Notes, tips and tricks for assembling, maintaining and expanding a DB-01

Content:

  • Foreword
  • Before you buy or build a DB-01
    • What does it mean to own, build and/or maintain a DB-01?
    • Can you build a DB-01?
    • Can you print a DB-01?
      • The different aspects
        • Costs
        • Operation
        • Time
        • My opinion
  • General information about DB-01
    • Size of a DB-01
  • General information about working with electronic components
    • About Dupont connectors
  • General information about 3D-Printing
    • Hardware
  • Order of assembly
    • DB-01V001 in basic configuration
      • Inner platform
      • Outer ring
      • Suspension
      • Legs
    • Electronic circuits
    • Let’s talk about … legs
      • The basic structure
      • The motors

Foreword

A warm greeting and thank you for your interest in the DB-01. As designer of the DB-01, I don’t just have to think about how I can make the DB-01 easily accessible to you. In addition to my will to give you the best of my performance, I particularly enjoy it.

Just as it was and is a pleasure for me to plan the DB-01 and to go the long way of development (and also to carry out further developments), you should also enjoy the time with your DB-01.

So that you have the greatest possible pleasure, I would like to give you the necessary knowledge, but also helpful tips & tricks and options on how to assemble and handle your DB-01. You can see them as a useful part of your DB-01 manual. For sure: if you can imagine the DB-01 spatially, it will always help you, save time and avoid mistakes.

This website is constantly being expanded and updated. If you have any questions, suggestions or constructive criticism, I look forward to hearing from you!

Before you buy or build a DB-01

What does it mean to own, build and/or maintain a DB-01?

For me, a DB-01 primarily means fun and joy in technology. The feeling of being able to, but ultimately also a huge portion of pride in having created the DB-01 and now contributing to the sharing economy.

But it is not a question of plugging the DB-01 with all possible technical plugs, in the sense of “I can do it”. The focus is on the respective areas of responsibility of a DB-01. The DB-01 can be modularly equipped accordingly.

Can you build a DB-01?

Even though I designed the DB-01 so that you can build it as easily as possible, it is still a complex piece of technology. But should I tell you something?

The DB-01 is undoubtedly a great achievement. From the first sketches, through the construction, to the programming of it. I, the designer of the DB-01, did not study. I have no job in the electronics or robotics industry. Sure, I can program, master 3D design and have the entrepreneurial bite to carry out such a project. But basically I’m just someone. But I had and still have a will.

If you have the will to build a DB-01 yourself, even if only in parts, then I will certainly assist you as best as I can.

Do you know what’s great too? You don’t have to build and master everything in one day. This website I offer you good step-by-step instructions on how to create your DB-01. The level of difficulty gradually increases. You will also always have to do a few different things in each phase. Print or order a few parts, read up on a topic, assemble something … And precisely because a DB-01 is not assembled in one day, you will always have varied jobs that you can easily change if you happen to be somewhere stop moving or need a break from an activity.

To see your DB-01 grow gradually, to understand and integrate the individual components, to be one step further towards the great result – a great feeling! You will surely enjoy it.

But…

Of course, you need to be aware that in addition to the cost of a DB-01, you need some time, you shouldn’t throw everything in the corner immediately, and you should sometimes be sensitive or patient.

Don’t work on the DB-01 in a hurry! Errors will creep in, and finding and fixing them will take your time and nerves. Be relaxed and enjoy the time with your DB-01.

Regardless of whether you build the DB-01 in whole or in part: you will probably deal with a lot of new things, learn a lot and in the end you will probably not be the same person. Not just discovering the many possibilities on a small scale and possibly in completely different areas of application.

We live in the 21st century with all of its exciting opportunities. When you’ve built the DB-01, you’ll know and feel “Yes, we can. I can.” This is the 21st century.

Can you print a DB-01?

The DB-01 is designed so that its components can be printed in terms of size with most / common 3D printers. Technically speaking, you can. But this answer is very theoretical. I would like to show you what it means when you buy a 3D printer and print the required parts yourself.

The different aspects

Costs

If you want to print the parts you need yourself and don’t have a 3D printer yet, the first step is to invest in a good printer. Acceptable 3D printers are now available for around 300 to 500 euros / dollars.

