Floppy Eject Gear - Flexibility

[jmacz]

A few weekends back, I finally got myself to finish cleaning, re-gearing my floppy drives.



After mentioning this in the What did you do to your Apple/Mac today? thread, @s_pupp and I had a quick conversation about how much the eject motor seems to struggle after the gear has been replaced, and he made the observation that the original stock gear seems to be very flexible (even before it begins disintegrating) implying that this flexibility might influence the torque, reliability of ejection.

I had used replacement gears from two sources:

• The original creator of the gear model available on Thingiverse who sells them on eBay.
• Using that original design (and his updated v2 version of the design) I printed some myself using 3D resin printing which is very accurate.

My resin prints were pretty stiff and hard. The ones I bought on eBay were even stiffer/harder.

Based on that conversation with @s_pupp I procured some Anycubic flexible resin and printed a new batch of gears:



This new batch using the new flexible resin was definitely flexible. Not loose. But bendy under pressure. Definitely felt more like the originals albeit they don't disintegrate in your hands when you bend them Very different from my original prints and the ones I bought on eBay.

I tested this new gear in one of my IIcis that had a floppy drive that was really straining to eject. That drive did eject but you can hear/feel it trying really hard to do so and barely getting it out instead of getting stuck. With the new gear in place, it seems better? It seems to be ejecting better, straining less, and seems to be more normal like I expect?

I don't think it's fully conclusive yet... this is one sample size and just a bunch of ejects in a small amount of time. I will keep watching it and playing with it. But if anyone else is printing their own gears, you may want to try the flexible resin and see if you also see a difference.

 

[macuserman]

Have you tried the gears from Mac effects? In my experience so far those have been the best. The eBay gears were not nearly as good.

 

[LaPorta]

Sometimes I think that somme of the metal areas/guides between the upper and lower part of the drive can become ever so slightly pinched...almost imperceptibly to the human eye. It may just be enough to cause a rough eject/binding. One way to check this is to feel the force with your hands between a manual eject on other drives vs. that one. You should be able to feel if there is a difference, even if slight.

 

[jmacz]

Have you tried the gears from Mac effects? In my experience so far those have been the best. The eBay gears were not nearly as good.

I have not. But I agree, the eBay ones did not seem great as every drive that I put one of those into resulted in a lot of straining to eject. But these flexible ones have promise. Will try them in a couple more drives and see if it holds. If so, it’s possible the eBay ones are too stiff. I remember seeing in the description that they are stiff “but should be ok”. Maybe not.

 

[s_pupp]

Very interesting. Many thanks for the update!

 

[bigmessowires]

I bought 3D-printed replacement gears from a seller on Shapeways in 2021, and haven't noticed any problems with my drives that use them. But I also haven't tested them more than a handful of times. https://www.shapeways.com/product/27DNUVPJA/replacement-floppy-drive-gear-for-macintosh

 

[CC_333]

I've been lucky so far; all my drives that work still have eject motors with their original gears intact.

I also got a pair of NOS drives about 10 years ago, and they seemed to strain just a bit when they eject, as I recall. It could've been due to the old grease, but I actually think it must be normal, since I've seen the same behavior on regreased drives, so perhaps they're calibrated such that there's just enough force to push the disk out enough for the user to grip it, but not so much that the disk flies out of the slot, like some newer manual-inject drives tend to do, in my experience (some lesser-used Zip drives do this too).

c

 

[s_pupp]

I bought 3D-printed replacement gears from a seller on Shapeways in 2021, and haven't noticed any problems with my drives that use them. But I also haven't tested them more than a handful of times. https://www.shapeways.com/product/27DNUVPJA/replacement-floppy-drive-gear-for-macintosh

I bought these after reading your post, and tried one in my wife's Mac Classic. The eject motor no longer strains to eject the disk, which is a big improvement over the eBay gear.

 

[tt]

I bought these after reading your post, and tried one in my wife's Mac Classic. The eject motor no longer strains to eject the disk, which is a big improvement over the eBay gear.

Which eBay gear are you comparing to the Shapeways one? Is it the molded one from Italy?

 

[s_pupp]

The gears I have found the Shapeways gears to work better than are:
this one, and this one, both shipped from the USA. I have not tried the Italian gear.
Both the above gears worked, but the drive motor nearly stopped half way through the ejection process. That does not happen to me with the Shapeways gear.

 

[bigmessowires]

I wonder what it is about the Shapeways gears that enables them to work better. Is it the model, or the material, or the printing method? Shapeways says they are "fine detail plastic" but doesn't provide other info about the printing process. Those Shapeways gears were designed by Stephen Arsenault, so maybe we can find him and ask him.

