A Better Hinge

[Bob La Londe]

http://tacklemaker.info/index.php?action=gallery;sa=view;pic=31
You shouldn't need to be logged on to see the image.

This is a pretty typical lead casting (sinkers, jigs, spinnerbaits, etc)
mold. The hinge shown works pretty darn well. It moves easily, and does a
good job of helping to hold the mold halves in alignment at the hinge end.
The opening (handle side) end has two alignment pins with radius ends that
mate the plates at that end. Over all my customers are atleast acceptably
happy with it. However to make a mold like this that finishes as to 1/2
inch (apx) plates with a hinge I start out by throwing away a third of the
raw material. Basically I start with 3/4 inch flat bar and remove 1/4 inch
to leave the 1/4" hinge bosses. It just irks me to throw away 33% of the
raw material on every one of these molds.

No. Bolting a flat metal hinge to the ends is NOT a better way. It simply
will not hold up over time, and even if its handled with kid gloves the heat
cycling will cause it to work loose. I've seen molds made by other mold
makers with tacked on hinges, and they get pretty beat up and very sloppy
over time. It often results in damage to the mold itself. Especially if
cores, pins, and other inserts or materials need to be placed in the mold
before casting. These one piece boss pinned hinges last through thousands
of heat cycles. I've done larger molds this same way that customers have
told me they have literally run tons of lead through. It would also require
another setup to drill and tap to tack on a sheet metal hinge.

Casting a billet with preformed mold bosses is not a great answer either.
The aluminum that results is more porous with the type of foundry I could
setup, and my quantity is to small to have them forged cost efficiently. I
think it might also drive up the per unit cost too much unless I could cast
or forge them in great quantities. On top of that castings or forgings then
have other machining that needs to be done to make them useable. One mold
company sells cast "blanks, but I absolutely hate to work with them because
the metal doesn't machine as nicely and the surfaces are more of a pain to
square up and also keep the hinges squared up with both haves coming out
aligned.

I did think of maybe using a third piece between the two plates with 4 pins
instead of the two I use now, but then it would not help as much with mold
alignment. It would also be slower and more cludgy for the customer to use
the mold. Every idea I come up with is also more manual work, or more
secondary setup work.

Maybe they way I am doing it is the best way to get a decent result within
my work constraints, but I can't help but wonder if there isn't a better
way.

Tangent:
If anybody is curious. No I do not use a round over mill to get the hinge
bosses. I tried that in the past and I was not happy with it at all. I cnc
mill a radius on the boss with a .001 depth of cut and then sand smooth when
it comes off the mold. It would be faster to use a round over mill, but
because of the lead on the cutting flutes and lack of consistency from one
to the next it would waste part of the useable surface of the mold plates.
Make larger mold blanks to make up for it then means slightly higher (few
cents per unit atleast) material cost and higher machine time clearing the
face of the blank. It works out to be a wash on that for cost and produces
a CNC cutting the radius gives better result in my opinion.

[Bob La Londe]

"Bob La Londe" wrote in message news:oktt7m$ch0$1...@dont-email.me...

***************
I sure need to remember to proof read before I hit send.

[rangerssuck]

Why not make the mold bosses separately, and have them drop into pockets in the mold, then get pinned or bolted in place? You could make them rectangular to keep them in alignment. Much like a mortise & tenon.

[William Bagwell]

On Fri, 21 Jul 2017 14:58:58 -0700, "Bob La Londe" <no...@none.com99>
wrote:

> Basically I start with 3/4 inch flat bar and remove 1/4 inch
>to leave the 1/4" hinge bosses. It just irks me to throw away 33% of the
>raw material on every one of these molds.

Unequal leg angle or a custom extrusion are the two thoughts that
come to mind.
--
William

[Steve W.]

How about machining the ends to use something like size 50 motorcycle
chain. Basically a pivot on each half. Then machine in 2 more alignment
pins to ensure proper closure. That would allow you to start with 1/2".
Sort of how hinged hand cuffs work.


--
Steve W.

[Jim Wilkins]

"Bob La Londe" <no...@none.com99> wrote in message
news:oktt7m$ch0$1...@dont-email.me...

> http://tacklemaker.info/index.php?action=gallery;sa=view;pic=31
> You shouldn't need to be logged on to see the image.
>

How does MIG welding a thicker bar on the end compare in cost and
effort?

