I use carpet tape all the time. If you buy the "outdoor" variety, your piece won't move at all, it's tenaciously sticky. If the base were concrete, you'd still be using a piece of "sacrifice" that gets a little cut-into when you cut your pieces. Sacrifice can last a long long time. Sacrifice is typically MDF or plastic (think of the white plastic cutting boards you see around, only bigger). A simple piece of 3/4 MDF makes a good sacrifice and you can screw-clamp or tape pieces down. If you do a lot of wet-cutting for steel and such, you don't want MDF! That said, the concrete base is out, since I re-engineered the piece over the last two days to be far more simple to build. I'll explain more below..

That looks incredible.... bring it on

You must write scripts for TV " the build up and That said, the concrete base is out, since I re-engineered the piece over the last two days to be far more simple to build. I'll explain more below then commercial just at the hanger lol can't wait to see what you've come up with

Haha...after I wrote that I got inundated with Chinese chat windows before I passed out for a few hours...

OK, well, it just goes to show that even after a year of planning there's always a better way to do something! Last year I built (with Robin) a large gantry robot that was the inception of the RoBLOKS concept. It used these wedges and rollerblade wheels to roll on Schedule 40 pipe or square tubing. It worked excellent and evolved to a modular system made of perfed tube.

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For various reasons I had to abandon the aforementioned design, the primary being that Allied tube wouldn't make the perf tube for me for anything less than 25 containers.. (25,000lbs/container!) I plan to revisit this concept soon as it was very amenable to jobs not normally associated with CNC and can cheaply and easily be expanded to near any length, for things like robotic boom cameras, mural painting etc. Alas, once my army of RoGRs is complete, I can make the tube myself...

So what does this have to do with now? Well, I learned back then that having the gantry suspended was the way to go. After some 6 months of working on RoGR, the concept faded from memory and I ended up with the design we have now, with the gantry supported. These last few nights I haven't been able to sleep well because my mind keeps churning over the design and suddenly a concept appeared that was a beautiful fusion of the past and present machines...

By using a tubular steel frame I can not only suspend the gantry but I can also eliminate nearly all of the machining needed to build RoGR, with nothing but drilling and tapping needed. Aside from making it easier for the DIY guy to build, it makes it far faster and easier for Lumenlab to build too, and I plan on building lots of these! On top of that, it is a superior design that allows for tremendous expansion possibilities as well as easy set-up, take-down, addition or subtraction ie modularity...can you tell how much I love this thing?!

The frame is based on 3.5" square steel tube. The X ways are simply bolted to the tube at the top, and the bracing is made with Schedule 40 pipe (1.9") that attaches to the frame with special flanges (will show below). Here is a crude drawing of the frame for the 50" x 50" RoGR. It is the same concept for the 26" x 50" RoGR, just narrower. I changed the ways to be larger: 35mm on the X and 30mm on the Y. This makes the bearing kit price rise a little, but lowers the cost on billet aluminum. The entire machine becomes slightly (~10%) more expensive but you benefit from far less labor in constructing it and far more possibilities in using it! Oh and for those who already bought the bearing kit...guess what, free upgrade!

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The bed sits on top of a "spine skeleton" (speleton?) frame of square tube (not shown). Imagine one piece of 3.5" square tube running the length of the bed (the spine), with several pieces of 1" running the width, supported by the large spine underneath. (The forums should have a drawing tool!) This arrangement is very very stiff; you can slap a couple layers of MDF on there and you are done with the bed!

The "speleton" sits atop angle-iron attached to the vertical supports. The supports are drilled to allow raising or lowering the bed, giving you plenty of options for Z depth. In the future, a kit will be made allowing the bed to ride on vertical ways for ridiculous Z depth. Combined with a rotating platform, the machine could carve statues! The "BIG RoGR" could cut a life-sized figure!

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Bolting it all together is a breeze with these nifty flanges:

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The frame design means we don't need those big alum X ways supports! We also get out of machining that pesky gantry split-block design. (That reminds me, I need to update the cut list!) Instead I've taken a piece of 3/4 x 8 x 12" alum and hung it from the 35mm ways on two 35mm pillow block bearings for each side of the gantry. This is a phenomenally strong arrangement. For BIG RoGR, I am trying to offer 50mm ways as an upgrade, whoa! (Trying to convince the Chinese factory to make them for us.)

All for now. Hopefully I'll have some more drawings tonight.

~Cheers

Gah! I was just about to order! Oh well, as long as gets easier to build.

Hey KoS, long time no chat! Well, the bearing kit has to go up by $100, but you save more than that on aluminum, so don't despair.

So if i wanted a RoGR and/or RoGR jr of my very own, Where would i start? Onlinemetals.com?

