[bdn103]

Hello everyone,
I have been stalking this forum and other for a long time now. I decided I would build a CNC machine last November, and I finally got around to ordering all of the parts (and funding them). In theory, the parts should be arriving this week.

My needs are at a hobbyist level. I plan on primarily cutting plywood / mdf and possibly some aluminum. I am also setting up the machine to attempt to do some 3D printing. The plan is to build the CNC first and then add the 3d print heads (plural) and additional electronics in the next couple of weeks… if I can get the CNC working first. Consideration for the 3D printing will be made during my build.

I currently work with computers and have a few year of engineering background from schooling, but I am lacking in the day to day experience many of you have.
This will be my first CNC build, and my first larger project in a while, so it should be entertaining to see what happens. Hopefully it will all work out.

So far I have ordered

CNC Router Parts Pro4896 machine
12” Z Axis
Nema 23 electronics with Gecko 540 drive with 4x motors with 3/8 shafts and Emergency Stop switch and 12.8A power supply
Hitachi M12VC router
Hitachi M12VC Router Mount
Home built PC running XP with Parallel port card and solid state drive (concerned about vibration and compatibility)
Pepperl + Fuchs Proximity switch
IGUS Energy Chain (2 sizes purchased from eBay)
Touch plate
Lighthouse LH6755-OD 120V Vacuum pump
Assorted Dust collection “stuff”
4x + 1 spare pneumatic cylinders with 6.5” stroke to be used for hold down
Pile of wood
4x trailer jack stands to lift and move the table
6x adjustable feet for a pool table

I hope to get the wood put together in the next few days for the table. I am taking a week off from work to assemble the rest the following week. I will post as progress is made.

I also wanted to thank Cory from CNC Router Parts. He has been very helpful and patient dealing with my questions.

Thanks

[ger21]

How do you plan on using pneumatic cylinders for hold downs?

[pete1961]

You may want to re-consider the 12" Z-Axis before you assemble. I went that route on mine to discover that CNCRP does not account for this with a taller gantry. So basically you will have the same gantry used on the 8" Axis. That being said with a Bosch Router mounted similar to your Hitachi at best you will have about 6" of daylight between the gantry and base. In retrospect I would have used the 8" version. The 12" Z-Axis would allow you to cut below the top of the 8020 framing if you intend to do that though.

[bdn103]

How do you plan on using pneumatic cylinders for hold downs?



I have been deeply conflicted on what type of hold down to use (since I don't have the practical knowledge). While part of the table will be vacuum, I don't have the enough power to the garage to do a 4'x8' vacuum table. The thought was to use the pneumatic cylinders as a horizontal clamp when working will full sheets of material. This way they can be used with standardized material size. Also, if I run them off the air tank, I wouldn't even need to have the compressor on while cutting.

[bdn103]

You may want to re-consider the 12" Z-Axis before you assemble. I went that route on mine to discover that CNCRP does not account for this with a taller gantry. So basically you will have the same gantry used on the 8" Axis. That being said with a Bosch Router mounted similar to your Hitachi at best you will have about 6" of daylight between the gantry and base. In retrospect I would have used the 8" version. The 12" Z-Axis would allow you to cut below the top of the 8020 framing if you intend to do that though.

Definitely good to know, but it is too late for me now since the boxes are already in the garage.

I actually had some concerns about this issue already with the spoil board taking up too much space, especially if you have to add a few sheets for a vacuum table and /or a sheet of glass for 3D printing. As a result I ordered some additional 8020 off eBay with the intent of raising the gantry... but I may have not ordered enough. I also didn't notice until Wednesday this week that their development table in the youtube video changed the gantry design, so I may have ordered the wrong materials since I was working off of their EASM machine plans at the time. I'll find out this weekend when I open the boxes.

[pete1961]

The youtube video gantry risers are 80X80 Material. That particular setup on the video has a nice clean look eliminating all the 8020 gusset brackets. The gantry side plates are 3/8" rather than 1/4" and would make that area stiffer in my opinion. With longer 80X80 Extrusion you could easily raise the gantry but most likely at the expense of rigidity. I'm leaving mine alone at this point until I have a need for more than 6" of clearance.

[bdn103]

Well, I made a little progress this weekend with the table. I wanted something that was really solid, but that I could still move. I still need to put the plywood down for the shelf and for the table top. This should really help to lock things in place. I am still debating on skinning the sides. The plan is to have the table larger then the CNC router. This way I can put my keyboard and mouse somewhere along with any of the additional table controls. Since the Pro kit requires clearance above and below the outside supporting 8020 for the V-CON, I was planning of putting 2 8x8x10 cut to length on top of the plywood table, line the top of the 8x8s with plywood (for a more even finish) and place the CNC router on top. This way I can get everything perfectly square on the table top without having to worry about the table being out of square. When I have things locked in place, I can drill through the 8x8s and the table and bolt everything down. I also figured the additional table weight wouldn't hurt.