If you were to order the required parts for a DB-01 from a service provider, you would probably already be at the same amount.

With your own printer, the actual production costs are negligible. Good filament costs less than 30 euros / dollar per kilo. In the overview list of the print data you will also find the weights of the individual parts. For the DB-001V001 basic model you need 3 coils, each 1 kilo. (See section “DB-01V001 in basic configuration”.) So calculate 100 euros / dollars for the filament.

With around 330 hours (almost 14 days) of printing time and 270 watts of power consumption by the printer (my Ender 3) and an assumed price of 0.30 euros per kWh, the printer’s power consumption for printing costs around 27 euros.

In addition, there are costs for maintenance and repair material. If time also means money for you, you should calculate your time for operation, maintenance, etc.

Either way: 3D printing doesn’t cost huge sums of money, but it doesn’t fall from the sky for free.

Operation

Not only do you have to have (or be able to use) a 3D printer, you also have to operate it. A 3D printer is (more or less) a complex machine. In any case, a precision machine. So you will have to operate and maintain them expertly. In addition, there is the interaction with the filament to be printed. This shows whether you wanted to save on the printer or on the filament. A decent printer with a correct heating bed and auto-leveling costs more. Poor quality or uneven filament brings frustration and clogged nozzles.

If all else fails, there are a lot of good help pages with the most common errors in 3D printing.

Time

Time comparison for 3 different approaches:

Option 1: Download the print data and send it to a service provider (and then wait days or weeks during production and shipping).

Option2: Go to the shop here, select all modules and parts easy (and then possibly also wait days or weeks during production and shipping).

Option 3: Download print data, slice it once, save everything on an SD card and put it into the printer. Then your printer can work. So you don’t only have the time to clean the printer, prepare print data, monitor prints and, at the end of the day, do some post-processing. Likewise, the time the printer needs. But you have to note: of course a printer could move super fast, according to the manufacturer. The sensible speed for printing looks very different. The time information in the overview table of the print data gives you an approximate indication of how long a part needs to be printed.

And of course you can also shoot several 14-hour prints without taking a break for the printer. But does the printer like it that much? Additional heat sinks have their right to exist! With such technical things it is like this: of course you can push something at the limit to the shortened end. But you don’t have to. A little sensible approach often helps. (Oh yes, this variant also takes a few weeks rather than a few hours.)

My opinion

Handling a 3D printer doesn’t always go smoothly. Sometimes it costs nerves. You will also have to invest some time in the topic. And of course, 3D printing costs.

Not just initial investment costs, but you also have ongoing costs. If you work with your printer and don’t modify or improve it, then you are one of the few. But it can be a valuable investment. And in the end, when you have learned to use your printer and you use it actively, then it is probably a great tool that can enrich your life in a pleasant way.

General information about the DB-01

To build a DB-01 completely, you have to install more than 1000 screws. All in the range from M2 to M5, starting at 8 mm in length, up to 400 millimeters. To print all necesary parts, you will need several weeks. Even if you print 24/7. That means, to assemble (and print) a DB-01, you also need some tools, a steady hand and some time.

You can of course download the firmware, the individual components of the operating system (Arduino Sketches), connect all components and it is good to go. But if you want to become a professional user with all knowledge of all components (or part of them) and their possibilities (which is not necessary), then you have to read in for it.

For example: the firmware I offer lets you use the voice control component with a few common commands, “plug and play”. If you want to edit the commands, this is not difficult. But you have to switch on the code editor and yes, “program”. Or you are looking for someone to make your adjustments.

The size of a DB-01

The DB-01 is not a small robot. Folded in its spherical shape, its diameter is around 1 meter. I do not know in which palace you live, but so far I have not found a movement pattern that would let him go through common doors from common interiors. Interiors are such a topic anyway …

If the legs are extended, the DB-01 needs a diameter of around 2 meters. Yes, and the first step doesn’t magically reduce it.

(Yes, I already have digital models, according to which the legs or the cover can be folded in such a way that the DB-01 can at least be carried assembled through a common door.) But what I want to make clear to you: the DB-01 is not a small robot.

General information about working with electronic components

About Dupont connectors

Pupont plugs are not perfect plug connections. However, many hardware components use this. So also different MCUs or motor cables.

