Ideas How to Cut small part

[Brad Shipton]

I am looking for ideas how to fixture a small part to be cut on my CNC or a suggestion where I could just order 16 of these. I can easily drill the hole for the shoulder screw. It is a small 3/8" thick x 5/8" x 1" piece of aluminum (circled in red in picture). The pieces will be cut from 3/8"x1" aluminum flat bar. I setup a small vise I can vacuum to my table, but it seems kind of slow and I will have to flip the part. I tested that idea and having the steel on the table makes me nervous.

Thanks

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[John K Jordan]

I am looking for ideas how to fixture a small part to be cut on my CNC or a suggestion where I could just order 16 of these. I can easily drill the hole for the shoulder screw. It is a small 3/8" thick x 5/8" x 1" piece of aluminum (circled in red in picture). The pieces will be cut from 3/8"x1" aluminum flat bar. I setup a small vise I can vacuum to my table, but it seems kind of slow and I will have to flip the part. I tested that idea and having the steel on the table makes me nervous.


Brad, this caught my eye. I don't have a CNC mill (never even used one!) and may not understand the issues here. But on my little manual mill for such a small part I would probably try machining it from a long bar of aluminum held securely but with the end extending into the air to avoid the need for flipping. Machine, drill, cut off the piece then manually advance the stock. I've done this on other (roughly similar) parts machined from steel and it worked fine - I didn't get any vibration or chatter. However, as stated, I have no experience with the fine points of CNC! Just my 2 cents before the experts get here!

BTW, I don't even like following the CNC forum since it makes me want one! I have a good friend with a big CNC in his shop and I've even avoided hanging out there. :)

JKJ, no you can't get a CNC, no you can't get...

[michael dilday]

Can't you leave a small tab or two and cut them out by hand? Or drill the hole first and screw it to a piece of wood then clamp the wood.

[Brad Shipton]

John, the cutting is basically the same, but the fixtures are trickier since I have a vacuum table that I cannot simply just screw or bolt things down where ever needed. The idea of the vise on the table for this is something that is going to take some getting used to. Extending the stock is a good idea. I was hoping to cut four at a time, but two would be okay too. I wish I could just buy these somewhere. What type of mill do you have? I would like one, but some of the little ones I have looked at seem a bit light and I have wondered how well they work.

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Michael, yes, that would work, but I already bought the stock and it is not wide enough to fit in the vise and cut all around the part. My local supplier only sells aluminum in full sticks, so I am not super keen buying another 20'-0" of stock.

[Brian Lamb]

Brad,

Given the material is aluminum, I would use the 3/8" x 5/8" bar and let it hang out the end of the vise. All you have to do is poke one hole, round the end and part off using your end mill. Use your end mill to part off, make several passes allowing say .030" thickness for the last pass. You'll have a sharp piece left over on the piece parted off, but you can touch that up against a sanding disc or belt and deburr them lickety-split.

I would whip them up on my CNC mill... and probably bought 3/4" thick material and holding on just .060" or so, made the part complete in pieces of 6" long material to fit in my vise, probably 5 in a stick, then flip them in the vise and machine the 1/8" off the bottom for 5 pieces at a crack.

[Brad Shipton]

Thanks Brian, that's what I will do. I realized a while after I bought the stock I should have went with a thicker material. I could have made a simple jig and used the mitee bite edge clamps I have to hold the stock in place. I originally planned to make them without my machine, but that would take a bit of time and they would not turn out as nice.

[Brian Lamb]

If you have mitee-bites, you could always place the clamp where it won't interfere and just radius the end and poke the hole. Cut the bar stock into slightly larger than 1" lengths on your chop saw.

[John K Jordan]

...What type of mill do you have? I would like one, but some of the little ones I have looked at seem a bit light and I have wondered how well they work.
...

Brad, I have the fixed column HiTorque from Little Machine Shop, R8: https://littlemachineshop.com/products/product_view.php?ProductID=4288
I added the power X-axis feed and air spring, and I'm (slowly) building a 3-axis DRO. I got a rotary table and a few other trinkets to play with.

I'm surprised at what this will do. I machined quite a bit of steel, brass, aluminum, and wood with it.

Just for fun here is a branding iron I made for a friend, machined from a cast slug of bronze with a 1/8" end mill, hand shaped with a Dremel, with a turned wood handle:
368335 368336 368333 368334

I also have a heavier Rong Fu mill-drill, currently in pieces rebuilding it, new bearings, etc., an LMS Hitorque metal lathe, and a tiny Unimat lathe (an antique, I think) with the original wooden box!

I also turn aluminum, brass, and steel on my wood lathe (with standard woodturning tools). Here's a lathe tool adapter - it will be epoxied into a wooden tool handle:

368337

Oops, sorry, I'm addicted to photographs and get carried away. I don't do a lot of machining but it is SO nice on occasion. That and the little weld shop tucked into my wood shop and I never want to leave the farm!