 

[jmacz]

I

The gears I have found the Shapeways gears to work better than are:
this one, and this one, both shipped from the USA. I have not tried the Italian gear.
Both the above gears worked, but the drive motor nearly stopped half way through the ejection process. That does not happen to me with the Shapeways gear.

I had the same issue with the eBay ones.

I printed my own (design from Thingiverse) using flexible resin and it’s a lot better. Drive doesn’t strain.

 

[tt]

The gears I have found the Shapeways gears to work better than are:
this one, and this one, both shipped from the USA. I have not tried the Italian gear.
Both the above gears worked, but the drive motor nearly stopped half way through the ejection process. That does not happen to me with the Shapeways gear.

The first ebay listing you linked is the same designer as the Shapeways gear, but the eBay listing is "V2" and the Shapeways one is "V1".

The fine detail plastic looks to be this one: https://www.shapeways.com/materials/fine-detail-plastic-3

Bummer to hear about the issues with the "V2" version from eBay I ordered, will see how it goes. I may try printing some as an experiment. The flexible material working better may be due to tolerances. If the gear isn't quite to spec, for example the center hole is offset to the outer diameter, then some flexibility would probably alleviate binding.

 

[Stephen]

I'm not here often so apologies I didn't see this sooner — I'm the publisher of the premium gear model on Thingiverse, which is available on Shapeways and eBay.

I can tell you a few of my own observations which may help narrow down the culprit of the issue.

1. Shapeways: The resolution and outline of 3D printing with "high detail" from Shapeways is poor. As a result, the overall diameter of the gear is at risk of being slightly smaller than the 3D model which the print is based on.
2. eBay: The resolution of the 3D printed gear which I sell on eBay is significantly better than Shapeways, at 20um. Comparing the gears under magnification is without exaggeration remarkably better.
   • I print these gears myself. As a result they are at risk of procedural or quality errors. While I have several steps in place to perform QA, it's possible there are gaps.

With this in mind, I suspect that some gears I print and sell on eBay are occassionally experiencing "stretching". This is inherent to the 3D printing technology I use to print at this improved resolution. As mentioned, I have QA in place to check for this and configuration in the print process to minimize / remove deformation.

However, one of the problems I have is that I only have a few original gears to serve as a reference. I've photographed my original gears at extreme magnification in order to produce the "premium" gear — the model is very nearly 1:1 with the original gear.

Additional original gears would be very helpful for further reference. If anyone would like to donate their original gears to me I would gladly pay shipping.

My Mission
If you check my product and prices on eBay you SHOULD expect to find I am the lowest price available. When I produced my first publicly available 3D model a few years ago, other sellers had gears listed at over $15 for 2 gears and then you still had to pay shipping. I knew it didn't have to be that way so I created an open source model for everyone to use and listed my gears on Shapeways for the cheapest price they would offer + a $0.50 "tip" (profit) for me.

Over time I found the quality of Shapeways just wasn't keeping up with the quality of consumer 3D printers and the prices on eBay had not dropped as much as I hoped. That's why I now sell on eBay myself with the intentional goal of undercutting the established sellers and driving their prices down.

There is no acceptable reason to charge $15 for small plastic gears. I want everyone to be able to enjoy their vintage hardware with the best quality gears at the lowest price I can offer and feedback, like from this thread and the broader community, is super appreciated.

 

[s_pupp]

A small size difference certainly could explain my differing experiences between eBay and Shapeways items made from the same file.

I’d be glad to send you a few original gears. I’ll message you directly.

 

[Stephen]

I carefully reviewed my gear design early this month and found a few small dimensional deviations when comparing my design to the original. I bought new calipers and found my old calipers were not as accurate as I thought, which is a little heart breaking because I've done a lot of work with the original pair and clearly had too much faith in them.

With all of that said, I've released "V3" design to Thingiverse which is also available for sale from my eBay shop. Thank you so much for the feedback, and a huge shout out to @s_pupp for graciously donating several gears. Having multiple of the same gears allows me to see the manufacturing tolerances and get closer to the original design!

 

[s_pupp]

I carefully reviewed my gear design early this month and found a few small dimensional deviations when comparing my design to the original. I bought new calipers and found my old calipers were not as accurate as I thought, which is a little heart breaking because I've done a lot of work with the original pair and clearly had too much faith in them.

With all of that said, I've released "V3" design to Thingiverse which is also available for sale from my eBay shop. Thank you so much for the feedback, and a huge shout out to @s_pupp for graciously donating several gears. Having multiple of the same gears allows me to see the manufacturing tolerances and get closer to the original design!

Good news! Many thanks for the update.