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CNC Construction Set V1

Posted: Sat Mar 24, 2018 9:45 am
by bnelson
I like the small but strong design of the CNC construction set plasma you are building. The small footprint really appeals to me. I have very little room and don't have a need to cut large sheets of steel. As a maker, It would be nice to CNC plasma cut parts for various projects.

I also like the fact that I don't have to mess with a water table.

Are you going to be posting plans for this plasma cutter? I would really like to build one. Also what are you plans for a THC?

Re: CNC Construction Set

Posted: Sat Mar 24, 2018 12:40 pm
by msimpson
The current build of the plasma cutter still needs some upgrades and modifications. You might have noticed that I raised the height of the gantry. I needed to do this for clearance of the hand torch. A torch sticking out the front of your machine means you have to build things a little different.

I have to add the following:
Upgrade Lead Nuts to Dumpster CNC nuts
Add thrust bearings to both sides of each axis.
Redesign the Z carriage plate
Upgrade Exhaust system

Now that I have had to raise the gantry, it might be better to rethink the gantry.

I am not ready to release it to the public, but anyone on this forum that wants a drawing or other file from the build, I would be happy to make them available from this forum.

Re: CNC Construction Set

Posted: Sat Mar 24, 2018 8:11 pm
by bnelson
I like the size and the Use of the 10 series for the base. I'm assuming if you change the gantry design, you will still be using the same base and rails?

Re: CNC Construction Set

Posted: Sat Mar 24, 2018 9:30 pm
by msimpson
Yes, the base and rails will not change. If there is anything you need from me, just ask and I will try and post it.

Re: CNC Construction Set

Posted: Sun Mar 25, 2018 11:23 pm
by msimpson
For the THC, the first one I am going to try is the CAP04 capacitive sensor. I am using an Everlast plasma cuter so I cant add an Ohmic sensor. The CAP04 uses capacitance to measure the distance to the stock so it can be used as an initial sensor, and a running sensor.

The folks at CNC4PC are sending me a CAP04 as well as a new UC300ETH breakout board that has DIN Rail support.

At some point I will test a couple torch voltage monitor sensors as well. Both my Everlast and Hypertherm have divided voltage outputs on the CNC control interface.

Re: CNC Construction Set

Posted: Wed Mar 28, 2018 10:48 pm
by bnelson
I have some leftover 10 series so I am going to start a build based on this size and design. Any links to the brackets you used to hold the base components together?

Any updates on the THC?

Re: CNC Construction Set

Posted: Wed Mar 28, 2018 10:55 pm
by msimpson
I could post a link, but the ones on Amazon are priced way to high. Go to your local home center and pick up some 2" gusseted braces. The ones I got I purchased from Homedepot.

SKU 824542
They cost $3.97 for two.

Any will work, as you are only going to be using the holes closest to the corners. If the holes are too small for 1/4" screws and Tnuts, drill them out. I think I had to. I have seen these on Amazon but they want over $7 for them and they are only $4 at home depot (pack of 2)

Note that you can also use #10 screws and Tnuts if you like.

I am waiting on CNC4PC, They are writing the manual for the C76 board as we speak.

I have a project box project I will be cutting out of 22ga sheet, and dont want to do it without a THC.

Re: CNC Construction Set

Posted: Fri Apr 13, 2018 11:52 pm
by msimpson
I got the THC in and have spent the last couple days getting it installed.

Its now installed and ready for some testing. Since it does not have to have the torch running, I can do some dry run testing just to make sure Mach is setup correctly.

http://www.kronosrobotics.com/cap-04-thc/


Re: CNC Construction Set

Posted: Wed Apr 18, 2018 10:39 pm
by bnelson
I have been following your posts with the THC and the CNC Construction Set plasma cutter



I just got to have one of these. The size is perfect for me.

Re: CNC Construction Set

Posted: Wed Apr 18, 2018 10:44 pm
by msimpson
While I did get the CAP04 THC to work. I don't think its the best fit for a plasma CNC. I will be testing some torch voltages based units in the future as well.

Re: CNC Construction Set

Posted: Thu Apr 19, 2018 8:56 am
by bnelson
Michael, if I decide to build this what kinds of build costs are we talking?

