plastic injection moulds - holes on external surfaces

[Daniele-san]

Hello.
a question that may seem trivial, and just to take away a doubt
we talk about plastic injection moulds
a hole (on an external surface of the printed part) perpendicular to the sense of extraction (so subsquadro) should always be created with undersquadro carts or there are other solutions?

Thank you.

 

[Vittorio]

hi, if the movement to create the hole has a few mm stroke, there are other systems that exploit the movement of the expeller plate.
If you place an image I can be more precise and recommend the best.

 

[Meteor02]

depends on the hole and the geometry of the detail, if the sform is sufficient you can also do destination in male and female mating two inclined surfaces the hole will become slightly oval alternatively a simple piston

 

[Vittorio]

depends on the hole and the geometry of the detail, if the sform is sufficient you can also do destination in male and female mating two inclined surfaces the hole will become slightly oval alternatively a simple piston

That's right. That's why I asked to post the image.
the cheap alternative is as you say meteor02 . there is to understand what utility has the hole to get.
if it is a passage of a good cable the system you suggested, if it is a threading hole it is for force a movement

 

[TECNOMODEL]

Hello.
a question that may seem trivial, and just to take away a doubt
we talk about plastic injection moulds
a hole (on an external surface of the printed part) perpendicular to the sense of extraction (so subsquadro) should always be created with undersquadro carts or there are other solutions?

Thank you.

Depending on the geometry, extractors can be used to "fleet" the subsquadro.
This is an example: https://ecom.meusburger.com/e/index.asp?id=406&rnd=77954

 

[Daniele-san]

hi, if the movement to create the hole has a few mm stroke, there are other systems that exploit the movement of the expeller plate.
If you place an image I can be more precise and recommend the best.

hello victorious, today I am not in the office so I can't post a screen shot but you place a section made by hand I hope it is enough, the hole not listed (a distance 2mm from the head) perpendicular to the extraction axis and diam 2mm
Thank you.

 

[Daniele-san]

depends on the hole and the geometry of the detail, if the sform is sufficient you can also do destination in male and female mating two inclined surfaces the hole will become slightly oval alternatively a simple piston

thanks for the surgery, this is not the case

 

[TECNOMODEL]

hello victorious, today I am not in the office so I can't post a screen shot but you place a section made by hand I hope it is enough, the hole not listed (a distance 2mm from the head) perpendicular to the extraction axis and diam 2mm
Thank you.

for that hole I think you have no alternative if you don't make a cart.
you can choose various systems to handle it, inclined plug, spring and wedge, hydraulic piston, but the trolley is inevitable.
another solution can be split the moving part of the mold in 2 along the axis of the piece and open the two half, thus freeing the hole. but it definitely costs more than making a cart and you would have a mold junction line on the piece.

 

[Vittorio]

hello victorious, today I am not in the office so I can't post a screen shot but you place a section made by hand I hope it is enough, the hole not listed (a distance 2mm from the head) perpendicular to the extraction axis and diam 2mm
Thank you.

Hello, I think the least expensive solution is a tunnel driven by a small air cylinder or oil.
what worries is the small distance 2mm from the upper face that does not give the possibility to put a small telescope to avoid the gripping of the spin. technomodel anticipated me writing. I think the solution is a cart ..traces of joints allowing.

 

[Daniele-san]

Hello, I think the least expensive solution is a tunnel driven by a small air cylinder or oil.
what worries is the small distance 2mm from the upper face that does not give the possibility to put a small telescope to avoid the gripping of the spin. technomodel anticipated me writing. I think the solution is a cart ..traces of joints allowing.

Hello victorious,
I've put a random fee to decide but it doesn't differ much, how much do you recommend?

 

[Vittorio]

Hello victorious,
I've put a random fee to decide but it doesn't differ much, how much do you recommend?

I'll give you an example. if the hole has a ø2 you must consider that the telescope has an external ø5 so your hole must place it at least 3mm from the top, I attach you image

 

[TECNOMODEL]

I'll give you an example. if the hole has a ø2 you must consider that the telescope has an external ø5 so your hole must place it at least 3mm from the top, I attach you image

In my opinion, the telescope is not indispensable. a cart made well, with a hardened soul, with its good conicacy performs egregiamente the work and does not bind you to minimum dimensions due to the outside of the telescope.
In addition, how would you fix the telescope itself? and what would the extractor move inside?

