Chuck Accessories / Thread Sizes

[wcndave]

I have a Scheppach 450 which according to the technical details in the manual has a 1" 8TPI thread on the headstock.

I ordered a package deal axminster chuck set that holds pieces internally / externally, which was also 1" 8TPI, http://www.axminster.co.uk/sessionID/DK ... 724871.htm
however they clearly do not fit, the 450 is about 3/4" bigger than the threads on the chuck.... i can't understand what I've done wrong - ie should there be a completely different measurement i should be looking at to make sure i order compatible parts?

also i cannot see how to get the tail centre off if i want to replace the end. the only way i can see is to put a spanner over the end and force it off with mallet, however as this would be from one side, or other, i am worried about damaging it and sending it off true from center - any idea appreciated.

finally what do people use when want to hold something that is not held at both ends, and also is not a bowl that could be attached to one end.

specifically i want to do wheels for childrens toys, so i use a forstner drill to cut pieces of right thickness so need some kind of mandrill that goes through the drilled center hole and then has a fastner at back, but have no idea where to get such a thing, and how it would actually fasten to the lathe.

i am knew to all this so sorry for my ignorance, hope someone can help me to enjoy this new hobby fully ;-)

 

[Davyboy]

They have probably supplied the wrong model which is what happened to me when I bought a DMT450 from Screwfix, there are TWO models, one with a 1"x8 thread & one with an M33x3.5 thread & there is opnly one digit difference in the serial numbers, e.g. 1948/1949 check your user manual, it will give you the numbers in there, Don't let them palm you off with an adaptor! You will need to change the whole machine, as I did.

 

[wcndave]

Any disadvantage to using M33 instead of 1" 8TPI? eg are there thousands of accessories for one and not the other?

I live in Italy and it's really hard / expensive to source stuff here, so i would rather replace the chuck set - any idea of a good version of the same thing for M33?

 

[CHJ]

The M33 X 3.5 is the more common standard in Europe.

See this chart of thread forms.

http://www.quest42.co.uk/woodwork/bin/AxminsterThreads.jpg

However there are variations on spindle nose location collars for different manufacturers.

Check your spindle nose dimensions against this chart before ordering a replacement chuck.

Most chuck models intended for M33 X 3.5 have the thread machined directly into the body of the chuck because there is not enough material to have an adaptor insert to allow swapping between different lathes.

 

[CHJ]

Re: the tailstock centre.
If it will not release when the handwheel is wound right back, (sometimes needs a sharp snap to stop, depends on whether the tailstock/centre design) you should be able to release it by passing a 8/10mm rod through the tailstock barrel from the rear and knocking it out.

 

[wcndave]

The M33 X 3.5 is the more common standard in Europe.

See this chart of thread forms.

http://www.quest42.co.uk/woodwork/bin/AxminsterThreads.jpg

i looked at that chart and could not see M33 on there - the other codes look more specific, which is good - however i never see those listed on accessories, and if each accessory suits one code, then that would really limit ones options...

I can't find anything on axminster for M33, so i guess will have to try to look locally as they are the only ones i know who deliver overseas.

Thanks for all the help so far!

 

[CHJ]

i looked at that chart and could not see M33 on there - the other codes look more specific, ....I can't find anything on axminster for M33, so i guess will have to try to look locally as they are the only ones i know who deliver overseas.

There are at least 3 references to T38 inserts for 33 x 3.5
Thread spindles on the chart. :!:


The spindle size has nothing to do with chuck jaw adaptors.

They are specific to the jaw carrier that is fitted in the chuck body.

All 80 - 100 mm chucks (and the 150mm I think) from axminster will accept all the axminster Jaws, I for instance use some 80mm jaws on my 100mm chuck.

The fixing hole centres and the safety tenon spacings are all to the same standard.

The hole spacing and safety tenon configuration vary between chuck manufacturer so not always guaranteed to be interchangeable.

 

[wcndave]

:? :?

Sorry, I really am new to this, so not familiar with all the various components, what they are called, and how they are described / measured.

