You probably already know this, but in doing a small search, I found this:
Here's a quote from this website:
"If the insert has an internal hole, a post can be used to hold it in place. Due to the manufacturing tolerances of inserts, rarely is the fit on a post firm enough to securely hold it in place. Sometimes all it takes is temporary adhesion between the mold surface and the insert while the plastic envelopes it. Application of water or petroleum jelly can provide enough adhesion to the mold face to dramatically reduce rejects due to inserts moving during the injection molding process."
Looks like a type of drywall anchor --- Hollow Wall Anchor
1/8" Hollow Wall Anchors with Screws | The Container Store
FastCap SB-ANCHOR 10 PC SpeedBrace Wall Anchor, PK/10
It's hard to tell from the pic, but looks like these:
I love McMaster-Carr. Those guys have the most thorough user friendly website plus so many parts!
Same here! And CAD models of most everything to boot:). I actually spoke to someone in Florida the other day looking for a part, that had never heard of them! I told him he should probably set aside the rest of the day to check it out:).
True! There is so much to see, I have to stop myself from burning up time by browsing around.
And the way they have it all organized is better than any small parts website that I've ever encountered.
They don't hustle you about getting the CAD files either.
A few vendor sites I've checked out want you to sign up to get their CAD parts, then they spam you.
Yes, but be careful when you use their products in your assemblies, they love the very high detail and most of their parts are moved all the way over to the right (if not in the red).
Is there a hole in the end we can't see in the screenshot? If yes, it looks very similar to plastic fasteners that you insert into drywall, and then insert a screw for hanging pictures, etc. The screw causes the sides to expand, which holds it tight in the hole.
Thank You all. The type of fastener I'm looking for would be very similar to hollow wall type anchor, but more robust/mechanical. What I'm looking for is something to use to hold hand loaded "dodge" type inserts in a mold while injecting plastic around them. Typically hand loads are either threaded on to the end of separate removable insert that then gets hand loaded into the mold. After molding the article comes out and the insert has to be un-threaded off the article , a new "dodge' insert threaded on and reinserted into the mold for the next shot. very labor intensive. the optional method is to have a pin in the mold that very accurately fits the ID of the "dodge insert this method has its drawbacks as well. Sometimes the insert may move due to the injection of plastic around it. Sometimes the accuracy of the ID of the "dodge" inserts renders some inserts un-usable. Sometimes you'll get plastic flashing into the hole when it moves off the pin a little. If I could find something like this that would hold the "dodge" insert a little firmer (it wouldn't need much) it would be a good solution. My other option is to use a detent clevis pin, but it's difficult to find one in the correct size. Most companies that make the detent clevis pins can make custom sizes, but I'm still unsure about them working. Sometimes molds can be operated at elevated temperatures depending on the material being molded. The ball detents a re usually cold form swaged in and I don't know how long these would hold up to the molding process as well. Whewww! thanks for all your help!
There's these guys:
Specialty Fasteners, Standard Fasteners and OEM components | S.W. Anderson Co. \
That one in your picture looks a bit like this one:
Jack Nut® Threaded Inserts On S.W. Anderson
There is also this:
Dodge Ultra-Mold Molded-In Inserts for Plastics | STANLEY Engineered Fastening
Hi Dan,Thank You. So yes those are very similar to the inserts I'm talking about. The problem is that they must be inserted into the mold onto a pin that fills the interior so it doesn't fill with plastic during injection and they (the inserts) tend to slide around due to the force of the plastic when it encompasses them. It isn't always a problem, but if the flow path the plastic takes when enveloping them is such that it wants to push them off they're seating then plastic seeps in behind them and ruins the part by either moving the insert or back filling the threads. My thought was something like the wall anchor but with very little movement on the order of .005/s (see slight interference below). This would hold it in place with enough force (doesn't take much). I don't think I'll find something already made. Will probably have to manufacture ourselves. This one would be for a 1/4-20 thread and the screw in the end (red) solid body is a 2-56 screw.
Yes, We have done this in the past and it does work. It is sometimes difficult on a hot mold when inserting position is not right at parting line, but buried in the mold. It also requires the operator to re-apply it every so often and it can also contaminate the parts if not applied judiciously. I think I'll mark yours as the correct answer as I have exhausted my willingness to search online for it and will either make my own or go the detent clevis pin route.
OK, here is something that is rolling around in my head. Maybe it won't work and maybe it would be too hard to manufacture.
Have you ever seen a quick release pin similar to this?
Well, could you make a quick release pin similar to this, in which the OD of the pin itself is just smaller than the minor diameter of the threaded insert. Then make the ball bearing that sticks out, just big enough that it would fit into the groove of the thread. You would either have to make it so that there was only 1 ball bearing going into the thread, or you would have to make it so that the distance, along the axis of the pin, between the two ball bearings is 1/2 the pitch (for a 1/4-20 thread, it would be .025").
Then, you could have your operators screw a threaded insert on the pin (using the ball bearings as the male "thread"), then put it into the machine. After molding, they push the button, which releases the ball bearings and the pin just slides out.
I have not looked into this enough to see how realistic this could be....but I wanted to get it here before I forgot about it.
Yes, This is the detent clevis pin idea I mentioned. They make non-locking ones so the operator wouldn't have to depress anything. They do make single ball ones as well. The issues with these and they may not be issues are the ball is only swaged in so if it ever failed I'd hate for the ball to come out and get caught in the mold. and they would have to be custom size to adhere to the Id of the Dodge inserts. Also don't know if they'd hold up to the heat in the mold which with PEEK could be 450-480 F. As I said that's probably the way I'll go.
Ahh, I saw you mention "detent clevis" but it didn't register that this was the same thing. LOL
It looks like a push rivet (Push-In Rivets - Drive Fasteners | EssentraComponentsUS )
After a lot of thought and perusing the Internet. In the end I came up with this. K.I.S.S. Dah! It has about .0025/s interference fit for about .125 then tapers back to about .0025/s clearance 2 wire slots to give it some flex and I think it should work. Sure is a lot less complex than the path I was going. Now I just wish PCS or DME or someone offered this as a standard item for the most common Dodge insert sizes. I'm sure they could mass produce them and get the cost down. wiring the slots is the big $$ draw for us as we don't have one so it will have to be farmed out. Only thing I can think of that may be an issue is if the retention force of the interference fit on cases with multiple inserts is enough to make part stick to "A" side on mold opening. But then we could just play with the amount of interference.
Very nice! A little collet. Sometimes the best ideas are the simplest.
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