As part of a custom machine I have been fabricating (later) I needed to
broach 1/4" keyways in 1 1/8" holes in two steel flywheels and two
collars. I figured no problem, just call up a buddy where I used to work
and see if they can press them in the shop. To my surprise they no
longer have an arbor press with a high enough throat to press the 12"
long broach. Several friends have home hydraulic presses, but they have
short strokes and you need to do a lot of resetting to get a broach
through, at least two presses and maybe three for each pass of the
broach, two passes per hole. That's a lot of fussing around. Hmm.

So, I sez, let's build a press just for broaching. I have two possible
hydraulic sources. The first is one of those cheap, 4 ton manual
Porta-Power sets. But they are very high pressure (10,000 psi) and use
small diameter cylinders. I didn't think I could find a sub 1" cylinder
with a 12" stroke. Even then it would be a lot of pumping.

My other source is an old 12 volt hydraulic system that operated a
Corvair convertable top. I built it into a tire bead breaking machine
about 35 years ago and it works fine for that, but I no longer use it. I
put a gauge on it and it just hit 300 psi as it stalled out.

A quick email to DuMont and they said I needed 700 pounds of force for a
1/4" broach in 5/8" mild steel. A 2" piston would give me around 950
pounds.

I looked on the HGR Surplus web site and they have lots of pistons. I
drove over and immediately found a 2" diameter, 12" stroke cylinder,
brand new for $19.99. Cylinders are real cheap at HGR, most are $10 or
$20.

Since I already had a C frame for the tire machine, I just cut it down
to the correct height and bored a few holes and mounted the cylinder on
top. The hydraulic pump mounts on the upright and the existing steel
braided lines were just right. I'm good to go, only a few hours of work.

I cycled her back and forth for a while to bleed the air then give it a
shot. It does flex too much, I'll have to add a strongback to the 4"
channel frame. And I actually had to start the car I had it hooked to,
the extra couple of volts gave me just enough to push through, but it is
at the absolute limit with a 1/4" broach. Every keyway broached
perfectly, and those shaft collars were tough steel.

Here is a photo:

http://home.wideopenwest.com/~dthomp.../broaching.jpg

Dennis

"DT" wrote in message
...
As part of a custom machine I have been fabricating (later) I needed to
broach 1/4" keyways in 1 1/8" holes in two steel flywheels and two
collars. I figured no problem, just call up a buddy where I used to work
and see if they can press them in the shop. To my surprise they no
longer have an arbor press with a high enough throat to press the 12"
long broach. Several friends have home hydraulic presses, but they have
short strokes and you need to do a lot of resetting to get a broach
through, at least two presses and maybe three for each pass of the
broach, two passes per hole. That's a lot of fussing around. Hmm.

So, I sez, let's build a press just for broaching. I have two possible
hydraulic sources. The first is one of those cheap, 4 ton manual
Porta-Power sets. But they are very high pressure (10,000 psi) and use
small diameter cylinders. I didn't think I could find a sub 1" cylinder
with a 12" stroke. Even then it would be a lot of pumping.

My other source is an old 12 volt hydraulic system that operated a
Corvair convertable top. I built it into a tire bead breaking machine
about 35 years ago and it works fine for that, but I no longer use it. I
put a gauge on it and it just hit 300 psi as it stalled out.

A quick email to DuMont and they said I needed 700 pounds of force for a
1/4" broach in 5/8" mild steel. A 2" piston would give me around 950
pounds.

I looked on the HGR Surplus web site and they have lots of pistons. I
drove over and immediately found a 2" diameter, 12" stroke cylinder,
brand new for $19.99. Cylinders are real cheap at HGR, most are $10 or
$20.

Since I already had a C frame for the tire machine, I just cut it down
to the correct height and bored a few holes and mounted the cylinder on
top. The hydraulic pump mounts on the upright and the existing steel
braided lines were just right. I'm good to go, only a few hours of work.

I cycled her back and forth for a while to bleed the air then give it a
shot. It does flex too much, I'll have to add a strongback to the 4"
channel frame. And I actually had to start the car I had it hooked to,
the extra couple of volts gave me just enough to push through, but it is
at the absolute limit with a 1/4" broach. Every keyway broached
perfectly, and those shaft collars were tough steel.

Here is a photo:

http://home.wideopenwest.com/~dthomp.../broaching.jpg

Dennis

'Nice piece of work, Dennis. This is a little late to comment about it, but
if you're going to use a multi-tooth broach in an open hole, a pull broach
might be a lot easier for home construction. The hole provides the only
guidance you need.

--
Ed Huntress

On Sat, 10 Jul 2010 20:51:23 -0400, DT
wrote:

As part of a custom machine I have been fabricating (later) I needed to
broach 1/4" keyways in 1 1/8" holes in two steel flywheels and two
collars. I figured no problem, just call up a buddy where I used to work
and see if they can press them in the shop. To my surprise they no
longer have an arbor press with a high enough throat to press the 12"
long broach. Several friends have home hydraulic presses, but they have
short strokes and you need to do a lot of resetting to get a broach
through, at least two presses and maybe three for each pass of the
broach, two passes per hole. That's a lot of fussing around. Hmm.

So, I sez, let's build a press just for broaching. I have two possible
hydraulic sources. The first is one of those cheap, 4 ton manual
Porta-Power sets. But they are very high pressure (10,000 psi) and use
small diameter cylinders. I didn't think I could find a sub 1" cylinder
with a 12" stroke. Even then it would be a lot of pumping.

My other source is an old 12 volt hydraulic system that operated a
Corvair convertable top. I built it into a tire bead breaking machine
about 35 years ago and it works fine for that, but I no longer use it. I
put a gauge on it and it just hit 300 psi as it stalled out.

