure to the tool making the cut (if that makes sense)
4. practice, practice practice

pens
1. mandrel
2. pen kit
3. bushings for the kit
4. drill for the kit
5. end trimmer, although there are alternative approaches it's worth getting one
6. wood (or whatever)
7. glue for tubes

 

[nev]

Hi guys!

So far I must admit, I have been very impressed with the members of this site and how helpful they have been. I am hoping you guys can help me out once again
Flattery will get everywhere
Right so here we go....

1) The lathe that I have is a three speed model however I tend to be only using the highest speed for everything (roughing down, detailing and sanding etc). Am I right in doing this or am I better off using the slower speeds for different parts and if so then what stages would i do it for?
generally speaking, the bigger and more out of balance the wood is the slower you go. so for example er..6" dia section of log would be put between centres and at slow speed rough down taking off bark and other knobbly bits till cylindrical, you also may want to clean and level end faces (with parting tool?) and create any tenons etc for chuck clamping.
same would go for rounding a hexagonal bowl blank ( i cut the corners off the square blank if not using a bandsaw).
then once everything is nice and balanced you can increase the speed. i tend to hollow bowls and the like in mid speed, small things like pens at full whack.
turn back to slow for sanding, that way the abrasive doesnt get too hot and give up too early.
then speed back up for polishing .
2) I was trying to part off a piece of work the other day (using a chuck to secure the work) with the parting tool, but when I got to the last 5mm, the piece snapped which ruined the piece. What is the correct way to part off? A YouTube video would be great if there are any!
Carefully. as you get to the end of your parting cut loosely place hand around timber to support it, that way it wont fly off across the shop. have a look at leos tops with a skew to see what i mean http://www.youtube.com/user/ArtesanoLeo?feature=watch
3) I would like to have a go at pen turning at some point but I am not sure what I actually need to do it. Now I know I need a mandrel to mount the wood and some way to drill the pieces but is there anything else that I need? Also where is the best place to buy the kits? I don't need blanks as I have enough wood to make some
Jon Taylor has a good how to for pens here http://www.woodturned.co.uk/html/cutting.html . I started with a rutlands kit for 30 quid and johns tutorial.
Vince at the turners workshop, timberbits and fun-E-turnz (on ebay) are all recommended for good basic kits.
Like I said before, you are more than welcome to come round and ave a go at a pen to see if its worth the investment, or for any basics etc. I'm about half way between Macdonalds and the botanical gdns.

just seen the other replies - must learn to type faster :roll:
Sorry for the questions but I thought that this is the best place to ask


---
I am here: http://maps.google.com/maps?ll=51.669203,-4.055689

 

[nev]

sorry, didnt realise how harsh that red ink was