Mightymill – Build log #3 -professional diy CNC router

The Mightymill is the name I gave my professional DIY cnc router build that I’m working on. It features IHSV57 servo motors, BT30 ATC CNC spindle, Durfill polymer concrete filling and more.

My build has finally begun and in this post I will take you on the building journey. Make sure you have read part 1 here and part 2 here .

Assembling the machine frame

It took a while, but finally I was able to move the machine frame in my recently cleaned shed and get it assembled. For me, the concrete filled machine frame was one of the most time consuming aspects of this build.

durfill UHPC machine frame diy cnc epoxy granite
Rolling the machine frame parts into the shed

The leg assembly was the most difficult to move. While I had put GD-60S wheels under it, it is till a top heavy assembly which weighs 120kg. With a bit of sweat and hurt, I was able to position it and get the assembly going.

diy cnc uhpc concrete epoxy granite farmer jack
Tractor / farmer’s jack is an incredibly useful device for such handlings

I was able to assemble it without too much hassle. To get it all square I had to use the Farmer’s jack to pull the legs inward as there was a slight misalignment. After that it is square (diagonal measurement) within 1-2 mm over a span of 1.6 meters. Which is fine for this application.

diy cnc uhpc concrete epoxy granite farmer jack mightymill fitment
Initial fitment of the extrusions

It all seems to fit pretty well. Time to go on to the next step.

Lets “rise” up!

It was time to make the riser plates. I used my old and not so trusted HBM BF25 manual mill for this. It actually had lots of troubles during this process. Wobbliness … (DC) motor brushed dying, and other fun electronics issues… But i got it going again and was able to finish the job.

mightymill bf25 diy cnc top plate
Drilling the gantry mounting plate
mightymill bf25 diy cnc top plate drill mill BAP300R bap300 honing
Honing out the holes to allow for a flat surface for the recessed cap screws
mightymill bf25 diy cnc top plate drill mill
Mounted on the extrusion
mightymill bf25 diy cnc bottom plate drill mill hgr20 hgw20cc sorotec
Milling and drilling the mounting plate for the HGW20CC carriages. 25mm alu plate

As you can see in the image, the side finish of my milling does not look very good. As I mentioned before my HBM bf25 is quite wobbly and not in a good state. There is still quite some play in the column and in the gibs even after tuning.

As the side surface is not a critical one for my application it is not too bad.

mightymill diy cnc bottom plate drill mill hgr20 hgw20cc sorotec  wetstone scraping
Flattening the mounting surface with whetstones

in a Dan Gilbart video I recently learned to make figure 8 motions when doing this. I tried it out and noticed it worked well. I did not actually check it on the surface plate but you notice that the surface is quite flat. Within >=0.0x mm I would estimate. Good enough for this part.

Whetstone set

This set of whetstones was affordable at 25$ and I was able to get it locally quickly.

harpening Stone Professional Grinding Stone Set for Knives, Double Sided Grain 400/1000 and 3000/8000, with Bamboo Base, Angle Guide
mightymill diy cnc bottom plate drill mill hgr20 hgw20cc sorotec y axis x axis
Mounting and aligning the HGW20CC carriages to the adapter plate

It all fit well without too many issues. With such precision applications be sure to torque bolts and screws correctly. It is essential that you do in precision applications to ensure equal load and proper contact between surfaces.

mightymill diy cnc 120x120 aluminium extrusion BAP400R BAP400
Milling the 120x120mm Durfill filled extrusions flat

After this I also ran the whetstones over it quickly to remove all the burrs.

In addition to this I had to buy the following items:

ItemLink
BAP300R holder – BAP 300R 50-22-5T, APMT1135-H2 KT1505Aliexpress
MT3-FMB22(M12) (BAP300R holder)Aliexpress
Cheap 3 axis DRO for mill / latheAliexpress
Items I used for creating and assembling these parts
mightymill riser
(temporary) mounting the 4mm thick steel side plates

I used some 3mm thick ground steel parallels for equal spacing vs the alu block.

mightymill diy cnc bottom plate drill mill hgr20 hgw20cc sorotec y axis x axis granite surface plate durfill
Mounting it all together on the surface plate.

I used this method to ensure that the side of the extrusions meet the adapter plate perfectly at the same reference plane.

mightymill diy cnc bottom plate drill mill hgr20 hgw20cc sorotec y axis x axis granite surface plate durfill
Semi assembled riser mounted to the gantry
Mightymill frame gantry assembly x axis y axis durfill  diy cnc
Assembled Y axis including gantry on riser blocks

Finally! it is starting to look like a CNC!

Conclusion – Mightymill build Part #3

Moving and re-assembling the machine frame was one of my biggest hurdles. But once I got going it went relatively smooth. The Farmer Jack’s helped a lot with this.

I ordered some new goodies such as Delta ASDA-M controller, 400W ECMA 20b optical encoder ac servo motors. A 1 meter 000 grade granite parallel (all surfaces) and some nice steel AC servo motor mounts. It is now all on the train from China. Hoping for it to arrive at the beginning of December.

The next step will be making the adapters for the ball screws and motors, mounting the extrusions to the table and making the z-axis adapter so it can all be mounted together.

Stay Tuned!

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Spikee
Spikee

Hi, My name Is spikee and I'm the Author of this post.
I have been active on various cnc communities over the past few years.

On this website I share tips&tricks, reviews and intresting resources relating to diy cnc and cnc router topics.

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