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Forum Index : Other Stuff : 3D Printer sugestions
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Gizmo Admin Group  Joined: 05/06/2004 Location: AustraliaPosts: 5078 |
Looking at buying a 3d printer for hobby use. I see there are a bunch of kits in the $300 - $400au range, so I was wondering if anyone has any recommendations. I see there are two common designs, the Prusa i3 and the Tarantula i3. The Prusa goes for around $310au, and the Tarantula for around $370. I'm leaning towards the Tarantula, its more expensive, but I like the construction. Couple of ebay links. Prusa Tarantula Does anyone have any experience with these, and any tips for a beginner? Glenn The best time to plant a tree was twenty years ago, the second best time is right now. JAQ |
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MicroBlocks Guru  Joined: 12/05/2012 Location: ThailandPosts: 2209 |
Two lines of thought after working with many 3d printers for about 6 years of which 3 years as the owner of a makerspace where these things have gone through some mayor work. 1) Use the expensive ones like UltiMaker are great machines. Just print occasional calibration, great quality. Good for prints that takes many hours. After 5 years the original model still performs very good. 2) Cheap printers, lots of hands on time. Calibration, unclogging, sensitivity to moisture etc takes lots of time. Good for printing small items in a relative short time. Occasionaly have to change some parts, not a bad thing as you can also use that to upgrade like better pulleys and bearings. With 3D printers there is a trend to have a big printing volume. In my experience that is only counter productive. Larger printers are expensive, so better buy 3-4 cheaper ones and cut your 3d model in 3-4 parts. Result is better print, less support material and 3-4 times faster. If something fails at 95% you will not start cursing! The 3d printers you choose are both not really good. The prusa construction is a lot better then the Tarantula. Personally i don't like a moving platform, you get a much better experience and less failures when the building platform only moves in the Z direction. A moving platform has backlash when it chances direction and a lot of inertia to overcome with each change. I like the Ultimaker style because they make the head as light as possible having much less inertia which increases speed and precision. Building one yourself is relatively easy. Especially the delta types. I have good experience with those, the head is light, the platform is static, can build tall things. I am currently using a corexy as a base for my manual pick and place tool and that base is perfect for a 3d printer. Buying a complete set of electronics,motors, belts and pulleys is not difficult as lots of those sets are offered for good prices. The corexy is described here: http://corexy.com/ One of the best firmwares to use is Merlin for the arduino controler and Cura on the PC as a slicer works great together with that. I currently have a prototype made from mdf with linear slides and it works good. Even using drawer slider works amazingly enough very good. Price difference between linear guides and drawer slides is about 300US$. :) Don't go for combining a CNC and 3d printer. If it is a good CNC it will be a superslow 3D printer, and if it is a good 3d printer it will be a terrible CNC as it has not enough rigidity. Both machines could do eachothers work but the results are not that satisfactory. Stay away of the models that offer changeable heads, except maybe 3d printer and laser engraving. For most choices in filaments that can be used a head that has a feeder on it works best. For best speed use 3mm filament and a bowden tube design. PLA works the easiest, ABS is more difficult as it needs a heated bed and for best results a closed environment to prevent air movement as that will warp it. Maybe best to look for what kind of materials you want to print with and the choose a printer that best suits those needs. If you need help with that, ask! :) Microblocks. Build with logic. |
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| Gizmo Admin Group Joined: 05/06/2004 Location: AustraliaPosts: 5078 |
Thanks Microblocks My limit on this is $400, its just a passing interest and if I need to spend more I'll put the money into something else, like the car. I would like to buy a delta unit, but they seam to start over $500. I also want to keep time spent to a minimum, so not keen on building one from scratch unless it comes as a kit of parts with a good set of plans. Do you know of any plans and bill of materials or kits for a delta unit? I did think about fitting my CNC table, but like you said, its too slow for this sort of think. Lots of torque, but max speed is about 500mm a minute reliably. I guess the idea is to plant the seed for me, spark the interest with a cheap unit and then build something better later on. The coreXY is interesting. Glenn The best time to plant a tree was twenty years ago, the second best time is right now. JAQ |
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| MicroBlocks Guru Joined: 12/05/2012 Location: ThailandPosts: 2209 |
The ones i had were mostly self built from separately sourced parts. The market is changing so rapidly that the ones i bought are already obsolete. The one that looks close to what i had is this: http://www.ebay.com/itm/3D-Printer-DIY-Injection-Model-Kossel-Auto-level-Delta-Rostock-Pulley-Reprap-/191834836651?hash= item2caa3f4eab:g:b94AAOSw0QFXB4rO I printed most of the connectors and special parts, now you can get them as injection molded parts, which should have result in a better construction. However, ponder for a while what kind of things (and how many) you want to make as that will influence the type greatly. Thingiverse is a good resource for models and it also shows what kind of stuff can be made. Microblocks. Build with logic. |