Why isn't the CAP4 a good fit?

Re: CNC Construction Set

Posted: Thu Apr 19, 2018 10:10 am
by msimpson
The cost of building the CNC Construction Set Plasma will depend alot on what you have on hand. I had most items on hand, including the G540 which is one of the most expensive parts. The G540 is probably a little much for this build so you could get by with something a lot cheaper.

If you change to a different driver, and have some of the extrusion, it could probably be built for less than $1000. But that does not include the THC. The CAP04 is $400 alone. Which I feel is a little pricey for what you get.

I'm using some left over 5 Start ACME screws from a previous build for the X and Y axis. Rack and Pinion would be better for a plasma cutter but would add much more cost.

There is also another added cost for a plasma CNC. Thats the plasma cutter. I own two plasma cutters.

Hypertherm Powermax 65 with both machine torch and hand torch and CPC interface and Remote. I think at the time I got it as a special bundle for $3200 a few years back. Prices have gone up though.

Evelast 50S with hand torch. Comes with computer interface. I think I paid around $800 a couple years ago. Comes with the PT60 hand torch. Very nice torch with lots of consumables now coming available. Looks like you can even get some shielded consumables which would allow you to build a ohmic sensor.

Im using the Everlast on this machine cause I think its better suited for this size machine. Once I get some more consumables I can start to dial it in.

You will also need an air compressor and a good desiccant filter system. The evelast is pretty easy on air consumption. The Hypertherm is an air hog. I had to move to a 60gal shop air compressor.

Note that you could even use the Harbor Freight 40Amp unit. You would have to mod it a little to add the ability to fire it remotely.

There is no comparison to the Hypertherm. Very easy to dial in. The manual gives full charts for cutting just about any metal using the various consumables.

Re: CNC Construction Set

Posted: Thu Apr 19, 2018 10:26 am
by msimpson
As for the CAP04 THC. Here are some things I dont like about it.

1. Since its capacitance base the aluminum Y carriage riser blocks interfere with it when you get within an inch or so of the left side (side the CAP04 is mounted on) This means if using the THC, you loose over an inch of X travel. Even though I am going to redesign the Gantry and Z axis, I like the sides, they really help keep the smoke and plasma dust contained so the downdraft can do its job.

2. With the Ring from the sensor mounted, it makes it difficult to really dial in things. It seems that the ring is always in the way. While capacitance systems are very accurate, the ring stays kind of loose so its hard to be real precise. Its also a pain to remove consumables. You have to take the sensor ring off.


3. Again hard to dial in as any cut outs or warping on previous cuts withing an inch of your current cut will affect the current height.

4. The current design of the Z axis and gantry does not allow me to raise the torch very high with the sensor attached. This means I cant use any of my plasma cutting fixtures. This will change once I do the gantry and Z axis redesign.

All that said, in my last video (the one you posted), Im cutting some used painted 16 gauge steel. It was all warped and just plain nasty. Could not have done as good a job without the THC.

Re: CNC Construction Set

Posted: Thu Apr 19, 2018 12:12 pm
by bnelson
I do have a 25 gal compressor and was already looking at plasma cutters. Im not ready to buy a new compressor so I am looking at the EverLast 50s or the 60s.

When do you think you will be doing the redesign?

Re: CNC Construction Set

Posted: Thu Apr 19, 2018 12:54 pm
by msimpson
I have already started. I will post some pics as I get some things fabricated.

Re: CNC Construction Set

Posted: Fri Apr 20, 2018 4:27 pm
by msimpson
I just got the new gantry built.
_MG_9973.jpg
Its a more conventional X axis. Next I have to design the X carriage. The sides of the gantry will have braces that will tie the X beam to the risers. These braces will also act as the motor and bearing mounts.

To do this however I have get my inventor 3D model updated.

The cool thing is I will have an 18 x 25 cutting area.

Re: CNC Construction Set

Posted: Fri Apr 20, 2018 7:40 pm
by bnelson
Wow
That's a lot different. Why are you changing it?

Re: CNC Construction Set

Posted: Fri Apr 20, 2018 8:50 pm
by msimpson
I needed to cut some angle iron for a project I am working on. Once my angle iron fixture was installed the torch could not reach the proper height with the CAP 04 installed.

