Author Topic: DIY machining tutorial? (Read 12501 times)

BANE · « **on:** May 21, 2009, 05:34:21 AM »

Hi all,

So the need for a mill and other various machines have been holding up my robotic building addiction lately. I finally bought a mini mill and rotary axis from harbor freight for ~$600. My intentions are of course to convert it to cnc later but after i get some more money and build a few robots. I have noticed that (I could have also not looked hard enough) no one has a tutorial on using a small mill to make parts on SOR and couldn't really find any that would answer some nooby questions on machining. I've been using all types of machines at work for the past two years and could make some detailed pics and vids on machining. Also I'll be constructing my robot so I would be showing how I can manufacture my parts. Would anyone be interested in a tutorial like this showing how to make all custom parts for $600? Heres a prototype of the robot I will be constructing. Anything you would like me to cover?

Bane

SmAsH · « **Reply #1 on:** May 21, 2009, 05:41:30 AM »

hey bane,
i think a custom machining tutorial would be a great addition to the site.
i have also been looking for some tutorials to cover this area of machining but have not found any.
what materials will you be working with?
and good luck with your robot!

BANE · « **Reply #2 on:** May 21, 2009, 06:24:14 AM »

Mostly Aluminum, lexan and various plastics. Maybe some steel.

Bane

lanamor · « **Reply #3 on:** May 21, 2009, 10:12:23 AM »

That would be a great addition. I've been looking into getting into a mini mill too but I don't know where to start.

SmAsH · « **Reply #4 on:** May 21, 2009, 02:26:53 PM »

yep, if this tutorial goes up i may actually get a mill or something similar...
or just use my schools

galannthegreat · « **Reply #5 on:** May 21, 2009, 03:00:02 PM »

Watch out because they run upwards of $500+, and not to mention the accesories you'll find yourself buying will run beyond the cost of the intial machine itself... But that aside, this would be something very helpful for people who would have access to them, and even something very good to know.

I also believe David Cook has some useful tips in his books and on his site.

http://robotroom.com/

BANE · « **Reply #6 on:** May 21, 2009, 07:50:08 PM »

Thanks guys.

Quote

Watch out because they run upwards of $500+, and not to mention the accesories you'll find yourself buying will run beyond the cost of the intial machine itself... But that aside, this would be something very helpful for people who would have access to them, and even something very good to know.

Your absolutely right on this. Buying the CNC conversions and accessories can make anyone reconsider this investment. At first i want to just machine manually to show what you can do with out CNC and how to make some of your own accessories. I later plan to make the CNC motor mounts with the mill it self. This will hopefully save people a great deal since i've noticed a lot of people selling CNC conversion plans or kits are taking advantage of things

. I just check with harbor freight and the mill is coming June 7 and the Rotary Axis sometime later. But then i will be done with high school and have more time to build robots this summer:D. Does anyone have suggestions on type of motors and controller to get? Maybe recommended (affordable) CAM software? I want to keep this project as cost efficient as possible.

Bane

galannthegreat · « **Reply #7 on:** May 21, 2009, 08:00:09 PM »

Very nice, I hope you enjoy your new toy!

madchimp · « **Reply #8 on:** May 22, 2009, 01:11:27 AM »

http://www.linuxcnc.org/ I'm sure there are winblowz software packages as well but I'm partial to tux

BANE · « **Reply #9 on:** May 22, 2009, 10:17:10 AM »

Quote

Very nice, I hope you enjoy your new toy!

any good free-ware for windows? I don't have linux

, got vista on my laptop and XP on desk

bane

galannthegreat · « **Reply #10 on:** May 22, 2009, 12:28:31 PM »

I know some of the CAD programs for Windows will work with most of the CNC systems, and I think Sherline also has programs for Windows, you should check that out.

BANE · « **Reply #11 on:** May 22, 2009, 03:02:20 PM »

http://grzsoftware.com/std.php

BANE · « **Reply #12 on:** May 22, 2009, 03:04:15 PM »

Damn, i just hate when they do this to me. Mill got backordered to june 19

. And the rotary axis is coming far before the mill

galannthegreat · « **Reply #13 on:** May 22, 2009, 03:53:47 PM »

Call and complain, and say how they promised you that it would be here on this date, and maybe if you get the right person, you can get something out of it...

