AlfaGTA's cambox

[implmex]

Hi Ross:
Whatever happened to the cambox you were asking about over on the EDM forum?
It seems you dropped off the face of the planet after Brian Pfluger first responded to your thread, and then we never heard back.
I thought this would be the best place to ask; seems you're normally pretty active on this forum.
Hope all is well.
Cheers

Marcus
Implant Mechanix – Design & Innovation - home

 

[AlfaGTA]

Marcus:
The response i got from Brian seemed to indicate that finding a wire machine with 32" of height was not going to happen.
The fact that i can't section the cambox led me to look at other options for the repair....
I did respond to Brian's post and i looked at the forum after that and there were no other posts forthcoming so i figured no further info there...
Sorry if i left anyone hanging.
Cheers Ross

 

[implmex]

Have another look at the original thread.

Hi Ross:
THis is an interesting problem for many of us, so we put our thinking caps on and came up with some wacky possible solutions (including a couple of wire EDM sources that can run very tall wires (48" and better).
I'd love to know what solution you chose and how it worked, so if you're willing, another photo documentary like the ones you've done in the past would be most welcome.
Please don't apologize for not re-visiting the thread; I figured you'd become too busy to poke around in Practical Machinist for a while, but your stuff is always so damn interesting, that I thought I'd just follow up and see if I could coax out some more information.
Cheers

Marcus
Implant Mechanix – Design & Innovation - home

 

[AlfaGTA]

Marcus:
Thank you for posting this here...went back and read the responses and you make some interesting suggestions....did not think of a sinker with the electrode pointing sideways (i think this is what you meant)
Not sure there is enough "Window" to get the electrode in on the long bores, will have to look at all that.

I have also thought about the use of guide bushings to use to locate a short bar with flexible drive...might be the way to go.

Othe solutions may be that of opening up the existing holes and fitting in bushings that are a loose fit on the enlarged hole, and securing the bushings in place with something like Devcon and using the follower shaft for alignment....

FYI this photo shows the cambox installed on the motor.

Cheers Ross

 

[implmex]

some pictures, some possibilities:

Hi Ross:
Here are some quick and dirty models of what I had in mind with the sinker EDM.
The first one is a simple side trode that can be inserted between the ribs and run sideways.
The second one is the method I described using a 3/8 copper rod as the trode.
Cheers

Marcus
Implant Mechanix – Design & Innovation - home

 

[implmex]

Another option, no sinker needed!!

Here's another possibility;
You need a long straight tube with a precise center hole; I'd thought to have an old beat up rifle barrel turned down and centerless ground to the diameter you want the bushings to be.
A bronze sleeve sweated onto a 1/4" diameter drive rod and then turned to fit with sliding clearance in the ex gun-barrel bore forms the boring bar, and is made with a cone socket and threaded stud on the end so you can thread on a home made roughing head or a finishing head and keep them dead nuts concentric to the sleeve.
The cambox is bolted to the mill table with enough room left at one end to mount a pair of vee blocks that will align the sleeve to the cambox bore.
Now you can rough out the first hole, then finish it so the sleeve will just slide through.
Advance the sleeve up to the next bulkhead and repeat until you're through the far end.
The sleeve supports the bar, and if you use a roughing head then a finishing head for each bore in turn, you should be able to maintain both alignment and good support for the bar all the way through.
If you can mount the cambox in such a way as to be able to drop gauge the sleeve occasionally you can nudge it as needed to keep it aligned.
I didn't bother to model the boring heads...they're pretty straightforward to design and make.
Your handy dandy 3/8 cordless pistol drill provides the power to the bar.
Cheers

Marcus
Implant Mechanix – Design & Innovation - home

 

[AlfaGTA]

Marcus:
Thanks for the replies. Will spend more time with this next week.....
At the moment I am watching the sun disappear on the face of "Half dome" in
Yosemite............. Weather is perfect a glorious day in a perfect spot.
Cheers Ross

 

[advt001]

Ross I think your type of work is awesome and look forward to your posts.