<![CDATA[SoliForum - 3D Printing Community — What kind of replacement Y rod?]]> https://www.soliforum.com/topic/8591/what-kind-of-replacement-y-rod/ Mon, 08 Dec 2014 08:34:09 +0000 PunBB <![CDATA[Re: What kind of replacement Y rod?]]> https://www.soliforum.com/post/74373/#p74373 I had requests for the files on my direct drive conversion, so I finally had a chance to do just that:
http://www.thingiverse.com/thing:583132

I have changed a couple of the files just a bit to make them more aesthetic.  Easy peasy though, and it fixed my circles.

]]> Mon, 08 Dec 2014 08:34:09 +0000 https://www.soliforum.com/post/74373/#p74373 <![CDATA[Re: What kind of replacement Y rod?]]> https://www.soliforum.com/post/74051/#p74051 If you really like to make a direct drive for y carriage,
move y drive motor to outside frame (left side),
make a U shape abs printed motor bracket,
use 4 holes for mounting the motor, a big hole
For motor shaft w/alum. Coupling, from McMater
buy a small alum. Coupling, one side w/5mm
Hole for the motor shaft, one side/6 mm for
6mm rear rod, driving rod.
The U shape has another 4 holes on its foot,
drill 4 holes on frame wall(left), mount the
Bracket to frame.
So no any extra bending force in between two
Brass bushings.

]]> Fri, 05 Dec 2014 04:03:32 +0000 https://www.soliforum.com/post/74051/#p74051 <![CDATA[Re: What kind of replacement Y rod?]]> https://www.soliforum.com/post/73977/#p73977 accusedmonk wrote:

I really like the results from my direct drive.  I upgraded to an 8mm shaft though, it's much easier finding couplings for 5mm to 8mm.

+1.  I had been meaning to do this mod just like yours.  Please check your PMs.  For others, the thread is here:

http://www.soliforum.com/topic/6145/gt2 … onversion/

]]> Thu, 04 Dec 2014 15:34:32 +0000 https://www.soliforum.com/post/73977/#p73977 <![CDATA[Re: What kind of replacement Y rod?]]> https://www.soliforum.com/post/73938/#p73938 Hey ward, neat idea - if you can get your hands on a lathe, just use a piece of 8mm rod and bore a 5mm hole in one end. Then use skate bearings (608zz) wherever you can fit them, tap a set screw (or two) to clamp up to the motor shaft if the press fit doesn't go so well, and let a slightly flexible motor mounting constrain the axial direction.

Ironman, good idea - if you want it to be properly flexible though, use two gaskets to make a real flexible mounting:
Motor | Gasket | Frame (oversize the holes) | Gasket | Plate (alu would be good)
Chop pieces of M3 rod, thread them in to the motor with loctite to make studs, and then bolt the assembly together with M3 nyloc nuts so you can adjust the precompression.

Maybe a bit OTT but it might do away with the need for a flex coupler, and be a bit more stiff in torsion?
The flexing of the frame kind of achieves the same thing though, so might not be much benefit, I don't know!

http://www.soliforum.com/misc.php?action=pun_attachment&amp;item=6965&amp;download=0

]]> Thu, 04 Dec 2014 01:51:51 +0000 https://www.soliforum.com/post/73938/#p73938 <![CDATA[Re: What kind of replacement Y rod?]]> https://www.soliforum.com/post/73928/#p73928 Since I run fish line I've thought about using a piece of thick wall tubing in place of the rod.  5mm I.D. Pressed onto the motor shaft.  Then skip the pulleys and run the fish line right around the tubing.  That way there is no coupling and if done correctly no wobble.

]]> Thu, 04 Dec 2014 00:56:43 +0000 https://www.soliforum.com/post/73928/#p73928 <![CDATA[Re: What kind of replacement Y rod?]]> https://www.soliforum.com/post/73927/#p73927 I really like the results from my direct drive.  I upgraded to an 8mm shaft though, it's much easier finding couplings for 5mm to 8mm.

]]> Thu, 04 Dec 2014 00:56:42 +0000 https://www.soliforum.com/post/73927/#p73927 <![CDATA[Re: What kind of replacement Y rod?]]> https://www.soliforum.com/post/73926/#p73926 I like the solid coupler idea...any kind of torsional flexibility kind of negates the whole reason for the upgrade!

How about solid coupling and something like this to let the motor flex better against the frame?

http://www.makergeeks.com/ne17stga4pa.html

]]> Thu, 04 Dec 2014 00:51:43 +0000 https://www.soliforum.com/post/73926/#p73926 <![CDATA[Re: What kind of replacement Y rod?]]> https://www.soliforum.com/post/73920/#p73920 jagowilson wrote:

Grob, what are the disadvantages to this mod? What are its quirks? Assuming you're using fishing line, what are the fastest speeds you can achieve? (Belts have natural backlash so high speeds with them isn't all that interesting to me)

Well, the obvious quirk is the motor sticks out. Can't avoid that. You'll probably have to adjust the shape of your side panels to accommodate it. No big deal.

Using a rigid coupler (as you described Claghorn) worked in the end, but it's really not great. The motor still flexes around a tiny bit (the sheet metal frame bends to accommodate this!!).