BANE · « **Reply #14 on:** May 22, 2009, 04:19:02 PM »

Already tried that; all I got was some Indian old guy wanting to help me figure out why there's a cup holder on my computer

..... well not really but it didn't get anywhere with it.

bane

galannthegreat · « **Reply #15 on:** May 22, 2009, 06:02:58 PM »

Wow, what a way to change the subject (the cup holder part). Did they even tell you why it would be so long?

BANE · « **Reply #16 on:** May 22, 2009, 06:29:39 PM »

I would go farther with my complaint but all that i have is "some idiot told me it would be here on that day" on the phone the day i ordered it. If i had an e-mail or something hard i would definitely go further $:-\$ . Apparently they don't currently have any in stock, so their going to have to build one or something.

Quote

Indian old guy wanting to help me figure out why there's a cup holder on my computer Tongue.

just to make sure.... this was a joke

bane

galannthegreat · « **Reply #17 on:** May 24, 2009, 05:02:35 PM »

Sorry I didn't pick up on that one, been a tough week.

daslRobotics · « **Reply #18 on:** May 25, 2009, 10:18:30 AM »

One of the guys from our lab created a tutorial on machining:

http://www.pages.drexel.edu/~rjg48/tutorials_DASL-131.html

Also for general robotics tutorials see our labs tutorial list:

http://dasl.mem.drexel.edu/tutorials/index.php

Admin · « **Reply #19 on:** May 25, 2009, 10:53:45 AM »

I myself won't be able to do a tutorial . . . all the equipment I use is located on a secure Navy base . . . they'll take my camera and maybe fire me if I'm caught . . . so I'll have to wait till I'm using equipment somewhere else. Probably not for a long time . . .

It's definitely in my list of priority tutorials, however!

hoosier122 · « **Reply #20 on:** May 25, 2009, 04:35:51 PM »

From another forum I frequent:

Quote

Originally Posted By 1Andy2:
I know it's hard to see, but there's a slot cut out of this nut, but not all the way through. The bolt running parallel to the leadscrew is so I can close the mouth and slightly bind the threads of the acetal nut against the threads of the acme screw. This takes up any backlash in the system.

<a href="http://picasaweb.google.com/lh/photo/pufuGZaxGDRYSXPF701a3g?authkey=Gv1sRgCNzOisKjlNiEWQ&feat=embedwebsite" target="_blank">http://lh3.ggpht.com/_KKSMATVGPec/SVXJPc_wSHI/AAAAAAAABFI/JVH_hO00BmY/s800/IMAG0212.JPG[/url]

The home made tap I used to cut threads in all the acetal transmission nuts. Drill press, hacksaw, and files.
<a href="http://picasaweb.google.com/lh/photo/7SgGSkIpXpcGUVKelobFgg?authkey=Gv1sRgCNzOisKjlNiEWQ&feat=embedwebsite" target="_blank">http://lh5.ggpht.com/_KKSMATVGPec/SVXJScDSf1I/AAAAAAAABFQ/OnQ7HsVMAPk/s800/IMAG0218.JPG[/url]

Ubuntu is great. And I love EMC2. Not just because it's free, but because it's very customizable and very powerful. You should give it a shot.

I'm not sure what you mean by conduit... but from the pics, you can see flex isn't really a problem due to the construction of the machine. The rails lie perfectly supported by the chamfered edge of each axis support.

As far as the linear bearings go, most all of the stress is from tightening each axis around it's rails, and the linear bearings are nested in either grooves or a shallow cut out in the mdf. Theoretically, I think the MDF itself would prevent the aluminum angle from "spreading" but I don't think I've tightened everything enough for that to happen, anyways.

The table is a torsion box made of 3/4" MDF. The rest is just regular MDF pieces, tho I did later add some bracing peices to prevent sag and hold everything square.

