tag:blogger.com,1999:blog-4339813531032979196.post2072103867277414246..comments2024-02-28T07:32:59.864+00:00Comments on HydraRaptor: Worm drivenopheadhttp://www.blogger.com/profile/12801535866788103677noreply@blogger.comBlogger29125tag:blogger.com,1999:blog-4339813531032979196.post-21576267492427741942013-02-28T22:05:09.700+00:002013-02-28T22:05:09.700+00:00This comment has been removed by the author.BUhttps://www.blogger.com/profile/11285593556960614005noreply@blogger.comtag:blogger.com,1999:blog-4339813531032979196.post-21908372803487142802010-01-08T19:05:15.479+00:002010-01-08T19:05:15.479+00:00Erhard,
Yes it does exceed the axial force ratin...Erhard,<br /> Yes it does exceed the axial force rating of the motor. I will see how long it runs for. I suspect the brass parts will wear out long before the steel ball bearings in the motor.<br /><br />Spur gears would avoid that, but the biggest ratio I can get is 7:1 with a 4" meccano gear and a small pinion. That would probably give enough torque but not fine enough control. I try to keep the step size less than 0.1mm of extruded filament, so that would need two stages of spur gear.nopheadhttps://www.blogger.com/profile/12801535866788103677noreply@blogger.comtag:blogger.com,1999:blog-4339813531032979196.post-36883131316646701632010-01-06T22:11:02.819+00:002010-01-06T22:11:02.819+00:00@nophead
If I see it right, the traction force of ...@nophead<br />If I see it right, the traction force of the worm pulley results in an axial force towards the stepper motor which would wear out the motor bearings. <br />I only found a remark on a stepper datasheet (Oriental) : The tolerated axial force should not overcome the motor weight.<br />My suggestions :<br />1. Add Bearing between worm gear and motor housing for axial load.<br />2. use cw and ccw worm gear on same axle to drive two gear pulleys opposite (mirror design). May conflict the state from "s0lstice" mentioned above about the helical-cut teeth ?!<br />3. add parallel spur gearing between motor and worm gear axle<br />4. get rid off the worm gear, use spur gear and/or the reprapable Cycloidal drive<br /><br />I would also prefer the vertically mounted stepper so we could place 2 extruders left and right and maybe one in the front with all the filaments can be driven by one motor. And with a 2nd driveshaft we could couple a paste gear pump or other future improvements.<br /><br />ErhardAnonymousnoreply@blogger.comtag:blogger.com,1999:blog-4339813531032979196.post-44903904634034235732009-11-04T14:09:03.264+00:002009-11-04T14:09:03.264+00:00@Charles,
Moving to smaller feed stock may be a ...@Charles,<br /> Moving to smaller feed stock may be a problem with softer plastics like HDPE, PP, etc. The force needed to extrude goes down with the square of the diameter, but stiffness goes down on a fourth power, so I think there will come a point where it buckles. Especially as these plastics are already less stiff than ABS and PLA and also require more force to extrude.<br /><br />Keeping the gab between the pinch wheel and the entrance to the barrel as short as possible will help of course.nopheadhttps://www.blogger.com/profile/12801535866788103677noreply@blogger.comtag:blogger.com,1999:blog-4339813531032979196.post-89555398933111743812009-11-03T10:21:18.916+00:002009-11-03T10:21:18.916+00:00I have bought plastic from NIP and 5lb was the min...I have bought plastic from NIP and 5lb was the miniumum order. I bought one green and one black, i.e. 10 lb in total.nopheadhttps://www.blogger.com/profile/12801535866788103677noreply@blogger.comtag:blogger.com,1999:blog-4339813531032979196.post-88907834593948970472009-11-03T01:56:34.587+00:002009-11-03T01:56:34.587+00:00@Dave
Would you double check that minimum order? I...@Dave<br />Would you double check that minimum order? I think it might be a 50 pound minimum order with 5 pounds being the smallest unit they will break it into. That's how it was with another plastics manufacturer I spoke to.Charles Edward Paxhttps://www.blogger.com/profile/05274865437692150653noreply@blogger.comtag:blogger.com,1999:blog-4339813531032979196.post-73899441375010059572009-11-02T23:40:24.764+00:002009-11-02T23:40:24.764+00:00I used 973g to print a Darwin so about $20, see ht...I used 973g to print a Darwin so about $20, see <a href="http://hydraraptor.blogspot.com/2009/07/hydraraptors-second-child.html" rel="nofollow">http://hydraraptor.blogspot.com/2009/07/hydraraptors-second-child.html</a><br /><br />I think Mendel is similar.nopheadhttps://www.blogger.com/profile/12801535866788103677noreply@blogger.comtag:blogger.com,1999:blog-4339813531032979196.post-79268309492143640262009-11-02T22:20:01.993+00:002009-11-02T22:20:01.993+00:00@Charles:
Just heard back from Donna at new image...@Charles:<br /><br />Just heard back from Donna at new image: price is $9.50 per pound for plastic: i think they have a 5 pound minimum order.<br /><br />Anyone know what the total volume of a printed reprap is? I'm wondering: @ $10/pound, what does that end up costing to print up a darwin or a mendle?Davehttps://www.blogger.com/profile/11987514110079695313noreply@blogger.comtag:blogger.com,1999:blog-4339813531032979196.post-65556245251801268342009-11-02T00:08:58.700+00:002009-11-02T00:08:58.700+00:00I look forward to knowing that price and quantity....I look forward to knowing that price and quantity. I'd like to see the community move to a smaller filament and I'm willing to invest some money to make the appropriate extruder and filament available to experimenters.Charles Edward Paxhttps://www.blogger.com/profile/05274865437692150653noreply@blogger.comtag:blogger.com,1999:blog-4339813531032979196.post-55095757284961530672009-11-01T23:37:26.325+00:002009-11-01T23:37:26.325+00:00@Charles:
Hi, I have submitted a quote to New Im...@Charles: <br /><br />Hi, I have submitted a quote to New Image Plastics ( I think I remember that Forrest got some plastic from them ). I will see what their pricing is, and what their minimum quantity is.<br /><br />I think that there are a lot of benefits in using a smaller filament size.Davehttps://www.blogger.com/profile/11987514110079695313noreply@blogger.comtag:blogger.com,1999:blog-4339813531032979196.post-87647043953524485012009-11-01T18:10:16.143+00:002009-11-01T18:10:16.143+00:00@ Dave
I'm using material from a Stratasys mac...@ Dave<br />I'm using material from a Stratasys machine giving a cost of $65 per pound. Just like an ink jet printer, when the cartridge reads empty and the machine will no longer allow you to print with it, there is still material left.<br /><br />If someone purchased 0.07 inch filament in bulk and sold 5 lbs rolls, it wouldn't cost any more than the 3 mm filament; approximately $10 per pound.Charles Edward Paxhttps://www.blogger.com/profile/05274865437692150653noreply@blogger.comtag:blogger.com,1999:blog-4339813531032979196.post-90016039276773729642009-11-01T14:31:35.686+00:002009-11-01T14:31:35.686+00:00@Charles:
What is your source for the smaller abs...@Charles:<br /><br />What is your source for the smaller abs filament? I believe that I'd like to try using it if the source is fairly inexpensive...<br /><br />thanks!Davehttps://www.blogger.com/profile/11987514110079695313noreply@blogger.comtag:blogger.com,1999:blog-4339813531032979196.post-19073944809718850392009-10-30T16:09:39.642+00:002009-10-30T16:09:39.642+00:00I posted about the Paxtruder and addressed some co...I posted about the Paxtruder and addressed some concerns. http://charlespax.wordpress.com/2009/10/30/paxtruder-0-2/Charles Edward Paxhttps://www.blogger.com/profile/05274865437692150653noreply@blogger.comtag:blogger.com,1999:blog-4339813531032979196.post-37849658700087593082009-10-29T08:44:59.305+00:002009-10-29T08:44:59.305+00:00Nop, my apologies yes you are indeed right you did...Nop, my apologies yes you are indeed right you did note it and I must have missed that bit.<br /><br />I use white grease quite often but the spray can came with a plastic pipe/straw that inserts into the nozzle and makes the spraying quite a bit more directional.<br /><br />It is still very messy though, half pressing the nozzle or pulsing quickly sometimes helps, but can be a bit variable.<br /><br />My usual technique is to do the best i can with the above then clean around the target afterwards <|:(Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-4339813531032979196.post-64903089153623962812009-10-27T19:49:27.739+00:002009-10-27T19:49:27.739+00:00Yes that would make sense to get a bigger contact ...Yes that would make sense to get a bigger contact area so better wear rate and max load, which would be a good thing. Not sure if it will improve the efficiency though as friction is generally independent of contact area.<br /><br />I might have to do a MK2 crooked version.nopheadhttps://www.blogger.com/profile/12801535866788103677noreply@blogger.comtag:blogger.com,1999:blog-4339813531032979196.post-50343446397176672802009-10-27T19:31:16.215+00:002009-10-27T19:31:16.215+00:00I think it's normal to use helical-cut teeth o...I think it's normal to use helical-cut teeth on the worm gear, to mesh better with the worm. Failing that (because you want to use standard square cut mechano gears), the other approach is to rotate the worm axis, so that it's not 90 degrees to the worm gear axis, but the same angle as the thread.Anonymoushttps://www.blogger.com/profile/11468079731100957673noreply@blogger.comtag:blogger.com,1999:blog-4339813531032979196.post-90043440983869399342009-10-27T15:52:47.426+00:002009-10-27T15:52:47.426+00:00Hi Andy,
Thanks, but I did note it "Before I...Hi Andy,<br /><br />Thanks, but I did note it "Before I greased it, it was only half as efficient, so worm gears certainly waste a lot of effort in friction. "<br /><br />I used old fasioned yellow grease from a tube. I do have Lithium and PTFE but they are in spray cans, so I find them impossible to use without spraying grease all over everything. I even tried spraying it into a small pot inside a bin but managed to get my wife who was behind me. Very dissapointing, how on earth are you supposed to use grease from a spray can?nopheadhttps://www.blogger.com/profile/12801535866788103677noreply@blogger.comtag:blogger.com,1999:blog-4339813531032979196.post-42345711780052316562009-10-27T15:29:07.390+00:002009-10-27T15:29:07.390+00:00Most excellent and solid work as ever.
