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For two years I've been working on a project I call "RoBLOKS". The principle is to build a system of modular robotic units that can be scaled or combined to perform nearly any function. The former-titled LLCNC machine was (ironically) being made to create the RoBLOKS pieces, yet I never considered it a part of the RoBLOKS system, until now that is! In building the machine, it came to embody the very things RoBLOKS is all about, and in a flash of inspiration, RoGR was born. RoGR stands for the "RoBLOKS Gantry Robot".

Because RoGR is extremely adaptable, and since RoGR uses many of the same parts that are used throughout the entire RoBLOKS system, and because RoGR can be used to make more RoGRs, or more RoBLOKS, I think it is only fitting to give RoGR the designation of RoBLOKS Module #1. Read the RoBLOKS page.

RoGR bearing kits are available

RoGR Servos kits are available


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Cut list beta; 6061 aluminum. Don't buy this until RoGR is done: Est 10/08


2 pieces

.5" x 10" x 12"

1 piece:

.75" x 3" x 6" (Z motor mount)

1 piece:

.5" x 6" x 11" (Z back plate)

1 piece:

.5" x 6" x 16.5" (Z front plate)

2 pieces:

.75" x 2.5" x 6" (Z shaft supports)

2 pieces:

.75" x 6" x 6" (Tool holder) beta

Alright, so tonight I took a few vids of RoGR "JR." RoGR JR is the weak iteration of RoGR yet has been cutting Q parts non-stop, and in these vids, RoGR JR is cutting out a Q42 back. This is the "lesser machine" with 40" of X on 20mm rails but the RoGR JR never fails. For the RoGR final iteration, I increased the rail sizes, switched to recirculating linear bearings, made it much easier to build, decreased the price by $3k, and expanded the functionality tremendously.

A video of the "forward looking" control software programmed for RoGR:



Coordinates:



The weight and pulley that manages RoGR's cord:



Cutting a Q42 back:



Repositioning:

EMC2?

http://www.linuxcnc.org/

Well, I awoke way too early with the realization that I could save some weight and machine-ops by re-engineering the gantry to a "split-block" design. The gantry is still 2.5" wide where needed, but the split-block design allows for easy "ways-clearance" by using any regular CNC router (no milling/ precision drilling), and cuts the weight of the gantry by some 6lbs.

A few pics (thanks Robin!) to illustrate:

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Do you think this would be possible: Build this temporarily with MDF/t-slots, then use the temporary build to cut and drill the aluminum? Maybe even replace parts piecemeal (for instance, use the MDF machine to cut/drill/route the gantry split-block, then install the new aluminum split block, after that continue machining and replacing the parts until no MDF is left).

I do.

Also, I am coming out with "micRo", a smaller machine that when finished will cost about $500, and is the same billet construction. I'm designing it so that all of the parts are interchangable with RoGR, but the micRo billet parts can be made entirely on a drill press. micRo can used to make the machined pieces for RoGR, then the parts from micRo become RoGR's Y and Z axis.

Cool!

I just got another idea... What do you say to someone, like me for instance, paying for the bearings, bar things, motors, screws, and shipping now, but waiting until you have everything so the shipping is less?

Absolutely. We'll work with you however you need. I'll have the motor kits ready for sale in about a week though (motors coming in same container as bearings). It's almost certain that the entire kit will be ready to ship by the time the bearings get here.

I'm crazy, I ordered a set of bearings!

This is surreal for me... I pretty much cannot believe I'm going to have one of these at my disposal.

If you're still on the fence go search for "cnc" on YouTube, it wont be long before you're convinced

You may want to put some kind of cover over that exposed threaded rod. If metal shavings get into the carriage part, it might sieze up after a while...

Indeed, I think it also

Nice work! Really respect!

There are "screw wipers" to prevent this. The machine we run now doesn't have them though, and never has problems. The nut/screw fit is too tight to allow chips to get in...and of course, we keep it lubed with "shedding oil" which allows the chip to fall off.

Are the dimensions of the bearings available? Or better yet, do you have them modeled in 3D already?

Actually, can we have the full 3D model?