So really apologise for the lack of knowledge (despite hours and hours of internet reading on the topic) and really appreciate help / patience!

I was expecting the thread code to be M33, however T38 is what it is. so i see where i went wrong there.

Thing is, not sure how to understand which one, as unlike the diagram in the link above, I have a register that is not uniform in width across it's length, or, i am not sure which bit is the register, A or B in this photo?

Having looked into it is seems that there are 3 ways to mount a chuck, one using a morse taper backplate

another is to use one that screws onto the outside of the spindle and the final is to attach it to a backplate.

lots of articles seem to talk about making your own backplates etc, and seems unnecessarily complicated for me

I would prefer one that attached to outside threads of spindle, however not sure if ANY M33 will do, or if i need one that has the right depth to fit over register etc, as that might possible be what ensures no run out?

I just really want to be sure i get the right fitting pieces for this.

any advice on where i can order this online in the UK would be great,

The last post describes the jaws fitting to the chuck, and what i bought had 4 sets of interchangeable jaws, however not sure what they would be called if i bought them separately....

On my other point regarding turning wheels etc, is some kind of expanding mandril what i am looking for? http://www.arceurotrade.co.uk/Catalogue ... g-Mandrels

sorry if i seem confused, there just seem to be so many different parts and options, all in different sizes, that all fit different sized machines, and no clear guide i have seen about how all these different components can fit together.

if there is a clear guide, then please point me to it and i will happily read before posting any more newbie comments :wink:

 

[CHJ]

Edit: Had another look at your Picture, I'm now confused myself.

My original comment

Your Arrow A equates to Dimension 2 on the Axminster chart

What diameter is section Arrow A?

You need a chuck fitting the same diameter as Dimension 1 no deeper than dimension 2 so that chuck does not foul on lathe casting.

my original comment

Your Arrow B is just the location groove for A chuck retention/locking screw if lathe is reversed.

What diameter/s is section Arrow B?
Although it carries a grove for safety locking screw it appears larger diameter then the thread which is unusual and may well be intended as the register.

The only other critical dimension for you is the distance Dimension 4 from the nose of the thread to the lathe casting.
Your chuck insert/thread selection must be shorter than your Lathe spindle for the same reason as above with locating collar.

would prefer one that attached to outside threads of spindle, however not sure if ANY M33 will do, or if i need one that has the right depth to fit over register etc, as that might possible be what ensures no run out?

That is standard practice and any of the 100 mm diameter Axminster chucks should be available with an appropriate 33mm fitting. You are correct in that the location on the register is the main controlling influence on concentricity of chuck, relying on the threads alone can result in chuck moving off centre under certain loads.

 

[CHJ]

As far as your need to turn wooden wheels, this can be done with simple home made adaptors/jigs turned on the lathe once you have a chuck and some dovetail jaws such as the Axminster pattern:

Basically you turn some scrap wood up in the chuck to hold the wheel for finishing be it the bore or outer, it depends on how complicated the pattern and method you choose, you can either bore the hole and use this to hold it while you finish the outer or visa versa.

Chuck: This one has thread directly in back of chuck. (You will need to copy and paste all of the line, link is incomplete)

http://www.axminster.co.uk/product-Axmi ... (Body-Only)-800680.htm

This chuck comes withe the appropriate back plate for the thread, should you change lathes to a different thread then just a replacement backplate is required.

http://www.axminster.co.uk/product-Axmi ... 809379.htm

Basic Jaws, there are many others, they come with all screws needed.

http://www.axminster.co.uk/product-Axmi ... -21941.htm

Might be worth an E-mail to Axminster to seeif they can confirm if a standard T38 fitting will fit the Scheppach.

 

[wcndave]

What diameter is section Arrow A?

A is 40mm if mem serves correctly

What diameter/s is section Arrow B?

Although it carries a grove for safety locking screw it appears larger diameter then the thread which is unusual and may well be intended as the register.

