[WATERJET71]

what's the best way to clamp or holddown a part is .125 thick aluminum I need to mill .025" step on one end. been doing them one at the time but it takes me along time to do them now I have to do 1000 parts so I need to design a fixture.

tx

[fizzissist]

TOGGLE CLAMPS, HORIZONTAL-HANDLE TOGGLE CLAMPS :: Carr Lane Manufacturing Co.

If need be, use a pair at opposite sides of the part if it's too big for one clamp, and a bar that runs alongside the cut, held down by the clamp on each end.

Mount a plate on the table, drill and ream locating pins to locate the part, mount your clamps....
Without a pic of this part, and supposing it's just a simple step...this would be a real easy solution.

[WATERJET71]

here is what part looks likemill step.PDF

[fizzissist]

One caveat....
Clamping the edges, as you would between vise jaws, will prevent "flapping" of the end of the part as you run over it with a face mill. (you'll get chatter, and non-uniform thickness, depending on how well you secure the part) Using an endmill will be ridiculously slow production time.

To gang them, you'll need to have parts that are very straight and parallel to start with, and still clamp them from the side, and I'd recommend over the top as well for security as well as stability. For that, you'd have a locating pin for each part at the end. I might do 5-up.

One product that I've used with excellent results is the TalonGrip stuff from Mitee Bite
Mitee-Bite Products Co.

It actually does work as advertised, and the clamps are only 1/16" thk., which would leave you with room for the cutter. They will indent into the part, but with a brass pad you could still get some side clamping force.

Keep in mind.....sometimes its just as well to do it the hard way and get the quality, as spend the time screwing with a fixture for short-run production.
Tough call, and only you can make it.

[doorknob]

What do you think about the small hex cam-action clamps from Mitee Bite for this application? The clamp would apply pressure to the edge of the part near where the milling is to be done, while the rest of the length of the part could be held in place in a pocket milled from an aluminum plate.

[fizzissist]

In a fixture plate, I think those clamps would work fine, you'd just have to mill a recess in the fixture plate to allow for the head thickness, which is larger than the finished part's thickness. Those actually may be a lot easier to use, because you just mill a recess, drill and tap for the clamp.

[OptionCNC]

Soft jaws or fixture plate and set up 5 or so at a time... with strapping to go across each one, with about .05 away from the edge being machined... make sence?
Id suggest using an endmill aswell, something with a .005 or .01 corner rad, to assist in "pushing" the part down, and you'll have minimal chance of chatter compared to a shell which will likely create a vacuum causing the part to lift, and scrap.

Had similar parts to this at an old shop. and thats what we had setup, worked great.

OR soft jaws with dovetail cut lip and relief on the sides where the EM will cut the step...

Do you have flatness requirements for the end tabs?

[WATERJET71]

Soft jaws or fixture plate and set up 5 or so at a time... with strapping to go across each one, with about .05 away from the edge being machined... make sence?
Id suggest using an endmill aswell, something with a .005 or .01 corner rad, to assist in "pushing" the part down, and you'll have minimal chance of chatter compared to a shell which will likely create a vacuum causing the part to lift, and scrap.

Had similar parts to this at an old shop. and thats what we had setup, worked great.

OR soft jaws with dovetail cut lip and relief on the sides where the EM will cut the step...

Do you have flatness requirements for the end tabs?

I like your idea, the only thing is with an endmill will take forever dont you think? I been using a generic flycutter and I been making arround 100 pcs an hour I ran this parts arround 500 a year but this time they need 1000 at once and I'm not whilling to spend over 10 hrs on this job. I will still make money but if there is a better and faster way why not.

[fizzissist]

Ok...How are you doing them now?

In a vise, one end at a time, flipping and doing the other end?

Why not set up another aligned vise, clamp both ends at the same time and have the program do both ends in one clamping? I could see your cycle time easily cut in half right there..because handling/clamping is a huge time sink.

