expansion turning spin/mandrin

[Ste_d]

Good evening to all
I am working on a project for the university that consists in the realization of a printed piece and subsequently worked on machine tools. the piece in question is a plateau for a modelling lathe. attach drawing of the finished piece and of the crude that comes out from the molding.
the point is this: I have geometric tolerances that force me to operate with a minimum disassembly of the piece for positioning. so I would have reasoned like this:

- on autocentre with external clamps rovesci I take it and I make the hole of 30mm and I raise it h7
- I touch the hub I need as a bar surface (reference) later
- turn the plateu and the muzzle on an expansion spindle or an expandable turning plug by tapping the previously worked face and touching the face on which there is the letter to that of reference for geometric tolerances (which would be the hypothetical face on which you would go to place the piece to turn).

the point is: instead of drawing this expansion plug, is there anything on the market? I found expansion spindles but I don't think they're doing my case. I need to turn that surface without encountering obstacles until the central hole so my plug must be inside and diameter smaller than 30mm!

I attach a photo of the example that gave me the prof, you see the difference between the classic turning plug and the expansion plug... in practice there is the nut that does not allow me to completely braid, while the other has the smaller threaded sapling of diameter that goes to compress an elastic material. . .

 

[marcofor]

Alternatively, you can also use internal elastic clamps operated by the lathe spindle line (if you use a cn), some manufacturers also have manual versions or you can use a manual hydraulic expander or an elastic clamp like those sold by cages (mitee bite):finger:

 

[Inventore]

to have tolerances between hole and hub face I would proceed in this way:
1) Take the piece with round clamps, holes with 28 tip and turning of the protruding part of the hub up to 62 diameter and a pavement to the face.
2) change clamps and take the piece from the newly turned hub and perform the face of reference and turning the outer part diameter 200
3) Now put the reverse clamps back and take the piece on diameter 200 and with the reference face spying on the clamps and turning the hole hub and bring the lengths to measure.

now there is a problem in the drawing: the inner face between the ribs cannot be performed at the lathe due to the three ribs and the sunshades should not arrive on the hub.

using an expansion plug on a 30 hole and then turning a 200 diameter is not the maximum as if the cutting force exceeds the clamping force you would have the result of ruining the hole with tolerance and throwing the piece

 

[Ste_d]

Alternatively, you can also use internal elastic clamps operated by the lathe spindle line (if you use a cn), some manufacturers also have manual versions or you can use a manual hydraulic expander or an elastic clamp like those sold by cages (mitee bite):finger:

I'll be looking right now, if you have links to make me understand what you mean, I'd be grateful!:finger:

If I understood well to have tolerances between hole and hub face I would proceed in this way:
1) Take the piece with round clamps, holes with 28 tip and turning of the protruding part of the hub up to 62 diameter and a pavement to the face.
2) change clamps and take the piece from the newly turned hub and perform the face of reference and turning the outer part diameter 200
3) Now put the reverse clamps back and take the piece on diameter 200 and with the reference face spying on the clamps and turning the hole hub and bring the lengths to measure.

now there is a problem in the drawing: the inner face between the ribs cannot be performed at the lathe due to the three ribs and the sunshades should not arrive on the hub.

with all these disassemblies the tolerance of 2 cents on parallelism, but above all on the perpendicularity of the axis of the hole, goes to be blessed! the purpose is to sway or return having as reference the central hole that consequently generates the perfectly orthogonal faces to its axis (naturally after having alesed it)! Moreover for the ribs no problem, they will be made to the frieze with drag, the sunflowers have to arrive there because in the true piece they arrive up there:biggrin:

 

[Inventore]

[/QUOTE]with all these disassemblies the tolerance of 2 cents on parallelism, but above all on the perpendicularity of the axis of the hole, goes to be blessed! the purpose is to sway or return having as reference the central hole that consequently generates the perfectly orthogonal faces to its axis (naturally after having alesed it)! Moreover for the ribs no problem, they will be made to the frieze with drag, the sunflowers have to arrive there because in the true piece they arrive up there:biggrin:[/QUOTE]ever heard of sweet bites? rectifies them and tolerance is close to zero. The hole is always the last thing to finish. I've done thousands in seven years as a lathe. . :biggrin:

