Small Gear Teeth Chipping Off

Today I noticed a small black piece of ABS on my table. I almost flicked it away and went about my day, but then I decided to check it out. I noticed it looked like it’d been printed. I’ve been printing only in white ABS for a while so I looked around and could not see anything chipped.

I then took the entire extruder head off and really looked closely.

The small gear was missing two teeth on one side of the gear.

Here’s my questions. I’m going to print a new gear tomorrow.

What infill settings do I use? Should I make the gear part completely solid?
Do I need to use support material or not?
I assume I should use the “fine” profile.

Should I print the large gear too and replace both gears?

I got the file for the gear from here:
http://download.lulzbot.com/TAZ/4.0/production_parts/printed_parts/TAZ_printers/

Is the “hi res” file truly “better” than the standard file?

My printer is not old by any means. I’m surprised teeth are breaking off already.

Is this a sign that something isn’t set up correctly?

Thanks for your help and suggestions.

That’s certainly not normal, and more than likely you’ll be unable to print a replacement since you’re missing 2 teeth. We can send one if you’re still under warranty. Please send in an email to Support@LulzBot.com with the following information:

  • Order number

  • 3D printer serial number

  • Contact information

  • Shipping information

Thanks!

It’s only one side of the “V” on the herringbone.

I’m going to try printing the gear tomorrow.

I’ll also get the other information at that time.

The gcode is available, which should print straight on your system. There is a directory of them here. There are plates with multiple quantities:

http://download.lulzbot.com/TAZ/4.0/production_parts/printed_parts/TAZ_printers/herringbone_small_gear/

It is not normal for the teeth to break off in regular usage. But you can print replacements. :slight_smile:

Thanks,

-Jeff

Hi,

I also had the problem of the teeth being chipped of in a few spots.

When printing, I suggest getting the large and the small gear at the same time, so they can be of the same print. My new gears have been printed with 40% infill, and from high res. file.
Also important, to enclose the printer somehow, in order to make the plastic compact.

And don’t forget to scale the parts, make them 1% larger, because ABS shrinks when it cools down

good luck

Scale the parts??? :astonished: :open_mouth:

Really? If Lulzbot printed them with ABS, and I’m printing with ABS won’t they basically be the same size without scaling?
Or did Lulzbot scale them? Which wouldn’t make sense to not incorporate into the stl file for users if they did.

Dammit…I’m printing two small gears as I type this. Straight from the file.

I’ll be sure to put some calipers on the parts and on the “original” to see what’s what.

After I get the small gear replaced, I’ll print the larger one.

So, I printed my own gear using the STL file, creating my own gcode in Slic3r with fine ABS profile with auto support. I changed the infill to 80%. Printed a pretty decent part, but not what I would consider perfect. I had to drill out the center hole to get it to fit on motor shaft. Getting support material out was a pain. A few of the herringbone teeth were not as smooth as I’d expected them to be.

I got the gear back on the motor, and decided to “test” my new gear by making two more small herringbone gears using the Lulzbot gcode provided on the linked web page a few posts back.

Guess what. The fan is running at 100% :open_mouth:

Why would the gcode from Lulzbot call for the fan to be running?

Am I wrong for assuming the gcode for these parts is optimized by Lulzbot?
Am I wrong to assume the gcode I’m using was for ABS parts?

I’m curious as to what I’m missing here. :question:

Update.

The newest parts using the gcode straight from Lulzbot, with no tweaks or changes, look awesome. :smiley:

So maybe using fan for small detailed parts, but not using fan for larger parts with long lines is best???

A fan will certainly help produce clean crisp edges, especially on smaller pieces with higher infill. When printing with ABS it’s a balance.

I noticed for the large herringbone gear the only gcode available is for .5mm nozzle.

Can I get the gcode for a .35mm nozzle for the large gear?

Please?

These look pretty damn good. :smiley:

The small gear that I put into my TAZ4 actually looks better than the one in the picture.

I just sliced mine own as the STL is present. But you should include some fan. I sliced a fine version and the new large gear looks better than the one shipped (was it medium print?).

I wish some of the other parts were present as STL. The extruder seems to be missing.

Well I’ve put together a geneva case for iphone https://forum.lulzbot.com/t/geneva-mechanism-for-iphone-4-4s/914/1

At the first try, the gears couldn’t fit, because the holes were to close, thus too tight on the gears
everything started to fit when I scaled the parts 1% in Slic3r

So my guess is that the large and the small gear could also be scaled 1% up and it could be much easier to install them without any backslash
When I have tried this I will inform of the results

cheers

I did not scale.

For the small gear, all I had to do was drill out a tiny bit of material from the thru hole so the gear could fit on the motor shaft. Otherwise it seems to be working perfectly. :smiley:

I have not tried fitting the larger gear yet.

So the first small gear I printed has now broken as well. :open_mouth:

Is anyone else having issues with their herringbone gears breaking, or chipping teeth?

We’ve printed a handful of small gears as well as a few large ones.

Just wondering if these gears breaking is “normal wear and tear of ABS parts”?

Or if perhaps there’s some other underlying issue we need to address?

My original small gear started to disintegrate within a month or so of getting the printer. The replacement I printed have been running for nearly a year. No problems with the large gear.

Do you recall anything about your settings for the gear you printed? Infill? Fan? Auto-support? Scale?
Did you simply upload the Lulzbot gcode and hit the “go” button"?

I know asking that is a long shot…but I gotta ask. :smiley:

I sliced the Lulzbot stl and printed in abs at 95% infill. No support, no fan, 100% scale.

I have never printed anything with Lulzbot gcode. The gcode I have looked at in the past was all 0.5 mm stuff anyway.

Thanks. Do you recall if you used a Lulzbot ABS profile like fine, medium, or fast?

What temperatures did you set?
We’re experimenting a little with elevating the extruder temp to 240 right now.

It would have been the Lulzbot medium ABS profile for Slic3r at 230 / 85C. Nothing special. I built it out of MatterHackers orange pro abs.