Start with the bearings. If you do all of your own metalwork, you'll want the bearings handy for reference. The motors and screws would be next. I said I'd have them for sale by now but I'm delaying because I've turned over a few new leads I'd like to track down first. I'm trying really hard to find the best value, not the cheapest price or the best quality (both of which are not usable for diametrically opposite reasons). Try to hold off on the metal until you really need it; let me be the guinea pig and spare you any wasted money or metal. The RoGR Y ways and Z blocks are done, so all that's left is mounting some things to the gantry blocks and making the frame. I'll order the frame and gantry block metal over the weekend and should be fairly well along on the final design by the end of next week. If any goblins show up I'll be sure to post changes promptly, and the solutions. I will refrain from taking the cut-list out of BETA until then.

Yeah, I'm getting back into action and the cnc bug has bitten me once again. I can't wait to get this project going.

How long before the other bits, like the motors, PSU and controllers roll out for sale?

the description for the barrings set needs its price edited. Would i be able to pre pay an estimated amount up front and possibly get a basic recommend tool list i'll need to work with/on/around RoGR?

I've received several promising samples, so I feel confident that I can have the rest of the gear for sale within the next two weeks. There are many details to arrange; I'm not just going to toss this stuff into a box and try to ship it to you.

BTW I placed the order for the RoGR bearings yesterday; 4000lbs worth! The factory is "kitting" each kit into a plywood crate that is roughly 8" x 10" x 72". Your bearings will arrive in pristine condition; they are too heavy to take chances with. I think you guys will be very impressed with the quality!


Welcome back.

Ok, to be sure I understand you. Can you link me to the bearings that need updating? Pre-pay an amount? I'm confused here. For the making of the pieces you will have detailed drawings, the bearings in-hand, or you can buy the cut pieces from me and simply bolt it together. I'm building robots to make robots so that you can ultimately buy the "DIY" pieces for cheaper than you can make them. The question is whether building the robot is important to you (mechanics), or what it can do (creatively) takes priority. If you buy the bearings now, you can buy the rest of the pieces as they come online, follow our plans with your materials, or make your creation based on your abilities and ideas.

Would it be totally ridiculous to start with hardwood rather than aluminum and just gradually replace the pieces over time as money becomes more available? I may have a source for hardwood off cuts.

Well, I'm fairly sure that machining hardwood is actually harder than machining 6061. Then there's the problem that you've used more time/energy and yet don't have the dimensional stability of billet (a humid day and your bot cuts gouges). Last; the billet price has dropped quite a bit due to the last revision, I believe coming in at around $150-$175 now. If budgeting is required, just take it in stages. It is best to measure twice/cut once with materials like this (ask me how I know ).

http://www.lumenlab.com/estore/product.php...=271&page=1


the listed price at the top correct but in the item detail/desc.
"and rails to build this machine for a special sale price of $399.00"

well my first RoGR i figure will be configured to build a few more RoGRs and jrs atm i dont see it personally as a diy because theres no way i could make something like this by myself. yet. so ill be buying part from ya all and bolting it together and i was hoping to get the cost outta the way
did i explain that right?

Hey KoS. Well, I happen to know that you have a controller, already soldered up.

For me, I think that what I can DO with a CnC is more to me than the building of it.

For that prototype with the skate wheels... Am I the ontly one that looked at those pictures and thought "Meccano!"

Hey there, brother! I have that controller still packed up nice and neat just waiting for the day I can actually use it. To be honest I have thought about it from time to time over the past few years with regret that I couldn't pay you back as I had promised. I don't know what your plan is regarding a cnc, but if I get mine working before yours I'll let you know and I'll help you out in any way I can if you need it.

Gah is right!

I'm glad you're making these design changes brainchild! I'm just glad I didn't go out and buy the aluminum! (I had my finger on the trigger a couple times though.)

To be honest, those giant aluminum blocks for the (sorry, I'm not sure of the terminology) Y supports never sat well with me.

I was also leaning toward doing something along the lines of a hanging "gantry" (did I get that right)... If for nothing else than to keep the aluminum out of the bearings and screws.

As long as changes are being made; can I put in a request for "supported ways"?


Jackpot!

Maybe this is how Skynet starts...

What about UHMW? Is there too much flex in that material? Anyone know is 6061 aluminum is cheaper than UHMW?

Actually...is this new steel tube design still going to be modifiable to handle cutting of 4'x8' material like the previous design?

Well, we can work something out once the prices are finalized. You guys are the pioneers here so you're likely to see changes in pieces and prices over the next month. This is why I've discounted the kits now, because I appreciate your pioneering spirit and support of the project.