You could mill steps for the beads in the end to retain strength and
minimize cleanup.

[Bob La Londe]

"William Bagwell" wrote in message
news:bme5ncpkt4c3bq28d...@4ax.com...

I may not go this way, but those are both ideas I had not thought of.
Unequal leg angle would be very good if I could find the right one. Think
they make one that's 1x6x1/2? Suitable unequal leg angle would probably
have to be your second idea. A custom extrusion. Maybe a couple of them.
If my work volume gets that high I might consider something like that.

[Bob La Londe]

"Steve W." wrote in message news:okv372$6l3$1...@dont-email.me...

************

Yeah Steve I have considered a connecting link type design. I'm not
convinced its equal or better, but it would definitely reduce wasted raw
stock. It’s a good idea.

[Bob La Londe]

"Jim Wilkins" wrote in message news:okvcnq$241$1...@dont-email.me...

********

I hadn't thought of that. I do have a MIG with a spool gun for welding
aluminum. I'm not very good, but I expect for a repetitive weld I could
setup, make a couple practice passes, and then do several at a time. I'm
not sure that overall it’s the best solution for me, but it is a good idea.

P.S. When I was learning to make molds, I had my first ultralight CNC mill,
and stock was more precious to me since I wasn't making any money with it I
often welded up mistakes in a plate and remachined it.

[Steve W.]

Bob La Londe wrote:
> "Steve W." wrote in message news:okv372$6l3$1...@dont-email.me...
>
>

> How about machining the ends to use something like size 50 motorcycle
> chain. Basically a pivot on each half. Then machine in 2 more alignment
> pins to ensure proper closure. That would allow you to start with 1/2".
> Sort of how hinged hand cuffs work.
>
> ************
>
> Yeah Steve I have considered a connecting link type design. I'm not
> convinced its equal or better, but it would definitely reduce wasted raw
> stock. It’s a good idea.
>

Machine one up and beat it to death in testing.

--
Steve W.

[Bob La Londe]

"rangerssuck" wrote in message
news:bcecbcf3-8922-4a42...@googlegroups.com...

************
That is a possible consideration. It deserves atleast weighing the extra
operation time vs the time saved roughing off stock and the better cost
efficiency on material. A press fit dovetail with a locking screw might
make for quick assembly. If I do a really good job it might even eliminate
one of my other secondary operations. Another good idea to think about.

[Jim Wilkins]

"Bob La Londe" <no...@none.com99> wrote in message

news:ol07rn$n2m$1...@dont-email.me...

Personally I'd sub that job to a certified welder friend who is much
better than I'll ever be, and ask him how he wanted the parts prepared
so that the beads stay below the upper and lower surfaces.

I am better on steel and build up shapes like bending brake hinge
forks that would require removing a lot of metal from a solid block.

-jsw

[Bob La Londe]

"Jim Wilkins" wrote in message news:ol0ivq$s0p$1...@dont-email.me...

*********

Now that's something I won't do. I used to just try to take certain types
of welding jobs over to the professional shops and leave it. I'd ask how
long, and that's when I'd come back to pick it up. I would never bother
them in between. The job was never ever done when they said. Not one time.
Usually I was told 2 more weeks several times (after an intitial 3-6 week
time window) before they finally did the job The last two times it was done
wrong. I just quit. Sure I get that Mr big farm owner or Mr government
contractor is a more important customer. I knew that up front that's why I
just asked how long and left. Its why I ultimately bought a decent dual gun
MIG welder and learned to weld aluminum in the first place. No point in
taking paying work to them if I can't get it done. I'm not good, but my
welds don't break either and ultimately they get done when I want them done.
Had nothing to do with money. I spent a lot on the welder. I took a lot of
years to pay it off. I'd have rather just had somebody do it and not worry
about it. Its why I work on a lot of my own stuff.

[Jon B. Slocomb]

On Sat, 22 Jul 2017 15:57:07 -0700, "Bob La Londe" <no...@none.com99>
wrote:

I don't know if it is worth the bother but you might want to look at
Lyman bullet molds. The hinge is in the handles and the mold is simply
two blocks aligned with pins.
see https://tinyurl.com/yamk6h5f
--
Cheers,

John B.

[Bob La Londe]

"Jon B. Slocomb" wrote in message
news:rlo7nclj4g7u2eiqh...@4ax.com...

