Maker bot (which was in and is junk) was disassembled by myself and useable parts salvaged for the new reprap (pursa i3) for the space the 3d print club will be putting together. The tantilus requires a new complecated hobb bolt that proved very hard to machine and is awaiting parts or a new extruder feeder. It will then be operational.
Things are looking up for 3d printing at vhs. Hopefully.
3D printer drop-ins will be on Saturdays as before. Iām waiting until the space it a bit more set up before putting it officially back on the calendar, but Iāll be there tomorrow closer to noon.
As @TyIsI says, itās the Tantillus that needs a new hobbed bolt. The best solution at this point is probably to redesign the extruder assembly to accommodate something more standard. I will give you the tour if you come down tomorrow.
We had two Makerbots, a Cupcake and a Thingomatic. One of them has been dismantled for parts and the other saved as a general CNC platform.
And Iām still waiting for @SteveRoy to start a thread about his Prusa i3 build for the VHS.
Oh, and Iāll be at the Tuesday open house if you canāt make it down tomorrow. A few people from the 3D printer work group are gathering Tuesday evening to discuss getting the training workshop up and running. Everyone is welcome to join.
Doing a bit of quick reading, the hobbed bolt for the Tantillus looks quite easy to make - poorly documented dimensionally from what I can find, but easy otherwise. I canāt make it out to VHS today to help, but perhaps next Saturday may work if you still need help with it.
This method of using a vice and tap definitely seems the easiest way to go: Making a Hobbed Bolt - RepRap
Having said that however, it does strike me as a very poor design to use a modified bolt as a drive roller. Manufacturing-wise, bolts arenāt make to any kind of precise tolerances, and any kind of variance (wobble, diameter, etc) over the bolt will result in inconsistent pressure on the filament. The worst part of a bolt for precision is its head, which has a gear on to drive the bolt⦠and I do remember those gears binding on the Tantillus from the very beginning, likely for this exact reason.
While looking into the hobbed bolt I did come across this alternate extruder design that uses a Dremel cutting bit (which is precision machined) rather than a hobbed bolt. I havenāt done any further investigation, but it seems to be a much, much better idea:
Thatās essentially the technique that @Daniel_DeGagne and I tried last fall. I printed the jigs and we used the green mill. The biggest challenge was that the design of the Tantillus bolt has the teeth so close to the end, you canāt support it on the ends with the cut in the middle as shown in those pictures. Your jig holds it on one end and in the middle with the cut end sticking out like a cantilever which causes quite a bit of deflection while making the cut. That and it will take a bit more thought to select the right tap so you end up with an even number of teeth.
You can buy standard M8 based hobbed bolts. There is room for some mild variance in the pressure, especially with 3mm filament and a good idler. I also really like the Dremel bit idea since those can be purchased at Canadian Tire. Either will require redesigning the extruder mount.
We hobbed some bolts at the space this afternoon. I think Luke or maybe it was @Daniel_DeGagne, Iām terrible with names, helped me to do it and took picture to document the process. Bleeding edge stuff when it comes to hobbing bolts, or at least I like to think so. There are two extra bolts of slightly different hobbed qualities to try if the one we installed doesnāt work.
The best of the bolts we made is installed and all we need now is RAMPS, Stepper drivers and an Ardunio Mega to get this beast moving again.
Thanks to @ashley for pointing me in the right directions on this hack
I have a RAMPS board, stepper drivers, and arduino mega that I donāt plan on using any time soon. Iād be happy to donate it to the cause. Theyāre off-brand copies from China, but they might work.
I am game for that. Bring it in on Tuesday and make we can get that printer working as well.
@ashley I imagine there are some routine maintenance tasks for the Tantillus before we plan to spin it up. Any special firmware settings that would need to be applied, or will the stock Marlin for tantillus work fine?
@ashley@Lukeo@lukecyca The filament bend radius is getting tight on that spool, it broke off on me tonight. I struggled to reload it because of the tight radius and I think piece broke off in the hot end. No damage but Iām going to open the hot end without help. Sorry, Tom.
Do not open the hot end. It is not as it seems and has to be pulled apart in once piece carefully or else the tension inside will not be calibrated properly and it will not print properly again. This is not a simple case of un-screwing the nozzle. I will be there tomorrow and can check any problems and get replacement parts as need be.
If you can push other filament through from the top while it is hot is your best chance, just do not open it up.
Iāve busted enough things in the last 46 years that I now know when to stop! It never feels good to make work for other people but this is probably a 5 min fix for an experienced person and a warranty wrecking job for me - so I had to walk away.
In hindsight I think I should have used a heat gun (away from the printer) to soften the filament and straighten a section of it - the bend radius is so tight near the centre of the spool that it just snaps off. I was using the filament loading wizard so the hot end was at temperatue but nothing extruded, the piece that broke off is likely blocking the entrance to the hot end.
Hey tom, I managed to come in and rebuild the hot end in pretty quickly. But the real thing was clearing the plastic which I found the correct thing to do was to use the temp setting to pre heat the nozzle to temperature. Then pushing the button to release the bearing on the filament and putting some thin tweezers in the front and pushing the filament further into the tube and then just loading a new piece of filament on top of it into the hot end pushing all of it through. This would of fixed it with out interfering with anything but as the hot end was now a little loose I reassembled it accordingly and is perfect working order.
Its no problem but yes there are quick and easy ways of doing things once you know how. Using new filament to push the old stuck piece through at temperature would of been the best solution.
Yes loading filament near the end can be a pain but heat gunning it wouldnāt help it would change the diameter of the plastic and this would clog the machine. Just load new filament if it is to much hassle.
The quickest way to load filament is to just preheat the machine and then just push the filament through by hand, the wizard is there as a guide but you can do it faster and easier by just preheating and pushing it through.