lathe jaws/chucks

[CRAFTY]

Hello,i am nearly finished building my lathe,i am having trouble finding a chuck to fit a 20mm shaft,if anyone knows if one can be got,or knows where to get one? i would be most grateful,if not i may be looking at making my own,ok thanks.

 

[CHJ]

Hello,i am nearly finished building my lathe,i am having trouble finding a chuck to fit a 20mm shaft,if anyone knows if one can be got,or knows where to get one? i would be most grateful,if not i may be looking at making my own,ok thanks.

I refer you back to this post

Specifically:-

......If you intend using standard turning faceplates and chucks then the spindle nose needs to be made to some very specific dimensions.

See Here

 

[woodpig]

Crafty, have you had any kind of thread cut on the shaft? If not, I believe Record Power do a plain 19mm insert to fit their SC4 chuck that you may be able to open out to 20mm.

 

[CRAFTY]

Crafty, have you had any kind of thread cut on the shaft? If not, I believe Record Power do a plain 19mm insert to fit their SC4 chuck that you may be able to open out to 20mm.

yes it has been threaded to 20mm both ends,thanks i will look into it :mrgreen:

 

[CRAFTY]

SC4 thread adapter,20mm,ohhhhhh yes,i be getting it A.S.A.P,great job WOODPIG,thanks a lot,save me messing around with making one and adding more danger,cheers :mrgreen:
my lathe is getting some bling \/

 

[Robbo3]

We did try to warn you about headstock threads!

Now you need to know the thread pitch. If it's 1.5 or 2mm you can at least get an SC4 chuck & thread adaptor but you are restricted to using that chuck or others with the same internal threads as the adaptor. If the pitch is something different your only hope is to get an adaptor machined to a common headstock thread, perhaps M33 x 3.5.

 

[CRAFTY]

so will this jaw fit the adapter? record sc4

 

[CRAFTY]

We did try to warn you about headstock threads!

Now you need to know the thread pitch. If it's 1.5 or 2mm you can at least get an SC4 chuck & thread adaptor but you are restricted to using that chuck or others with the same internal threads as the adaptor. If the pitch is something different your only hope is to get an adaptor machined to a common headstock thread, perhaps M33 x 3.5.

i know but i could not get a hold of the engineer that morning to have the threads changed to 1" by 8 tpi,when i did he had already done it to 20mm

 

[SVB]

20mm x ??? Pitch?

 

[CRAFTY]

SC4 thread adapter,20mm,ohhhhhh yes,i be getting it A.S.A.P,great job WOODPIG,thanks a lot,save me messing around with making one and adding more danger,cheers :mrgreen:
my lathe is getting some bling \/

ok they come with both 1.5 and 2mm pitches
i will find out what the pitch is on the shaft,cheers

 

[J-G]

I hate to pour water on your fire, crafty, but you still have a very serious problem whether or not you can source an adapter to turn your M20 thread into a thread found on standard chucks. The most important part of a lathe spindle is the REGISTER - not the thread - and your spindle doesn't have a 'register' so any chuck you try to fit is unlikely to run 'true'.

Further, every time you remove and re-fit it, the amount of run-out will be different so any compensation you may have been able to adjust for will be irrelevant.

An out-of-balance blank is one thing, and starting at low speed can be brought into balance allowing the speed to be increased after a little work but an out-of-balance chuck will continue to be a danger however much work you've done.

I would seriously consider either sticking to spindle work or decide on a chuck and get a new spindle made with the correct register and mounting thread to suit.

Incidentally, the 'Standard' pitch of an M20 thread is 2.5mm but since you have had the spindle made with no technical input you will need to measure that or speak to the maker.

 

[Keithie]

I'm enjoying crafty's threads as I'm learning loads.

Please can someone explain what 'register' is (not the one they take at old folks homes in the morning to make sure everyone is still there!) ..thanks

 

[CHJ]

I'm enjoying crafty's threads as I'm learning loads.

Please can someone explain what 'register' is (not the one they take at old folks homes in the morning to make sure everyone is still there!) ..thanks

Look at the links I keep providing in previous posts, the Axminster chart gives all the details. There are several other references but that's as good as any for someone to start with.

 

[Keithie]

http://www.quest42.co.uk/woodwork/bin/A ... hreads.jpg

Got it ...I'd tried basic online searching & failed ..then looked at the resources you provided ...far more accessible ..ty

(maybe I need to get past this learned dependence thing !!)

 

[CHJ]

CRAFTY , before you spend any money on chucks or adaptors I seriously advise you to attempt to get that spindle spinning and sort out the associated problems.

1. I do not believe that your headstock assembly is anywhere near robust enough to carry a 100mm steel chuck, the forces involved when you start cutting and the weight is soon going to hammer the bearing outer housings loose.

2. You have made no provision so far as I can see to locate the spindle laterally to take any thrust loads, so even between centres turning will not work as it is.

 

[woodpig]

so will this jaw fit the adapter? record sc4

Yes. When you're ready to get a chuck the SC4 is pretty good for the money. There's also a good range of accessory jaws that fit it.

 

[CRAFTY]

so will this jaw fit the adapter? record sc4

Yes. When you're ready to get a chuck the SC4 is pretty good for the money. There's also a good range of accessory jaws that fit it.

great stuff,i will put them on my list,thanks.

 

[Keithie]

omg...I've finally understood how dangerous what crafty is doing. I really hope there isnt going to be serious injury.

Would those who've been advising him on here be liable if there was?

I remember someone telling me to use the tip of a skew chisel as a hollowing tool...lol..luckily I'm not quite as green as I'm cabbage looking. Does Crafty know when you're teasing /misleading him ?

I'm a novice crafty so dont listen to me ... trust the experts!

 

[SVB]

Would those who've been advising him on here be liable if there was?

Don't worry, we're not in the US (yet).

I think the relevant Case law can be found with reference to Darwin vs Brave!

S