I haven't had a chance to try out the flexible coupler for real yet, so not sure whether this introduces any issues (e.g. if the torsional stiffness is still not quite good enough). With a rigid coupler, I got rid of most of the hysteresis from the y axis. I should probably print out a circle test some time and post it... Aaah in the land of free time haha!

I'm on GT2 belts, and haven't really got to properly speed testing. I'm not sure this would reliably lead to speed increases, but if it's done well and the drive efficiency is better than the original setup (one less radial force applied to the rod, less friction) then I'd expect some ability to up the speed before the y motor skips - then there's the question of whether you're now limited by the x axis and it's tiny wee motor!

]]> Thu, 04 Dec 2014 00:43:28 +0000 https://www.soliforum.com/post/73920/#p73920 <![CDATA[Re: What kind of replacement Y rod?]]> https://www.soliforum.com/post/73917/#p73917 grob wrote:

You want a coupler with high torsional stiffness but fairly free in angular and offset misalignment - oldham / spider coupler would be best.

Yea, the link above is to a spider coupler. I almost think a rigid coupler would work fine with my plan to let the shaft itself determine the motor position, but that would work best only if I could screw the motor down in a zero gee environment :-).

]]> Thu, 04 Dec 2014 00:34:48 +0000 https://www.soliforum.com/post/73917/#p73917 <![CDATA[Re: What kind of replacement Y rod?]]> https://www.soliforum.com/post/73916/#p73916 Grob, what are the disadvantages to this mod? What are its quirks? Assuming you're using fishing line, what are the fastest speeds you can achieve? (Belts have natural backlash so high speeds with them isn't all that interesting to me)

]]> Thu, 04 Dec 2014 00:30:53 +0000 https://www.soliforum.com/post/73916/#p73916 <![CDATA[Re: What kind of replacement Y rod?]]> https://www.soliforum.com/post/73914/#p73914 Firstly, good plan - direct drive is a worthwhile mod if you can handle the motor sticking out the left of the printer about 100mm!
You'll have to design and print a bracket, just model everything up in cad and see how you can get it to fit. smile

Hardened steel is the best choice for the linear rails (more abrasion resistant), but you'll get away with that or stainless (even non-precision stainless rod stock - worked for me) for the pulley drive - tackle rigidity with bearing blocks in good spots, rather than relying on the stiffness of the rod too much (not sure anything 6mm diameter would be able to stay straight enough in the stock SD3 setup!).

I use a rigid coupler but it's hideous; so lucky it aligned of it's own accord finally. You want a coupler with high torsional stiffness but fairly free in angular and offset misalignment - oldham / spider coupler would be best. The common one-piece helical couplers are way too flexible in torsion for this job - the one you've posted would be fine.

]]> Thu, 04 Dec 2014 00:28:16 +0000 https://www.soliforum.com/post/73914/#p73914 <![CDATA[Re: What kind of replacement Y rod?]]> https://www.soliforum.com/post/73913/#p73913 jagowilson wrote:

If you loosen the set screws on the pulleys they will align themselves even if the rod is stiff. That's because the belts have trapezoidal teeth and they don't like to be misaligned one bit!

Ah, but I have fishing line :-). When I installed it, it worked out very well to position just one pulley so there was no tendency to slide, then do the 2nd one so I knew if any sliding happened it was all due to the 2nd being misaligned, so I only had to tweak one pulley at a time.

]]> Thu, 04 Dec 2014 00:27:59 +0000 https://www.soliforum.com/post/73913/#p73913 <![CDATA[Re: What kind of replacement Y rod?]]> https://www.soliforum.com/post/73912/#p73912 jagowilson wrote:

IronMan you need to get a vape!!! love my mech mod, cig free for 4 months

Go You for 4 Months!!

I am actually using the ZOOM E-cigs...they make the situation(s) quite tolerable!  I also keep thinking "you've gone this far, don't f$%k it up now"...

Sorry, off topic smile

]]> Thu, 04 Dec 2014 00:27:54 +0000 https://www.soliforum.com/post/73912/#p73912 <![CDATA[Re: What kind of replacement Y rod?]]> https://www.soliforum.com/post/73911/#p73911 If you loosen the set screws on the pulleys they will align themselves even if the rod is stiff. That's because the belts have trapezoidal teeth and they don't like to be misaligned one bit!

]]> Thu, 04 Dec 2014 00:22:08 +0000 https://www.soliforum.com/post/73911/#p73911 <![CDATA[Re: What kind of replacement Y rod?]]> https://www.soliforum.com/post/73909/#p73909 It is all sort of speculation at the moment. If I rig up a bracket to hold the motor outside I could make the holes large enough to allow the motor to shift a bit, then use a 5mm to 6mm coupler to attach the motor to the shaft and tighten the screws to hold the motor in place with the shaft itself aligning it properly. But I have no real idea what kind of bracket I could rig up yet.

There are other problems like getting the pulleys on the rod aligned. Previously I've positioned them by fiddling with them till the rod doesn't slide back and forth. Now there wouldn't be any way for the rod to slide, so I might want to come up with a way to reposition the pulleys exactly before I take it all apart again :-).

The sort of coupler might be what I want:

http://www.fscoupling.com/5mm-to-6mm-ja … -p-56.html

]]> Thu, 04 Dec 2014 00:20:18 +0000 https://www.soliforum.com/post/73909/#p73909