Building winning wood constructions
HECO brand ambassador and expert carpenter Philipp Kaiser provides a step-by-step guide to how he created his silver medal-winning complex wood construction…
Schramberg manufacturer HECO-Schrauben announced a new brand ambassador earlier this year, 23-year-old Philipp Kaiser, from Rot an der Rot.
A winner of the silver medal at the Carpentry World Championships 2022, and also a runner-up European champion, Kaiser clearly knows a thing or two about working with wood as well as the properties of the HECO product he used to help him achieve his impressive result at the world championships.
Here, Heco-Schrauben’s Application Technician Dirk Drexlmaier asks the carpentry medal winner to explain more about complex wood constructions…
With this model, Philipp Kaiser won at the 2022 Carpentry World Championships.
Dirk Drexlmaier: Hi Philipp. Thank you for taking the time to answer a few questions. First of all, let us know exactly what a carpentry competition entails.
Philipp Kaiser: The European championship 2022 took place at the roofing and wood trade fair in Cologne. We contestants had a total of 22 hours, spread over three days, to construct a wooden model. The construction was very contorted and complex which is why the major challenges were the flawless implementation, time pressure and, above all, the accuracy of the fit. Points were deducted for dimensional deviations of anything from 0.5 mm. The HECO-TOPIX-plus screws which I used for the entire model, demonstrated their benefits in various areas, and helped me to overcome these challenges.
When constructing his model, the screws in which Philipp Kaiser placed his trust included the HECO-TOPIX-plus board screw which tightens firmly thanks to the MagicClose effect.
DD: Which benefits are those exactly?
PK: I'll happily show you on the model itself. Let's start at the bottom on the edge of the joist: This is where the three pieces of timber converge at a single point – you'll quickly see the contraction effect, or MagicClose, which the different thread pitches of the screws provide. Firstly, I countersank the head of the screw in advance. In general, this is not absolutely necessary, the same going for predrilling too, but if the wood has an unfavourable fibre orientation, there's always a chance of a little raggedness which would lead to a points deduction in competition. The screw begins to pull even before the head has reached the wood at all. That way, you can screw in the head nice and flush because the screw has already tightened with a good deal of force. It is common to countersink part-threaded screws a little deeper in order to achieve the desired contact pressure. With HECO-TOPIX-plus however, this is not necessary in this case.
DD: Let's have a look at the next detail then – the triangular notch…
PK: This is a particularly tricky area for two reasons: Firstly, I have to screw very close to the edge in this area – you usually predrill in such a case in order to prevent the risk of the wood chipping. However, with the HECO-TOPIX-plus screw, this step can be omitted because, thanks to the special tip geometry, it is even possible to screw very close to the edge unproblematically. That saves valuable time. Also, you would actually need the help of a second person for this detail in order to hold the pieces of timber in the correct position. However, in competition, you're on your own. In this regard, it is particularly practical that the HECO-TOPIX-plus screws, with the GripFit effect, adhere mechanically to the bit – as if they were magnetic – and you can thus screw one-handed. That way, you have your second hand free to hold the pieces of timber yourself, and you do not need to use your feet, for example. Of course, that makes you quicker, which is a major benefit, especially in competition.
DD: The next junction – the corner – is a real challenge: This is where a total of four pieces of timber converge at a very acute angle. How did you fasten this?
PK: In competition you are not allowed to glue anything; I had to screw everything in place. In such a case, it is a good idea to use concealed screws because it looks nicer. That's why I fastened the first two pieces of timber with a board screw as it can be countersunk easily and without a risk of splitting thanks to the small head. When it comes to part-threaded screws with a small head, you often have the problem that they hardly take hold. With HECO it's different: Thanks to the contraction effect of the thread, even the board screws tighten firmly. To fasten the other two pieces of timber, I then used a visible full-threaded screw. If you screw them in flush, the result is very clean.
DD: Finally, we're going to look at the ridge point…
PK: Here, on the ridge, the screw covers a large distance through the first tilted piece of timber. A normal countersunk screw would have to be countersunk very deep in order to generate the desired contact pressure. With the HECO-TOPIX-plus screw, thanks to the thread, it was no problem to screw it in flush over such a large distance and still pull everything together.