*************

That’s a decent idea John. I actually have some Lyman and Lee stuff, and
atleast on paper I am a dealer for Lee Precision. Unfortunately those molds
do not open far enough to load hooks, pins, screws locks, wire forms, etc,
easily. Its definitely a good form for bullet molds and allows a home
boo-lit caster to own several molds and only one set of handles. Thanks for
the thought John.

[whit3rd]

On Friday, July 21, 2017 at 2:59:05 PM UTC-7, Bob La Londe wrote:

> This is a pretty typical lead casting (sinkers, jigs, spinnerbaits, etc)
> mold. The hinge shown works pretty darn well. It moves easily, and does a
> good job of helping to hold the mold halves in alignment at the hinge end.
> The opening (handle side) end has two alignment pins with radius ends

There's some options with extra parts (mainly, though, I don't like loose
parts...). In particular, your alignment pins could go through the
mold and a wedge can snug the halves together. On a lathe, it's
only gonna take a bit of a head on the protruding pin end, that engages
an external wedge of the sloped-metal-with-keyhole type.

With a CNC setup, the wedge can be simpler, if you slot the pin, but
that might eventually score the mold. Internal wedge (like for Morse taper
release) also needs a radius'ed edge;

[Carl Ijames]

On Friday, July 21, 2017 at 2:59:05 PM UTC-7, Bob La Londe wrote:

> This is a pretty typical lead casting (sinkers, jigs, spinnerbaits, etc)
> mold. The hinge shown works pretty darn well. It moves easily, and does
> a
> good job of helping to hold the mold halves in alignment at the hinge end.
> The opening (handle side) end has two alignment pins with radius ends

Just to go further outside the box, if you have a hydraulic press you could
bend a short L on the end of your bar to give you the raised material for
your hinge. You'll get some distortion between the edge of the die and the
bend so you will have to make your mold maybe 1/2" or 3/4" longer than
before. Either keep the radius large to prevent cracking or set up a torch
(or crab pot propane burner) and firebrick oven with a slot just big enough
to stick in the end you are about to bend and experiment with how hot you
need. The $30 harborfreight IR thermometer (frequently on sale or coupon
for $20) goes to 968F for easy measurement. Most cheap ones don't go nearly
that high. Not sure what the emissivity of aluminum is up there so you need
to calibrate if you want actual accuracy but reproducibility should be good
and you will just keep trying an indicated 25F higher each time until you
get a good bend so who cares :-). Definitely want a real press brake or air
over hydraulic for speed, then quench in water immediately after bending.
I've done the heat and bend but never bothered with this but if you want
maximum strength you could age at 400F for an hour to get the region you
heated somewhere near T5 while the rest should still be pretty much T6.

--
Regards,
Carl Ijames

[Bob La Londe]

"Carl Ijames" wrote in message news:ol5oa...@news4.newsguy.com...

**************
Yer jacking with me right? (pun intended)

[Bob La Londe]

"Bob La Londe" wrote in message news:oktt7m$ch0$1...@dont-email.me...

*************************************************************

First off I want to thank everybody who made suggestions. Just about
everybody put some real thought into options. Thank you. I'm going to keep
mulling it over, but for now the way I am doing it is the simplest easiest
method. Yeah it wastes 33% of the raw stock, but then I have seen other
machined parts result in much greater waste than that. For now the material
waste will continue. Down the road if my volume increases some of the other
options will certainly be considered again.

[et...@whidbey.com]

On Fri, 28 Jul 2017 10:15:31 -0700, "Bob La Londe" <no...@none.com99>
wrote:

Greetings Bob,
I'm curious about your description of the faults of round over
cutters. I use some HSS ones but for steel I use mostly carbide
cutters. In fact, I use carbide cutters almost exclusively now. I have
old HSS ones in many sizes and only use them when I don't have a
carbide one. If I have to do a lot of milling I buy another carbide
one if all I have is the HSS version. But even the HSS ones cut
accurate radii. As far as neding extra mayerial all the cutters I use
would be able to mill the bosses as shown. I also have and use cutters
that can mill the bosses in one pass but you would need to stand the
molds up which would require another setup. One of the reasons I like
the carbide cutters is that they are ground with a finer finish so the
parts look better. I also sometimes use carbide router bits meant for
wood to machine metal, even stainless steels. They typically have a
pretty rough grind on them which leaves a poor finish on the parts. To
correct this I make a brass lap, charge it with diamond paste, and lap
the router bit cutting edges to a much finer finish. This process
doesn't take long. Carbide router bits have saved my butt a few times
when I have forgotten to order a cutter or when a cutter fails for
some reason. Living on an island makes getting cutters in a hurry
tough.
Eric

[Bob La Londe]

wrote in message news:h0ipnc9clc1avk0ke...@4ax.com...

