American 7260 crawler crane

[eef7260]

Hi Lorenzo

I made the basic shape by milling ( see figure 1 & 2 )
It's not an real socket with an key , sorry it's a bit fake.
I made 2 holes ( see figure 3 )
I put the rope trough one hole then make a not and then stick it up again trough the other hole.
After the milling i made all the round edges with a file and sand paper.
It's not the most easy part to made but it can also be done with a saw and a drill and a lot patience and some skills with a file and sandpaper.
Hope this made some sense.

Eef

[lorenzo]

Thank you Eef. That makes sense. Interesting way you did it.

[9W Monighan]

I never thought about a wire EDM for plates. That would be soooo much more accurate than a lazer. Boy would I like to have one of those. I've been toying with the idea of getting a old ram type EDM but I have never used one. I almost bought a couple last year cheap from a shop down the road but there was some electronic problems with them and I was afraid of not finding parts. Alot of the guys that make small engine parts use these to erode away metal to simulate castings. Usually they grind or machine the electrode to the form.

[eef7260]

Hi Steve

Wire edm are great machines and i am lucky enough to have access to them.
Once you start using them you see more and more applications for it.
In fact the profile of the bottom and top flange , the 6 bars and the tooth profile is also done with it.
it could also be done with laser cutting ( less accurate but accurate enough ).
The fact that i used it is simply because i have access to it.
If there was a laser cutting machine available for me i would have use that.
In fact wire edm is a bit over specified for the job.
Don't know how things are in your area but over here there a lot of company's that do laser cutting for real fair prices.
You only need to deliver a decent cad file and wait for 2 weeks or so.
The thing is now i don't have to wait , i do it myself and it cost me nothing ( only time )
But if i had not access to edm i would seriously consider laser cutting for some parts.

Eef

[D8R]

I have used laser as much as possible (unless I couldn´t make drawings) on my D8r and I think it´s very accurate. i do a lot of tabs and holes to fix parts together and normaly I only have to use moderat forces to get pieces bond together (before welding or brazing). My latest used supplier has a special gas when cutting with laser so faces will not be burnt.
With an edm machine it should be possible to make differences in hight of the material, not only cut through it I think.
Dan

[eef7260]

Hi Dan

Don't get me wrong laser cutting is indeed very accurate
In fact it's probably more accurate then needed for most of our work.
I think i would prefer a laser cutting for my parts.
like i said i am lucky enough to have access to wire edm so i use it.
But you i can tell you we reach accuracies of 0.003 mm in holes with wire edm.
Thats not with one simple cut but but wit 5 or 6 cuts.
The last few cuts are done with a very low amp just to polish and take off the last few microns.
OK thats far over specified for our parts but it can be done with wire edm.

Eef

[Heavy Metal]

Thanks for sharing Eef. Now THAT is how you make a nice part!! Joe

[rc_farmer]

Very good work.

[Stuff]

oh my that is amazing!

[pugs]

Very cool build.

[tc1cat]

Most of us can only dream about having access to either a lazer or wire edm. Your workmanship is outstanding. Your build looks like it should be in a museum.

[D8R]

I think that most of us using those types of machinery have either access at work or contact a local company. I have had a couple different companies heling me ($$) depending on what type (thickness) the part will be done from. I have used the laser cut parts because it give me an acurance that I have problem to achive. I don´t have any education on metal working so every step is big for me. But , yes it´s a dream to have a small laser, but hard to see that coming. Maybee a CNC mill is closer (i hope).
Eef, a question about that EDM, it looks like a wire between the heads, how do you get that wire into a hole? And isn´t there another machine that can partly cut through a plate to get difference in height??
Dan

[eef7260]

Hi Dan

The wire is shot in with a small but powerful water jet ( you need a small start hole )
The water jet acts as a guide for the wire and it keeps it perfectly centered.
The wire goes done with jet while the machine slowly feeds the wire.
On this machine i used 0.25 wire but 0.1 or 0.05 mm wire can also be used.
Don't know exactly what you mean with the second question , make me a simple drawing so i can answer that one.
here is a nice youtube that explains a lot
http://www.youtube.com/watch?v=GDLZBz2uOL0

Eef

[pugs]

I believe he is asking about a sinker edm, that would give the ability to do blind holes and shapes that are not through like a wire edm does. There is also hole popper edms, which are used to put small holes into hard metal for the wire edm to start in or just to have holes put in.

[doodlebug]

Hey Dan, look at this link, maybe that's what you where asking about?
http://www.lindsaybks.com/bks9/edm/index.html
Later, Neil#2 aka doodlebug.

[eef7260]

Hi Guys

Some time ago i got a pm with the question how i did the window rubbers.
I will post it here also so it might be useful to others as well.
The trick is very simple but it took me a while to figure it out.
Buy yourself a thick black Permanent marker.
Stick a needle in the center of the tip and let it stick out 5 mm or so.
Take a windowframe and let the needle be the guide , and follow the contour of the window on both sides.
Practice a bit with a dummy windowframe and play a little with thickness of the of marker for desired effect.
Or change the shape of the tip a little with a knife.
New markers gives a better and nicer layer ink.
Hope this info is useful for someone.
And here is the result.

Eef

[dirtpusher9]

Wow, that is some serious craftmanship. I've seen this model on the net before and it is awsome.

[JensR]

A beautiful machine and beautifully machined!

[TheMachinist]

Wow this machine is simply amazing! The Grapple is a work of art!
Jordy

[sparkycuda]

Marvelous craftsmanship!

Ken