@victor With reference to the hexapod design debate, It also got me thinking that modifying the SCARA to a parallel arm design might be an improvement. You suggested this configuration before, but maybe using RC servos might be an option. The resolution could be an issue, but I did spot a hexapod milling robot which does seem to produce relatively detailed shapes. Hexapod Milling Perhaps aby martinprice2004 - Robots!
The servos I have chosen are Hextronik HX5010, which do have double bearings. The recommended ones for hexapods seem to be Hitec HS-645MG but these retail at £21.99. They are metal gear type The Hextronic are £7.49. I have only purchased 4 at the moment for some single leg trials. The HX5010 are high torque units so should be up to the job, but I want to confirm this first. As you can see the coby martinprice2004 - Robots!
Yes I might double up on the Tibia and Femur joints. The Coxa joint has a 3mm bearing underneath, but there are many hexapods running about with this setup, in fact the majority of purchased kits of this size use a single sided servo design. I have read that it depends on the servo type. As I am using low cost servos, this might be an issue. At first I will be running without onboard batteries,by martinprice2004 - Robots!
Heres an image of the design progress so far. More info on the Helium Frog websiteby martinprice2004 - Robots!
Blender 3d should be able to do this. Just import the .stl remove the vertices below the cut line and then add in a surface to close the solid. Then export as a .stl. Repeat for the other half of the object.by martinprice2004 - General
There seems to be a lot of duplicate parts in your design, for example the cups that hold the plants. This leads me to think that rapid prototyping is the wrong way to go about things which as it stands is a process for small quantities and one off parts. You might be better reprapping some tooling for these parts (such as a mould for cold casting or a buck for laying paper mache/ hessian fibreby martinprice2004 - General New Machines Topics
Having looked around a bit last night, it appears that probably the best and simplest solution for control board is the following item. Not too bad at £35. I think I should be able to add a bluetooth plug in module at a later date to go wireless. Dagu Robot Controller It includes simple connectors for upto 48 servos (I need about 18) and also has an arduino mega based chipset so I should be famby martinprice2004 - Robots!
I am looking to develop an open source repraped Hexapod robot and would ask if anyone has spotted one on the net. I don't feel like reinventing the wheel, so If there is any firmware available for the Arduino Mega or CAD models floating around could you post links here please. Is there anyone here that would be willing to collaborate on the design or could share their knowledge please? A couby martinprice2004 - Robots!
All details including 3dmodels, partslist and firmware has now been uploaded. They are avaialble at my site or on thingiverse. Thingiverse Helium Frog SCARAby martinprice2004 - Robots!
It looks like development on the SCARA is on hold at the moment as I work away from home at the moment. I will put the code up on my website as soon as I can and also post all the models.by martinprice2004 - Robots!
Here is a website detailing a bike frame made with printed ABS lugs and aluminium tube. Its reinforced with carbon fibre, but I could see that with an improved design, this could be eliminated (for example bolt through design or clamping on the lugs). Be sure to check out the instructable, there is a neat use of a printed mould (mold) to get a good finish on the parts. Printed Bike Please postby martinprice2004 - Let's design something! (I've got an idea ...)