Dupont plugs are not only not waterproof. They can wobble and create a bad connection.

However, this can be prevented by observing a few things.

  • Never use individual plugs, but plug strips. This gives a tight fit.
  • If necessary, fix plug connections with shrink tubing, which completely envelops the connector package.

General information about 3D printing

Hardware

Before you start printing your DB-01, you should set your printer correctly. You should not only do this before the first print, but also check it from time to time. Remember: the drive belts can “wear out” over time and have to be retightened. Loose drive belts can lead to unwanted results in printing.

Place your printer in a final location on a stable and heavy table. If your printer doesn’t have a housing, avoid drafts and consider fluctuations in room temperature.

If your printer is in the final position, align it straight with a spirit level. Start with the frame and adjust the feet, check the frame linkage for warping. You may have to readjust the screws so that you release tension from the frame.

If all of this fits, level the printer bed.

Now you need to adjust the distance from the printer nozzle to the printer bed.

You should now print a calibration cube and compare the dimensions between theory and practice with a caliper. In practice, your 20 mm cube may only have 18 or 19 millimeters. You have to save the values ​​of the assumed and actual height in your printer. Your printer will adapt accordingly.

When you’ve done that, print a new calibration cube, compare the results, and see if your printer behaves properly and as expected.

If you did everything correctly, you now have properly set up printer hardware.

Order of assembly

DB-01 has a modular structure in many areas. Whether on a large or small scale.

If you want to build a DB-01, you are probably wondering where to start with which components. I recommend that you first build a DB01 (V001) in its basic configuration – without additional modules. Once you’ve assembled it and it’s running, you can still expand it with additional modules and functions. This procedure will also help you as a DB-01 newcomer to maintain an overview, not to get bogged down and really get to know (and use) your DB-01.

But regardless of whether you “only” build the basic configuration first, you will probably always have enough things that you can do in parallel or to continue working elsewhere. A DB-01 does not have to be built through from point A to point Z. Rather, there are several sub-steps associated with a wide variety of activities.

While the 3D printer is printing its 10-hour components, you could, for example, crimp cables, create connectors, cut threaded rods, assemble something, calibrate motors, adapt source code, create new 3D models …

Think about: I would like to give you a recommendation. If you have to crimp 140 cables on both sides, you could measure a single cable 140 times, pull out the box with the plugs 280 times, grab the pliers 560 times … or you could concentrate and coordinate processes. This is guaranteed to save you hundreds, even thousands, of unnecessary and time-consuming hand movements.

DB-01V001 in basic configuration

You may have already seen the long overview list of all print data. Or the explanation of the print data. Don’t worry: you don’t need all parts for a DB-01V001 in basic configuration. However, it may be helpful to have a look at the explanation of the print data before you print the relevant part.

Look at the table for the needed parts. Fast in mental arithmetic? 330 hours and 40 minutes printing time. So if you operate your printer for (almost) 14 days, 24/7 and replace the parts like a ninja, then 2 weeks vacation is enough to print all parts for the basic version. Everyone else will gradually print the parts as needed.

The weight, only of the printed parts, will – in this configuration – theoretically be a little less than 2218 grams.

Print large parts first

Print large parts first when the filament spool is full enough. When the spool is almost empty, you can weigh the remaining filament or measure the length and print smaller parts to match the remaining amount. This way you can make optimal use of the material on a spool. I know how annoying it can be to wait for the 3D printer when you first print large parts … You can of course insert a part that you currently need. As soon as you have understood the structure of the DB-01, you will know for yourself when you need which part.