Just a qui...Most excellent and solid work as ever.<br /><br />Just a quick observation, (you have probably apready done this but not noted it) some lubrication on your worm gearing would help reduce wear and noise etc and promote eficiency. <br /><br />Either White Grease (Lithium) or something that is Teflon/PTFE loaded.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-4339813531032979196.post-27466536030298502152009-10-27T12:21:51.352+00:002009-10-27T12:21:51.352+00:00Hi Khirali,
I don't think it will get hot en...Hi Khirali,<br /> I don't think it will get hot enough to soften PLA with the current I am using at the moment, 1 - 1.5A. It would be the motor mount itself that would be the biggest problem, rather than the PCB carrier. If it is a problem I will re-make it in ABS.<br /><br />I decided in the end not to mount the PCB on the extruder because I also used it to control my milling spindle recently.<br /><br />Yes it would be a good idea to cover the gears to keep the dust out, thanks. Have to get it working before it can make its own dust cover though.nopheadhttps://www.blogger.com/profile/12801535866788103677noreply@blogger.comtag:blogger.com,1999:blog-4339813531032979196.post-86573893782011740802009-10-27T10:42:20.756+00:002009-10-27T10:42:20.756+00:00Sorry, I forgot to write in my previous comment:
...Sorry, I forgot to write in my previous comment:<br /><br />I think you also want to cover the gears with some plastic, if not it will collect all dust in your room nophead;-)<br /><br /><br />KhiralyAnonymousnoreply@blogger.comtag:blogger.com,1999:blog-4339813531032979196.post-89846882493392878342009-10-27T10:36:18.019+00:002009-10-27T10:36:18.019+00:00Hi!
Is it a good idea to mount the pcb using PLA ...Hi!<br /><br />Is it a good idea to mount the pcb using PLA on the stepper motor?<br /><br />The stepper motor can get hot, and the PLA is prone to deform, no?<br /><br />Best Regards, <br /> KhiralyAnonymousnoreply@blogger.comtag:blogger.com,1999:blog-4339813531032979196.post-86663686048270679662009-10-27T02:41:12.255+00:002009-10-27T02:41:12.255+00:00@nophead
I have run the Paxtruder for several hour...@nophead<br />I have run the Paxtruder for several hours with no noticible wear. The Delrin probably increses the friction, but that hasn't been a problem. A major benefit of using the Delrin is that the filament contacts the pulley along more of its' length. The paxtruder is also smaller and has fewer parts. Two of the next version can fit on the MakerBot. http://www.youtube.com/watch?v=HMjVrmLJvIUCharles Edward Paxhttps://www.blogger.com/profile/05274865437692150653noreply@blogger.comtag:blogger.com,1999:blog-4339813531032979196.post-29263205888520511222009-10-26T20:08:38.041+00:002009-10-26T20:08:38.041+00:00I don't think it will be a big problem because...I don't think it will be a big problem because the filament exerts a back pressure (that is why it oozes) so it will take up the slack. Also I can move backwards very quickly compared to the forward motion. I have just run it at 8 times the normal speed with no noticeable reduction in torque so it will go even faster.<br /><br />So the plan is to step back as fast as I can to a point where the pressure becomes 0. On restart I can step forwards to where it was very quickly and then drop to the normal speed. Backlash will only kick in if I try to make the pressure negative, which is probably the point where I want to stop anyway.nopheadhttps://www.blogger.com/profile/12801535866788103677noreply@blogger.comtag:blogger.com,1999:blog-4339813531032979196.post-51975830155432318122009-10-26T19:55:11.308+00:002009-10-26T19:55:11.308+00:00Great! I always enjoy reading your blog. Great wor...Great! I always enjoy reading your blog. Great work! I'm not sure, is it a good idea to use a driving mechanism prone to backlash? You will lose the ability to reverse to motor direction (to prevent oze).Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-4339813531032979196.post-84966224188827829712009-10-26T18:49:50.054+00:002009-10-26T18:49:50.054+00:00Update:
It is much quieter running at twice the s...Update:<br /><br />It is much quieter running at twice the speed, i.e. 32mm/s of 0.5. 16mm/s must hit a resonance of the motor, or the sound box or both. Unlucky!<br /><br />Also 1.5A is not a lot of power because this is only a 0.8R motor. It is actually less power than I was putting through the tiny stepper motor I used with the GM17 gearbox (0.3A into 27R).nopheadhttps://www.blogger.com/profile/12801535866788103677noreply@blogger.com