Vulcan Modules
Analysis for where modules can be reused between Vulcan systems. A part that can serve many purposes makes a case for a higher investment.
Motors
Brushed
The purist in me doesn't like this idea, but the reality is they're cheap and fairly powerful and require much less complex drivers. The major drawback is the brushes wear out, but the target audience consists of the best candidates to fix such an isue
Brushless
A module that combines a brushless motor and driver will be extremely valuable in many places. If this is feasible, it will probably be worth including several of them in the final design.
Something in the range of 150KV.
However this also goes back to building the motors.
Can get one right in our target range intended for small vehicles (skateboard or bike)
- Motor $100
- ESC $100
This might be a winner. If the specs are accurate, I can get 4KW from a 2lb motor (plus an esc). And we can simply limit it's power when on 110V@15A. Lots of features we'll need; speed and power control, braking. I can put the power and esc electronics in a separate box with one cord so the motor can be used in hand tools.
I'm also starting to see the appeal of ODrive. The ESC is already $100, adding a bit more for precision control doesn't seem like a bad deal.
I do need to pay attention to the torque, even a high power motor may not have enough torque (particularly at low speeds).
- https://things-in-motion.blogspot.com/2018/12/how-to-estimate-torque-of-bldc-pmsm.html
- T = 8.3 * I / KV
Stepper
Also sort of bugs the purist because these compromise on both cost and power, but they're plentiful and provide great control.
I have a bit to learn, but the module should incorporate the stepper and a driver.
Induction
A 2.25 HP motor will use 15A@110V.
The module definition will include RPM under load. So for some motors, a gearbox may be required. The module should also be large enough to fit many different motors.
The idea is that for the larger machines, the motor can be moved quickly. So it should have handles that make it easy to carry, some key mechanism that makes it easy to seat in place and then a stronger locking mechanism to lock it down.
I think there should be a gear protruding from the module. This can seat inside something (like a pulley) or mesh with another gear. It means that the module can slide in horizontally without needing to attach belts or chains.
ICE
Preference for diesel, but it could also be gas, or we could do a base engine block and have it convert to either. This really doesn't need need to be built from the ground up, it should be designed for the most commonly available replacement parts. And it should really be parametric.
Control
Linear
Probably built off either the brushed or brushless motor, a standard linear drive will integrate into many cnc systems. It can also be helpful in systems that are not fully automated, for instance, positioning a stop on a miter saw.
PCBs
Vulcan PCB It may be possible to take multiple related circuits and merge them into one PCB. It's then feasible to make many prints of that one board.
For instance, I expect many of the low level electronics boards to be built around the ATMEGA328P TQFP. A design that makes it easy to add standard sensors and comms would allow for a single board to work in many different roles.
Handle
For many hand held devices, we will need a handle. It should have a trigger connected to a potentiometer, a thumbwheel connected to a rotary encoder and a 3 position switch. Either litium cells or AA battery clip.
There is a dedicated micro controller. When it boot it checks one bit to see if it should go into master or slave mode. In slave mode, it will listen as a I2C device and can run many programs. In master mode the switch chooses either the trigger or thumbwheel and the output varies based on that.
If the input voltage is zero, the output voltage comes from the internal supply. If a voltage is supplied, the handle only acts as a controller.
Case Studies
- Flash light
- circular saw
- drill
- hand vacuum
Gearbox
In different sizes (to fit the standard motor sizes) to manually switch gear ratios.
Casting/Templates
MDF
Useful for creating templates that can be followed with a router and molds for greensand.
For templates, we can create a dovetail or puzzle-piece lock for fillers or common shapes.
Steel
Only useful in the cases of the highest reproduction, but we can make a steel mold and then cast either aluminum or copper in it. Once the router is in place, this may be useful.
Hardware
Both easiest and most important. Choose standard sizes. I think it's worth using overkill sometimes to allow for reduced stock.
- threaded rod
- bolts/nuts/washers
- wood screws
- bearings
- hinges
Structural
Standardized part sizes to quickly assemble temporary machinery.
Rods
Based on the [D8. Angles are multiples of 45° lengths form two progressions;
- UL: Unit length
- An = 2n UL
- Bn = √2 * An
This will be color coded so all A units will be green and all B will be blue. Panels will adhere to this as well.
The primary shape is a "double C", like an I beam with a 2 T slots. The end will form a second T slot.
Construction. All connections with in the flange are face glued. The web to flange must be end glued. All connections are reinforced by drilling, tapping, countersink and bolt with a nut on the opposite end.
- A 4: 1 x 1 x L
- B 2: 5 x 1 x (L+4)
- C 1: 3 x 1 x L
- D 8: 1 x 1 x 1
- Each B, connect D in corners
- Each B, connect A along edges, with space of 1 to D
- Connect B:C:B
Connectors
- I: 3x3x4 can connect C in many square ways
- Half C: 3x3x5 smallest unit that contains a T slot, two bolt holes allow it to be connected
- 45° : Has T connector off hypotenuse and one side and threading to add half-C to the other
I'd like a way to tighten the I connectors, but it has to be done from the side, without making them too complicated or weakening them.
Holes
A standard size can be fitted with a
- bearing
- thread adapter
But larger holes will reduce strength and a beam with many holes will be significantly weakened.
Other
- Gears
- Wheels
- pulleys
Tool Holding
Primarily done with tapers and collets, but I'm not sure which standard to follow. These will be used to hold
- drill bits
- end mill
- router bits
- fly cutters
I think my preference is for something like an NMTB taper driven by dogs rather than something like a Morse Taper with a tang. If something goes wrong, it seems like this would be easier to fix. On the collets I'm not sure between something like ER (probably 32) and R8. The R8 is longer and that seems like it would be more stable, but if that's not useful it could be wasted. CAT40 ER32 is available for less than $40 with another $50 for a set of collets.
Sheet
Lots of constructions can be made from sheet metal.
- Materials to use
- Brake (vice?)
- Roller
- Press (3D printed forms)