 

[Ste_d]

ever heard of sweet bites? rectifies them and tolerance is close to zero. The hole is always the last thing to finish. I've done thousands in seven years as a lathe. . :biggrin:

I've heard of it. but I still have too many disassemblies and tools for such a piece (indeed for which the prof pisses). Maybe it works as you say, I don't question it since the experience... but I have to find a system to do so as to minimize disassembly and be sure that tolerances are respected! This thing doesn't have to be done, you have to give me an exam!

 

[Inventore]

I've heard of it. but I still have too many disassemblies and tools for such a piece (indeed for which the prof pisses). Maybe it works as you say, I don't question it since the experience... but I have to find a system to do so as to minimize disassembly and be sure that tolerances are respected! This thing doesn't have to be done, you have to give me an exam!

I understood that:
But on a rough piece of fusion they perform before the roughing and then the finishing ones....:biggrin:

 

[Ste_d]

So you think the correct cycle would be what you wrote me before?

Are these elastic thorns that mean marcofor? ! http://www.cagelli.com/it/prodotto....pid=977&hash=4d66e599d45bdc0a3e75c484702b3e51
http://www.cagelli.com/it/prodotto....pid=765&hash=53b2573914da5966e95e5160eebe2a9dlittle domandina... How do you rotate? I see a base with holes... Wouldn't you just take it with the clamps?
Besides... always so eye... do they expand radially (type internal clamps) or become conical?

 

[Inventore]

So you think the correct cycle would be what you wrote me before?

Are these elastic thorns that mean marcofor? ! http://www.cagelli.com/it/prodotto....pid=977&hash=4d66e599d45bdc0a3e75c484702b3e51
http://www.cagelli.com/it/prodotto....pid=765&hash=53b2573914da5966e95e5160eebe2a9dlittle domandina... How do you rotate? I see a base with holes... Wouldn't you just take it with the clamps?
Besides... always so eye... do they expand radially (type internal clamps) or become conical?

the second ones are for work centers so you would need to realize the exhaust pocket and the sunbeds after making the other work on the lathe...

In my opinion, if the prof wants to use the expansion clamp:

 

[Ste_d]

He wants that to make me do a few disassembly... the purpose is also that we say.. find the least number of phases and sub-phases!

You know nothing about how they expand? it would be ideal if they were like internal clamps... Then I don't understand what those holes are for on the base.. .

 

[SHIREN]

Hi.
the solution of the expandable plug that theoretically should keep the piece firm on the spindle and also should ensure a perpendicular alignment between the hole from 30 and the face of the plateau is too "lunatic"

if there is such an age
I don't know if you noticed that the plateau has three open sunshades
pass a tool above you have a cut break that causes you vibrations that dark bring you out tolerance
the ratio between hole 30 and the outer diameter of the plateau 200 is too large
"friends make-up" they're talking about
the piece is realized

1. grasping the outer diameter 200
2. we're going to get rid of the hub
3. and spy on the face with the nerves
4. you turn the piece
5. you grab the hub
6. turning the outer diameter 200
7. change the bites using those "sweet" rectifies
8. the plate on 200 and leans on the plan already worked on sweet bites
9. if you lavore the plateau's beech
10. you make the hole 30

all in a 1/2 hour including na tazzulella and cafe' and na cigarette
It's obvious that I'm expecting a match from friends and family make-up
Thank you very much
Good Sunday

 

[Inventore]

c.V.D. :biggrin:

 

[zeffiro62]

take it for the diam 66mm, turn it back to the diam 200mm and make the bevel at the diam 30mm, turn it for 200mm and finish the 30h7 and height 35mm the quotas 10mm, 20mm and the diam66m are not functional on the plateu then leave them crude.

Sorry but there I hadn't seen the drawings for which it leaves the expanding thorns or the turned inner clamps if you can't!