Yes, it won't even need "modification". You can certainly cut a 4x8 sheet out of the box if you don't require more than 50" of cut at one time. If you do, a kit you simply bolt on will provide a carriage for the sheet. The overhead design has allowed lots of new possibilities.

looking great! keep up the great work, I can't wait to see how it turns out. Reading this thread and others just has sucked me into the world of cnc. Thanks a lot

Sweet, thanks. Having a robot is an incredible experience...it is one of the enabling technologies that represents the "quickening" of our age. I'm really happy to be a part of the change!

HAH... i think you're right...


All the new mods look really promising, BC. Keep us posted!

Hey Guys,

This is my first post, so bear with me. I work in a machine shop making parts from alumium and steel. As Joe mentioned you can use a vacuum but usually you leave extra material with hold down holes that can be easily removed later.

Brain, do you have specs on the motors yet?

Welcome to the 'Lab!


Well, the three NEMA 34 motors are >400oz/in and the one Z NEMA 23 is >275oz/in. The motors are all wired biphasic, and two extra amps are given on the amp-drivers for torque-inductance variability.

So, great news!

Yet....

I really shouldn't be so obsessive-compulsive....

When I take my kid to the playground, I look for some way to do Google searches...

Riding the slide with N800 in-hand...w00 family values.

Anyway, the frame design has evolved and it is beautiful! No more pricey connectors, just a simple "bias-cut-3-way-tube-interface": which is not enough terms to explain much; it needs no welding, is simple to expand and understand (especially with a simple drawing, hint hint Robin).

Yeah, pretty sure that kills the salvaged printer motors I have.

Yea...In no way being pretentious, this is a different ballgame.

Man, i can't believe how much i can't wait until i can get my grubby paws on this thing.

Question: What is the cutting area (XYZ) of the ROGR JR? I don't see why not, but will the smaller one be able to be built the same new way of using the square tubing?

Also, being new to CNC - i'm having a little trouble with the tangibility of the whole thing in terms of what i should be buying, and how i'm actually supposed to know what to do with the items i purchase when i purchase them. So far there is a bearing kit (is this the same for the ROGR JR?). I know the framing stuff is supposed to be purchased separately to reduce shipping, but will there be some kind of schematics posted to tell how to actually build?

I know it's probably asking a lot, but without elaborating an unnecessary amount, my main question is: For the CNC newcomer, how would we know what to do and when to do it to achieve the end product?

If you tell me, look kid - you're in over your head... go learn and come back when you know what you're talking about. - that's fine. Just let me know!

Thanks so much... and don't burden yourself with posting anything that's going to wear you out, i'll understand. I'm just so excited to be a part of this - i'm a quick learner and i hope to contribute in my own way eventually.

(my main area of expertise is in Video/3D/Web/Graphic Design - if you ever need anything related to these - don't hesitate.)

In my view, just like they did with the original PJ, Brainchild and associates are essentially stripping down the cnc router to its essence. Everything is being done to make it easy to access for the average DIYer who has some ambition and some fundamental skills. So, I, being a newcomer to the world of cnc robotics myself, have every confidence that the upcoming plans and parts will be enough to get me going.

Tho, to be honest, I was around when Joe put together his first cnc machine and in following his progress, I could see for myself that it was something that I could replicate. And once you have the basic idea of how the machine and the assembly works, they are all rather similar. And in viewing Joe's subsequent builds and their increasing complexity, you start to appreciate the technical elegance of the RoGR. We will enter this world with a very high level of capacity and capability right from the start with what looks like a fairly low entry cost relative to that capability when you look at other commercial offerings (just like the original PJ in its time).

For me, the hardest part is gonna be learning how to use CAD software.

In any case, I'm chomping at the bit myself, as I am really eager to get this going. Hopefully the other parts come online soon, the design comes out of Beta and the build docs get posted for us all to immerse ourselves in. Yeah, this is gonna be just like my first pj build all over again!

So what is the big idea here BC?

The machine must move back and forth side to side and up and down. move in measured steps to follow plot points on a grid.
The issues are smooth bearings a flatish table and enough weight so when all the spinny things that are dancing around in motion don't lose a step or loose a bolt and the work piece stays put.

A big assed router is like an off weight gyro, forces torque every witch way etc .
How does your design address those variables??

Yeah, I think that covers me, too. The mechanics of building the machine is something that I know that I can do. Figuring out the CAD software so that the machine can do what I want... That's another matter.

@prospector: "those issues" are really nonissues. The router will put a torque load on the gantry, but gyroscopic effects aren't an issue, because the router will not be changing planes. (In a 4 axis setup, it might, but you just move it slowly and wait for it to settle, and it'll be fine.) Gyros don't impede motion in an X, Y or Z axis, what they impede is rotation along any axis that is not their own.

The trick with a CnC is to have repeatability and predictability. Input A produces result B. Far more important than gyroscopic effects is the more practical concern of moving a cuting bit through your material. This causes more torque and strain on the gantry than anything else, and the answer is the same. Make the gantry stiff enough to be able to take it without flexing. Make the motors strong enough to move it all.