 

[Vittorio]

the telescope is indispensable in case the soul grips, the conical soul is not a soul from commerce and therefore costs more both the seat and the soul itself.
we do not even know the n° of the pieces to print or at least the rhythm of production. Sure. If you have to produce only 10 prints, it's fine to remove it by hand. I did not draw the whole system to extract the telescope and move the soul because it was only an example to make daniele-san understand the concept of space 2mm.
I recommended the best mechanically. It's a tunnel and I think it's partly fixed, so I think an air or oil cylinder is suitable.

 

[TECNOMODEL]

the telescope is indispensable in case the soul grips, the conical soul is not a soul from commerce and therefore costs more both the seat and the soul itself.
we do not even know the n° of the pieces to print or at least the rhythm of production. Sure. If you have to produce only 10 prints, it's fine to remove it by hand. I did not draw the whole system to extract the telescope and move the soul because it was only an example to make daniele-san understand the concept of space 2mm.
I recommended the best mechanically. It's a tunnel and I think it's partly fixed, so I think an air or oil cylinder is suitable.

you can safely insert a piece of expeller on a cart, if the matrix is hardened and the work done correctly the soul will not grip.
the insertion of the telescope will create lines on the piece that would result unsightly, moreover the telescope must be shaped in the front, therefore it needs to have a fixed orientation, all things that require further processing, tolerances and possibility of errors that can affect the quality of the piece.
personally it is a solution that I would not adopt.

 

[Vittorio]

you can safely insert a piece of expeller on a cart, if the matrix is hardened and the work done correctly the soul will not grip.
the insertion of the telescope will create lines on the piece that would result unsightly, moreover the telescope must be shaped in the front, therefore it needs to have a fixed orientation, all things that require further processing, tolerances and possibility of errors that can affect the quality of the piece.
personally it is a solution that I would not adopt.

Of course, but we don't know how many pieces you have to print and if the piece to get goes inside a wall or is a very high design piece.
All right. if we want to open a discussion about what is best for a mold.. This is not the place
It seems to me that the subject of the discussion was another. Do you need a movement? the answer is "yes" then with other available data we will face the best for the construction of the mold.

 

[TECNOMODEL]

Of course, but we don't know how many pieces you have to print and if the piece to get goes inside a wall or is a very high design piece.
All right. if we want to open a discussion about what is best for a mold.. This is not the place
It seems to me that the subject of the discussion was another.

It is not my intention to make a controversy, but I believe that in a deeper way, more aspects can contribute to a better choice, which will obviously have to do the op.

 

[Daniele-san]

Depending on the geometry, extractors can be used to "fleet" the subsquadro.
This is an example: https://ecom.meusburger.com/e/index.asp?id=406&rnd=77954

hi technomodel,
returning to your previous intervention,
taking inspiration from a solution that I have already had time ago on a particular plastic (linear potentiometer knob),
for which I had to create (for the grip and hold of the knob) a circular subsquadro diam. 2.2mm deep 0.3mm.
would it be possible to do the same intervention within the tree (on two surfaces)?
besides feasibility would be advisable?
would I have an external surface deformation quoted 7.8mm or other non-conformities?

Thank you.

 

[TECNOMODEL]

hi technomodel,
returning to your previous intervention,
taking inspiration from a solution that I have already had time ago on a particular plastic (linear potentiometer knob),
for which I had to create (for the grip and hold of the knob) a circular subsquadro diam. 2.2mm deep 0.3mm.
would it be possible to do the same intervention within the tree (on two surfaces)?
besides feasibility would be advisable?
would I have an external surface deformation quoted 7.8mm or other non-conformities?

Thank you.

would not be feasible using flexible expellers, with a subsquadro so reduced I would blur the elasticity of the material, if it allows its type.
first freeing the outer ø when you go to extract the piece from the inner soul the same "opens" leaving the subsquadro out, then falls into size thanks to the elasticity of the material.
should be evaluated if the material allows it and, if possible, adjusted that subsquadro to create an invitation to the extraction and bending of the piece.

 

[Daniele-san]

would not be feasible using flexible expellers, with a subsquadro so reduced I would blur the elasticity of the material, if it allows its type.
first freeing the outer ø when you go to extract the piece from the inner soul the same "opens" leaving the subsquadro out, then falls into size thanks to the elasticity of the material.
should be evaluated if the material allows it and, if possible, adjusted that subsquadro to create an invitation to the extraction and bending of the piece.

usually for this type of components we use nylon from dupont zytel st801
but the knob was in abs

 

[TECNOMODEL]

usually for this type of components we use nylon from dupont zytel st801
but the knob was in abs

if I recall the zytel is a glass load, with a fairly high percentage.
Could make you some trouble.
with the abs, instead, you could do it quietly.