Thanks, I've been trying to design around a bulldog lite extruder but was having trouble figuring out the dimensions. Frankly it disgusts me that they promised to open-source the drawings upon getting funded but won't even give us a mounting pattern. I'd use something else but I haven't found an alternative that is just right. Most of them are ridiculously expensive too.by 691175002 - Mechanics
Either of your proposed situations would be sufficient to make H-Bot superior to CoreXY. I personally think the hbot is superior to corexy in all situations, as the non-planar belt path used for corexy bugs me. If your gantry is flimsy enough to rack, it will probably be problematic regardless of what system you use. CoreXY doesn't prevent inertia or other forces from affecting the gantry.by 691175002 - Mechanics
Surface finish is just one of many requirements of a 3d printer. The quality some users manage to achieve is amazing, but you have to remember that a lot of tweaking and tuning went into every single print. The stratasys goes from .stl to finished part with almost zero user input. The heated build chamber in commercial printers allows enormous prints without any warping, and their reliabilityby 691175002 - General
This would be an amazing feature if the user could specify it for specific surfaces. No need to use it everywhere. I highly doubt that 5-6 axis 3d printers will ever take off. The advantages are far too small compared to the complexity and expense added.by 691175002 - General
What exactly is the problem with pointing out that low cost 3d printers are inferior to their 400,000$ industrial brethren? If you watched a Fortus machine print for 5 minutes you would understand the difference in capability. Hell, at least people expect industrial printers to work out of the box. In the hobbyist community we jump on new users who expect a printer to work without a bunch of cby 691175002 - General
The amount charged should be total if it is like my order. I placed a 150$ order from Canada, paid 15$USD in shipping and then another 14% in tax (damn you HST). The total was around 42CAD after the conversion, so most of what I paid was tax and the us/cad conversion. A friend in Alberta only paid 5% tax so he got a "better" deal in that sense.by 691175002 - General
They are very cheap for many products but their quality is uncompromising. If you order the steppers, sensors, bearings or even fasteners it is very obvious that they are not your usual ebay fare. If you think Misumi prices are unreasonable, hop over to Mcmaster-carr and a Nema17 will run you 90-400$. That being said, I don't need top of the line parts for my personal projects so I stay away frby 691175002 - General
There is a review of this hotend in the newest reprapmagazine and it was not particularly complimentary. QuoteReprap Magazine, Volume 2 Pages 54-55 I have to say this is the longest melt zone I have ever seen on a hot-end, and I do not believe it’s to a benefit for the user. ... I spent a very long time using the Pico, trying to understand how best to use it for many different materials and was nby 691175002 - General
As a buyer I've purchased a lot through aliexpress and been pretty happy every time. Never had anything go wrong , so I don't know how well they handle problems. I generally just assume some percentage of my purchases will go wrong, and often buying from ebay/aliexpress is much cheaper even with a 10% failure rate.by 691175002 - General
Quotevegasloki Quote691175002 I would consider mic6 plate with a few kapton heaters stuck on the bottom. It will be perfectly flat and evenly heated. Have you done this? Not yet, but I plan on having about 2KW of on the bottom of a 24" square plate of quarter inch mic6 this summer.by 691175002 - General
I would consider mic6 plate with a few kapton heaters stuck on the bottom. It will be perfectly flat and evenly heated. Heated build chambers can be simple, but there are a lot of subtleties as well. Many extruders (especially the all metal ones) rely on proper cooling to avoid jamming, which becomes harder when the ambient temperature is 70c. As well, many people include fans to help with deby 691175002 - General
You really shouldn't need to cool the electronics - the SMD chips are designed to only require PCB heatsinking. You absolutely should not need to cool the stepper motors unless they are sitting right above the heated bed. Most of these components are designed to run hot. Nothing will really happen to a stepper motor until the insulation starts burning, and silicone is generally good to 80c+ asby 691175002 - General
My biggest concern with color mixing is what happens when a filament is left unextruded for many hours (or even days) while the extruder is hot. This situation would not be unusual, especially once you start approaching 5 colors. Although I guess you could just purge every color between layers if it was a problem.by 691175002 - General
3mm takes significantly more force to extrude which is why all 3mm designs are geared.. I have always assumed 1.75 is more suited to bowden for that reason.by 691175002 - General