Possibly over temperature protection shutting down the hot end. See discussion below:- Forumby martinprice2004 - Reprappers
I have not had this problem on a Reprap, but have had it on other machines I have built. A few things to try. My guess is that the wooden cabinet may help a potential difference build up between the PC and reprap over time. It gets to a point where it starts causing data transmission problems down the USB cable, which locks up the software / arduino. Have a look at the earthing of the machineby martinprice2004 - Reprappers
As for the tilt and slide off there are several mechanisms that could simplify this such as the Jansen or Klann meaning that you would only need a linear X axis to acomplish a "peel back" and slide. How about a twist to release the part. The vat could be circular and the Vat Z axis on a lead screw, raising to the next layer would naturally twist the glass off the part? You could rotate the projeby martinprice2004 - Polymer Working Group
DeuxVis Wrote: ------------------------------------------------------- > You might be interested by some effort already > done on that idea : > - > source-3d-dlp-printer no thats not how that one works, its just it has a top projector.by martinprice2004 - Polymer Working Group
I have been following the DLP Resin printer development with interest, particularly Gary Hodgson et al. Gary Hodgson Website One thing I have noticed is that they all seem to mount the projector below and build the part hanging from the build surface. It is also difficult to overcome the stiction of the new layer from the glass. Would it be possible to invert the machine and produce it the othby martinprice2004 - Polymer Working Group
Congratulations. The first self replicating Delta! Its nice to see that it is accurate enough to produce good quality parts. I'm sure there will be many more of these produced in the near future. I like the 3 adustable end stops located on the centre platform. A nice touch and a neat alternative to leveling the base plate.by martinprice2004 - Delta Machines
I would post any ideas you have about the design as there are many here who would be interested. A forum is for sharing ideas and getting inspiration from others. Just ignore the "It won't work" comments. History is littered with genius ideas that have been delayed by critics. Its not useful to compare the price of a printer from Canon etc. to that of a reprap, as many printers are sold as Lossby martinprice2004 - Developers
You will have a job converting from .stl or scad. It seems Open scad produces very bad .stl files which seem incompatible with many CAD systems. Ok for printing only. Believe me I have tried and it seems most .stl files are incorrectly scaled and have surface errors. This also includes most files on Thingiverse. Your supplier is clearly having problems with the surface gaps (non manifold parts)by martinprice2004 - 3D Design tools
Yes the above design is a little wide (about 1metre), but I was thinking if you designed a cantilevered rising table (similar to ultimaker etc.) the machine could be wall mounted with no base plate. This would overcome some of the space limitations which would be present with a desktop machine. An additional problem is that the x axes bars are long and prone to sagging in the middle. There are aby martinprice2004 - Delta Machines
Heres a concept I came up with a few months ago. Its a sort of half delta half cartesian. Its on the same lines as your one.by martinprice2004 - Delta Machines
Yes the quest for ever greater resolution for FDM can be a bit of a waste. After all its really the extrusion of the molten plastic that is the restriction on a cartesian reprap in XY. The Z axis can cause some problems. It looks like there are a few delta robots in the pipeline that may be setup for FDM. It will be interesting to see the parts they produce. My guess is that it wont be linear diby martinprice2004 - Delta Machines
Heve you tried to reprap the pattern for sand casting. It might be easier than making it from wood. You could add draft angles and maybe finish the surface by hand.by martinprice2004 - Look what I made!
Do a google image search for "parallel robot" and you ight get something like your first idea Heres a link to a springband design as per your second idea Delta robot designsby martinprice2004 - Delta Machines
I think a good start to this project would be to take an existing design and convert it to reprapped parts. Are there any open source designs floating around?by martinprice2004 - Robots!
I did a google for printable LED and it does appear that LED matrices can be printed with conventional processes such as screen printing, so this idea does appear to have some merit. Whatever inks they are using could be used on a reprap. The resolution might not be as high, but it could be sufficient. What do you mean by using LED's in reverse?by martinprice2004 - Developers
The general concensus here is that the layers are a mechanical bond "hot forge" rather than a melted fusion, but I dont think anyone knows for sure. This would be logical as the deposition speeds some people run at probably wouldn't give the lower layer time to melt. Using this type of joint doesn't mean that it is weaker than the parent material. I've done hot forge operations in metal and whenby martinprice2004 - Wire and Thread Embedded Extrusion
On my reprap variant I have used tie wraps to hold the x axis rails in place as well as the linear Z axis bearings. It was an experiment to reduce the number of fasteners and simplify the build. The bars pass through reamed holes and the Z axis bearings sit in a simple V groove. The tie wraps make an excellent mechanical joint and is comparable to a bolted one if designed correctly. I can't compby martinprice2004 - Mechanics
This is an interesting development as there has been many a discussion of how to remove the stepper motors from a reprap to make it easier to reproduce. It would also be very good for large bed repraps where belt drive starts to become less accurate. The only downside of course is that you could potenially remove stepper motors for something more simple, but you do add a camera. Is there any waby martinprice2004 - Developers
I have often thought that a xy table where the build platform slides over a surface would be a nice idea. I was thinking of a PTFE plate under steel, but a floating build bed would be great! The Maglev idea would need some serious control software to keep the flux levels stable. These ideas do seem a little fanciful at first, but as electronics are now seriously cheap, this may be feasible. I dby martinprice2004 - Mechanics