All about glue

The degree of rigidity and stability that can be obtained with a glued construction is significantly higher than can be obtained with screws. The assembly is as strong as if it were made from a single piece of material. All joints must be left to dry for at least 24 hours to ensure a rigid construction. Assembly proceeds in two stages gluing and then screwing, and should therefore take at least two days. 'Gluing' is not really the correct term here it would be nearer the mark to say that the...

Part New solutions to old problems

Elektor Electronics is proud to present an unprecedented home construction project a CNC PCB drilling machine which is economical, accurate, quick, and bristling with new ideas. Large-scale electromechanical projects have tended to be the exception rather than the rule in Elektor Electronics but these exceptions have always been well received. Many readers will have fond memories of the Plotter and Plotter Mark 2 projects, which hundreds of constructors across Europe have built and which even...

Table Drilling command

0 T T T 1 1 B B B B B D D D D D Addressing bit 7, byte 1 '0' bits 2 and 3, byte 1 '11'. T (3 bits) 'Target' These three bits select the output stage for the drilling command. The machine can be fitted with up to four arms, and each of these arms has its own drill and a dedicated driver stage on the controller board. The targets are numbered from left to right, starting with Target 1 ('000') at connector K10, where the solenoid for the first arm is connected. The corresponding drill motor is...

Step Fitting the mechanical parts to

Take the pack containing the four cone bearings and the two packs labelled 'Mechanik 1' and 'Mechanik 2' out of the packaging. These comprise a complete set of mechanical parts for one axle (Figure 5). The cone bearings consist of two separate parts, an outer race and an interior part with the rollers. The bearings are rather oily this oil should be cleaned away except on the race and on the inner part, so that only the moving parts are lubricated. Push two of the races into the holes in the...

Boring Story

Next, holes are bored in the circuit board using drills of various diameters. In general, three drills are used the commonest is 0.7 mm or 0.8 mm, used for almost all small components such as resistors, capacitors, ICs it is even suitable for the leads of some electrolytic capacitors. A 0.9 mm or 1 mm drill is used for most connectors, square pins and the larger diodes. Larger connectors, solder pins and similar components require a 1.2 mm or 1.5 mm drill. Usually a mini-drill is used in a...

The strobeedge trick

How can the controller know which of the bytes is the first and which the second Counting is one option, but not a very reliable one a single transmission error and all successive commands will be wrongly interpreted. The error must be detected and the controller reset. Alternatively, the data bytes could include further information to allow the controller to identify which is which. However, this also has its disadvantages. The marker bits naturally reduce the amount of real information...

PCB drilling machine

After discussions with several readers during the HobbyTronic Fair in Dortmund, Germany, and several e-mail enquiries and telephone calls, we have decided to describe briefly once more the operation of the PCB drilling machine, along with its advantages and capabilities. Basic features of the PCB drilling machine Our project is a CNC machine which carries out operating commands calculated with the help of a computer. Conventional CNC machines are constructed using linear components, such as...

The drive system how it works

Drilling Machine Drive Unit

When we started looking for a simple design for the drive system to give precisely the high gearing ratio required for our machine, we were met by shaking heads the experts told us that high ratios could only be obtained by using multiple separate stages, each with a small ratio, multiplying together to give the total desired. Using an ordinary planetary drive a practically-realisable gearing stage with a ratio of up to about 7 1 can be built. This is due to the fact that multiple spur wheels...

The first test

The TanBoDrive driver software requires that the drilling machine be fully functional, both electrically and mechanically. The input data in this case drilling data in Excellon format are specially processed and transformed into the required commands, in the form of motion commands and drilling commands, to be sent to the microcontroller. More than this TanBoDrive cannot do. Linear interpolation, as required for interpreting HPGL-format files, is included otherwise the machine could not even...

Drilling Machine

M ller Radix GmbH www.radixgmbh.de In this final part on the construction of the PCB drilling machine, all its functions are tested and the machine is calibrated. The machine is then ready for its first job. By the time you read this, the first PCB drilling machines have already been delivered and perhaps also assembled. It is therefore high time that our description of the machine be completed. All that remains is the calibration of the machine. The machine must be calibrated...

Part PCB construction

Pcb Construction

M ller Radix GmbH www.radixqmbh.de The controller board contains all the electronics for the plate motor and four drill arms. As a matter of course, the board population is in accordance with the actual number of drill arms you have in use. All the components of the circuit can be built onto a single-sided printed circuit board. The PCB and component layout are shown in Figure 1. The power supply as far as the transformers is also built onto the circuit board it provides a 30 V...

Cartesian coordinates a heresy

Drilling Machine Mechanism

Has anyone every seriously wondered why CNC machines always work using the Cartesian coordinate system Why are X-, Y- and Z-axes always used Why, when such machines are so difficult to build The linear guides must be absolutely parallel, because otherwise the carriage will jam. The axes must be at exactly 90 degrees to one another, or else everything goes askew. The table must be absolutely true and the whole machine must be solidly fixed to a base. These are all disadvantages. But the greatest...

Part The controller

Pcb Cnc Circuit Board Drilling Machine

Muller Radix GmbH www.radixqmbh.de Our PCB drilling machine provides a link between a Windows PC and the motors and solenoids of the machine itself a microcontroller integrated with a high current drive circuit. In the previous instalment March 2001 we described in detail the basic principles of the CNC drilling machine. The controller is just as unconventional the machine is not driven directly from a PC, but indirectly via a special controller circuit. For trouble-free...