[watsonstudios]

It all started in January when I first started looking into buying a mini mill (Sherline, Taig type) to play around with machining. Well, one thing led to another and I came across this site and the ideas have been flowing ever since.
After initially buying the Solsylva plans, I was looking through these threads and realized I could design my own machine. I started cruising Ebay for parts and started designing my machine based on the parts that came available. I would search for the axis' first. I started with the X axis and found some 1 inch Thompson supported rails (48") with double pillow blocks for a smokin' deal. Then, the search was on for the Y axis. I found a slide assembly with 16mm supported rails and carriage. The Z axis went through two design changes, I wanted to be sure of simplicity and rigidity. The first version had too many variables that would compromise rail parallelism and squareness so I opted for another all-in-one slide assembly. I think I now have a very rigid design and just need to incorporate the leadscrews & steppers.

My main line of work is 3d computer graphics & animation. To help with the design process, I was able to download CAD files for almost all of the parts I used for my design - then assembling the machine in 3d to work out any issues and explore ideas as I went along. I would see parts on Ebay that looked promising - download the CAD files & incorporate them into the design. The only problem is that if I liked the design, I really had to win the auction to get the parts I wanted.

Critiques appreciated - let me know if you see any potential issues.

Enough rambling, here's some pics - 3d rendering first.

[benn0280]

i just wanted to comment and say a few things, first off... i think its looking really nice so far. So far as i can tell, my only question as far as sturdiness would be you choice of having only one pair of bearing on each axis. Although, it should be noted that I've never seen pillow block bearing like that in person.

This is my first post here at CNCZone... i've been lurking around for a couple weeks now, soaking up as much info as i can...I too have been thinking long and hard about designing my own table setup, and surprisingly, the image i had in my head is pretty much been fabricated by you.

at any rate, i think it looks pretty smokin. you've got my attention.

Jon

[watsonstudios]

Thanks for the comments. I found that pillow blocks are very rigid and the pillow blocks I have are double-length blocks so there are 2 sets of linear bearings in each block. The X axis blocks are 6 inches long and very tight on the rail - the weak point here is how rigid the frame is. The Y & Z carriages each have 4 linear bearings in each, a scaled down version of the X axis blocks - and since the carriages are one solid unit with not a lot of space beween the rails, they are very rigid with no noticeable play. All my axis' utilize double pillowblocks with supported rails. Again, It was just luck that I got the parts I wanted on Ebay.

[thkoutsidthebox]

Looks great. What programs did you use to do your 3D model and rendering?

[watsonstudios]

I use 3dstudio MAX with Vray rendering plugin. I was able to download all the 8020 extrusion, bearings & slide assemblies in either DXF or IGES formats. THK & IKO guide rails and carriages were also available for download when I was working out the Z axis design.

[Popeye]

Very nice, simple and clean.
How are you securing the gantry to the bearing blocks?

[watsonstudios]

Very nice, simple and clean.
How are you securing the gantry to the bearing blocks?

If you look at the pic of the closeup of the pillow block, the black piece of 1/2" aluminum sitting on top of the pillowblock is bolted to the 3060 extrusion from underneath and then there are 4 bolts going up through the underside of the pillowblock overhang to fasten the pillowblock to the 1/2 aluminum. I've attached a simple rendering of the area.

[Popeye]

Have you thought about tyeing the end cap on the gantry into that black plate to share a little of the load? Not being critical, just trying to help That would eliminate any potential twisting of the gantry beam.

[watsonstudios]

Have you thought about tyeing the end cap on the gantry into that black plate to share a little of the load? Not being critical, just trying to help That would eliminate any potential twisting of the gantry beam.

I think it's ok for now, it would take an extreme amount of force to twist that gantry. It's fastened to the plate with 4 5/16" screws and weighs close to 40 lbs. without the router. I would probobly break a bit before there was any significant movement in the gantry, either twisting or rocking. Being that the endcaps are only 1/4", I don't think it would add much rigidity - but then again, it can never be too rigid.

[3Dsigns]

Woooooooooahhh!! Sweet!
I like this!
Just the basic design I've been looking for.
Would these round rails and blocks be strong and tight enough to use on a 4x8 router, with a 3.5 hp or more router?

I have over half a ton of 80/20 aluminum including a 3060x60'' piece i plan to use for the gantry. I also have two of the square thompson rails which are exactly 60'' long as well. Would building the gantry be a good place to start?

How are our going to mount your screws?
Are those rails stainless?
Can those blocks be tightened later to take up any "slop"?
Also, will you be using a screw/bearing for each side of your X axis?
Thanks
Looks great.