A quick email to DuMont and they said I needed 700 pounds of force for a
1/4" broach in 5/8" mild steel. A 2" piston would give me around 950
pounds.

I looked on the HGR Surplus web site and they have lots of pistons. I
drove over and immediately found a 2" diameter, 12" stroke cylinder,
brand new for $19.99. Cylinders are real cheap at HGR, most are $10 or
$20.

Since I already had a C frame for the tire machine, I just cut it down
to the correct height and bored a few holes and mounted the cylinder on
top. The hydraulic pump mounts on the upright and the existing steel
braided lines were just right. I'm good to go, only a few hours of work.

I cycled her back and forth for a while to bleed the air then give it a
shot. It does flex too much, I'll have to add a strongback to the 4"
channel frame. And I actually had to start the car I had it hooked to,
the extra couple of volts gave me just enough to push through, but it is
at the absolute limit with a 1/4" broach. Every keyway broached
perfectly, and those shaft collars were tough steel.

Here is a photo:

http://home.wideopenwest.com/~dthomp.../broaching.jpg

Dennis


Very nicely done! Either add another lenght of challen at 90' to the
back of the press..or simply add a pair of 3/16' x 1' bars down each
side of the press. This will prevent bending of both the back and the
top and bottom of the press. The secret would be installing them at a
distance you can get other work pieces into the press without the bars
interfering..such as a large gear. Personally..I think Id make a
totally new assembly using a better configuration, but..shrug.

Very well done Sir!!

Gunner

One could not be a successful Leftwinger without realizing that,
in contrast to the popular conception supported by newspapers
and mothers of Leftwingers, a goodly number of Leftwingers are
not only narrow-minded and dull, but also just stupid.
Gunner Asch

Nice. I love doin' stuff like that. Very satisfying.

I went to HGR Surplus:
http://www.hgrindustrialsurplus.com/
_12 acres_ of surplus stuff!! Jeez, I could spend a week there.

Bob

On Jul 10, 8:51*pm, DT wrote:


I looked on the HGR Surplus web site and they have lots of pistons. I
drove over and immediately found a 2" diameter, 12" stroke cylinder,
brand new for $19.99. Cylinders are real cheap at HGR, most are $10 or
$20.


Here is a photo: *

http://home.wideopenwest.com/~dthomp.../broaching.jpg

Dennis

Nice.

I want to get a couple of hydraulic cylinders so went to the HGR
website.
Lots of cylinders, but most are one of a kind and have no specs
listed.
So that was disappointing. Oh well................

Dan

awesome project.

i

On 2010-07-11, DT wrote:
As part of a custom machine I have been fabricating (later) I needed to
broach 1/4" keyways in 1 1/8" holes in two steel flywheels and two
collars. I figured no problem, just call up a buddy where I used to work
and see if they can press them in the shop. To my surprise they no
longer have an arbor press with a high enough throat to press the 12"
long broach. Several friends have home hydraulic presses, but they have
short strokes and you need to do a lot of resetting to get a broach
through, at least two presses and maybe three for each pass of the
broach, two passes per hole. That's a lot of fussing around. Hmm.

So, I sez, let's build a press just for broaching. I have two possible
hydraulic sources. The first is one of those cheap, 4 ton manual
Porta-Power sets. But they are very high pressure (10,000 psi) and use
small diameter cylinders. I didn't think I could find a sub 1" cylinder
with a 12" stroke. Even then it would be a lot of pumping.

My other source is an old 12 volt hydraulic system that operated a
Corvair convertable top. I built it into a tire bead breaking machine
about 35 years ago and it works fine for that, but I no longer use it. I
put a gauge on it and it just hit 300 psi as it stalled out.

A quick email to DuMont and they said I needed 700 pounds of force for a
1/4" broach in 5/8" mild steel. A 2" piston would give me around 950
pounds.

I looked on the HGR Surplus web site and they have lots of pistons. I
drove over and immediately found a 2" diameter, 12" stroke cylinder,
brand new for $19.99. Cylinders are real cheap at HGR, most are $10 or
$20.

Since I already had a C frame for the tire machine, I just cut it down
to the correct height and bored a few holes and mounted the cylinder on
top. The hydraulic pump mounts on the upright and the existing steel
braided lines were just right. I'm good to go, only a few hours of work.

I cycled her back and forth for a while to bleed the air then give it a
shot. It does flex too much, I'll have to add a strongback to the 4"
channel frame. And I actually had to start the car I had it hooked to,
the extra couple of volts gave me just enough to push through, but it is
at the absolute limit with a 1/4" broach. Every keyway broached
perfectly, and those shaft collars were tough steel.

Here is a photo:

http://home.wideopenwest.com/~dthomp.../broaching.jpg

Dennis

DT wrote:

Here is a photo:

http://home.wideopenwest.com/~dthomp.../broaching.jpg


When you pushed the broach though, did you let up once or twice to allow the broach to
recenter itself? Reason I asked is I used a hydraulic press once and tried to just take
one long stroke. There was angular misalignment and the broach snapped.

Nice solution to your problem at hand!

Wes

In article ,
says...

When you pushed the broach though, did you let up once or twice to allow the
broach to recenter itself?


I'm back, I was gone for a day. I did press it in stages to allow everything
to self center. Especially when you are broaching a thin part (mine was 5/8")
there is opportunity for the broach to tilt as only one or two teeth are
contacting at once.

This was a quicky solution and it worked, but it needs upgrading. I will add a
3" channel strongback at 90 degrees to the existing upright, that should
stiffen the press quite a bit. The way it was, every time a tooth cleared the
bottom of the workpiece, the flexing allowed the broach to jump ahead until
the next tooth engaged.

--
DT