The table was 3/16" out of square on the diagonals, so I am fairly happy with the dimensions. I read a lot of stories about tables being out or square after welding or screwing together, thus my plan for the 8x8's.

The jack stands make it really easy to move and I still have the rigidity of fixed feet when the stands are retracted. I think I am going to paint circles on the floor once I am ready to start to level the table, this way I can always return to the same spot.

I also ordered additional 80x80 material for the gantry today. Hopefully it will arrive by next weekend.


Thanks


Attachment 229458

[bdn103]

Well,

I walked into this project with a large number of fears about the lack of instructions and documentation (perceived) from myself. As the assembly commenced, everything was labeled extremely well and all of the assembly components were individually bagged. It is an amazing feeling to know that you only have 10 screw / nuts / bolts to figure out at a time before you move on to the next section. This took a marginally difficult assembly and made it fairly simple. So instead of doing a step by step (which is fairly well detailed on CNCRouterParts), I will just go over the mistakes I made and why I deviated from the set plans.

First off, the 8020 assembly is beautiful system to work with. Everything fits, aligns, and tightens as it should. I am going to use 8020 for many of my future projects.

Attachment 232852


First off, with the base assembly, I found it somewhat difficult the tighten the bolts on the bottom side of the metal plate used to join the rails together. This would have been much easier if I had help, or not skinned the table with plywood. I had purchased additional angle brackets... so I used them temporarily to hold everything nice and tight together while bolting.

[bdn103]

One of the areas I deviated in was the table design. I heard lots of horror stories about metal twisting when welded or wooden tables being out of square when tables were being constructed. The CRP4896 machine needs to have flush sides because the gear assemblies go below the bottom rails of the base of the machine. my solution to this was to build a wooden table, and then use a pair of 6"x6"x10's to set the base on. The thought was that I could square up the base independent of the table, and when square, I could simply drill through the 6"x6"x10' and the table to bolt everything together (harbor freight carries the long drill bits for ~$10).

[bdn103]

Follow the recommendations about squaring up the angle brackets to the cross supports. Tighten then down and then slide them into the side rails. I played games with this for a couple of hours before I re-read the instructions where I missed this part.

Attachment 232858

Also, measure the cross supports with respect to each other. I had 2 supports that were slightly longer then the rest. It took a little effort to get them all the same length.

Once this was done, we spent a few hours trying to get everything as squared up as possible. With everything being square, we got it down to under 1/32" off on the diagonals with respect to each other. We were content with leaving it there.

[bdn103]

The gantry riser was one of the areas of concern for me. One of the goals of this project was to be able to use the machine for 3D printing as well. I therefore wanted to take advantage of the 12" z-axis to the best of my ability. The standard table design does not appear to change if you are using the 8" of the 12" ballscrew z axis, so our additional travel is available to you through the table. I also wanted to add a possible vacuum table to the machine as well, which would add about 3 inches. All of this resulting in the need for a higher z-axis / gantry. I bought some additional 8020 40 series 8016 to use to raise the z-axis. My concern was how to cut it to length.

The material cut beautifully in my carbide tipped compound miter saw. I was pleasantly surprised. Cuts were nice and even with no sharp edges. I then took a 1/2" x 6" x 8" aluminum plate and drilled the required holes needed to align the two pieces together. Below was a picture from when I was testing fit.
Attachment 232860

A couple of things to note. The 8020 material is slightly rounded and has a high spot between the track. When I assembled the addition to the gantry, it initially tended to bow out or in. I eventually compressed these with a clamp, tightened everything down and found the gantry to be nearly perfectly square...but the gantry is now pre-loaded. I am still debating about adding an additional aluminum plate on the inside. of each riser. If anyone has any input, I would greatly appreciate it. If the gantry was slightly off of vertical (but the same amount on both risers) I do not see a problem with it... But I am sure someone can enlighten me.

[bdn103]

The pre-assembled z-axis made the gantry assemble simple. I did something stupid here that I will attribute to a lack of sleep.



Please be aware that the the gantry sled support arms (circled in the picture) can be installed up side down. The holes are not center drilled If you do this, the sled will not clear your gear rack. If you assemble everything in order, this would not be a problem, but I was missing a set of hardware for the gear rack (that Ahren sent out next day...thank you), so I proceeded forward without the gear rack in place. I spent a little time looking at this wondering where I went wrong.

[bdn103]

Cable management was fun. While I would have loved to have bought the cable management kit, this project was already over budget and I was looking to save some money. The whole machine went together fairly quickly. Then I spent an entire day messing with e-chain. It helped to remind you how well the rest of the kit was thought out. The e-chain I picked up was from ebay and cost me $80 shipped. With that, some additional bolts and fasteners, I was able to get everything together. It may not be as pretty as the kit, but it works. The e-chain is surprisingly rigid and strong. It drills well and can easily be bolted to the 8020 material. With some scrap material laying around, the e-chain project got finished.

Attachment 232868