Hi Thomas - Knowledge has no order. Peter
Type: Posts; User: peteeng
Hi Thomas - Knowledge has no order. Peter
Another Board - I've been wanting to make a board with a guide post so people cut bread straight. So I finally got around to starting one. I'll call it the mitre board. Today I profiled it and cut...
Hi All - Although this is the Milli thread I'll chuck some of Epoch into it as Epoch is the proto Milli 5 axis mill. I have started detailing the tilting B axis so have looked at the plate that I'll...
Hi - The Scoot on that page is a couple of versions old. The main specs are the same I have extended the Z to 320mm lately. The page is due for an update. The machine base is now made from pressed...
Hi Spot - My steel uses E=210Gpa that's the only difference. I agree that the mesh density for the purposes of deflections should not be critical. But once I understand what Fusion is doing then I'm...
Morning All - over coffeee I had a further play with the tube model. I made the mesh finer and used an adaptive mesh setting. Plus I set the connections at bonded. This took more time to solve (due...
Morning All - This morning I refined the mesh, used "offset bonds" vs bonded and the result is much better. I also made the cross areas much closer. So now I would be happy to progress to a more...
Hi Spot - to illustrate the point. I modelled three steel tubes in fusion. The tube is OD45 and ID 35. The rod has the same area so is 28.3mm dia. One tube consists of three pieces so in the...
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...