Project: ‛Doozer’
🚨 This is an ongoing project, tool is not functional yet 🚨
The Doozer CNC Gantry is a custom built CNC tool platform, essentially a computer controlled robot that can use a variety of attached tools following computer instructions. Most commonly envisioned for use with an attached WEN 2347 Variable Speed Rotary Tool, to act as a 'desktop' scale CNC milling machine; the Doozer CNC has been designed with modular expandability in mind, allowing it to utilize a variety of cutting, marking, and other tools to create a work platform that can perform a fair number of computer controlled tasks. The Doozer CNC was designed and built by 👤 Karen Englebeck.
Project Objectives
Project Status
07/15/2020 - Latest!
Looking at the assembly process, it seems likely that I'll need to disassemble the Y axis assemblies at some point, in order to attach the gantry. I decided to work backwards and start by assembling the X-axis traveler and Z-axis carriage.
Drilled out the threads on the first four bearing blocks. (3 out of every 4 screw holes need to be drilled out to allow free-spinning of a long M4 bolt. The 4th hole in each remains un-drilled so that the original tapped threads can be used from the reverse side. Found a few places where the brackets needed to be modified. Original brackets were modeled on the mistaken belief that the bearing blocks used M3 screws.. rather than M4.
Unfortunately in working to assemble the components, it was discovered that the package of M4 T-nuts I had ordered, actually contained M3 T-nuts. (I have so many now!)
I placed an order on Amazon for M4 t-nuts, and for an assortment box of M4 bolts and M4 hex nuts (of which I had none!) Project returns to hold state until those parts can arrive. (Expected Delivery by 7/21)
Starting to realize how little structural assembly remains, and how close the project is to progressing to the electronics stage. Still, there is the Tool-mounting assembly, and the actual work-surface to be designed and implemented, but I am definitely getting close to the point where the mechanical portion of the machine will be completed, and it will be time to start figuring out how to make the thing move.😳
Development notes (this section is in flux)
- Error creating thumbnail: Unable to save thumbnail to destinationJUST WATCH THIS FIRST!!!!!!!!!
- Error creating thumbnail: Unable to save thumbnail to destinationHow to determine motor coil pair wires
- Error creating thumbnail: Unable to save thumbnail to destinationInstalling GRBL on the Arduino (WITHOUT CNC HAT!)
- Error creating thumbnail: Unable to save thumbnail to destinationTutorial Page for grblShield seeError creating thumbnail: Unable to save thumbnail to destinationthis video for more
- Error creating thumbnail: Unable to save thumbnail to destinationTuning and making the steppers turn! (using UGS)
- Error creating thumbnail: Unable to save thumbnail to destination
- Error creating thumbnail: Unable to save thumbnail to destination
Project Development History
07/15/2020 - Starting to look like something
Looking at the assembly process, it seems likely that I'll need to disassemble the Y axis assemblies at some point, in order to attach the gantry. I decided to work backwards and start by assembling the X-axis traveler and Z-axis carriage.
Drilled out the threads on the first four bearing blocks. (3 out of every 4 screw holes need to be drilled out to allow free-spinning of a long M4 bolt. The 4th hole in each remains un-drilled so that the original tapped threads can be used from the reverse side. Found a few places where the brackets needed to be modified. Original brackets were modeled on the mistaken belief that the bearing blocks used M3 screws.. rather than M4.
Unfortunately in working to assemble the components, it was discovered that the package of M4 T-nuts I had ordered, actually contained M3 T-nuts. (I have so many now!)
I placed an order on Amazon for M4 t-nuts, and for an assortment box of M4 bolts and M4 hex nuts (of which I had none!) Project returns to hold state until those parts can arrive. (Expected Delivery by 7/21)
Starting to realize how little structural assembly remains, and how close the project is to progressing to the electronics stage. Still, there is the Tool-mounting assembly, and the actual work-surface to be designed and implemented, but I am definitely getting close to the point where the mechanical portion of the machine will be completed, and it will be time to start figuring out how to make the thing move.😳
07/10/2020
I utilized the Harbor Freight compound mitre saw, with the installed wood-cutting blade, and experienced no issues with cutting through the aluminum extrusion. The only issues I encountered were due to missing clamps.
I attempted to assemble a few pieces utilizing the brackets I already had. The 3D printed PLA brackets worked like a charm, but the lasercut acrylic brackets shattered under the mechanical stress created by the V-slots in the aluminum extrusion.
A full 8 hours later, I had a mostly assembled Y-Axis (the left one). In the process of assembling it, I discovered that my design for the "T-Nut" holder brackets needed reworking. After a bit of redesign work later that evening, the files were sent off to Ben for printing. Within a couple of days, the new parts were dropped off.
While the amount of assembly work that lays ahead of me can be quite daunting, I can say that I'm excitedly looking forward to the next time I'm able to head down to the shop to work on this project!
In the meantime I've begun collecting video tutorials on the electronics portion of the project. While I'm not 'there' yet, I know it's looming on the horizon.
06/26/2020
Bits were ordered for milling new brackets using the shop's CNC. With the shop's lasers temporarily out of commission, this represented the only option for stronger brackets within my reach, without outsourcing. An attempt was made at milling a bracket out of aluminum using the shop's CNC. Unfortunately, the bit began slipping halfway through the job (my fault), and the job had to be halted. Having lost confidence in the idea, I cleaned up and unbolted the aluminum plate from the waste-board, effectively rendering that part unusable.
HDPE remains an option in the future, though COVID-19 has changed a lot of things.