Then have the program alternate between ends where it finishes on one end, allows you to change parts, then starts the cycle from the end it finished, and alternates.... That would even save time with rapids.

[WATERJET71]

I'm doing this on a manual mill I just got a Haas mini mill but its just sitting there its not installed yet.and yes I'm doing one at the time and then flip it. I dont mind to do it that way but I'm always looking for a better way .
thank you for all this help since I'm new at machining well not new just havent been arround machines for at least 20 years I'm in to sheetmetal but machining that's my background.

[OptionCNC]

using an endmill would be faster than using a fly cutter...
Consider the DIA of your fly cutter, your off part go to location (lead in) then cutting your part, then the lead out... I assume since its 1.39 length of step you would be using a 2" shell or or 1.5". your adding 1.5"- 2" (1/2 dia. of cutter x 2) worth of excess travel for your fly cutter to move. by looking at the part its what, 5/8 wide? Use a 3/4 EM, your lead in and lead out is now under an inch total, higher rpms, faster feeds, that part from green button to green button should be under 20sec. with part pumper...

If you have 2 vices setup for the same part at once 2 ever 30 sec.

my 2 cents anyways

fixturing for high production.. but if your limiting or quoted the job on 10hrs, then im sure you'll take the appropriate steps

[OptionCNC]

I'm doing this on a manual mill I just got a Haas mini mill but its just sitting there its not installed yet.and yes I'm doing one at the time and then flip it. I dont mind to do it that way but I'm always looking for a better way .
thank you for all this help since I'm new at machining well not new just havent been arround machines for at least 20 years I'm in to sheetmetal but machining that's my background.

ahhhhhh, i assumed CNC job... once you get the Haas up and going this job would be a walk in the park

[WATERJET71]

ahhhhhh, i assumed CNC job... once you get the Haas up and going this job would be a walk in the park

ha ha walk in park?? I hope is that easy... its going to be a chanlenge I have not a clue about cnc I'm scare I think I was drunk when I made up my mind and get the mini mill ha ha

[OptionCNC]

haha, thats some great decision making!
Its pretty straight forward once ya pick up on the basic stuff. CNC can be as complicated as you want it to be. with a mini mill you be starting out fairly standard, good for learning.

[WATERJET71]

Yes That's why I went that way with a small mill. I almost got an Okuma a couple of years ago. but that thing was way too big for what I needed.
One question how long do you thing it would take some one with a manual machinist background to learn the basics of programing.I program laser,waterjets,nc turrets. so how long do you think it would take me to kind of run small set ups. 3 months? I know that question might not have an answer but just kind of getting an idea of what' i'm getting myself in to.

[fizzissist]

Yes That's why I went that way with a small mill. I almost got an Okuma a couple of years ago. but that thing was way too big for what I needed.
One question how long do you thing it would take some one with a manual machinist background to learn the basics of programing.I program laser,waterjets,nc turrets. so how long do you think it would take me to kind of run small set ups. 3 months? I know that question might not have an answer but just kind of getting an idea of what' i'm getting myself in to.

If you already program the listed machines, I'd think milling would be easy for you....I mean, if you already know G-code, it's just some different words for different functions.

For the parts you're talking about here...it's about as simple as you can get. Really, really simple. I'd use a nested subroutine or macro, but you can get started with a really dirt simple program and grow from there on these parts.

Me? I'd been hookin' the CNC up and holding the job back just because i'd love the challenge!

Some sample code here:
MultiCam - Support - M & G Codes - Sample Files

[WATERJET71]

If you already program the listed machines, I'd think milling would be easy for you....I mean, if you already know G-code, it's just some different words for different functions.

For the parts you're talking about here...it's about as simple as you can get. Really, really simple. I'd use a nested subroutine or macro, but you can get started with a really dirt simple program and grow from there on these parts.

Me? I'd been hookin' the CNC up and holding the job back just because i'd love the challenge!

Some sample code here:
MultiCam - Support - M & G Codes - Sample Files

Thanks for the link. I have alot to read on my vacation trip. ha ha