[watsonstudios]

How are our going to mount your screws?
Are those rails stainless?
Can those blocks be tightened later to take up any "slop"?
Also, will you be using a screw/bearing for each side of your X axis?
Thanks
Looks great.

Working on the screws now, I'll post progress on that later.
The rails are not stainless, just hardened precision rails(McMaster part#59585K55) and the blocks have adjustment set screws to squeeze the bearings to the rails.

I am going to try using 1 leadscrew on one side of the X first. Even though the gantry is quite heavy, it takes very little effort to move. I don't feel racking will be a problem with this gantry - if so, I can always add another screw & motor.

As for utilizing this design for a 4' x 8' router, The X rails would be no problem at 8feet - You might want 2 double pillowblocks on each side though. My gantry is 3" wide - I'm sure another foot would be fine - remember, There's half inch thick aluminum mounted to the front of the 3060 and supported rails mounted to that, which really adds to the rigidity of the gantry. I don't expect any measurable deflection.

[3Dsigns]

Working on the screws now, I'll post progress on that later.
The rails are not stainless, just hardened precision rails(McMaster part#59585K55) and the blocks have adjustment set screws to squeeze the bearings to the rails.

I am going to try using 1 leadscrew on one side of the X first. Even though the gantry is quite heavy, it takes very little effort to move. I don't feel racking will be a problem with this gantry - if so, I can always add another screw & motor.

As for utilizing this design for a 4' x 8' router, The X rails would be no problem at 8feet - You might want 2 double pillowblocks on each side though. My gantry is 3" wide - I'm sure another foot would be fine - remember, There's half inch thick aluminum mounted to the front of the 3060 and supported rails mounted to that, which really adds to the rigidity of the gantry. I don't expect any measurable deflection.

Thanks!
Can't wait to see the progress. That's going to be one sweet machine!
Thanks!
Wayne

[Greolt]

Critiques appreciated - let me know if you see any potential issues.....................

I am going to try using 1 leadscrew on one side of the X first. Even though the gantry is quite heavy, it takes very little effort to move. I don't feel racking will be a problem with this gantry - if so, I can always add another screw & motor.

I really like the way your design is coming together.

However it will save you some time and considerable frustration to drive the gantry from both sides right from the start.

Because I assure you that you will in the end.

This machine is going to be capable of fairly good performance but to stop your gantry shuddering on direction
change you're going to be dialling the acceleration way down which is the biggest killer of overall performance.

So save your self some angst, drive both sides. :stickpoke

Have fun and keep the posts coming, Greg

[watsonstudios]

Thanks for the advice - I might just drive both sides.

This build has been going pretty smoothly considering I only have a drill press, miter saw & some air tools to make parts. Here is some pics of installing the leadscrew in the Z axis. Anti-backlash nuts courtesy of Dumpster CNC. I also picked up some Delrin for the blocks to mount my leadscrew end-bearings in.

[zoltan]

Hi,

I have sent you a pm. Did you get it?

Zoltan

[3Dsigns]

A question on driving both sides of the gantry with separate motors...
Will the drive it in sync?

In some of the big machines, the "columns" of the gantry seem to extend lower than the table on each side and are connected underneath by some kind of beam. Is this type design driven by a single lead screw under the table?
Thanks

[agent.5]

What size is your machine? Is your X-axis 48"? And, guessing 36" for y-axis?

I like to use 3060 as the gantry and wonder what is the length limitation of such application.

[watsonstudios]

What size is your machine? Is your X-axis 48"? And, guessing 36" for y-axis?

I like to use 3060 as the gantry and wonder what is the length limitation of such application.

Yes, you are correct in the dimensions - I don't know what the length limitation would be for a span of 3060. I know 36" is well within any measurable deflection.

[watsonstudios]

Here is the finished Z axis, minus the router mount - just need to mount the stepper, which I haven't purchased yet. I decided to make the top motor plate with Delrin instead of aluminum because It's easier to drill large holes in. I'm still shopping around for the motors & drivers. I want to get a kit that has everything (motors, drivers, power supply, etc.)so I'm comparing right now and making sure I like the features of the driver boards since there are a lot of options that these boards can have. I plan on using at least 400-500oz motors to get good torque. More to come...

[Greolt]

A question on driving both sides of the gantry with separate motors...
Will the drive it in sync?

I'm not familiar with other controllers, but Mach will slave two drives together quite happily

In some of the big machines, the "columns" of the gantry seem to extend lower than the table on each side and are connected underneath by some kind of beam. Is this type design driven by a single lead screw under the table?
Thanks

Yes driving from the center underneath is a popular method on the common homebuilt moving gantry style machine.

Greg