Shipping from China has become intolerably slow. It was slow before, but it's a matter of months between ordering and receiving now. As thicker brackets will require longer screws, I will probably go forward with the brackets I have, and attempt to build a usable machine, then consider upgrading the brackets... even if it's just a matter of farming out 3D prints to those with larger printers. The laser cutters may again return to functionality, in which case, that's another option to consider.
The very very last of the ordered parts from AliExpress, however, have finally arrived. So all components are present now.
It is time to start plotting out the lengths of the aluminum extrusion segments that need to be cut.
01/31/2020
All 26 of the brackets that would fit on the 4.7"x4.7" bed of my 3D printer have now been printed. The shop's laser-cutter did indeed become operational, and with some uneven pacing, I have been able to now laser-cut 11 of the larger brackets out of 3mm acrylic sheet. This leaves 4 that Ben has offered to 3D print for me, and then 11 more brackets to be cut. I may undertake to get some more of these punched out over the weekend, or early next week.
AliExpress parts have been trickling in slowly. Chinese New Year has again ground much of the sellers' operations to a halt, and shipments which already take weeks, tend to take a few more weeks.
I'm not entirely confident in the resiliency of the brackets that I have thus far. I know that things will change when I add bolts and aluminum extrusion and other rigid components.. but I still have my concerns about the longterm viability. I do still hope to have aluminum replacement brackets.. either made by my machine, or on the shop's CNC machine(s), or by farming the job out.. but at ~50 brackets.. it's no small ask for anyone. Failing this, I am keeping the idea in mind of milling a full set of (albeit thicker) brackets using Polypropylene or HDPE/Polyethylene cutting-board material, which I know can be milled with the big CNC table at the shop. But that would be an added expense.
For now, it's mostly a waiting game. Waiting for nuts, screws, and washers.. as well as a few various and sundry bits and bobs that remain on order.
I am, however, getting undeniably close to the point where I'll have to start cutting aluminum.
01/16/2020
The next phase in this project, aside from waiting over a month for overpriced machine screws from China (and trust me, they were the cheapest I could find!) is to begin cutting out the brackets. Original plans were to 3D print a set of them first for putting the machine together for proving.. and honestly, that's still an option for a lot of them. I may start putting some of the odd-colored filaments at my house to work on the smaller, large quantity brackets. Other brackets I will either use the big CNC table at the shop to mill out of 'plex' (whatever scrap acrylic, plexiglas, or whatever I can find), or to ideally make use of a laser cutter.
Once the proving set of brackets is done, I can see if adjustments need to be made. I'll also be able to start trying to bring the machine to life.
Known elements still to be done:
- Tool Mounting Plate
- I have located a couple of aluminum chunks that may be able to be milled into a permanent mounting block for tools. This has been set aside for future use.
- Work Surface
- This will be made out of 2525 aluminum extrusion.. and while I have a fair amount, I don't have huge quantities. The final design of how this will work is still on-hold, pending some more practical forward progress. There is a possible future where this extrusion ideal is abandoned, and replaced with a couple sheets of MDF and some standard SAE threaded plywood anchors.
- Deflector Shields
- Simple angled plates for keeping sawdust from fouling the Y axis screws. Mountings for these will be designed once the Work Surface is sorted out.
01/05/2020
At the end of the day, it's all going to be made of metal, mostly aluminum extrusion with steel rods. While the machine will hopefully be capable of occasional milling of aluminum, the 'router' will still be a Dremel. The Doozer's more common use will be for milling materials that are much less resistant: Acrylic, ABS/PVC/Polystyrene Sheet, MDF, Pressboard, Veneer, and Balsa Wood.
01/03/2020
I had the opportunity to speak with Keith Legg on New Years Eve, in regards to machining some of the needed custom brackets for the linear rod , motor, and threaded rod bearing mounts. That part of the equation is a resounding GO.
This evening I re-inventoried my box of previously acquired components.. motors, rods, screws, and so on.. and I’m looking forward to returning to the design process with renewed enthusiasm. Looking forward to beginning finalizing the design, so I can finally begin BUILDING.
Soon, I hope!
09/20/2019
Email received from AliExpress. All components of the targeting laser assembly ( crosshair & dot lasers and USB power adapter ) are now in the hands of couriers in the USA.
Beata donated a 2-port USB power converter to the project after I'd ordered the single-USB version, so I may utilize the dual-port unit instead (one for each laser)
09/18/2019
All off-the-shelf structural components have been purchased, and have arrived. All components are measured and 3D modelled in SketchUp Make 2016. The 3 axis assemblies have been assembled in SketchUp.
Currently developing a modified 3D model of the tolerances of the aluminum extrusions, that model will help me easily create functional 3D-printed parts that fit properly.
Maximum workspace dimensions seem to be coming in at (305mm x 250mm x 180mm), which is approximately (12in x 11in x 7in). These are the maximum lengths that the linear rails and bearings can accommodate. I suspect these lengths will reduce somewhat as the actual gantry is designed.
What even is a ‛Doozer’?
The Doozers are a race of characters from Jim Henson's Fraggle Rock television series. Doozers love to work all day long. They're tiny, green creatures who usually sport construction helmets, boots, and tool belts. Doozers stand approximately knee-high to Fraggles, at six inches tall.
When compared to the other races within Fraggle Rock, they are by far the most technologically advanced. Most Doozers are construction workers, while others are architects or miners. With the help of various Doozer machines and vehicles, they build elaborate constructions all over Fraggle Rock, like towers, buildings, roads and bridges. Doozer constructions are the Fraggles' favorite snack, and they love to eat the buildings that the Doozers build. The Doozers don't mind their buildings being eaten -- if the Fraggles didn't eat the constructions, the Doozers would run out of building space!