12" I3V Build

[Dustin B]

Oh and how freely should the delron wheels turn? Really tightening the screws on the aluminum build plate makes it so they can't turn. Can't get things that tight on the wood. Loosening it so the wheels turn really freely more than just the wheels turn. What I think is the best middle ground between the two still has the wheels a little stiffer than I'd like. Is it preferrable to have a the wheels a little stiff to help keep things under control?

[BLKKROW]

Oh and how freely should the delron wheels turn? Really tightening the screws on the aluminum build plate makes it so they can't turn. Can't get things that tight on the wood. Loosening it so the wheels turn really freely more than just the wheels turn. What I think is the best middle ground between the two still has the wheels a little stiffer than I'd like. Is it preferrable to have a the wheels a little stiff to help keep things under control?

You want the wheels to spin but not wiggle or be loose on the rail.

[Dustin B]

You want the wheels to spin but not wiggle or be loose on the rail.

By spin do you mean you start them turning and they will continue to spin on their own, or just that they turn with minimal force? Seems tricky to get them tight enough to not wobble and still spin freely enough to continue turning on their own once started.

[tsteever]

I too had the question of how tight the wheels should be when building. What I found to be a good tension was tight enough to take the wobble out, and then just a tad tighter to keep things in control. You still should be able to spin the wheels with minimal force. They will not spin freely at that point. There is a small window on spinning smoothly under control and binding. If there is wobble, they are too loose. If they spin freely when you flick them...too loose.

[Dustin B]

K, that's along the lines of what I was currently thinking. I think I have them slightly too tight right now. They currently don't take constant force to turn. It goes up and down slightly. I think I want to back it off until they require consistent force to turn rather than jerk a bit through turning as they currently are. I might end up talking to my father in law (designs and sells hydraulic systems) and see what he can get for replacement bearings that might work better.

Thanks for the great explanation printbus. That helped a lot.

[printbus]

Printing better quality parts than what you received shouldn't be an issue. Multiple people have chimed in with how they were quickly able to print better looking parts. I'm sure Colin prints his parts as fast as he dare, which doesn't help with print quality.

On the z-rods, I have mine touching the tops of the motor shafts. I wanted to minimize the possibility of the helical coil of the couplers acting as a vertical spring. Clough42 suggests adding a small ball bearing or BB between the motor shaft and the Z-rods, so that's another option to consider.

EDIT: BTW, many people have decided to move away from the OEM spool mount for a couple of reasons, so bear that in mind before you trim off the z-rods to clear it.

[Dustin B]

Ah, now I get it. They came assembled and I never took one a part. There is definitely a washer between the bearings but it must not be thick enough compared to the ridge in the middle of the wheel (I didn't know there was a ridge there, but makes complete sense it has to be there after I think about it, how else would the wheel be captured). So ya the ridge being thicker than the washer between the bearings means tightening down will pull the inner races closer together than the ridge in the wheel allows the out races to come together causing all the issues. Someone else mentioned using the 5mm washers supplied to replace the washers between the bearings in the wheels. I'll see what's up with mine tonight. I might have some shims from my RC stuff that will allow me to fine tune it, if not I'll be doing some looking around tomorrow after work.

[Dustin B]

And I just realized that my Traxxas Slash RC uses 5x8x0.5 teflon washers in the wheel hubs. So maybe just adding one of those to the washer that's there will solve my issues. If not, 2 or 3 of the teflon ones likely will. A package will be a couple bucks at any place that carries Traxxas parts.

[printbus]

Interesting approach for the insulator. You could probably market that... I'd make up another one, without any of the holes and maybe oversized a bit, for use as a cover insulator over the glass. Placing the additional one above the glass when heating should help the bed heat up faster and reach a more uniform temperature. Placing it above the glass when the printer isn't in use would help protect the glass from dust, finger oil if you have nosy people around, and damage should something fall onto the glass.

How the hot end fits into the extruder has came up before, at least with the hexagon hot end. IMO, the need to do something may depend on how well your mounting plate fits the U-channel in the hot end. If the plate grabs the channel pretty well, there's likely no issue. Instead of sanding down the extruder for a better fit, a more common solution is to shim up the hot end. I used to add multiple layers of kapton tape with a small hole for the filament cut into the kapton. Once you're printing, there's at least one printable shim design out there somewhere specifically for use in that space between the hot end and the extruder.

I resolved that gap, along with numerous other nuances I saw with the extruder parts, in my Greg's Wade suite redux available on Thingiverse.

[Dustin B]

1/8 scale nitro clutch bell shims are 5mm inner too. Easily found down to 0.1mm thickness too.