Yes on both accounts. The drawings are being reworked now to reflect several last minute changes. When we're done, probably this week, I'll post them, as well as any g-codes, drill files etc for making the pieces.

Some lube is always good

Another question, if you don't mind Is there some kindof anti-backlash mechanism on there, or is it a tight enough fit that backlash isn't an issue?

Backlash on the nut? You could preload or "side bind" the nut, but it isn't necessary. For the ways, I have decided to embed a bronze bush and set screw in the center of this piece.

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The set screw can tension the bush against the ways, eliminating any lash in the gantry assembly in a linear fashion. Better than shimming bearings!

Preloading is the method of eliminating backlash in a ball screw assembly. This is accomplished by the use of one group of ball grooves in opposition to another to eliminate backlash. Preloading increases stiffness (resistance to deflection) and provides for accurate positioning with very little increase in applied torque or load capability.

This is if you use a Ballscrew, If you use a nut type you will need to provide an auto adjusting backlash compensator. I.e a spring or such, Look at Dumpstercnc's antibacklash nuts, I use them and they work very well.

Joe

What do you expect the total cost of the project to be?

For micRo, about $500-600 for the mechanics, and for RoGR, about $1000 (includes motors). You'll still need drivers which you can buy from us, elsewhere or make yourself. If you're handy with an iron, you can talk another micRo or RoGR owner into engraving your PCBs, allowing you to save about $300 over commercial drivers. You also need a computer. We're running our bot on a 6 year old "emachines AMD" that cost under $300 when new.

I do not know your motor specs of the ones you are using or planning to use but Geckodrives.com are coming out with a new 4 axis driver which will be around 150 i think, they will have individual drivers for sale for 30.00 each, supose to be in production by end of this month, If you are into CNC already you know Geckodrives are the leaders in the most reliable drives, I run 4 g201's not on my 4x4 machine and works great.

Here are pictures of the completed drive, the smallest i have ever seen. in one picture you will see the new drive MB on the left and a g201 mb on the right (which i have are 2.5"x2.5" total)

specs are 50vdc, 3a drivers. (Called: G-250)

I will be buying a 4 axis system (Called: G-540) as soon as they have them finished and will test on my CNC 4x4 Hybrid machine.

It should run the RoBLOCKS with no problem at all, once again depending on the motors, and how they are wired, serial or parallel. (bi-polar only of course).

Driver board:

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Driver board comparison:

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And rendering of completed 4 axis driver system:

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Joe

Very interesting. Gecko just keeps it coming...

OK, RoGR Jr (now micRo) building RoGR.

Got to the shop today, found 100lbs of billet at the doorstep:

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Sweet, new billet. God this stuff is huge. The NEMA 34 motor looks puny next to its 2" x 4" x 6" mounting blocks.

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Note that the router spindle in the pic is nearly 4" diameter...this metal is thick .

RoGR builds RoGR #2:

Next was to machine a billet spindle holder for the big router...the little ones die too fast....This piece is machined out of 3/4" alum with a dying "hobby router":



A completed tool holder: The result is great:

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Brain.. which router did you decide to go with.

To all: I know it sounds silly but are there routers that run quieter than others?

I use the Hitachi 2.25hp variable speed router it is quieter than alot of routers, may people have confirmed this.

Brain, good move on the router, the rotozip lasted my about a month at the most, can't beet a good air cooled router. what was your feed rates, stepdowns when cutting the alumn.?

Joe

I was running this piece at 200mm/m by 1mm steps with a 5/16 carbon steel double flute and water/air. A little slow but the cut was really clean. This piece ran for about an hour.

Rigid R2930

Got the second piece of the tool holder done, each of these is 3/4" solid billet alum, 6" across at the bottom...

Drilled and tapped for 6mm alan-cap screws. The piece on the right shows the two mounting screws needed for using a "big" router on micRo. For RoGR, there are 3 screws.

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My mini-lathe makes the boring and tapping really easy compared to my POS Chinese drill press.

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It came out great I think!

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Also faced and finished one of the Z ways end supports; the machinist's square reads perfect for all of the cuts.