Back when I had to double the height of the riser blocks, I kind of Knew I was going to have to redesign it.
KRCCS gantry.jpg
This design also puts it back in line with a router or spindle.

Re: CNC Construction Set

Posted: Sun Apr 22, 2018 11:34 am
by msimpson
The new gantry is coming along. It is more in line with that of a real construction set as it will support all types, Router, Spindle, Engraver, marker, Drag knife, and Plasma.

The design so far:
KRCCS Plasma V2 b.jpg
The actual machine:
_MG_9975.jpg
The braces also serve as motor and bearing mounts. The brace did not need to extend the full 14" of the riser, but my risers are scrap and consists of two pieces. This helps tie them together. It also serves as a bit of a shield to keep plasma dust down.

The next step is to start working on the X carriage.

Re: CNC Construction Set

Posted: Sun Apr 22, 2018 1:03 pm
by msimpson
I have found it very difficult to cut the hardened steel 20mm rails with my band saws. I have bi-mental blades but not making enough progress to keep it up.

I could use my Hypertherm plasma cutter, but fear I could severely distort the rods, so I broke down and just ordered 2 300mm supported shafts. They are only $15 each so not that big a deal. Just going to take a week to get them. So it looks like I will make a temporary X carriage plate to use my existing unsupported rails. At least that way I can use all my existing Z motor mounts and carriages.

Re: CNC Construction Set

Posted: Mon Apr 23, 2018 10:41 am
by msimpson
I got my rails cut.
_MG_9980.jpg
I ended up using a cutoff wheel. I had a thin metal cutoff wheel mounted on my RotoZip. Saved me from having to buy some for my Dewalt angle grinder, and cut like butter.

Re: CNC Construction Set

Posted: Tue Apr 24, 2018 9:40 am
by bnelson
I have a couple odd shaped 20mm that you use in this build. I would love to cut them down and use them with this project. Can you give specifics on how you cut them.

If I can use my old 10 series extrusion, and cut down these rails, I can build one of these on the cheap.

Re: CNC Construction Set

Posted: Tue Apr 24, 2018 10:41 am
by msimpson
I used a Rotozip with a angle attachment. It uses thin 3.5" metal cutting disks. The Dremel disks are also compatible. Disks cost about $1.50 at Home Depot.
_MG_9981.jpg

The D handle option on the Rotozip, makes it very easy to cut the rail straight.
_MG_9984.jpg
Honestly, I have had this Rotozip setup for years. First time it was actually of use. Cut through the stuff very quickly and cleanly. Note that you can also use a thin cutoff disk on an angle grinder. Just not as easy.

Harbor fright sells a little 3" handheld, but 3" is really pushing it as even a little wear on the disk and it cant cut through. If you were going to cut a lot of these, you might consider a small 6" cutoff saw like this one.
https://www.harborfreight.com/6-in-55-a ... 61204.html

Note that once I cut through the rod, I removed the rod from the supports by removing the screws under the supports. Note that you want to cut the rod so that you have at least two screws holding the rod to the support. If not, dont cut it.

Re: CNC Construction Set

Posted: Tue Apr 24, 2018 12:31 pm
by bnelson
Thanks. That helps a lot. I have an angle grinder. I will look for a metal cut off wheel. I am also going to start looking for some corian.

I assume you are painting the corian. What paint are you using?

Re: CNC Construction Set

Posted: Tue Apr 24, 2018 5:24 pm
by msimpson
Im just using some Krylon Colormaster spray paint I picked up at walmart. In the old days they had a plastic specific Krylon, but its all the same now. \

Note on machining Corian. Its machines much like a hard wood, but easyer. It is basically acrylic with embedded silicone. I love the stuff. I picked up a whole counter top at restore for $23 and have used only half for both iterations of this build. Some parts I may eventually do in aluminum but only after I am happy with the final results.

Re: CNC Construction Set

Posted: Thu Apr 26, 2018 5:49 pm
by bnelson
How are you cutting the Corian? I can use my KRMX02 to machine it. Feeds and speeds?