Things you need to build a DB-01V001
For the inner platform:
1 x db01v001p002v002= 7:50 hours, 60 grams
4 x db01v001p003v001= 0:04 hours, 4 grams
16 x db01v001p004v002= 7:44 hours, 24 grams
8 x M5x150 pan head screws
8 x M5 nuts
24 x M5 washers
For the outer ring:
8 x db01v001p005v002= 32:30 hours, 270 grams
12 x db01v001p006v002= 8:48 hours, 54 grams
16 x db01v001p010v002= 6:30 hours, 42 grams
16 x db01v001p011v001= 0:18 hours, 6 grams
For six legs:
6 x db01v001p017v004= 19:12 hours, 132 grams
6 x db01v001p018v004= 16:56 hours, 126 grams
6 x db01v001p019v004= 43:18 hours, 288 grams
6 x db01v001p020v002= 18:54 hours, 138 grams
6 x db01v001p023v002= 60:18 hours, 402 grams
6 x db01v001p024v003= 108:18 hours, 672 grams
42 x M2x6 pan head self tapping screws
42 x M2x8 pan head self tapping screws
18 x M5x170 threaded rods
18 x M5x240 threaded rods
72 x M5 self locking nuts
72 x M5 washers
Electronic components:
1 x Arduino MEGA2560 R3
1 x NRF24L01 + PA + LNA
1 x NRF24L01 RF
18 x LDX-218
1 x XL4016
3 x PCB005-2-EU
1 x Capacitator 4.7 uf
Cables & stuff:Use silicone cables!
18 x 350mm 24AWG (2 red, 2 orange, 2brown, 2 blue, 2 green, 2, yello, 2 white, 2 grey, 2 violet)Dupont male to Dupont male
6 x 300mm 24AWG blackDupont male to Dupont female
6 x 300mm 24AWG redDupont male to Dupont female
18 x 350mm 24AWG blackDupont male to ferrule
18 x 350mm 24AWG redDupont male to ferrule
30 x Dupont 3 pin connector
2 x Dupont 8 pin connector
2 x Dupont 10 pin connector

If you look at the physical structure of a DB-01, you can divide it into 3 areas. The inner area, the outer ring and the legs.

The inner stuff

Here you have the middle plates on which the electronic components sit. These plates (for example db01v001p002v002) can be positioned flexibly in terms of height and can also be stacked. For this purpose, appropriate spacers (for example db01v001p004v002), which cover the 8 screw connections of the plates, are printed.

This firmly screwed inner part is fastened to the outer ring with springs and is therefore protected against impact.

The outer ring

The outer ring consists of several sub-elements that are screwed together. The recesses to accommodate motors are clearly visible.

The motors are already the first part of a leg. The suspension of the first motor – and thus of the whole leg – can be solved in different ways. I haven’t found the perfect ideal path myself yet. Yet! I would like to show you different possibilities.

Suspension

Inner platform, outer ring and each individual leg are shock-absorbing with springs.

The inner platform is stored with 16 springs in order to avoid impacts on the electronic components.

The suspension of the legs results from necessity. This ensures that the legs always rest on the ground, regardless of unevenness.

For testing purposes only, I also have a completely stiff, printed engine mount (db01v001p026). But even on perfectly smooth floors, I prefer a sprung suspension.

How many springs you attach to a leg to make the suspension stiffer is up to you, but must be adapted to the weight of the legs and the terrain. I use 14 springs per leg. This makes all in all 84 springs for the legs. The weight of the platform can also become noticeable in further expansion stages. Additional batteries in particular can quickly increase the weight. The suspension of the inner platform may then have to be modified – but don’t worry about that for now.

For example, if your DB-01 is used in a level hall, I would prefer a stiffer suspension. For big jumps in the terrain or stairs, I would choose a softer suspension to make the legs more flexible.

Legs

In order to produce and integrate the legs, a number of different steps are necessary.

Starting with printing. I rotated the 3D files specifically. Do not change the alignment in your slice program. On the contrary: it is better to always check it – you will discover the system behind it. This saves supports or compensates for misalignment when printing in height.

Then you have to align and assemble the motors. I have corresponding Arduino sketches.

But that also means that you should have set up your 7.4V power supply somehow. Whether stationary or mobile with batteries.

Cut the threaded rods, screw all parts together correctly, fix errors ;-). DB-01V001 is even easier to use than V002. But you can easily upgrade to the larger version later.

Screw the legs together

It’s probably hard to imagine if you don’t have relevant parts in front of you. As soon as you have the parts in front of you, you will be able to screw everything together correctly with the help of my instructions.

I assume that you have all the printed parts, screws, nuts, washers, all motors and all motor brackets in front of you. You should also be aware of which version of the leg suspension you want to build. The associated construction steps and assistance can be found in the corresponding chapter.

1.) Mount motor 1 between these two p006v. Use M3 x 50 screws, washers and lelf-locking nuts.

