Hi Spot - They are the same order of magnitude and I'd have to understand how you restrained the model and loaded the model, meshed and connected the models to figure out the difference. 2.631/3.11=...
Type: Posts; User: peteeng
Hi Spot - They are the same order of magnitude and I'd have to understand how you restrained the model and loaded the model, meshed and connected the models to figure out the difference. 2.631/3.11=...
Well since you won't tell me what systems you are using I can't help. A triangle is a triangle whether its equilateral or not. There are various systems to optimise shapes. Its not the FE that's the...
Hi Spot - What is your tool chain? CAD? - FE? - all of the issues you describe are sorted by the good CAD and Fe suppliers. If your using beam elements then its very easy. The difficulty is only in...
Hi Sus - Its not about "mass" - its about geometry. Machine parts are generally in bending so its bending stiffness you need. This is a function of its geometric inertia. So maximising every parts...
Hi Spot - Its your connections that are driving the solution time up not the mesh. If the mesh was contiguous it would solve in seconds. Plus with a space frame such as you have there is no value in...
Hi all - Been on a small trip to a machine expo and have had time to sort the 5 axis router I'm working on. I tried two ways to make it smaller and failed. Seems the 80mm spindle drives a lot of the...
Hi Spot - Make the same external shape in a suitable wall thickness plate that results in the same weight as the space frame and see if its the same stiffness... I was at a machinery exhibit today...
Hello Kadkam - Converting an arbitrary NURBS curve to "lines" and "arcs" is a bit tricky : 1) there will be no actual arcs in the nurb 2) a nurb is rubbery polynomial entity that depends on its...
Hi All- I think Milli will need a chip compactor as well. Peter
https://youtu.be/5z0YCTkhhss
Hi Craig - Its only for the Z axis which is a 550mm long screw so 16mm is fine. Peter
Hi Rod - I don't think 30mm is too big for a 2.6x1.8m bed machine. Initially it was only for the Z axis rails, but by the time you add spacers (which I dislike, extra things means extra compliance)...
Hi All - I have been looking at the stack height of rail and cars vs ballscrews and std nut housings. Only one is equal which is using a 30mm rail/car and a16mm ballscrew. The next build will use...
Hi Max - Good video - consider it practice for when you cast your next machine! :) Use lots of wax on the mould... Peter
Hi Max - You seem to be fixated on a slab for some reason. Buy damped machine feet and that's money well spent. This slab/plinth thing is going in the wrong direction? If its a test case for machine...
Hi TKMS _ Ops thks for the correction. Peter
Hi - I agree a timber plinth is all that's needed. Audiophiles place their turntables on timber plinths and they swear by it. Peter
https://youtu.be/ENkpMNQW0Uo
Hi Max - If you have a steel frame inside the slab you have neutered the whole idea of using the slab as a damper. The load will stay in the steel as steel is 200GPa and your grout is 30GPa. So you...
Hi Craig -There are 3 Scoots in the wild. Scoot is production ready. How many would you like? I'd like to sell 1 every month that would give me confidence to start moulding/casting parts vs...
Hi Nord - In one thread I've done extensive vibration analysis on construction extrusions. What came out is this:
1) Hollow sections suffer from acoustic noises as they are organ pipes. These noises...
Hi Max - Be careful using traditional steel reinforcement. I would not use steel in it at all... If it is connected to the frame in such a way that it is in the loadpath then you defeat the purpose...
Hi TKMS - sorry you're using a compression bit which means the chip is being pushed down the hole so the chip thickness has to be small to stop the bit from choking. So a 1/8" tool from amana says...
Hi Max - Re reading your #1 I think you are conceptualising "vibration absorption" incorrectly. If you want to "absorb" vibrations at the contact between the machine and its base then you need to use...
Hi Nordic - Expanding PU foam from the hardware will do the same thing, easier and cheaper.... Peter
Hi Craig - I have nothing against 2nd hand parts. But when I design a machine its designed for production. Which means the supplier has to be able to supply one or 100 parts, prefer 1000 parts. If...
Hi Max - The top of the cabinet as you describe it, although it could vibrate it probably won't. It is also not in the critical path so even if it did vibrate it would not affect the tool very much...
If you want to work in inches then its Fz= feed in/min / rpm / N N=no of teeth so a 0.1mm Fz = 0.004in so an example 40in/min/12000/2= 0.0017" so this is too thin a chip... If the chip is too...
OK - so CL= Feed/ (RPMx No teeth) so 1016/24000/2=0.021mm per bite as the tool moves. That's a very fine cut so your either making lots of dust or if your machine is not rigid enough its rubbing...
Hi Pippin - In my design the Z axis rails are attached to the z axis plate. The Z motor is attached to the Z plate as well. In this machine I'm moving from an I beam Z axis to a tube. Initial FE says...
Hi - How many teeth? and what are you cutting? plywood, hard timber? Peter
Hi TKMS - what chipload do you run at? If you do not know about feed per tooth (Fz) then you need to look that up. If your Fz is too big then your overloading the tool and hence will choke the tool...