Cutting an ally block

[DAPPH]

I've got a block of aluminium around 30cm long and 5cm deep that I want to cut down its length.

A brief google suggests that a jigsaw with a wood blade, and plenty WD40, is the way to go - any other suggestions?

A decent coarse wide bladed hand hacksaw at about 4-6 tpi . With one of those the job ought to be done in just over 25 min of gentle but firm strokes .
Due to knackering the blade on my band saw on a masonry nail hidden in some wood , the last block of 2 x 2 x 10 aluminium I cut was cut length wise in half with a newish hard point cross cut saw. I ran the saw along a block of square cut wood , tested for true to cut square & clamped to the aluminium that was held in the vice . I cut it dry as this was the easiest way , stopping every few minutes & using a stiff nylon brush to clean the teeth of any debris .

 

[addjunkie]

Wot now power feed, obviously time to go buy a new lathe, now youve learnt the basics.

Are you sure it has no feed, what machine is it?

Tool grinding is important if you want to start getting a good finish.

 

[roofman]

Doesn't have any more chuck speed!

Mine did which was identical to yours...i fitted a motor pully an inch taller as i always struggled with too slow of a turning speed,this mod aslo made the power feed faster too as it was all relative

Turning by hand (no power feed). You're almost certainly correct about the rake angle - I have the lathe book that everyone recommends (the old one - forget it's name!), but having it and reading it are two different things!

 

[roofman]

Wot now power feed, obviously time to go buy a new lathe, now youve learnt the basics.

Are you sure it has no feed, what machine is it?

Tool grinding is important if you want to start getting a good finish.

they have a power feed..i once owned one,you can see it here from an old pic off my puter

 

[skotl]

Wot now power feed, obviously time to go buy a new lathe, now youve learnt the basics.

Are you sure it has no feed, what machine is it?

Tool grinding is important if you want to start getting a good finish.

It's a Denham Mk 2 - circa 1944!

It doesn't even have a lead screw (it did have one, but this has been lost/broken at some point in the last 70 years.

 

[addjunkie]

http://www.steves-workshop.co.uk/tips/toolgrinding/toolgrinding.htm

 

[roofman]

It's a Denham Mk 2 - circa 1944!

It doesn't even have a lead screw (it did have one, but this has been lost/broken at some point in the last 70 years.

look above Scott..same as this fella which i had

 

[addjunkie]

A machine to learn with at the right price i suspect, but no feeds or screw cutting will hold you back

 

[DAPPH]

I have a vertical wood bandsaw and would probably free-hand a length off that slab. Otherwise I'd use the Bridgey in horizontal mode and slice it with a narrow 4 or 5" slitting saw.
I'd also always aim to have as little metal hanging off the chuck as possible; I know the tailstock centre is in but you only need a midgie's todger of setover and your part still ends up tapered due to the reducing diameter, it's exaggerated by the longer workpiece.
I'd also shorten the tool overhang and maybe have a bit of stiffness in the cross-slide gib strip, both of which could help with the finish.
Good effort on setting up a 4-jaw, takes infinite patience sometimes

Setting things up to turn between centers to my mind is even better for you can take it off when it's heated up because of tuning , then drop it in a bucket of cold water to cool it down , then take you accurate measurements before putting it precisely back in the between the centers for further turning .
Getting a nice smooth turned surface I'd use the highest speed I have and a rounded honed up tip on the cutting tool , always cutting from the tail stock making a couple of very light finishing cuts .

 

[skotl]

http://www.steves-workshop.co.uk/tips/toolgrinding/toolgrinding.htm

Perfect! Thanks for this

 

[roofman]

It's a Denham Mk 2 - circa 1944!

It doesn't even have a lead screw (it did have one, but this has been lost/broken at some point in the last 70 years.

Has it not

Oh, also.

It might seem nice and convenient to blame Bonaparte and the French for the introduction of metrics, but 100 years before he was born Bishop Wilkins published his ideas for metric system of weights and measures.

Honestly, if you don't like using decimal measurements and need someone to blame, I'm afraid it's the English

was,nt the Romans using units of 100 as a scale...basic metric right there and a lot older than bishops head or whatever his name was

 

[DAPPH]

Oh, also.

It might seem nice and convenient to blame Bonaparte and the French for the introduction of metrics, but 100 years before he was born Bishop Wilkins published his ideas for metric system of weights and measures.

Honestly, if you don't like using decimal measurements and need someone to blame, I'm afraid it's the English

That ole Bishop was French saboteur , incognito & a savant

Wikki says he travelled to mainland Europe , bet he spoke French fluently as well , as this was the common language here in the British Isles at the time amongst shouters & rulers . Not to mention the Welsh ............................. DON'T mention the WELSH !
Just remember the old saying .... " Bishops make strange bed fellows " . Evidently he all so wanted us Brits to take up a new common language that he hoped to spread across Europe .. sounds far fetched till you realise it's too much current EU stuff .

 

[DAPPH]

Has it not

was,nt the Romans using units of 100 as a scale...basic metric right there and a lot older than bishops head or whatever his name was

Funny you mention that , evidently a Centurion was in charge of any number of men from about 78 to well over 130 .

 

[Parm]

Skoti

Why didn't you say you wanted some 25mm bar, ive got about 2m of Ali bar that size and I would have been happy to post to you

 

[skotl]

Would've been lighter to use a lump cut out of the middle of an old pair of handlebars...


Edit: There's no fun in that though. This way, there was setup and turning practice.

Exactly! It's all for fun

I'm going to drill down the centre section to take some of the weight out, though.

 

[skotl]

Skoti

Why didn't you say you wanted some 25mm bar, ive got about 2m of Ali bar that size and I would have been happy to post to you

Cheers, Parm, but where's the fun in that?

 

[DAPPH]

You could always cut it in half ,thus reducing the weight by half

 

[Parm]

Cheers, Parm, but where's the fun in that?

In that case, the next mission should be to bore out the ends to make it lighter and make some end stoppers

 

[Wedg1e]

If you reckon the top speed is somewhere between 600 and 900 rpm then that's probably about where I'd have been turning alu anyway, so not a kick in the nads out

 

[ronan]

Jody here in welding tips and tricks uses an ordinary bar of soap to lubricate his saw when cutting aluminium.