The project Maggie Muggs™ aims to create a mini-jet capable of flying. This project is spearheaded by Larry Cottrill, the designer and father of the creature we are about to tell you about. Cottrill is the founder of Cottrill Cyclodyne Corp. based in Iowa (USA), a company dedicated to designing low-cost engines for aviation.
Specifically, Maggie Muggs™ is a ramjet, i.e., a stratoreactor. Stratoreactors are a type of jet engine without turbines and compressors. The turbines work thanks to the high speed at which they operate. The operating process is simple, the air is injected into the combustion chamber already compressed, where it will be mixed with the fuel for burning and subsequent expansion through the exhaust nozzle. The outgoing jet carries very high velocities and is responsible for the thrust force it develops. We have divided the article into three parts, in addition to this one, we have the explanation of the assembly of the diffuser and combustion chamber and the final start-up.
It would be a dream for everyone to build one of these devices that would be able to propel a device through the air. Now it is no longer a dream, but a reality just by following the steps below.
But before I start with the practice I would like to make one thing clear. This engine is under development and its licence allows development and modification of the design for non-commercial purposes only. It can be built for educational purposes or as a hobby, but never for profit. You should also be aware that the commissioning of these reactors can be dangerous and you must take appropriate safety precautions, as flammable gases are handled. Cottrill makes it clear that any risks you may take during construction and testing are your own responsibility.
Materials needed for the support
- Titanium (or aluminium) tube to create the reactor support.
- Aluminium angle plates to make the base of the bracket.
- Strong metal glue (Nural type).
Note: All measurements are detailed in the following image.
Procedure for making the support
First we will start by creating the structure for the minijet support. To do this, we will follow the steps below:
- We need to create an N-shape structure with the titanium/aluminium tubes we have. To do this, we will cut the tubes with a metal saw, taking into account that the cut must be at an angle (we can use a cutting guide).
- Once the pieces have been cut, we can create a wooden structure like the one in the photo to hold the pieces in place while the glue dries, although this is not necessary. To do this, you can print out the measurement scheme above and draw the structure on a piece of paper and then place the wooden fasteners at strategic points to create the N-shape you are looking for. If you are careful, you can also draw the structure on a piece of paper and use it as a guide to place the cut pieces.
- Once they are in place, we will proceed to glue the pieces together. This type of glue usually comes in two tubes and has to be applied in two different ways. mixed in equal parts to make it workAlways make sure that the mixture is homogeneous. Once we have the mixture, with the help of a toothpick we can start to glue all the joints of the structure. By the way, sanding/scratching the areas where the glue joints will be made can help the adhesion of the glue, because if the metal is too smooth, the glue will not stick. the glue will hold worse.
- After waiting the time indicated by the glue manufacturer (usually 24h), we can continue with the next step. Now we can build a model with cardboard or use some kind of square or guide so that the two N-structures are at the required angle. Then proceed as in step 3, mixing the necessary glue and gluing the joints to join them to the aluminium brackets.
- When the glue has hardened, our finished structure should look like this:
Do not underestimate this part, even if it seems unimportant, support is essential. Remember that the engine generates a lot of thrust force and during the test it can be thrown out of control. It must be well anchored on something stable to avoid this, which is why the bracket is so important. In the following articles you will be able to follow the assembly of the combustion chamber and the start-up of the minijet engineDon't miss it.
More information - How to build an authentic homemade minijet engine. Part 2 (diffuser and combustion chamber), How to build an authentic homemade minijet engine. Part 3 (completion and commissioning)
Source - Cottrill Cyclodyne