xclusive585 Wrote: ------------------------------------------------------- > > Totally untrue. > The Largest CNC milling unit I've ever seen, had a > moving bed. The gantry could go up some 20-30 > feet, the bed was about 70 Feet long and 20 feet > wide, and could easily hold parts weighing 100,000 > Lbs. (50 tons) > I was curious as to this machine you have seen. I goby martinprice2004 - Extruded Aluminum Frames
In industry the main method of welding is with a fixed part and a six axis robot equipped with a welding torch moving around the part to perform the welds. However the other way is sometimes employed where the weld torch (or spot weld head) is fixed and the component is manipulated by the robot under the head. It actually produces better welds as gravity is always working in the direction you wanby martinprice2004 - General
In the past I have reworked shrink cracked parts by holding them under the extruder head and injecting molten plastic into the crack. Its a bit messy, but does repair the part well. A bit of cleaning up and the part is quite functional. So using this as a repair tool would work and be much neater. Other uses for this could be:- Adding raised text in a different colour to a part. Adding detailsby martinprice2004 - General
Just spotted this on Kickstarter. An excellent use of 3D printing. 3D Doodle Penby martinprice2004 - General
Its common on conveyor lifters to add a counterweight to reduce the effective mass that is lifted and hence reduce the work done by the motor. Its also common on fork lift trucks. I believe the mass is set to around half the maximum lift weight or half the expected mass to be lifted in the case of a conveyor. The mass is connected so it hangs the other side of the top roller and assists the liftby martinprice2004 - Delta Machines
Hello All I'm Martin from a small village near St Neots, Bedfordshire. I would be happy to come for a meeting. Just tell me the time and place. Its probably best if we get an email list as this part of the forum is not visited very often. If anyone wants to contact me direct just go through the HeliumFrog my website.by martinprice2004 - Beds/Herts/Cambs RepRap Usergroup
Nice design. A couple of suggestions You only need 1 motor to lift the bed. A lead screw has great mechanical advantage so the motor will cope easily. You can remove all the idlers except the ones around the motor pulley. The Makerbot Cupcake had a similar setup without idlers and worked OK. I modified my cupcake and had a sliding motor setup. This removed all the idlers including the ones arouby martinprice2004 - Polar Machines, SCARA, Robot Arms
Of the FREE ones I have used the two that pop out are Blender and Autocad123. Blender is really great for 3D form modelling and animation but is not really a CAD package as it has no history tree and you cannot dimension the sketches etc. to make fully parametric models. You can model functional parts but it is not easy and they are not easy to modify accurately. Its great for sculpture and freby martinprice2004 - 3D Design tools
I have just read these posts for the first time and it is most informative. i would like to build a machine capable of metal milling using belts and bushes, so any progress in this department is helpful. Nophead suggested that the original mendel roller bearing setup was nice as it can be adjusted. The downside that I can see is that the bearings are point loaded. Perhaps they could be improvedby martinprice2004 - Mechanics
Sorry, but I cannot see anything in the original post about removing moisture from ABS. The post was about springiness. I have ordered rolls of ABS from China and it came loose on a diameter of about 1 metre. I assume this is how it is collected as it comes out of the production extruder. I recoiled it by hand onto a more conventional size spool (Garden hose sized) and did experience springiness.by martinprice2004 - General
I thought this might be a good idea, but wasn't sure of an effective temperature. If you are only looking for about 80 degC then how about boiling water poured over it in a tub.by martinprice2004 - General
@bobc The point I was trying to make, which I clearly didn't convey well was as follows:- There are 4 professional people in the organisation, who tell you they have lots of experience and a long career record. I read from this that they all have earned or are earning a decent wage. To four people with that combined income, why are they asking for complete strangers to take all the risk in theiby martinprice2004 - General
Harmonic drive robotby martinprice2004 - Let's design something! (I've got an idea ...)
I too spotted this on Kickstarter and if you read down the page, they do in fact credit Johann for his Rostock, they don't credit me for the Helium Frog delta, but that is OK as it is much more Rostock than Helium Frog. If we carried on like this the credits would need to be longer than those at the end of a film, begining with Dr Adrian Bowyer. I can see nothing wrong with selling the delta desiby martinprice2004 - General
As suggested above if you are only to use this for 3D printing you will almost certainly regret using lead screws for movement. They are extremely slow unless you buy the more expensive high pitch ones with anti backlash ball screws. If you don't believe me have a look at this video of a delta robot with 1mm pitch lead screws (my first attempt at a printed delta) HF Delta Then take a look at tby martinprice2004 - Look what I made!
