MOLD MAKING: SMALL PARTS FAMILY MOLD part 1

Hi Folks, in this episode, I make an injection mold for 2 small clear plastic parts for a customer. There is lots of machining, so i will split it up into a couple of parts.

Enjoy!

[warriorfox]

Great video but quick suggestion, when you’re cutting parts in a vise and only using one end of the vise like when you milled the parts to length you should really put another block in the opposite end to keep your moveable jaw square. If you put an indicator on your moveable jaw on the opposite side you will be able to see how much the jaw twists out of parallel to the solid jaw. This makes a huge difference with precision and actual holding strength.

[EdgePrecision]

Can I make a suggestion on manually touching your tool off? Try this. Get something that's round (I use a .50 diameter dowel pin). Of course measure the diameter precisely. Jog your tool down close with a gap of less than your pin diameter Now rotate one of the flutes of your tool if necessary at a good angle to where you are going to slide your pin under the tool. Now bring the pin lightly up against the tool sitting on the top surface of your part now jog the spindle up with the handle jog set to the finest (.0001") jog rate. You should be able to feel the pin slowly sliding under the tool. Keep going until the pin passes under that flute. Now pull it back and check all the other flutes to make sure there is not one that sticks down farther. Now move the pin out from under the tool. It is important not to jog the Z axis with the pin under the tool. Jog it down a klick or .0001" try the pin and keep going till you feel a drag. You may have to go up and down a klick or so. Again don't jog with the pin under the tool! Just test it with with the pin while not jogging. You will see you can quite easily feel .0001" this way. This actually takes longer to describe than to do once you try it. This is much better than using a shim or paper. Try it. It will be much faster and just as accurate as your scope. Obviously you have to add the diameter of you pin to the tool length offset. Or tell the machine to calculate that height above Z zero.

[Proudbmodest]

To close a hole, use a ball bearing with a diameter larger than the hole diameter, put it on the hole and give it a few whacks. This will nicely tighten the hole by compressing around the circumfrence. This works well when dowels are loose in a press fit hole.

[dnaboylab]

learnt a lot from this long video. thanks

[jonnyhifi]

Fascinating ! Thank you so much for posting this . I have a background in fdm printing - but am moving to injection molding some parts - so am trying to understand something about cnc milling and mold making - so this is super helpful.

[JohnSL]

Great video. What is the tolerance you use between the insert and the pocket? Also, given that this is a prototype mold, what is the advantage of using steel instead of aluminum for the insets? I'm curious because all my molds are aluminum, and I've never had issues.

[bluesteel]

Putting the part in the freezer for a few minutes will bring it size, tolerances/sizes vary according to temperature

[debaserNYC]

This is just my ignorance here, but isn't there a more automatic way of touching off with a probe or something? Would something like that be on a more complex (expensive) mill?

[marvtomson]

you certainly have a strange way of touching off ??? I either use parchment paper, or brass shim stock. Drop your RPMS down much lower and then bring your head down till it just twists the paper or shim stock. Leaves you at about .0002 from surface for tooling. But that''s just my way.

[johncarey]

Given your attention to detail and precision elsewhere, I was a little surprised that you had one small piece in the vice, but nothing at the other side of the vice to "balance" things ... I should say that I'm not a machinist, so my comment is probably completely worthless ... :-D

Other than that, I'm really enjoying the mixture in the content in the channel. Keep up the good work ... :-)

[VincentFogarty]

We normally call this a two cavity mold

[jaayspott]

very cool! what software were you using when you were showing us the 3d model?

[Anilkumar-sqtp]

Sir, 1) What's the Best way
to take bearing.
2) How to reduce bearing time of mold.
3) In what way we can maintain and design to reduce bearing time .
4) how to use tolerance for mfg of mold.
Kindly Can you make a video for the same with good and tough mold as example.