Re: CNC Construction Set

Posted: Thu Apr 26, 2018 5:49 pm
by msimpson
Feeds and Speeds for Corian I am using:
1/4" two flute carbide (woodworking bit)
15,000 RPM
50IPM
1/16" DOC.

Corian is pretty forgiving, you can go faster or slower, and more or less RPM. It will also cut well at 1/8" DOC, but you will need some pretty good metal clamps for that.

Overall the above settings are the sweet spot I use.

To cut my panels to size I use all kinds of methods. I cut full sized counter tops down to smaller sizes with a hand held Jig Saw. To cut them to exact size I have used the following:

Jig Saw: Little rough and can leave waves.

Circular Saw: A hand held circular or panel saw is pretty good. And you can get pretty good cuts.

Table Saw: This has the best finished, especially if you use a plastic cutting blade.

Band Saw: I have a Laguna SU14 saw in my shop. I use this most of the time to cut to part size. It has a 1" carbide tipped blade so its held up for years.

KRMx02: If you don't have a table saw or a band saw, or circular saw you will still need to cut down to some rough sizes, then cut out to exact part size on the KRMx02. I don't do this as Its just a lot faster to cut rectangle parts out with other means.

Re: CNC Construction Set

Posted: Fri Apr 27, 2018 12:23 pm
by Bobtail Farm
msimpson wrote:The current build of the plasma cutter still needs some upgrades and modifications. You might have noticed that I raised the height of the gantry. I needed to do this for clearance of the hand torch. A torch sticking out the front of your machine means you have to build things a little different.

I have to add the following:
Upgrade Lead Nuts to Dumpster CNC nuts
Add thrust bearings to both sides of each axis.
Redesign the Z carriage plate
Upgrade Exhaust system

Now that I have had to raise the gantry, it might be better to rethink the gantry.

I am not ready to release it to the public, but anyone on this forum that wants a drawing or other file from the build, I would be happy to make them available from this forum.
Thank you for the offer and will take you up on it when it ready for prime time!!! Lookin' great, by the way.

Re: CNC Construction Set

Posted: Fri Apr 27, 2018 2:10 pm
by msimpson
I just completed the Z axis and have my CNC Construction Set machine back up and running.
_MG_0009.jpg
_MG_0010.jpg
I now have the range to use my fixtures:
_MG_0006.jpg
Or to cut on top of the recessed slats:
_MG_0007.jpg

The Z carriage was designed to be removable. All I have to do is remove a few slats and the carriage can be easily replaced. This will allow me to quickly change from a VFD spindle or plasma torch, or anything else for that matter.

I have added all my thrust bearings and new Dumpster CNC nuts. Very rigid.

I still have a couple things to do.

1. I need to get the THC installed
2. I need to design a spindle Z carriage

The Z motor and bearing mounts need to be redesigned. They were based off some NEMA 23 mounts I purchased from Amazon. Dont like them as they have no adjustment at all. I had to add an inch of risers to clear the motor and mounts. This means I had to push the Y gantry risers back to gain an inch so I could still get my 25" Y travel.

Now that I have my plasma angle iron jig working again, I can design and cut some better motor and bearing mounts.

I ended up with a 15" cutting travel on the Y axis so my full cutting range is 15" x 25".

Re: CNC Construction Set

Posted: Fri Apr 27, 2018 4:32 pm
by msimpson
A little more about the Z-axis.
X carriage assembly3.jpg
While not shown here, there are spacers between the ACME nut and the Z carriage plate.
X carriage assembly2.jpg
The Motor/Bearing mount consists of two NEMA 23 mounts (one on top of the other). I did have to do some milling on the holes so that the long #10 bolt would mate. This bolt was used to stiffen the assembly. A 1/2" bearing is sandwiched between the two bearing blocks. On each side of the bearing block is a thrust bearing and washers.
X carriage assembly.jpg

Re: CNC Construction Set

Posted: Fri Apr 27, 2018 4:44 pm
by msimpson
This machine is now a little more inline with an actual CNC Construction Set. With the interchangeable Z plates it can be set up for various CNC functions. Im not sure I will use a 2.2KW spindle, as I have to hold it in place while I engage the ACME nut.

