pinning

[Digger1]

I need to know the ins and outs of putting pins into a model to securely attach another part to it. The Darkstar Oberth's nacelle pylons are giving me some problems. I want to drill holes into the hull and into the pylons. I just need to know if there are any special tricks to doing it?

If it's too complicated, I might just take some adhesive to it. Problem is that I took the placement tabs off so I can't let it rest while the adhesive cures so I'll have to hold it. I was thinking actually using pins and adhesive (of course) but maybe I should just go with the adhesive.

[Warped Speedster]

For plug-in type pins like you're talking about. Go ahead and mount some short brass locator pins in the pylons but don't glue them in yet. Make them short with sharp points on them that will leave an imprint on the adjoining hull surface. When you think the pylon is lined up pretty good, go ahead and press it in making the pin marks on the hull. Now drill the holes to size. Now make some longer pins for more strength for final glueing. If the holes don't line up perfectly you can fudge them one way or another with a file or X-acto knife. Then fill in any hole slop with thin evergreen strip and CA. It's slow tender work any way you do it.

If you can drill through from inside the hull, then that might even be an easier way of lining them up. Pin vise only.

I'm not sure what your situation is with all the parts you're assembling, but here's how I do "Pins" for some other applications, if they absolutely need them.

To make a long story short. For glueing a couple halves together that need pins. I just glue the male locator pin where it needs to be along the models inner surface, and let it dry. (I usually use brass rod for the male pin) Then I make a drilled female locator piece from plastic (the goes-inta) and let it float losely in position attached to the male pin. I make sure the female tab is also touching the inner surface of the model where it can be glued in place. I use a tube glue (like testors or something) to temporarily hold it in place. The tube glue will let it slide into the position it needs to be in before drying. Then line up the two model pieces you're putting together, and let the female tab's glue set-up in that position. Now your two halves are all perfectly straight with your locator pin and hole in place.

You can also just make locator "tabs" from plastic strip. Male (one strip) and female (two strips). Just line them up in the inside surface of your model and glue them in place. Where applicable.

Obviously these methods may not work for all parts or situations.

For other flat shaped parts, I guess you could use a pin vise, and drill through both pieces to spot your pins and holes. Then fill in any exposed holes later.

Actually I usually don't use too many locator holes for most projects. But there are times when you absolutely need to have them for fiddly parts, or for guick referancing and temporary fitting.

Hmm, it ended up being a long story after all. Hope it helps.

[TER-OR]

On part A, securely add pins, glued nicely with epoxy. These can be bits of coat hanger, music wire, nails, whatever.

On part B, drill holes larger than the pins. Put a ball of epoxy putty in the hole, and push the parts together and tape securely or use a touch of superglue to hold them in place once you're satisfied the position is correct. The epoxy putty will take several hours to cure, but you won't have to go through tribulations making the alignment perfect.