You are right, this is larger, about 35 at widest part and 30 on smallest.

however if this were the register, would not seem to offer much additional stability given it's so close in size to the thread....

 

[wcndave]

From your suggestions, looks like this

will fit over my arrow B and that as you say, the "B" section is where you lock it. there is no larger opening to cover my section A.

BTW: section A does have a short 5mm hold bored in about 6mm deep in one place only that seems to do nothing, so perhaps this is a safety locking hole for other types of accessories...

For wheel turning, i think i want something like this

however not quite sure what is used here (in the drill chuck), seems to be some kind of home made bolt, however just doing that doesn't seem to guarantee no run out...

 

[CHJ]

Looks like the standard T38 fitting is what you want, the register does not have to be long as long as there is enough material to locate in the plain bore at the back of the chuck. If as you say there is a taper it could be the manufacture did it as a work-around for making it absolute precision, no problem as chuck will just screw on and centralise to suit itself.

 

[YewTube]

wcndave,

I have been trying to follow this thread and it seems to have got over complicated if I have understood it.

I have checked the specification for the Scheppach 450 Lathe and in all cases and from all suppliers it has a spindle size of 1"x8tpi and comes with an adaptor to M33. (This should be a collar with a female 1" thread and a male 33mm thread that screws on the spindle.)

The Woodturning Chuck Set from Axminster is 1"x8tpi with a 3/4"x16tpi insert. (This is collar with a male 1"x8tpi thread and a female 3/4"x16tpi thread that screws inside the back of the chuck.)

The solution should be as follows.
Make sure the adaptor is off the lathe (and it looks to be from the photo) and the the insert is not in the chuck and with any luck they will go together.

Hope this is the solution to your problem.

Bill

 

[wcndave]

I cannot see that any adaptor is on the lathe...

the threads shown on my photo are 33mm and that piece is solid from outside to inside.

i believe as another poster noted, that in Europe, this machine has M33 and in UK 1"

in fact one reason i was annoyed is that i looked everywhere and could also only see that this was 1" 8TPI, so i had done my research, but still got wrong result

 

[jasonB]

The hole in section A is for a pin or spanner to hold the spindle firm when you want to unscrew the chuck.

Re your earlier post about machining backplates, this is really only for metal working lathes or as a last resort you could get one turned on a metal late to fit yours but as its a common size thats not needed.

Jason

 

[frugal]

BTW: section A does have a short 5mm hold bored in about 6mm deep in one place only that seems to do nothing, so perhaps this is a safety locking hole for other types of accessories...

It is probably so that you can put a 5mm rod in there to hold the spindle steady whilst you screw and unscrew the chuck onto the spindle.

 

[Happy amateur]

I don't know about wcnddave but I am very confused by this thread.
The chuck advertised by Axminster that was ordered also comes with a 3/4 16 adaptor. Could it be that the adaptor is already screwed into the 1" x 8 in the chuck. The register is the face that the chuck tightens against, the vertical face at the back end of the spindle thread.

Fred

 

[wcndave]

almost certain that the confusion arises from the fact that nearly every specification you look at for this lathe says it is 1" 8TPI, however looking in the manual, there are two model numbers, one has M33, and this is what I have.

I guess cos it's common in Mainland Europe.

so seeing that M33 is actually fairly common I feel happy now that I know what i need to do, so thanks for the help everyone!

as a beginner, i had tried with roughing gauge and was easy, however just tried skew for first time, and ripped up all my wood with catches... oops - quite tricky to start with....

my only outstanding question is some kind of mandrel, hopefully not home made, to turn things like toy wheels on... still open to suggestions on that.

thanks again for all the replies, great forum!

 

[Bodrighy]

The skew is not the easiest tool to master though once you do it is really versatile. I presume that you are doing spindle work so just practice with the spindle gouge until you feel comfortable. Have a go at making simpler things like dibbers, small mallets, rolling pins (good practice for turning a nice flat spindle) etc as it is much nicer when you have something to show at the end rather than just a piece of wood with beads and coves all over it.

pete