Dear Forum members, We are pleased to announce a new Mechanical Design Forum prize draw! Courtesy of 3Dconnexion we’re giving away a SpaceMouse Pro – their NEWLY LAUNCHED product (RRP Â£249). Below is a pic of this fantastic prize. Please CLICK HERE for full details of how to win! Hot topics overspeed passed doesn't matter how many I overseen, I HATE over-speed tests ! I know it will be ok because my designs are not that close to the limit. but still I was as nervous as a kitten today as my rotor sat at 3600rpm for its two minutes - and too make my blood pressure higher, client witnessed test as well M3 tapped holes - minimum pitch? I'm designing a part with lots of M3 tapped holes. Basically it's an aluminium block 20mm thick with lots of M3 holes on one face. What's the minimum pitch between M3 holes? Is there a standard somewhere? I have 2 annoying holes that need to be super-close! maxon motor problem Hello friends! here is another problem i have to discuss. usually motors have 2,3 or four holes on front face to fasten them on their mounts. i have a maxon dc motor of dia 1mm which does not have holes to mount rather it has threads on its one step just coincident with shaft but having dia greater than its shaft. i have to mount the motor by fastening through its outer threads and inner threads on motor housing. will the motor loosen during working? how to avoid its loosening? Good Enginerring Drawing book for beginer I am a recent mechanical engineering graduate and currently working as a design engineer in a metal fabricating company. I would like to understand more about engineering drawings and am wondering if someone could recommend me a good engineering drawing book for a beginer like me. Cool How can I calculate force required to destroy of a iron hollow cylinder? How can I calculate force required to destroy of a iron hollow closed cylinder when we have internal exploding ? i want to calculate (Δx) and get the energy by Forced * (Δx) , so i should have strain. Use ultimate tensile or stress of Pr/t for calculating strain of destroying of explosion ? Unanswered questions The best mechanical/industrial drawing books ? Does anyone know about of some recent changes of drawing standards? New specifications, "amendments", regulations, etc.? For mechanical drawings. I am interested for metric ISO standard. In other words: which is the latest/the best manual...... Hyperstatic supported pipe The pipe is anchored at point A and simply supported at point C. The force FB represents the weight of the pipe and the force FD represents the half weight of a section of pipe (135'') continuing in Z...... Question small motor shaft i have come across a problem. please help me in this. i have purchased a maxon motor whose shaft diameter is 1mm and its shaft length is 2.9mm. i have to mount a pinion of face width 4.5mm on it. now if i use it in same situation the pinion will act as cantilever beam whether or not? what should be alternate safe solution? Drill string design questions??? For my graded unit I have chosen to do a drill string design, just out of random with no prior knowledge in this field. Reason being is the aim of the unit is to test and also teach us how to apply what we are learning to the real world. I therefore have to make up a specification list that I think my client would present to me and then complete it. MEMS resonators I am trying to model a mems resonator using comsol software, and the core of the resonator is a Piezoelectric rectangular plate clamped at the center on either sides (center of the length). For our resonator to work, this structure must vibrate in contour or in plane mode with little or no out of plane deformation. What are the conditions for this to happen?? Also, can anyone please tell me how to calculate the vibrational fundamental modes or eigenfrequency for this structure? Recent Articles Electronic (Transistorized) Ignition System by kareem mohamed NX PMI basic tutorial by Ivan Daft Punk helmet model tutorial by Ivan Thanks to all for their contributions to the Knowledge Base!