If I recall correctly there was a project to print homes for hermit crabs a while back. I think they used ABS for this. I googled "rapid prototype hermit crabs" without quotes and came up with several links.by martinprice2004 - Polymer Working Group
I like the idea of ABS dust / paste, sounds like a great idea. I was unaware that parts could be produced this way cold. Is it just like a very thick version of ABS Juice and could you recycle your old parts by just dissolving them in a vat? Any more details about this would be appreciated. This would mean you could mix in fillers easily to experiment with various compounds. Perhaps by alteringby martinprice2004 - Plastic Extruder Working Group
I used to design conveyor systems a few years back and I can support using UHMWPE for bearings as it is highly suitable for what you are using it for. In fact I would suggest it is the best available. One key use is for chain guides and tensioners. It is also used for this in automotive engines for timing chain guides. Another material to consider would be Oilon. This is basically oil filled nylby martinprice2004 - Developers
You need to specify what type of robots your interested in. For pick and place there are quite a few that would be suitable, Delta, SCARA etc on this forum. Another one suitable is COREXY Core XY Another good website for "Organic"robots is trossen robotics. Here you will find humanoid, hexapods and wheeled robots. trossen robotics forum Also have a look on thingiverse as there are a few thereby martinprice2004 - Pick-and-Place Electronic Assembly (and robots!)
This sort of happens anyhow by proxy. The better and faster machines get more attention and consequently more people build and develop them. Unfortunately this Darwinian evolution leads to dead ends. Its been tried many times, the examples I can think of are for aircraft wing designs and for wind turbine development. These make subtle changes and improved things, but no radical alternatives camby martinprice2004 - Robots!
Some interesting points here. Its a common misconception that a machine cannot produce a part more accurately than itself. It can. If it couldn't we would never be able to produce the accurate machines we have today from the wooden ones we had in the middle ages. Its been suggested above that "averaging" is one means. You could use several guides for each axes and average across them. Another tby martinprice2004 - Developers
I can't really see how printing the internal structure of a part in a curved manner would help at all. The base of the part is still flat and when you build the part up to level, the shrinkage would be the same and so would the curl of the part. You could try a convex print bed, but the lift varies depending on the size and shape of the part so this would be difficult. You could try printing ridby martinprice2004 - Developers
Could be a communication down the USB cable . I had this many times. Try moving your cable or relocating your machine slightly. Also have a look to see if you have your motor wires wrapped close to the usb line in or cable tied together. That could be causing communication problems. This would explain why when you disconnect one motor the problem goes away. Check you have good earthing also. Ifby martinprice2004 - Reprappers
Rather than adjusting the end stop, which is tricky to get right, a better way is to index in z using code in your start gcode file and then resetting that point as your new 0,0,0. Now when you print, all your positions are offset up by the z amount you placed in the first line of code. You can have a look at your print, and then on your next run, you can adjust it in code rather than moving yourby martinprice2004 - General Mendel Topics
Printing a boat hull on a reprap would be very hard as it is thin and quite large. This tends to make the part have internal stresses which make it crack or distort whilst printing. This is why the Tantillus reprap case is so difficult to print. You might need to make it in short 25mm sections and glue it together. As an alternative, have you considered printing the sections and keel and then asby martinprice2004 - Let's design something! (I've got an idea ...)
I just spotted this delta robot printer on youtube which seems to have slipped under the radar a little. Youtube video It seems to have some nice universal joint designs.by martinprice2004 - Delta Machines
I don't know what electronics you are using, But if you have separate motor driver boards like on Ramps, it might be worth switching the two over to see if the problem moves axes. Some of the cheap pololu type driver boards only do 8x microstepping even if they are set to 16x. This should in theory make the one axes twice the size of the other, but it depends on what scaling you have set in the fby martinprice2004 - Mechanics
Could be several things. If the extruder continues to move, but fails to extrude its probably one of the following. 1) the pinch wheel has stripped the plastic. Try reducing the pinch pressure slightly. 2) Temperature has gone down. It may have switched off. There is an over temperature setting in the firmware that switches off the extruder. I have had reading spikes and in the end have disableby martinprice2004 - Reprappers
Excellent Progress. It doesn't matter that what its making isn't too neat it shows it is feasible which is the main thing. Things will only improve now. First SCARA print......Another one chalked up for the (ACL) Anti Cartesian League! I would certainly get a bowden extruder on it as soon as possible to take the load and inertia off the arms. The sine wave problem in X might be that the arms aby martinprice2004 - Polar Machines, SCARA, Robot Arms
Another Parallel SCARA arm video here. The working envelope looks quite large, but I am not sure its able to move in straight lines across all of its envelope. Dex Tarby martinprice2004 - Polar Machines, SCARA, Robot Arms