Hammer A3-31 converted to "CNC"

[Lisa Starr]

I just completed converting my Hammer A3-31 to a "CNC" controlled table. It cost about $300.00 and it is working great. I'm awaiting the arrival of more PLA for the 3D printer and will print a case for the control/screen and a belt guard once it arrives. Here are a couple photos of the setup.
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I programmed an generic Arduino Mega with a 3.5" TFT touchscreen shield to control a stepper motor. Here are a couple shots of the screens.
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When it is powered up, it automatically "homes" the table and then presents screens depending on your desired actions. It moves at 400 RPM, so it takes about 18 seconds for it to traverse the entire travel distance of the table. I programmed it to allow you to move to an absolute position or to step up or down a particular distance. It has error checking programmed to prevent moving out of range and taking to large of a cut.

I planed with it yesterday for the first time and it worked very well.

Thought others might like to see.

[Steve Wurster]

Wow, that's awesome! And here I thought I was cool with just a little homemade disc that goes over the wheel so I can use a drill to lower and raise the table quickly. I didn't even do the belt / chain hookup. You went full tilt!

Do you have any pics of the stepper motor setup under the table there?

[Lisa Starr]

Here are the pics of the stepper motor. The first is shot from the rear of the machine and the second from the front, under the table.

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[Ron Selzer]

Nice workmanship, like what you have done
Ron

[ChrisA Edwards]

That's super cool, would love to see a YT video of the whole thing plus a list of components and sources if you would care to share.

I can't tell from your photos, but do you think it would be possible to keep the OEM dial gauge in place for (backup) reference?

It looks like you removed the table locking mechanism? If I don't lock my table, it guarantees snipe.

[Dan Friedrichs]

Lisa, that is awesome!!! Tell us more details.

What size stepper motor is that?

Does the stepper have an encoder and closed-loop control, or do you just rely on counting the number of steps?

Did you write all the software for the UI?

I did a similar motorization of mine, but left the interface manual, and used a brushed DC motor (not a stepper): https://sawmillcreek.org/showthread....-31&highlight=

[Lisa Starr]

Dan, It is a relatively cheap NEMA 23 High Torque stepper from StepperOnLine and can be purchased on Amazon. I also purchased the Stepper Driver and 36 Volt power supply from them.

I didn't go with the closed loop, but will upgrade if I have problems. I wrote the code and have a number of parameters on the setup page to fine tune the performance. After extensive testing, I'm not having any trouble with skipped steps, so probably won't make that upgrade.

I've measured the movement and the maximum it has been out of sync is .016 mm, so I think plenty close for wood. It isn't a project for the faint of heart, and a background in coding is a big help. I didn't have experience in C/C++, but was a programmer in FORTRAN, COBOL and BASIC, so it wasn't too difficult to pickup another language. There is large support community on the web that freely shares code.

[Jim Becker]

THAT...is very kewel!

[George Yetka]

Wow I only have a few hundred cranks left in me before my back is completely done from my Hammer, I should get on this.

[Bert McMahan]

Holy cow I need one of those. Any plans to post your code anywhere?

[Jacques Gagnon]

Fantastic work Lisa! Between your parallel guides for the slider and the motorized A3 you have given a lot of inspiration to some of us. Thanks for sharing.

Regards,

J.

PS: good thing you did not have to set up a reader for your FORTRAN cards 😂.

[Dan Friedrichs]

Fantastic work. Very cool to hear that it didn't require an encoder on the motor, as I imagine it simplifies it quite a lot.

[Ralph Okonieski]

Excellent! I am a big fan of Arduino and have done a few projects. I use the Arduino and a remote to open or close the gates on the dust collector so I do not have to bend to do that. It will open or close multiple gates at one button press. Your project is much more complicated so you have my respect and admiration! Well done!

[Chris Parks]

A bit of a story that I won't go into but I did the same thing a few years ago and had problems with it due to getting the electronic installation wrong and damaging the control electronics. It will be re-installed shortly but the difference with mine is no computer at all just some kind of chip with programming. I recently built a touch screen controlled router table and the A3 electronics are built around the same electronics. I have no electronic knowledge, a friend did it all including the coding.

Go to the top link in this search, why do we have to do this stupid work around to links on other fora I don't know. The conversion to the touch screen control is late in the thread so read it right through.
just another router table - Google Search

[John Barfield]

Hi Lisa,
That is very impressive. Do you get snipe without the lock handle? johnbarfielddesign.com