**********************
I have only purchased a few round over mills, but they all have all seem to
have a slight angled lead to the radius area. Also, I haven't found a
standard for the overall geometry and dimensions for the rest of the cutter
that I can use to program the cut. I use them all the time to rough radius
the end of alignment pins on the lathe, but on the mill I would only use
them on outside edges. The inside edge needs a clearance cut on those I
have in order to cut the radius. I did that before, but I only over did
them on the manual mill to finish after the mold was complete. I never
cared for it. That was time I WAS NOT spending doing design and setup work.

The other issue I have is power and speed. The round over mills really are
not IMO well suited for high speed milling. I can't low speed mill on the
24K high high speed spindles. They really have about zero torque under 10K.

Oh, yes. I have used router bits in a pinch many times. Since I also have
a small CNC router I do have a decent selection of router bits on hand at
any given time.

[Steve Walker]

> ---
> This email has been checked for viruses by AVG.
> http://www.avg.com
>
Build the hinge separately, then dowel and bolt it to the ends of the
mold halves.

[et...@whidbey.com]

On Mon, 31 Jul 2017 10:04:41 -0700, "Bob La Londe" <no...@none.com99>
wrote:

<SNIP>

Bob-you can run a .375 dia. carbide round over bit at 20,000 RPM on
aluminum. The carbide bits I use have a lead into the radius but the
complete 90 degrees of curve is there. They have a different grind
than the HSS ones. And as my mom would say "They go like sixty".
Eric

[Bob La Londe]

"Steve Walker" wrote in message
news:3a-dncS4Y7DfXeLE...@giganews.com...

***********
Thanks for the suggestion.

[Jim Wilkins]

"Bob La Londe" <no...@none.com99> wrote in message
news:olql88$me9$1...@dont-email.me...

One-piece dowel plus bolt:
http://www.palmerbolt.com/product/14-inch-socket-shoulder-screwsstripper-bolts/

[Bob La Londe]

"Jim Wilkins" wrote in message news:olqpii$4ui$1...@dont-email.me...

*************************************
I just use one piece press in dowel pins now. I drill the two halves as a
mated pair with a 'D' drill, drill the inner hinge boss out further with an
'F' drill, and then press in the pins. Pretty much permanent, and if they
ever do have to be separated I can just press the pins into the center.

[DoN. Nichols]

On 2017-08-01, Jim Wilkins <murat...@gmail.com> wrote:
> "Bob La Londe" <no...@none.com99> wrote in message
> news:olql88$me9$1...@dont-email.me...
>> "Steve Walker" wrote in message
>> news:3a-dncS4Y7DfXeLE...@giganews.com...

[ ... ]

>> Build the hinge separately, then dowel and bolt it to the ends of
>> the
>> mold halves.
>>
>> ***********
>> Thanks for the suggestion.
>
> One-piece dowel plus bolt:
> http://www.palmerbolt.com/product/14-inch-socket-shoulder-screwsstripper-bolts/

Note that I have bought socket-head stripper bolts and
discovered that the thread was not truly concentric with the shoulder.
(It might have been concentric with the OD of the threads, but the PD
was certainly not concentric. Luckily, it was close enough so I could
make it work, but the upper piece would cycle as I turned the screw into
the lower piece.

Enjoy,
DoN.

--
Remove oil spill source from e-mail
Email: <BPdnic...@d-and-d.com> | (KV4PH) Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

[Jim Wilkins]

"DoN. Nichols" <BPdnic...@d-and-d.com> wrote in message
news:slrnoo2f21.29...@Katana.d-and-d.com...

I used them to assemble a lathe milling vise and had no such problem.
There was a slight variation in tightening torque but no movement.
The brand is "Precision Socket Screw, Inc."

Holo-Krome claims "perfect concentricity between threads and
shoulder".

-jsw