Workholding Help

Good morning folks,

I am hoping to get some advice for how to hold a workpiece in the HAAS i’ve been trying to manufacture efficiently. I can’t really afford a machine of my own so I somewhat rely on the HAAS for making small runs of these enclosures. I bring all my own tooling and i’ve gotten pretty efficient at setup/teardown of my project to help save time. My parts take 4 operations for 2 different parts and 1 operation for one of the parts. So essentially it’s 2 setups that are somewhat different. I was initially thinking of using a Pierson Workholding vacuum table with the replaceable plates for swapping setups quickly, but the idea of having to hookup an air line and all that seems like it’s not really helping me out since I need to take it out every time I’m done. The other approach I thought about was some soft jaws in the vice, but the only issue I have with this is that I can’t run more than 1 part at a time (I was hoping to be able to run at least 2 at a time to make it faster. I can cut the time per part down in half by running them in one setup). The third option I was looking into was a mitee bite soft jaw mounted to the fixture plate to allow for multiple parts at a time without any kind of vacuum system needed. Eventually I’ll have to get my own machine but until then I need a flexible workholding solution that will save me some time. Currently it takes me about all of one day to machine these. Also I can’t use tabs on the plates because I have to chamfer each one and the chamfer operation cuts through the tabs.

No help on holding, but I would like to watch you make them. My father was a maker, I was a “holder” growing up. Keep me updated

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Can you show the piece inside the raw stock it’ll be machined from? I.e. drawing for tools paths. That will gave a better idea on how to fixture this. Also, what are the steps? Starting configuration and after machining. Approximate length, width, and thickness and material. Also do inside features have any chamfers or bevels? Tolerances? A dimensioned drawing would help greatly. If you don’t want to post you can PM it to me.

What kind of volume are you talking about? Running multiple parts will greatly speed up run time by having index-locators that once first part is run you just load next part material and hit run. More volume the better tooling can be made for accuracy and reduced machining/set-up time.

You won’t need a vice and they aren’t particularly good for reputability and can induce stresses and deformity to parts such as these.

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So the stock should be consistent. The plates are pretty simple 1 op but the two halves require 4 ops each. One for the inside, one for the outside, face, and back. Starting configuration is basically cut the raw stock down to size. I have access to 1" thick x 10" x 12’ bar stock and also 1" thick x 6" x 12’. So Any way to utilize the bigger stock without cutting it down smaller will be awesome. I was even thinking about running 8 parts at a time with a pallet (see photo below)

Afterwards we deburr, sandblast, and paint. So surface finish isn’t paramount but tolerance in specific areas are important. These are the areas that require the most tolerance. @Photomancer I’ll DM you the file so you can look at it in more detail. It’s difficult to make a drawing of it since there are so many little details and curves. We’ve optimized it as far as I know how to for cut time reduction. (eg. dog ears are made for 1/4" mills, less time spent with small mills, etc.). The most time consuming part is the heat sink with the long 1/8" slots. But with reasonable pass depth and correct speeds and feeds we’re able to get that time down.

We’ve run them several times but have had issues with alignment between the operations and also some serious finish issues that couldn’t be covered up with paint. We’ve run them using parallels and vice but the vice causes flex and also causes chatter.


Final assembly:


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What about drilling mounting holes before cutting down your stock, then using the mounting holes to screw the blanks to a fixture?

I think that’s got to be the best way to do it for the plates. I don’t know if it would work well for the thick parts where there is a bunch of material removal. Maybe if I can leave some material where the bolts are used.

Will you be at the Space sometime. Easier to sit down talk about and show you where to order tooling parts. Identify key interface dimensions.

I can meet up pretty much whenever. I need to run some more parts soon so possibly next week?

No problem, let me know when you run them, I can get a better idea of what needs to be done.