The reason I am putting so much effort into this build is that I will be doing a couple conversions on my KRMx02 and will have this machine to fall back on for both plasma and milling.

Re: CNC Construction Set

Posted: Sat Apr 28, 2018 11:53 pm
by msimpson
I started working on mounting the CAP04 THC to the new Z plate.

One major disadvantage of the CAP04 is its a pain to mount.
I had to make a special mount to attach to my Z Plate.
_MG_0034.jpg

You also have to mount the controller enclosure to your Z axis.
_MG_0041.jpg

The CAP04 THC is now mounted and works beautifully. I have full THC access to the entire 15" x 25" cutting area.
_MG_0045.jpg

Re: CNC Construction Set

Posted: Sun Apr 29, 2018 11:51 pm
by bnelson
I like the overall look. It looks very solid. How does it run?

Re: CNC Construction Set

Posted: Mon Apr 30, 2018 9:08 am
by msimpson
With the new ACME nuts and thrust bearings, this is one solid machine. In addition the new gantry is much more inline with a CNC Construction Set.

I have already started a VFD spindle based Z axis that I will be testing. The first one will be a 2.2KW (3HP) because thats what I have on hand. Once I get it up and running, I will work on a new removable table top.

As for the plasma portion, The CAP04 is much better mounted. I can easily remove and replace the ring as needed. For instance I wont use the CAP04 when cutting angle using my fixture. One major disadvantage of the CAP04 is that it does not work with narrow stock. As it gets close to the edge, the height is off. I will be testing a conventional (voltage based) THC. I also want to add a floating head for touch off control as well. A floating head works best for my narrow stock fixtures.

As for the design. The design is pretty well set, except for the Z axis motor and bearing mounts. I dont like the off the shelf mounts. Setup was difficult and I had to use my mill to modify them. Now that I have angle iron fixture working, I know I can make something much better and easier to install.

I started the write-up on the new version 2 of the CNC construction set, so I will probably close this topic and start a new one soon. That way I can post my drawing files in the forum as needed. I want to make is clear at this point, you will need a KRMx02 to build this machine. And any special parts I make that cant be made with the KRMX02, I will offer them as products, so you wont get stuck.

Also any of you folks that are in my area, are welcome to come and checkout the machine, and get some hands on if you like. Just contact me so we can set something up.

Re: CNC Construction Set V1

Posted: Thu May 03, 2018 12:23 pm
by msimpson
I just finished the design for the Z Spindle carriage.
Z carriage Spindle Assembly.jpg
Just a few extra holes needed, so its going to be the same carriage and risers for both the Z Plasma Carriage, and the Z Spindle Carriage.
KRCCS Assembly V3 with router installed.jpg
I just cut the parts, and will be installing it today.

Re: CNC Construction Set V1

Posted: Fri May 04, 2018 10:20 am
by msimpson
The design works pretty good.
_MG_0096.jpg
Its easy to get on and easy to get off. I chose a Bosch router and K2CNC mount because I had them on hand. The CNCRouterParts mounts will use the same holes.

I changed four of the bearing truck screws so they would go through the Z plate. This helps a lot with rigidity. I will probably do this on the Z plate for the plasma carriage as well.

My next step is to design the modular table for the spindle. It will probably be modeled after the design I did for the KRMx02 mod I am working on. Just smaller.

Re: CNC Construction Set V1

Posted: Wed May 09, 2018 10:12 pm
by msimpson
Sorry we lost a few postings, as we had to restore the forums from a backup on 5/6/2018.

In any case the spindle carriage works fine but I am not happy with the height.
I decided to go ahead and rebuild the Z axis to solve this an make it easier for others to build. I ordered a 1000mm supported drive shaft. It will be cut in half.

This will give me two 500mm supported shafts. The base will be cut off of about 200mm of the end. This will yield two round shafts at the top that I will use to mount the motor and bearing holders.

I will post some pics as soon as I get the design complete in INVENTOR.

Also note that I built a table top for the spindle out of melamine coated particle board. And while this has worked very well. I want to use 10 series 1030 extrusion. Since I have started my KRMx02 dual gantry build, I should end up with enough extra extrusion to use on the CNC Construction Set build.