Seriously guys, spend five seconds researching your claims before making them. Modern belts have essentially zero stretch. Your belts are not stretching, your machine has just gotten loose and all the parts are jiggling around. Belts are used literally everywhere in ultra high precision machines. Cnc mills costing more than most houses use belts to drive their ballscrews. Such mills maintaiby 691175002 - General
For the first few pages of this thread I would have voted to ban tekwizard as a troll. Did he seriously equate conservation of energy to thinking that the world is flat? On a somewhat unrelated note: Just so everyone is aware, the stratasys patents are publicly availaible and have dozens if not hundreds of detailed drawings and explanations of how to build a variety of different hotends. Itby 691175002 - General
Maximum axis speed is of little importance when compared to acceleration. A typical 3d printer will run acceleration in the order of 300"/s^2 or higher (around 1g). Throwing a 150g printer nozzle around at 1g isn't a big deal. Try that with a 50KG gantry. Just look at some youtube videos of infill printing. A typical router would walk across the floor while bending itself into a pretzel if iby 691175002 - General
Frankly I couldn't tell if he was being sarcastic when talking about print quality. Kept talking about how nice the printer was while posting pictures of garbage.by 691175002 - General
I don't think building something like this will ever be practical. I would attempt SLS with glass powder before trying FDM. Both processes will trap a lot of air so your transparent sections won't really be that great. You will need to work above the strain point which means that the heated chamber must be 800f+. If you really wanted FDM then the nozzle would have to be graphite (just like thby 691175002 - General
Note that it is unlikely the cad models have correct tooth profiles for the proprietary geometries like gt2, htd and other curvilinear belts.by 691175002 - General
I am looking for a Nema14 stepper with ~60oz/in. They exist here: but I can't find anywhere to buy. Anyone got any leads?by 691175002 - Stepper Motors, Servo Motors, DC Motors
They put up 100 of them a week or two ago at 1500$ and by the looks of things they had to lower it to 1200$ to move a single unit. Compare it to the 400$ jr or 550$ full size model and ask yourself if fitting in a box is worth the extra 800$.by 691175002 - General
The option you proposed would work but would be awful for many reasons. Just redirect the step/dir into the servo/stepper amplifier/driver of your choice.by 691175002 - General
Has anyone tried making a liner out of graphite instead of teflon? Both are low friction but graphite is good to several thousand degrees. The stratasys patent mentions graphite as an alternative to teflon as well.by 691175002 - Plastic Extruder Working Group
While microstepping does not reduce torque, many of its claimed advantages are lies. Using 1/16 microstepping will not give you 16 times more accuracy. You can maintain reasonably accuracy with half stepping, but anything beyond that is very unreliable. The only material advantage of microstepping is improved smoothness (note that DSP/advanced drivers will already perform smooth commutation soby 691175002 - Mechanics
WD40 (water displacement) is not actually intended to be a lubricant. It is notorious for drying into a horrific black gooey mess that ruins everything. My first choice would be Mobil Vactra 2. Beyond that, a generic white lithium grease will also do a good job and is available in tubes and spray cans pretty much anywhere. Pretty much anything designed for lubrication will be fine, this isn'tby 691175002 - General
I know the stratasys fortus 900 uses ballscrews. I suspect that they have custom, or at least $$$ screws with exceptionally high pitch and some hefty servos to drive them though. The calculations I did took into account that the screw is only rotating. Spinning up a 10 gram screw is just as hard as moving a 1Kg mass once you take into account the mechanical reduction that a typical screw proviby 691175002 - General
You have to remember that with a 3d printer, feature size is sort of a continuum. While you might be able to achieve a certain layer height and mechanical resolution, in the end you are squirting plastic out of a nozzle. For example, you are never really going to get a perfectly sharp corner.by 691175002 - General
Screw systems are favoured on machines with large moving masses that require precision under extreme cutting forces. Neither is the case for a 3d printer. Many systems in the 0.001-0.005" range use belts, and I even provided a link to a belt system with 4 micron accuracy. Its just that belts tend to be equally or more expensive than screws and it is harder to get the required reduction for higby 691175002 - General
There are no inherent limitations of timing belt systems, it is all in the implementation: Has belt systems that can go to 4m/s with 4um/m accuracy. There are 8x4 foot routers that use 2" wide steel reinforced timing belts and can rip through metal with accuracy in the thou range. H-belt systems are incredibly fast and precise as well: You just need to use belts properly. Screws of any tyby 691175002 - General