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Tomorrow is time to square, face, and machine the X-ways support blocks (or BLOKS??). Here is a drawing of the motor/screw mounts (thanks Robin!). The simpler side of X only has the 30mm ways and the screw termination into the bearing.

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A squaring cut to the side of a Z shaft support:

Nice looking router mount... thick aluminum.

Joe

Thanks Joe. I'm building this one to make more RoGR parts. Since RoGR is thick alum, the machine needs to be strong, capable of tapping etc.

Nice job, question are you going to be offering full kits If so what do you think the cost will be?

Many Thanks again nice job,
JamesRS

Thanks. We will offer full kits. As of this time, micRo will be about $500, and RoGR will be about $1000.

Do you have an estimate as to how soon these kits will be available?

Great I'm not in a immediate hurry,do you think in a couple of months?

Thank you,
JamesRS

What is included in kit?

About two months. A RoGR is being built (ala this thread) specifically to build more RoGR parts ~en masse. This economy of scale will provide the difficult to make machined parts at prices we can all afford, and in a hurry.



Indeed.


I'm trying to include all of the mechanics: machined billet, motors, screws, linear bearings, thrust and ball bearings. Stage "two" is hardware drivers, computers/controllers, tools.

This thing is looking great.

I've always dreamt of building my PJ our of machine aluminium.

Will be following this thread closely. Keep up the great work!

Thanks. It is totally fun to build.

what size is the aluminum extrusion base? is the 80MM or 50MM?

Of those choices it's probably 80 mm. If you look at the aluminum cut list the X axis blocks are 4" (101.6 mm) wide.

That would be 100mm, or 4" x 4". Extrusion at that size is not a con$ideration unless from the Orient, and then, it is still too costly. Evolving, you can see that extrusion can not give rigidity, flatness and economy such as concrete. There are certainly other materials; but what can give the ease, ubiquity, adaptability, rigidity and longevity? If the tubular frame is truly needed, 4" steel square tubing is the better choice, especially if carefully welded at the corners. Even still, you'd be looking at over $200 for a frame that can't come close to the stiffness of cast concrete costing about $25, including rebar and fiber additive.

More RoGR building fun today, plus a few other things...

The gantry "split bloks" came today...the top pieces are 1" thick, the bottom are 1.5" thick.

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Here Robin and I are facing the 2" thick X-ways supports. I've recently changed the spec down to 1.5" thickness...it's the "sweet spot" for "cut-throughs (bit length)" , plus, two inches is just excessive.

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To make the RoGR parts ~en masse, I certainly can not de-burr each piece by hand. Vibratory tumblers would help, but typically cost several hundred$ to thou$ands, take forever (and the media is also too expensive). A couple of years ago I had began work on a project I humorously called "BucketHorse", but never finished. Tonight it was quickly and rudely manifested to debrade/abrade big billet machined RoGR parts. The cost per tumble-finishing unit is about $25, and the lasting seems good. Parts are:

5 gal bucket
4 mounted "caster" wheels
12v wiper motor
1"x3" alum angle
heavy duty 12v PS (cheap battery charger)
abrasive sand
various scrap alum for mounts

The bucket lifts off, the only coupling being a piece of c-channel scrap and half-a lovejoy coupling I had, oh... and some grease:

A pic of the tumbler in action:

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The wiper motor:

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Even got a video:



A single piece of extruded angle scrap provides the "flip" inside.

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FWIW, This machine runs with 40lbs of sand plus the "work".

X ways getting machined for motor mounts...

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Wait a minute. Is the tumbler for sanding the routered pieces? In that case: genious. If not: I didn't get what it is for :-P

^^ You can think of the tumbler as a sanding device. I'm pretty sure the more industry related term is "deburring".

Does the inside of the bucket turn white instantly?

Here's a couple links I found with pictures...
http://www.engineeredabrasives.com/equipme...rr/default.html
http://www.surfacepreparation.com/deburring.html

I gotta tell ya brainchild: Those parts are looking beautiful! There's just something about machined aluminum metal! Maybe I just like shiny stuff...


The concrete base idea is great! Cheap , super rigid , and cheap (like you said)...