What type of CNC do you use? I know zilch about them - I don't even know what my buddy has except it's big enough to machine truck wheels! He said he makes parts for firearm modifications too.

JKJ

[Brad Shipton]

I have a 4'x8' entry level machine for woodwork projects, but I seem to be constantly building gadgets. I am convinced the problem in my shop is me. haha.

Thanks for sharing what you are doing with your milling machine. It looks like a very handy machine, and you are turning out some very nice things. The machine most seem to go with on the Felder forum is too large for my current space, but I trust many of them to have researched the options before taking the plunge. I have been ordering things from Travers Tool lately and they keep sending me the catalogs. I have looked at the benchtop size machines many times now, but I am suspicious about what they can do. The size they can mill would work very well for my typical projects, but I am concerned they cheap out on milling the parts to meet the price they can sell the units for. I have seen the little one at princes auto (Canada's version of Harbor Freight), and it does not look like a machine for me.

Brian, that is a better idea and sounds like a better plan. I can mill the stock to width, and set them into a jig for final sizing. Easy peasy. I will not bore the hole with my CNC, but I will mark the center point.

[John K Jordan]

... I am concerned they cheap out on milling the parts to meet the price they can sell the units for.

i researched before buying and understood that although several brands of mills (and lathes) come from the same factories, the LMS HiTorque models are made to higher standards both in materials, precision, and fit/finish. Another friend of mine has bought several cheap lathes but said he disassembles the entire machine and deburrs, polishes, and carefully adjusts everything on reassembly - he said the machines are practically unusable without this.

JKJ

[Steve Burke]

You could buy a larger piece of flat stock the thickness you need. Draw the part up in whatever design program you have, nest several out for the size stock.
During the design leave at least 3 tabs to hold it, then when its finished running, snip the tabs then blend them with a scotchbrite wheel on a air powered die grinder.

[Robert Bonenfant]

Hey Brad,

On a Cnc router we would use a vacuum table and fixtures - Wouldn't recommend it for doing parts this small. On a cnc mill you would need to setup a fixture and have some Mitee Bites setup to hold the small parts. Ill link a video series I really enjoy below - Titans of Cnc, he explains alot about metal cutting and setting up fixtures for different parts. Also you state your current space is to small for the machine you need ? We have two 4x8 Smartshop 2 and there foot print is small - Most cnc shops pile machines as close as possible to optimize profit and optimize heat removal.

Good Luck - Series below is really cool to watch - Hes on Youtube as well if you dont want to make a account.

Titans of Cnc
http://academy.titansofcnc.com/

[Brad Shipton]

Thanks for the link Robert. I really like those Hass machines and milling steel is fascinating.

I found some 3/4" stock in my pile from the previous project, so milled the pieces quite easily now. I also was able to improve the design.

Great help.


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[Brad Shipton]

Someone at work had a rock tumbler and she helped take off the burs so I do not cut myself. They turned out pretty respectable.

https://lh3.googleusercontent.com/d6cU7S_lOeFOJCznJNK4OavuUdiDH-LffNPcKhr4HNPN0x-naDmQ_SPMBnoRbBzXsjJeYTPyoNBdlRxu3G5Cy9AwXG4pCvvSy zTNBOH58RfDgafHCiNSzrDcjEWgWznIW-f-Sz3yumR8f7QPDK0hT4g9uVSWK8k0OMEDjZREERLCfIy3rEM7rl Cr24f9UUoYsbMtkfemY_OfPHKVhrIzwWjKt-zdvWcVC0cjhYpwU5t2dZ9RjaMZ0nm4ROIcnHJjBdf3pW9RAk0q gh4jftIA3g73c5Vovg5yWYiyf0XNfumj59ebOThfg2aPlZDfP7 1NZorGsKXgkZZIwSCVOB2QfN2XjHjPN3VrjJbxM58jT-DidybEU8APNZ2rYaDfymIOIvonN1mCnA5EEBUdPKV2mBw6tQdr FyfMG025YMHkj8QWIDiwXDSv8ytLDhZMv9USJM_6syFcXTcyy8 ZF4UBodjrszZfXLOGm_TWAmGPbOOZ3clOZfkiLrWT9yM43yZOu GO8kazEn-XMWH1c3FyYmHoF_by-mudHaXj-pjOY6j7O86knEe6dLjm6dDeiF3xEP3XARbyEtbPaHPRxBshEn2 emFfDqt-Izcu0KqDe5kTg=w750-h948-no

[Brian Lamb]

Nicely done! Using a tumbler is a common way to deburr small parts in the metal working industry.

[Ted Reischl]

I have faced the same issue and got fed up with it. Soooo, I built a vise. First I tried the cast iron vises, made me nervous as a cat in a room full of rocking chairs.

I used to sell these, still sell the plans but anyone with any skill at all can just design their own make them up. Take a look here and scroll down the page for a pic, there are some videos also. Not trying to sell you the plans, just trying to help.

https://www.tedreischl.com/cnc-router-vise/