Hi Dale. Now, I haven't yet finalized the name scheme, so I don't want to confuse anyone about which machine is which...I just kinda make it up as I go! Instead of a "JR" appellation...it may be better to simply to refer to the basic mid-sized machine as "RoGR". "JR" would be "micRo" and "SR" would be MACrO hehe...the only important thing here is that I intend to make the mid-size machine the "small shop standard" which is modularly compatible with the rest of RoBLOKS. Standard RoGR has a true cutting size of 26" x 50" without any additions. It is made in such a way that a full sheet of MDF or ply can be simply fed into the machine in 26" x 50" (or smaller) "chunks" while supported by the standard work-roller-feed supports. So long as the work piece can be moved and clamped under the ways, it is possible to do the same machine ops as a 4' x 8' (or larger) machine.


Quite simply, this thread will chronicle the building of a RogR that goes out of beta. It is a build-as-we-go process that will expose any flaws or weaknesses; as the design is forever changing -however; I wouldn't have started this thread unless the machine was a viable, usable entity worthy of building. The first design gets loads of use in our shop right now. The latest changes are very exciting to me though, because I sense the machine becoming nearly "perfect" , with the design becoming practically as simple as it can be, and the functionality very high.

After we reach this point (I'm thinking within two months), the information contained herein as well as our drawings etc will become a "guide", and several tutorials will be added as to the usage of the machine. (Interested in contributing to this open-source resource? Please PM me)

You seem like a very intelligent person...I can't believe you'd have any problems understanding this process. Any questions just ask, I'm passionate about the project and enjoy any challenges that present themselves! BTW, if you have a resumé, please submit it.

Heh, I'm glad you asked. Today I went to the local bottle-gas store which very conveniently sells steel tube, and they can order damn near everything they don't stock. The guys that work in this place are funny, knowledgeable and helpful.... plus they have fresh coffee all day long... I mean that stuff is important to me. After it was said and done, I spent $300 on all the tube and have enough surplus to begin the next build. I bought one 20' length of 3.5" 11g square steel tube; cut into 5 pieces (only four needed for upright supports). I bought three 20' lengths of 2.5" 11g square steel tube, which is cut in a convoluted matrix of lengths that needs a diagram to explain, but is probably most conservative with steel...

$300 is a lot, but the cuts are made, and it is some $90 cheaper than the best online metal slingers. I have a tendency to overbuild too, which serves me, but costs me too. I'm already shaking my head saying "this metal is big for this job". Going to 14g on the 2.5", and heck, going to 2" brace with 3" uprights can save a lot of $, but doesn't set you up well for the long term "expansion"....alas...nah...keep it big!

Now about this "gyro witch router problem" you mentioned, yikes that sounds scary....the RoGR steel frame is bolted together with 1/2" bolts in a "three way interlocking interface". You could easily set a bus down on this frame, probably 2 or 3 buses. It is phenomenally rigid: (No point in doing it twice.) From this context, that mid-sized router spindle looks puny, and I really doubt that even 40-50lbs force could be applied to the cutting bit without bogging the router or destroying the bit. That is practically insignificant compared to the rigitidy in the frame.

PS, Frame construction begins Weds night! I'm totally excited...

Lots of pics please!

Now about this "gyro witch router problem" I think the gyro witch gets really bitchy after a few too many trips to the cauldron.
Where are you sourcing the "three way interlocking interface". ????

My guess is that Brain is referring to a really simple but very strong joint shown in the image below (the two bottom corner joints). I could be wrong of course.

Okay Im lost is it being bolted together with nifty flanges or Drilling bolt holes Brain you are a genius man but my ADD mind is turning to mush trying to keep up with your Buildarama

I saw Square tubes and round tubes and flanges... in a cube shape with no cross braces..and then a skate board wing ding. Im with you too much is never enough?

How many wires on them nema motors 4 6 or 8?

more than likely the nema34 are 4 wire and the nema23 are 8 wire, all wired bi-polar and should be wired parallel which gives better performance. but will depend on your controllers amp rating.

But Brain can clarify.

Joe

The picture was an example of the type of joint. If you didn't get that, it might be best to wait until after Brain's Wednesday construction attempt to see what he's doing.

Good luck with the frame build BC. I too wish to see lots of pics!

yaK

Oh you know it....

I'm counting the hours.

Haha, I noticed a more amorous "witch" as it were, but hey, that's the whole witch thing...


Indeed. Thanks for noticing. This simple joint is the "rock of ages" for RoGR.


Buildarama is germius for sure. You are the greatest germius that has ever livered.


Thanks, it's exciting!

http://www.toshare.it/spime/ when are we gonna get this here?