hardest plastic for joining axles?

[mmagliaro]

I think the ideas in that drawing will work, but only if I drill small holes through the tube into the epoxy and
set a small screw or wire pin in there.   I think that no matter what, that whole slug of epoxy is very small and
if the plastic tube doesn't have enough grip on the steel shafts by itself, that whole thing will spin in there.

And remember, the whole point of this is to make sure that it won't spin, even if the plastic tube doesn't have enough
grip.

[narrowminded]

If you've got some 1.5 mm round and some delrin why not try a couple of mockups? You may find it'll never work, or....    Good luck!

[mmagliaro]

If you've got some 1.5 mm round and some delrin why not try a couple of mockups? You may find it'll never work, or....    Good luck!

My Delrin and acrylic/Lucite rod arrived in the mail today.  That's exactly what I intend to do!

[mmagliaro]

I got a better quality Delrin rod to test.   

Also, revisiting the axle itself, and not making it out of drill rod.

I got some Beryllium Copper C173, and also some Nickel Silver 792, both of which are much harder
and have much more tensile strength than 260 or 360 brass (about double, actually).
So if I can drill into those without too much agony, I think I will go that route instead of the hardened steel axles.
It will leave the door open for drilling and pinning later if I decide I want to do it.

[peteski]

I got a better quality Delrin rod to test.   

Also, revisiting the axle itself, and not making it out of drill rod.

I got some Beryllium Copper C173, and also some Nickel Silver 792, both of which are much harder
and have much more tensile strength than 260 or 360 brass (about double, actually).
So if I can drill into those without too much agony, I think I will go that route instead of the hardened steel axles.
It will leave the door open for drilling and pinning later if I decide I want to do it.

While I don't have a proof, I think that most of the axles on contemporary N scale model steamers are made from stainless steel (not hardened steel).

[mmagliaro]

Well... okay... the point is to find something harder than "regular" brass, to allay any fear of bending,
but not so hard that it will be misery trying to drill a small hole into it.

Hardened or stainless, either way, it's pretty darn miserable to drill that stuff.

[peteski]

Hardened or stainless, either way, it's pretty darn miserable to drill that stuff.

Not when using Tungsten-carbide drill bits!   




Just giving you hard time Max. 

[Lemosteam]

Max, you could "roll your own".  in other words, buy some soft or soft high carbon steel rod, make the part, heat it up, and dunk it in oil to cool it.  You just need to flash harden it to get it close enough.  Carburization probably ins't necessary.  I have done this with softer HSS drill bits to give a harder resharpened edge.

[mmagliaro]

Max, you could "roll your own".  in other words, buy some soft or soft high carbon steel rod, make the part, heat it up, and dunk it in oil to cool it.  You just need to flash harden it to get it close enough.  Carburization probably ins't necessary.  I have done this with softer HSS drill bits to give a harder resharpened edge.

Ha.. make my own "O-2"  oil-hardened rod.   But then I wouldn't be able to drill through the plastic tube and the metal
rod in one step after I get it all quartered and tested, which is what I would want to do if I try to drill and pin this.

I am probably grossly overbuilding this.  After testing that 680 Loctite stuff with a hard steel axle in a plastic tube,
it seems to hold like mad, so I think using that, plus a small flat on the axle tip with a pin though the plastic tube into
the void where the flat is, with JB or loctite, is probably a much simpler way to do this and really ought to hold fine.

Peteski, I actually have found cobalt wire drills, which I like a lot better than carbide because carbide wire drills
break off if you breathe on them.   I managed to drill a #80 hole with a cobalt bit through the stainless steel
rod on a Kato Mikado.  It's no fun, let me tell you.  It took 3 bits to do it.   That stainless is hard hard HARD.  But it did work.

[peteski]

Peteski, I actually have found cobalt wire drills, which I like a lot better than carbide because carbide wire drills
break off if you breathe on them.   I managed to drill a #80 hole with a cobalt bit through the stainless steel
rod on a Kato Mikado.  It's no fun, let me tell you.  It took 3 bits to do it.   That stainless is hard hard HARD.  But it did work.

Once I acquired a Micro-Mark miniature drill press the TC bit breakage was drastically reduced. Plus, the resharpened TC bits are cheap enough so even if few break, that is no big deal.   Since graduating to using those split-point TC bits I avoid using standard bits as much as I can. TC bits work *SO* much better.

[Lemosteam]

Ha.. make my own "O-2"  oil-hardened rod.   But then I wouldn't be able to drill through the plastic tube and the metal
rod in one step after I get it all quartered and tested, which is what I would want to do if I try to drill and pin this.

I am probably grossly overbuilding this.  After testing that 680 Loctite stuff with a hard steel axle in a plastic tube,
it seems to hold like mad, so I think using that, plus a small flat on the axle tip with a pin though the plastic tube into
the void where the flat is, with JB or loctite, is probably a much simpler way to do this and really ought to hold fine.

Peteski, I actually have found cobalt wire drills, which I like a lot better than carbide because carbide wire drills
break off if you breathe on them.   I managed to drill a #80 hole with a cobalt bit through the stainless steel
rod on a Kato Mikado.  It's no fun, let me tell you.  It took 3 bits to do it.   That stainless is hard hard HARD.  But it did work.

Ah, that's the beauty, you only have to do it on the wheel end, and not the end you are drilling.  No need to get the noire rod red hot and only dip it in to the length you want, then let it air cool from there.