2.) Align motor 1 via a sketch (or a special test station) in the middle if you haven’t done.

3.) Fasten the two servo disks to the motor 1. Find / choose a position of the upper disk on the drive mandrel, in which the retaining bracket and the following parts would be as centrally aligned as possible.

4.) This first motor now can be attached to the outer ring of the DB-01. (How to attach the first motor can be found in the corresponding chapter “Suspension”.)

5.) Screw a large and a small motor bracket together. Use the screws supplied with the servo for this. Liquid threadlocker is recommended here. I prefer the nuts of the screw connection towards the inside of the robot. This allows you to be visually inspected better.

6.) Attach motor 2 in the small motor bracket of this construction with 7 M2x6 pan head self tapping screws.

7.) Push a large motor bracket into p017v004.

8.) Push a small motor bracket into p018v004.

9.) Cut 3 M5 threaded rods 17 centimeters long.

10.) Connect p017, p023 and p018 by screwing them together with the 3 threaded rods. Do this with washers and self-locking nuts. Make sure that everything is correctly seated and that you tighten the nuts evenly.

11.) Mount motor 3 in the (small) bracket of p018 with 7 M2x8 pan head self tapping screws.

12.) Assemble the servo discs of motor 3.

13.) Press a large motor bracket in p019.

14.) Press a small motor bracket in p020.

15.) Cut 3 M5 threaded rods to a length of 24cm.

16.) Connect p019, p024 and p020 using the 3 threaded rods. Use washers and self-locking nuts. Make sure that everything is correctly seated and that you tighten the nuts evenly.

Electronic circuits

You don’t have to, but it’s a good idea to experimentally build the circuit before you put all of the components in your robot.

Personally, I even (or of course) have 2 assemblies. One to experiment on the workbench and of course one in the DB-01. Experiments are carried out on the workbench. What turns out to be good here is implemented in the robot and further tested there.

Advantages:
Your DB-01 is not inactive just because you are working on the software.

Disadvantage:
Costs for duplicate hardware and an appropriately set up work area on your workbench.

Let´s talk about … Legs. | Legs or Arms?

Before you build your legs together, you should do a good job of understanding the structure.

Arm? Leg? Hand? Foot? Well, somehow the DB-01 runs a lot. The temptation is obvious to call it “leg and foot”. But DB-01 also acts a lot … with feet? So when I imagine the “leg” movement of a DB-01, I can better describe and represent it in space with an arm.

The basic structure

A DB-01 has 6 legs / arms. 3 on the right side and 3 on the left side. Each leg consists of 3 segments and a “foot”.

The foot is a complex thing, but we shouldn’t be interested here. First of all, we are talking about this long construction, starting with the attachment to the outer ring of the DB-01, right up to the foot.

Each of these 3 segments consists of 3 parts (first end cap, leg cover, second end cap). The end caps are the connection points to the motors and serve as fastening for the 3 internal threaded rods each. The leg covers p024, p024 and p025 serve as a distance between the end caps, for stabilization and to protect internal components.

Although the DB-01 is octagonal, there is a clear alignment for the front, back, left and right.

If you have already hung center plates (p001, p002, …) into the outer ring (built from 8 p005 and a few parts more), then you will always see the orientation of the robot clearly. You need to keep your legs and motors aligned. Note the left and right sides and how they are aligned accordingly. The LDX-218 and LDX-227 have two axles, but only one is driven and made of metal. This axis must always look forwards / upwards. If you remember that, that’s half the battle.

The metal mounting brackets on the motors must correspond to the motor orientation in the respective receptacles on part p017 – p022. If you push the brackets the wrong way into the receptacles, you have to fiddly remove them again. The metal brackets should, once pushed in, sit pretty tight.

Then you get the printed parts in the right order.

The motors

A major difference between DB-01V001 and DB-01V002 is the number of motors used in the legs.

V001 uses a total of 18 engines: 6 LDX-227 and 12 LDX-218.

V002 uses a total of 42 engines: 6 LDX-227, 30 LDX-218 and 6 Nema 23.

Adjust the servomotors before installing and screwing them in

Take a look at my code snippets. You will also find sketches to adjust your servo motors.