Generic tubing lugs

On Fri, 07 Oct 2011 17:39:03 -0500, in rec.bicycles.tech DougC
wrote:

Oh, I'm /never/ responsible. People on my street call me 'the Teflon
Dunce' :)

I know of no commercially-made examples, but I've seen online that a lot
of people build motorized trailers. If the trailer & hitch is strong
enough I know of no horrible side-effects. Building a solid hitch is
where most people seem to have issues (with all kinds of trailers, not
just motorized ones) but having access to any kind of welding method
would help a lot with that.

What a lot of people do is they take the front wheel+fork off of a
scooter or pocket bike, add a tongue that hitches to the bicycle
somehow, and then add a longer throttle control.

I'm going to go with a wireless control where the torque and speed are
limited in the end device. I want to get a *very* gentle push up to
about 20 km/hr or so. The speed is easy; the torque limiter is a
harder question. It has to cut out at about three ft/lb regardless of
what the throttle input is... I'm still chewing on that one.

But, if you suddenly dump the whole battery into the trailer motor, it
could easily lift the back bicycle wheel... and that would be an
"adverse consequence", I think; I can't see how it could have a
positive outcome, anyway.

I think it's a good idea, but it'll never be marketed because it
depends on the rider staying out of the throttle; yeah, right!

Jones

On Thu, 06 Oct 2011 23:27:58 -0500, in rec.bicycles.tech AMuzi
wrote:
Any particular reason you don't want it fillet brazed?

!Jones wrote:
Simple answer, really... I've never done it.


If you can reliably fill the inside of a sleeved joint, you
can surely make a decent looking & strong fillet braze
(where you can see it) with the same materials and with much
less trouble all around.

Your wall thickness to diameter on 1/4" tube probably won't
indicate any structural improvement with a sleeved joint.
Considering steel bicycle frame values of roughly 30 to 40,
I wouldn't consider sleeved joints until/unless your 1/4"
tube gets down to 0.2mm or about seven or eight thousandths
of an inch at which point you'd have other bigger troubles.

Maybe you just like the looks of sleeved joints, and no
one's wrong about their own opinion, but it isn't a logical
choice.


--
Andrew Muzi
www.yellowjersey.org/
Open every day since 1 April, 1971

On Oct 7, 4:32*am, !Jones wrote:
I want to build a contraption out of brazed 1/4" steel tubing. *I
can't find any manufactured lugs in this size. *Actually, this is the
first time I've looked. *I suppose I could start with a pipe fitting
and drill out the threads. *I'd rather find the real thing, though.

Has anyone else ever looked? *Successfully, I mean?

Jones

You'll be lucky to find any. You can make faux sockets by welding or
simply overbrazing an additional thickness of pipe on both parts
before cutting and fitting for the joint. People like Aircraft Spars
stock 1mm wall tubing in outside diameters 2mm apart, so you get a
tight sliding fit without having to use a lathe. They usually have
good quality chromoly and seamless stainless in at least two grades.

Andre Jute
Visit Andre's books
http://coolmainpress.com/andrejute.html

On Oct 7, 8:30*am, !Jones wrote:
On Fri, 07 Oct 2011 08:04:02 -0500, in rec.bicycles.tech DougC

wrote:
-Are you making a bike rack?

Yeah... sort of. *That's the best two-word description. I doubt you or
anyone else wants an essay.

I'm going to attempt to put a 20" electric hub onto a BOB-style
trailer device. *I don't want to ask for advice on that because giving
it might make you responsible for adverse consequences. *Yes, it will
"jack-knife" under excessive power... and that would probably be
called an "adverse" situation.

I have an 80's set of Bruce Gordon's touring racks ..
to go with the thin-wall 4130, [ 3/8" /10mm ]
he used a sort of lug, seemed to be a potato chipped flat washer,
that went between the 2 tubes at T joints.

I think, the thing you would need to do, is essentially tool making ,
to make a die to bang a bunch of flatwashers into the needed shape
with some efficiency.

Then you will have a thickened place that the 2 tubes meet,
and should braze up quicker than building up fillets.

!Jones wrote:
On Fri, 07 Oct 2011 11:50:29 -0400, in rec.bicycles.tech Frank
wrote:

Alex Wetmore's blogs have shown some pretty detailed rack building
procedures

Who? I'll Google it and read.

Jones


Here you go:

http://alexwetmore.org/?cat=162

--
- Frank Krygowski

ugh caught a load of ---- for mentioning epoxy.
triangles obviate need for fancy end joints, allow for wood and/or
temp test metal construction where with wood - ask the cabinet shop to
cut - you mount hardware onto then real time eyeball function and
fit.
third - round tubing is a PITA. use square or rectangular tubing and
ease up ....
you can epoxy then braze or weld if the rig is right.

On Oct 9, 9:21*am, Zarniwoop wrote:
On Oct 7, 8:30*am, !Jones wrote:

On Fri, 07 Oct 2011 08:04:02 -0500, in rec.bicycles.tech DougC

wrote:
-Are you making a bike rack?

Yeah... sort of. *That's the best two-word description. I doubt you or
anyone else wants an essay.

I'm going to attempt to put a 20" electric hub onto a BOB-style
trailer device. *I don't want to ask for advice on that because giving
it might make you responsible for adverse consequences. *Yes, it will
"jack-knife" under excessive power... and that would probably be
called an "adverse" situation.

I have an 80's set of *BruceGordon'stouring racks ..
* to go with the thin-wall 4130, [ 3/8" /10mm ]
he used a sort of lug, * seemed to be a potato chipped flat washer,
*that went between the 2 tubes at T joints.

I think, the thing you would need to do, is essentially tool making ,
to make a die to bang a bunch of flatwashers into the needed shape
with some efficiency.

Then you will have a thickened place that the 2 tubes meet,
*and should braze up quicker than building up fillets.

They are little fittings like a bottom bracket bridge reinforcement.
I have them for sale - give me a call (707) 762-5601
Regards,
Bruce Gordon