1. Scope and provider
These terms of use apply to the use of the website maschinenbaurechner.de (the „website“) including all calculation tools provided there. The provider is Daniel Müller, Adalbert-Stifter-Straße 16, 84577 Tüßling, Germany (see legal notice). By using the website you agree to these terms.
2. Description of services
The website provides calculation tools for mechanical engineering that can be used free of charge in the browser. Individual additional functions (in particular the export of verification documents as PDF and of contour points as a data table for SolidWorks, Excel or CSV, hereinafter „pro functions“) are subject to a charge and are offered in three forms. A single purchase unlocks the pro functions of exactly one calculator against a one-off payment and without a limit on the number of exports; how long that unlock is guaranteed to be usable follows from the minimum operating period below. The monthly subscription unlocks them for all calculators except those with CAD export (Cam design and Spur gear geometry) for as long as it runs. The annual subscription unlocks them for all calculators, including those with CAD export, for as long as it runs. The verification documents of individual calculators are released free of charge; which ones these are is stated on the pricing page and at the calculator itself. The prices applicable at any given time are shown on the pricing page and in the checkout.
For the single purchase, the provider guarantees a minimum operating period (Mindestbetriebsdauer) of 36 months from the date of purchase. Within that period the unlocked pro functions of the purchased calculator are available without any limit on the number of uses, and the provider keeps the calculator operable by supplying the updates required to maintain conformity with the contract, including security updates. After the minimum operating period has elapsed, operation continues for as long as the provider operates the website. The verification documents, contour data and other export files generated with the pro functions remain with the customer without any time limit; using them does not require continued access to the website.
3. Purchases via Paddle
Chargeable pro functions are not sold by the provider itself but through the payment service Paddle acting as merchant of record (Paddle.com Market Limited, London, United Kingdom; for purchases from the USA Paddle.com Inc.). Your contractual partner for the purchase is Paddle; Paddle’s own terms and cancellation policy apply in addition and are shown during checkout. Refunds and withdrawals are handled by Paddle.
4. User account
Individual functions may require a user account. Sign-in works without a password via a link sent to the e-mail address you provide („magic link“). You are obliged to protect access to your mailbox; actions carried out through your account are attributed to you. The account is not transferable.
5. Calculation results and liability
The calculation tools and their results are produced with the greatest care on the basis of the standards, guidelines and accepted engineering rules named in each case, and are safeguarded by documented test cases. Nevertheless, errors cannot be ruled out. The results are neither individual consulting nor an engineering service; the underlying model assumptions and limits are stated in the tools and documents.
The results are design aids and guidance. They do not replace independent checking, calculation and release by a professionally qualified person, taking into account the specific application, the applicable versions of the standards and internal requirements. Responsibility for the use of the results, in particular for safety-relevant designs, lies solely with the user.
The provider is liable without limitation in cases of intent and gross negligence, for injury to life, body or health, and under the German Product Liability Act (Produkthaftungsgesetz). In the event of slightly negligent breach of material contractual obligations (obligations whose fulfilment makes the proper performance of the contract possible in the first place and on whose observance the user may regularly rely), liability is limited to the damage typical for this type of contract and foreseeable at the time of conclusion. Liability is otherwise excluded.
6. Availability
The provider endeavours to keep the website available without interruption as far as possible. There is no entitlement to constant availability; maintenance, further development or faults may lead to temporary restrictions. Statutory rights in the event of defective performance remain unaffected. This section concerns temporary interruptions during ongoing operation; the minimum operating period under section 2 and the provisions on discontinuation of operation under section 7 remain unaffected by it.
7. Discontinuation of operation
(1) Should the provider discontinue operation of the website or of an individual calculator, the provider will announce this in text form at least twelve months before the shutdown date. Customers holding a single purchase and subscribers will be notified at the e-mail address given at purchase; the discontinuation will additionally be announced on the website.
(2) From the announcement under paragraph 1 onwards, no new subscriptions are entered into and running subscriptions are no longer renewed. A subscription period running at the time of the announcement therefore ends at the latest one year later and in any case before the shutdown date; it is performed in full.
(3) If the minimum operating period of a single purchase under section 2 has not yet elapsed at the shutdown date, the provider will refund the share of the purchase price attributable to the remaining time. Refunds are handled via Paddle (section 3). The reports, contour data and other export files created with the Pro functions are not affected; they remain with the customer and can be used without access to the website.
(4) Further statutory rights of the customer, in particular the rights in respect of defects in digital products and the update obligation under sections 327 et seq. of the German Civil Code (BGB), remain unaffected. The provisions of this section apply in addition to those rights and do not restrict them.
8. Permitted use and copyright
The contents of the website (in particular texts, software, diagrams and design) are protected by copyright. The calculation results generated with the tools and the exported documents may be used for your own purposes, including professional ones. Not permitted are the reproduction or making publicly available of the website itself, systematic automated extraction of content (scraping), and interference with the technical infrastructure.
Use is furthermore excluded where it would breach sanctions or embargo rules of the European Union, the Federal Republic of Germany or the United Nations. This concerns in particular provision to the Russian government and to legal persons established in Russia, as well as to persons and entities in Belarus. Users warrant that they are not themselves subject to such a restriction and that they will not pass the results on to such destinations indirectly. The provider is entitled to block access where there are indications of a breach.
9. Changes to these terms
For a completed purchase and for a running subscription, the version of these terms of use published on the website at the time the contract was concluded applies. A change to that version only takes effect if the customer agrees to it; silence on the part of the customer or continued use of the website does not count as agreement. The provider may offer a change, for example in the case of new functions or a changed legal situation, and will communicate it in text form.
Every published version remains retrievable at its own permanent address, together with the prices and the scope of services that applied at the time. Which version applies to your purchase or your subscription is shown in your account.
For free use of the website without a purchase, the version published at the time of the respective use applies.
10. Final provisions
The law of the Federal Republic of Germany applies. Vis-à-vis consumers, this choice of law applies only to the extent that it does not deprive them of the protection of mandatory provisions of the law of their habitual residence (Art. 6 Rome I Regulation). Should individual provisions of these terms be invalid, the validity of the remaining provisions remains unaffected.
This English version is provided for ease of understanding. In the event of discrepancies, the German version of these terms of use prevails.
Version: 4 August 2026, English version 4 August 2026