Detailed and Weathered FVM GEVO -- BNSF 5719

[Sokramiketes]

Unfortunantly the drill bits shown are extremely brittle carbide.  They're meant to be used in a drill press with zero side load... so you have to be really adept to drill by hand without snapping them.  The HSS drill bits (that only go down to #80) available from your hobby shop last longer because they can bend a bit before breaking and are much better for hand drilling.

The solution?  Vince Kotnik just stabs the plastic shell with a sharpened piece of the same diameter (.004"?) music wire that he bends his grabs out of.  The stub of sharpened music wire won't snap off in the shell.  And because the diameter is so small, you really don't need that drilling action.  And the "drill" won't walk on you like it would if you were spinning it.  Just press it firmly into the shell.

Another plus is that the fit is tight.  You can put the grabs in dry and just dab some thin CA on the back of the shell to lock them in.  No worries about dipping into a glue blob and trying to fit the grab in a tight hole with glue squeezing out.

[ednadolski]

We need a tutorial on how you bend the grabs so they look all consistent. 

I think that some key prerequisites are plenty of light and magnification, plus tools that can reliably hold on to wire that small.  I like the Xuron  Tweezernose pliers (http://www.micromark.com/XURON-TWEEZER-NOSE-PLIER,7466.html) for forming the wire parts. I also have a generic, relatively wide pliers with non-serrated jaws for holding the grabirons to form the drop-style grabs, plus a good pair of fine point tweezers.

I first clip a small piece of the 0.005" stainless steel wire and form a 90-degree bend about one-third the way from an end.  To form the second bend, I position the pliers at the appropriate distance from the first bend, including a small allowance since the bend is never going to be a precise angle, but instead will have a curvature thru the bend (similar to the upper corners of an ice hockey goal, where the post and crossbar intersect).

The second bend has to be coplanar with the first.  To make this, I lay the wire down flat on a hard, flat surface, atop a small piece of graph paper (10 squares to the inch), and position the wire on the grid lines.  I then hold the wire in position on the grid using the very tip of the Xuron pliers, with the side edge of the pliers at the point where I want the bend to be.  Then, I bend the protruding wire to form a 90-degree angle, parallel to the first bend.  The bend is made by pushing the wire with the tip of the fine tweezers.  I don't actually grip the wire in the tweezers, and it takes a bit of care to avoid pushing the wire up and of of plane.   The grid paper really helps in keeping things square.  To form multiple grabirons of the same size, I mark very fine pencil lines on the grid paper where the bends need to be.   If the two bends are coplanar, then the part will lie flat on the paper, but if it doesn't, then I hold it in the pliers and tweak the bend until they are coplanar or at least close enough.

These two bends yield a straight-style grabiron.  To form a drop-style grabiron, I place the part in the tip of the wider pliers, with its midbar parallel to the tip edge of the pliers, and set in by a few scale inches - however much you want the drop to be.  After doing a few parts, it gets easier to judge exactly where it should go.  (This is where magnification and light are your best friend ).  Once the part is located, I simply close the pliers securely and then bend each leg of the grabiron with a fingernail, being careful to keep everything square and in its proper plane.   Adjustments can be made before releasing the part from the pliers.  Once satisfied, I trim any excess length from the grabiron with a Xuron shear cutter.

This is a manual method and it is not suited to making large numbers of parts, but suffices for making enough parts for a single loco.  My rambling description of course makes it sounds way more involved than it is.  It does get easier with practice, but again just by the nature of the small parts and the process, it's reasonable to expect some number of rejects and lost parts.   If I find myself doing this more often than on occasion, I'll probably try to come up with some kind of bending jig,  perhaps something made out of printed circuit board material.

Ed

[ednadolski]

To make this, I lay the wire down flat on a hard, flat surface, atop a small piece of graph paper (10 squares to the inch), and position the wire on the grid lines.  I then hold the wire in position on the grid using the very tip of the Xuron pliers, with the side edge of the pliers at the point where I want the bend to be.  Then, I bend the protruding wire to form a 90-degree angle, parallel to the first bend.  The bend is made by pushing the wire with the tip of the fine tweezers.

I found this web page that better illustrates the basic idea of bending wire for grabirons & handrails:

http://6axlepwr.com/HTC_BRAKE_LINE_BENDING.html

Same idea, tho the Xuron is more suited for bending N-scale grabirons.   I may try these tweezers if they help keep the parts from flying away on me 

Ed

[noblerot]

I found this web page that better illustrates the basic idea of bending wire for grabirons & handrails:

http://6axlepwr.com/HTC_BRAKE_LINE_BENDING.html

Same idea, tho the Xuron is more suited for bending N-scale grabirons.   I may try these tweezers if they help keep the parts from flying away on me 

Ed

Good info Ed, thanks for the link. All N scale detail parts seem to behave like springs when they hit the floor Have you made any templates from stock handrails? I was wondering if it would be possible to copy or scan them to get a template.

[ednadolski]

I usually make templates for the grabirons and cut levers, and sometimes the end handrails.  For side handrails I just hold them up against the original ones that I cut from the model. (Since the originals are relatively thick, you just need to take care to consistently sight along either a top edge or bottom edge, one or the other.)  Templates need not be elaborate, just a single, fine line will do.   Better than a photocopy or scan might be to print out a scale drawing to actual size.  Really handrails have a surprising amount of forgiveness, in that they don't need to be super-precise -- just install them straight/level/square and they usually look OK. 

Ed

[chessie system fan]

The solution?  Vince Kotnik just stabs the plastic shell with a sharpened piece of the same diameter (.004"?) music wire that he bends his grabs out of.  The stub of sharpened music wire won't snap off in the shell.  And because the diameter is so small, you really don't need that drilling action.  And the "drill" won't walk on you like it would if you were spinning it.  Just press it firmly into the shell.

+1 on the wire.  I've always taken a guitar string and cut one end at about a ~10 degree angle (as close to straight as I could).  This leaves a little burr and a pointy tip.  A perfect drill bit!

[noblerot]

I usually make templates for the grabirons and cut levers, and sometimes the end handrails.  For side handrails I just hold them up against the original ones that I cut from the model. (Since the originals are relatively thick, you just need to take care to consistently sight along either a top edge or bottom edge, one or the other.)  Templates need not be elaborate, just a single, fine line will do.   Better than a photocopy or scan might be to print out a scale drawing to actual size.  Really handrails have a surprising amount of forgiveness, in that they don't need to be super-precise -- just install them straight/level/square and they usually look OK. 

Ed

 I did some handrails years ago from NSN, B40-8 kits and that's what Mr.Coots provided, just simple straight lines to follow on the instruction sheet. His stanchions were fold over the top of the wire so you could wrap all the stanchions then glue a couple of stanchions in place to hold everything together, then slide the rest one at a time to fine tune them and glue or solder them once it all lined up. It was easier than you would think and they were surprisingly strong.