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| Gizmo Admin Group Joined: 05/06/2004 Location: AustraliaPosts: 5078 |
To be fair, I see there are a few delta printers for around $450, I could do that, but how accurate are they compared to a XYZ table style printer? Glenn The best time to plant a tree was twenty years ago, the second best time is right now. JAQ |
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| MicroBlocks Guru Joined: 12/05/2012 Location: ThailandPosts: 2209 |
Precision is good. Biggest influence are the ball joints. Better quality, better results. If standard ones are not satisfactory you can always change them. The build volume is a bit smaller in the X and Y directions but the Z is often much larger. Height adjustment is a bit easier as the platform is fixed, so you need to adjust it by setting all the arms to the same height. As that can be done in software by using a sensor it is much smoother then a XYZ table as there is no physical Z axis that has to go up and down. This results in more consistent layers. Microblocks. Build with logic. |
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| Gizmo Admin Group Joined: 05/06/2004 Location: AustraliaPosts: 5078 |
I've started sourcing bits for my printer. Most of the electronics are on order, as are the belts and arms. Trying to source the rails and linear bearings. I thought either go for V slot rails and wheels, or two 8mm rods and linear bearings per upright. A set of 3 V slot 2040 rails at 500mm long, and 9 mini V wheels cost about $88 from a company called MakerStore (http://www.makerstore.com.au/ ). Their 8mm rod and linear bearings are cheaper and possibly easier for me to use, but they are out of stock of the 8mm rod and not responding to emails. I'm now reluctant to place an order with them, if they dont respond to emails how long would it take them to send an order?! Can anyone suggest a reputable supplier, either ebay or in Australia? Glenn The best time to plant a tree was twenty years ago, the second best time is right now. JAQ |
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| MicroBlocks Guru Joined: 12/05/2012 Location: ThailandPosts: 2209 |
I had a few pieces from this ebay seller. Arrived within time and quality as expected http://stores.ebay.com/Bearing-Wholesale-Lots That was over a year ago. I prefer these (Linear guide rails ) now as they are so much easier to use. This seller i never used, just to show you what parts i mean. On the picture the trucks have 2 tapped holes, four tapped holes is much better! Rod and bearings often have a bit of play that will result in a less good end result. They can also not be flat, which is really not good. The hiwin ones i never had a crooked one. Microblocks. Build with logic. |
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| Gizmo Admin Group Joined: 05/06/2004 Location: AustraliaPosts: 5078 |
Thanks. I eventually had a reply from makerstore, they are out of 8mm rod with no date on when stocks will arrive, so I ordered the V slot rails and V wheels. I suspect my decision to buy the parts and build a delta printer from scratch will cost me more than a kit version. But its more of a challenge and I'll have a better machine in the end. Now wait for the bits to arrive and start designing the thing. Glenn The best time to plant a tree was twenty years ago, the second best time is right now. JAQ |
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| Gizmo Admin Group Joined: 05/06/2004 Location: AustraliaPosts: 5078 |
With all the bits I've started building the thing. Lots of fiddly design it as you built it, but its getting there. I draw up the parts in cad then print at 1:1, and stick the templates to aluminium with a glue stick. I've used this technique a lot, works well, and once the part is cut and drilled, drop it in a bucket of water for 5 minutes and the glue dissolves. 
Trial assemble of the rails, arms and effector. 
Now the fun bit, wiring it all up. 
Glenn The best time to plant a tree was twenty years ago, the second best time is right now. JAQ |
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| Gizmo Admin Group Joined: 05/06/2004 Location: AustraliaPosts: 5078 |
The printer is up and going. 
First print, a 20mm square test block. Played around with the extrude speed as it grew. Using PLA for now, I havn't rigged up the bed heater yet. 
2nd print, a 1/4 size cup. 
Calibration took about an hour to get it right. Next I'll order in some ABS and get the heated bed working. I also need to rig up a part cooling fan, the coffee cup has some issues where the new material was printing over area's that had not solidified yet. Glenn The best time to plant a tree was twenty years ago, the second best time is right now. JAQ |
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| MicroBlocks Guru Joined: 12/05/2012 Location: ThailandPosts: 2209 |
That looks good. PLA needs active cooling, ABS not so much, lower speed will give the ABS time to solidify a bit before the next layer. Also making the print area enclosed so no drafts of air cools down one side of the print quicker then the other resulting in warp. Also the slower it cools down for ABS the better the result. Microblocks. Build with logic. |
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