 

[marcofor]

take it for the diam 66mm, turn it back to the diam 200mm and make the bevel at the diam 30mm, turn it for 200mm and finish the 30h7 and height 35mm the quotas 10mm, 20mm and the diam66m are not functional on the plateu then leave them crude.

I had not noticed pdfs I thought the application referred to the drawings the solution zeffiro62 is the most practical keep in mind that if the numbers are important the particular you can pull it finished on a lathe with counterheads and motorized.

 

[SHIREN]

I had not noticed pdfs I thought the application referred to the drawings the solution zeffiro62 is the most practical keep in mind that if the numbers are important the particular you can pull it finished on a lathe with counterheads and motorized.

take it for the diam 66mm, turn it back to the diam 200mm and make the bevel at the diam 30mm, turn it for 200mm and finish the 30h7 and height 35mm the quotas 10mm, 20mm and the diam66m are not functional on the plateu then leave them crude.

Sorry but there I hadn't seen the drawings for which it leaves the expanding thorns or the turned inner clamps if you can't!

Hi.
You can't take it from 66.
you have to go back
Thank you.

 

[Ste_d]

Hi.
the solution of the expandable plug that theoretically should keep the piece firm on the spindle and also should ensure a perpendicular alignment between the hole from 30 and the face of the plateau is too "lunatic"

if there is such an age
I don't know if you noticed that the plateau has three open sunshades
pass a tool above you have a cut break that causes you vibrations that dark bring you out tolerance
the ratio between hole 30 and the outer diameter of the plateau 200 is too large
"friends make-up" they're talking about
the piece is realized

1. grasping the outer diameter 200
2. we're going to get rid of the hub
3. and spy on the face with the nerves
4. you turn the piece
5. you grab the hub
6. turning the outer diameter 200
7. change the bites using those "sweet" rectifies
8. the plate on 200 and leans on the plan already worked on sweet bites
9. if you lavore the plateau's beech
10. you make the hole 30

all in a 1/2 hour including na tazzulella and cafe' and na cigarette
It's obvious that I'm expecting a match from friends and family make-up
Thank you very much
Good Sunday

I will try to tell the professor this solution... even if I already know that he sends me to the ass for too many disassembly... I know that maybe you would do it like that but what do you want to do?! I try!
cmq in this case the surface marked with the a would be that at the base of the hub...

take it for the diam 66mm, turn it back to the diam 200mm and make the bevel at the diam 30mm, turn it for 200mm and finish the 30h7 and height 35mm the quotas 10mm, 20mm and the diam66m are not functional on the plateu then leave them crude.

Sorry but there I hadn't seen the drawings for which it leaves the expanding thorns or the turned inner clamps if you can't!

I can't because it's so conical! I thought about it!

 

[SHIREN]

I will try to tell the professor this solution. . . even if I already know that he sends me to the ass

Hi.
in case your prof sends you or would send you he has to do a piece of work in your or in his background this would be a prob your
in case he would not be convinced of the following work
from me described
I would suggest you first denounce the prof by the principal
because with his (stronzata) theory of expansion plug
(he who should be the top of knowledge)
is sending you a wrong processing process and maybe even dangerous!!!!!!! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! !
but what is it?
Tell him to do the job
in case things are like you
I highly recommend you change school
Thank you very much

 

[zeffiro62]

do as you want ste_unipi my solution is correct, of the deform you don't freghi you have the tempered clamps and 25mm of grip to the limit you make the turned clamps on the inside of the diam 200mm

 

[zeffiro62]

if the prof object that you can't take it for diam 66 because conical (form of fusion) and tells you that you haven't taken sure you can always make a diam 29mm cap with centrino and support the counterpoint so if you sure you don't run away while you work it

 

[Ste_d]

we change school, we are the best in Italy after torino! but in fact it is the assistant who breaks the balls, otherwise I want to try to hear the prof... I would also simply do as you say that I think much more technological and functional. the true prof is director of the department of mechanics and author of the book they use in all Italian universities for technology. . .