Everything is good this way, except the spindle holder. The bosch router is simply too heavy for the way things are right now, so the tool hangs down at a slight angle, rather than perpendicular to the table. I'm considering options on how to brace this, but for right now, the machine does what I need it to do.

Yes, the router has enough overall power to probably handle steel. The problem is that it's a wood router, designed for high speeds rather than high torque. Yes, it is a variable speed motor, but the way you vary the speed is by lowering the electron pressure (whee, fancy terms!). Less current to the motor means lower speed, but it also means lower overall power. So that 2.25HP rating is only applicable at the highest speed setting. Even so, I think I could get away with machining aluminum.

But that's not really what I had in mind for it... instead, I'm going to try my hand at machining some hard foam, use that foam to make silicone molds, use the molds to cast wax models, and then use the wax models to make ceramic cores for aluminum casting. For things. Of a cool nature. We'll see. If it works out, I'll post pics.

Anyways, here's some general pics of the whole thing:

Drivers, power supply, breakout board, cooling fans and E-stop wired and mounted inside a PC box. This way I can unplug the motors and use this box for another CNC machine like a cnc plasma cutter or EDM or something, assuming I ever buy or build one.
http://lh3.ggpht.com/_KKSMATVGPec/SWVCMfa4RYI/AAAAAAAABKs/J09SFkXYbaU/s800/DSC_0260.JPG
http://lh6.ggpht.com/_KKSMATVGPec/SWVCOY_7MQI/AAAAAAAABK0/mSQ3P2uRRj4/s800/DSC_0261.JPG
http://lh3.ggpht.com/_KKSMATVGPec/SWVCG32eEsI/AAAAAAAABKk/dj5BVBEgE14/s800/DSC_0259.JPG

Torsion box bed. The X-axis has dual rails to accommodate this. Also I suppose it adds stability to the gantry:
http://lh5.ggpht.com/_KKSMATVGPec/SWVCcBSrMxI/AAAAAAAABL0/sm3Sdw1n1WM/s800/DSC_0269.JPG

Linear bearings nested in the MDF. This is kind of an older shot. The z-axis lead screw in this picture is not 3/8 acme.
http://lh6.ggpht.com/_KKSMATVGPec/SWVCQW1jDcI/AAAAAAAABK8/RwHweY4eap4/s800/DSC_0262.JPG
http://lh4.ggpht.com/_KKSMATVGPec/SWVCSHvy6QI/AAAAAAAABLE/45om_1RrGc4/s800/DSC_0263.JPG

Also an older shot, but showcases what kind of motor couplings I use. 3 part lovejoys couplers.
http://lh3.ggpht.com/_KKSMATVGPec/SWVCaPJB8JI/AAAAAAAABLs/1YJf0bQ2Id0/s800/DSC_0268.JPG
I've since modified that clunk mounting arrangement to this:
<a href="http://picasaweb.google.com/lh/photo/_c8ZvlIX9_fVOvBsy3Iw1Q?feat=embedwebsite" target="_blank">http://lh4.ggpht.com/_KKSMATVGPec/SdJhI8DqfJI/AAAAAAAABXI/4qGVei––17M/s800/DSC_0280.JPG[/url]

Wider shot of the machine:
http://lh5.ggpht.com/_KKSMATVGPec/SWVCeK9HIAI/AAAAAAAABL8/0bVADBRamks/s800/DSC_0270.JPG

And here's some upgrades since I took that shot:

The heavy bosch router puts alot of weight on the front of the gantry, causing the y-axis rail support board to want to twist, so I added some bracing pieces here. Also pictured is a new y-axis leadscrew (the old one was bent... you would not believe the amount of headaches that caused before I was able to diagnose it) and new, flanged bearings with setscrews.
http://lh4.ggpht.com/_KKSMATVGPec/SdJhEPANpyI/AAAAAAAABWo/FUHJZ5jUkY0/s800/DSC_0276.JPG
http://lh5.ggpht.com/_KKSMATVGPec/SdJhF9n3_0I/AAAAAAAABWw/F7k1uOiVhjw/s800/DSC_0277.JPG

The x-axis bearing support boards I made adjustable, too. The board is vertically and the MDF flange on the bottom of the table is slotted horizontally. In retrospect, I should have just used more flange bearings, for adjustment.

