N Scale Truck Reamers?

[SandyEggoJake]

So far I'm aware of three brands of HO Scale Truck Reamers (and I own one of these tools below from my HO days) but have yet to find anyone selling such for N scale. 

Any suggestions?

http://www.reboxx.com/Tools.htm

[peteski]

That is one of my -to-do projects. I bought 2 1/8" 60 deg. single-flute countersinks and the plan is to trim them and join them into what looks like the Reboxx one (except for N scale). But since each flute will face opposite direction the reamer will have to be twirled back and forth to ream both sideframes. Not ideal but workable.

[narrowminded]

That is one of my -to-do projects. I bought 2 1/8" 60 deg. single-flute countersinks and the plan is to trim them and join them into what looks like the Reboxx one (except for N scale). But since each flute will face opposite direction the reamer will have to be twirled back and forth to ream both sideframes. Not ideal but workable.

I'm suspicious that you'd be OK and maybe even better off with just one cutting end.  Cut the thing off and grind the blank end to 60 degrees at the proper length but plain surface.  Flip it end for end, working each pocket individually.  I suppose with care and a cutoff wheel the second end could have a cutting relief cut in it at the angle to be a reverse cutter but not sure it's necessary or worth it. 

A lathe and a toolpost grinder (Dremel mounted on toolpost) would make short work of this but could probably be adequately accomplished with care in a drill chuck with a hand guided tool.

[mmagliaro]

I've always been curious about something with these tools.

It seems to me that since the axle point just has to ride in the cone-shaped hole inside the sideframe,
it wouldn't make much different what the angle is as long as it doesn't ride on the face of the tapered axle.

Is there something magical about an angle of 60 degrees, or is that just "a good spot"?

[peteski]

I'm suspicious that you'd be OK and maybe even better off with just one cutting end.  Cut the thing off and grind the blank end to 60 degrees at the proper length but plain surface.  Flip it end for end, working each pocket individually.  I suppose with care and a cutoff wheel the second end could have a cutting relief cut in it at the angle to be a reverse cutter but not sure it's necessary or worth it. 

A lathe and a toolpost grinder (Dremel mounted on toolpost) would make short work of this but could probably be adequately accomplished with care in a drill chuck with a hand guided tool.

No,  my idea is to have it double-ended. I have 2 countersinks and will trim the shanks so each countersink is half of the desired length of the tool. Then I'll use a piece of brass tube and epoxy to join them in the middle (so they look like the Reboxx tool.  When I use it and spin it clockwise, one side will do the cutting, counterclockwise, the other side.

Max: I have no idea about the need for 60 degree angle. Might be because it is often used for countersinking?

[Lemosteam]

Since I have been designing FXD truck frames, I have developed a theory on the cone point.  Since the axle point can never reach the bottom of the truck cone, it would not make sense to have the point taper be the same as the truck taper or the design would risk too much friction. I suspect that the truck pocket is a larger included angle taper than the axle point to avoid this. Unfortunately, I cannot measure either accurately.

As a result, I have resorted to cleaning out the bottom of my truck journal pockets with a spherical 107 Dremel engraving bit instead (0.8mm sphere). Spun gently only by hand, this ensures that the axle point can only make a single point contact inside the pocket and the user can judge how deep to keep grinding.

[glakedylan]

IIRC
the Reboxx Tool is designed according to NRMA specs
and
on their website they note the 60 degree tips
i would guess that is why 60 degrees has been mentioned
and why it would seem to be a good geometric to abide by
sincerely
Gary

[glakedylan]

i.e.:

REBOXX EXXACT SOCKET Hand Tool

Forms a clean 60 degree conical side frame journal to the NMRA standard.  Dirt, paint and manufacturing debris removed.

http://www.reboxx.com/Tools.htm

[Rasputen]

No,  my idea is to have it double-ended. I have 2 countersinks and will trim the shanks so each countersink is half of the desired length of the tool. Then I'll use a piece of brass tube and epoxy to join them in the middle (so they look like the Reboxx tool.  When I use it and spin it clockwise, one side will do the cutting, counterclockwise, the other side.

That's a good idea!  I wonder what overall length you need for the cutters to do something to the slippery plastic that most trucks are made from.
I guess you could squeeze the outside of the truck at the same time you are spinning the cutter.  Would a single flute be better than something with six flutes on it??

[SandyEggoJake]

Crickets.  Confirming my hunch such a tool hasn't been commercially made for N scale.

If not, planning to price a one time run.  Sure, I could make one, but life is short.  I'd rather work on models.  And suspect it might be a fun little side project. 

@mmagliaro    As already stated, the 60 degree cone in the side frame is the NMRA standard... allows at least a 5 degree relief off the max NMRA standard 50 degree axle point. 

Biggest question remaining is length.  With the HO version, the smaller one seems more popular.  Thus for N scale the analogy would be 0.540 in, which have been used by MTL, Athearn, BLMA, Fox etc.  For larger spans, a user can slightly pinch side frames to bring them to the ream points; not ideal but far better then a tool that is too long, which risks carving side frames too deep. 

Any interest in such a tool?

[glakedylan]

Any interest in such a tool?

yes. i would be interested.
thx
Gary

[peteski]

That's a good idea!  I wonder what overall length you need for the cutters to do something to the slippery plastic that most trucks are made from.
I guess you could squeeze the outside of the truck at the same time you are spinning the cutter.  Would a single flute be better than something with six flutes on it??

Gee, I should have kept it a secret and started making and selling these!   
But seriously - thanks Bryan!  One of those things where I bought those countersinks probably 5 years ago and they are just sitting on my workbench (along with 1000 other things to do).  At first I thought of soldering them together, but I think epoxy will work just a as well.

As for the length, I think I'lll make it the length of the medium size FVM wheel-set axles.   If the truck sideframes are closer together, I can spread them, if too wide (like you said) I can squeeze them while spinning the cutter.

Why single flute?  I chose it because IMO it cuts cleaner and has a less aggressive bite than multiple flutes. I also think that it was cheaper then multi-flute countersink. 

[up1950s]

That is one of my -to-do projects. I bought 2 1/8" 60 deg. single-flute countersinks and the plan is to trim them and join them into what looks like the Reboxx one (except for N scale). But since each flute will face opposite direction the reamer will have to be twirled back and forth to ream both sideframes. Not ideal but workable.

There is another way to toot that flute . Just use one reamer witch is married to to a fine thread adjuster and at the end is a smooth 60 deg point . This way it is adjustable , though would have to be stuck in the other way to get both sides .

[up1950s]

Yea I know  ... which

[peteski]

There is another way to toot that flute . Just use one reamer witch is married to to a fine thread adjuster and at the end is a smooth 60 deg point . This way it is adjustable , though would have to be stuck in the other way to get both sides .

True, but way too complicated. It is not like I'm reaming some high-precision part - just a simple plastic side-frame with loose tolerances..