http://lh3.ggpht.com/_KKSMATVGPec/SdJhGsgS-hI/AAAAAAAABW4/Vst9aSvu7m4/s800/DSC_0278.JPG
http://lh5.ggpht.com/_KKSMATVGPec/SdJhHh9MlFI/AAAAAAAABXA/OKNjrW4LKqk/s800/DSC_0279.JPG

Some cross-bracing on the bottom of the table to help keep the table from vibrating or swaying. Once I aligned all the leadscrews, to nuts, to motors to an acceptable degree, there was very little of this to correct anyways, but these cross braces take it all out:
http://lh6.ggpht.com/_KKSMATVGPec/SdJhKsHh-kI/AAAAAAAABXQ/miJS6QYUqgI/s800/DSC_0281.JPG

Don't hesitate to ask more questions trog. If you're serious about doing this, I can help you avoid some of the mistakes I made. Save you some time and money.

Here's an action shot:

<a href="http://picasaweb.google.com/lh/photo/FC3ZQuPvY7j-4k3RcJAWjQ?feat=embedwebsite" target="_blank">http://lh4.ggpht.com/_KKSMATVGPec/ScBBlikJsHI/AAAAAAAABPQ/Eqyp3hCR_dc/s800/DSC_0275.JPG[/url]

BANE · « **Reply #21 on:** May 26, 2009, 05:06:53 PM »

Thanks guys,

I've been on the phone with Harbor Freight a few times an finally came through. The mill will be shipped first class tomorrow

. Apparently it was the rotary axis that they didn't have in stock and it was going to hold up the order. I'll do some testing first and start shooting some footage. I believe the tutorial will be better if the majority is videos on youtube.

Bane

SmAsH · « **Reply #22 on:** May 27, 2009, 12:26:50 AM »

yay! so what will the videos entail?
you explaining it then doing it?

BANE · « **Reply #23 on:** May 27, 2009, 07:15:15 AM »

pretty much it smash. I really hate it when someone makes a video and it has really poor lighting and video quality, so i'm working on getting some better lighting a white background. I want to make the videos have some standard format and to be as professional as possible. I do have some old video editing software that I'll break out and figure out how to work it. As far as the contents i would like to make a few general machining videos and get feed back on what people want see next.

maybe it would be a good idea to get a list together. EX. how to drill and tap?, how to mill?, how to mill a radius with a rotary axis?, tips and trick on fixturing and setups, mill and drill speeds?...... i don't really know all that people might want but feel free to add to list.

Bane

SmAsH · « **Reply #24 on:** May 27, 2009, 03:06:52 PM »

i think how to mill in general would be great to have as one of the first ones, then maybe some
more that will help with other aspects of milling eg drill tapping... i think im learning this at school today too

but definitely make some for the harder stuff as there aren't many good free videos on that stuff.

BANE · « **Reply #25 on:** May 27, 2009, 04:13:23 PM »

quick update:

yeah, just got mill. I comes assembled and weighs 150lbs, ouch, think i might have hurt my back.. lol. Will post pictures shortly.

Bane

Admin · « **Reply #26 on:** May 27, 2009, 04:34:30 PM »

For lighting, no such thing as enough. What looks bright to you will be dark for your camera. For my vids, I do it when the sun shines in the windows, with a bunch of desklamps aimed in, and it's still often a bit dark.

The only real solution is to buy professional lighting/umbrellas, but that involves spending money . . .

BANE · « **Reply #27 on:** May 27, 2009, 08:01:53 PM »

just for now i think i'm going to get standard cheap florescent bulbs with white paper in front of them, maybe about 8 or so bulbs lighting a cubic yard (the milling area)

darn it, can't find my camera cable

bane

SmAsH · « **Reply #28 on:** May 28, 2009, 12:23:43 AM »

well, do a few tests of different lighting situations and use the best one!

BANE · « **Reply #29 on:** May 30, 2009, 05:04:29 AM »

pic, really need to get this guy set up somewhere

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Author Topic: DIY machining tutorial? (Read 12501 times)