There aren't enough trackballs on the market.
Also, forefinger operated trackballs are evil. I feel sad that there are only two thumb-operated models on the market, and they're both mediocre.
Somebody said Logitech hates thumb-trackballs, and sics their lawyers on anyone who markets one. If true, the entire patent system and anything tangentially related needs to die a fiery, painful death.
I am not sure if you are proposing using these as a trackball or using these to hold the ball in the housing. either way i'll keep an eye on you ;)
Last year, I considered the same idea to use ball transfer bearings as supporter of the ball. But there is a problem about cleaning. The bearing could not opened to clean, it seems. The ball will get dirty by dust and dirt from the hands and they will be transferred to the supporter bearings.
How would you sense the ball’s movement, if it was encased in one of those?
Or you mean you’d rest the trackball ball on 3 of those ball transfer units? How big are they?
Concerning finger trackball vs thumb: [...] I do not see how one could use the transfer units
There aren't enough trackballs on the market.
Also, forefinger operated trackballs are evil. I feel sad that there are only two thumb-operated models on the market, and they're both mediocre.
Somebody said Logitech hates thumb-trackballs, and sics their lawyers on anyone who markets one. If true, the entire patent system and anything tangentially related needs to die a fiery, painful death.
^It's a matter of having enough space to mount the transfer bearings (units).
Some things I'd like to see in the trackball:
1. "stick up" a bit more from the surface. This also makes it easier to "twist"
2. having the option to actually detect twists would be great. You can use it for scrolling or whatever.
3. I think having a heavier ball would work out better here in a lower friction environment, especially with a high DPI sensor.
A very dense trackball on very low friction bearings would be great, if it could be done in a reasonably cheap way, without too much required maintenance of the ball or bearings. (By reasonably cheap I mean, the mechanical parts assembled DIY for, say, <$50 or at the outside <$100.)With out a large group buy this trackbal wouldn't be on the cheap side:
I wish you luck in your device of evil, just the same. What could be cool, though, is if you could post enough, like sensor firmware sourcecode, that were a different housing manufactured, someone like me who can't code his way out of a paper bag, could consider building a durable thumb trackball.
Its still going to get gummed up and need periodic cleaning, though. No way around that unless you add a high-pressure oil scraper ring so the part of the human-operated ball touching the ball bearings is always pristine.
With out a large group buy this trackbal wouldn't be on the cheap side:
-30 dollars for the bearings
-17 dollars for the billiard ball
-30 to 80 dollars for a laser mouse*
-Who knows how much for a 3D printed housing
If you try these bearings and they work well, I’d love to hear about it and try to build one myself. My initial plan is to just make the standard little 3 static bearing type of trackball, and maybe harvest an initial ball from a Logitech or something.
Has anyone created a trackball that makes use of ball transfer bearings?
In just about every current trackball design the ball has to slide against a surface at some point in it's rotation. Stainless steel rollers have thus far been one of the better design solutions in reducing the amount of sliding against the ball, but some rotations go against one of the rollers causing an awkward pull on the ball for the duration of the direction.
http://www.omnitrack.us/mediumduty/plain-fitting-ball-unit-MG-m.php
Three of those would eliminate the sliding action in all directions, last a very long time, and produce a single low friction value for any direction of travel. They are essentially drop in and could easily be replaced in the event of a malfunction (at a low cost).
The design of this hypothetical trackball would have the following features:
-3 ball transfer units of the type that I linked to
-Aramith 57mm trackball
-3d Printed housing and buttons
-Electronics transplanted from another popular mouse with a superior sensor (a g400s or g502).
-Outer shape should be ergonomic, similar to the MSE or Marble FX. Should contain many buttons, DPI changer switches, and a place for a scroll wheel.
Thoughts?
4MM11-MI-05-17 looks like an interesting one there, with an 8mm housing diameter and 8.5mm total height including the 2.5mm long M2 bolt. I don’t think the aluminum housing or 5 kg max load would be any problem for this kind of use case. I wonder how smoothly these balls spin.
http://www.alwayse.com/en/products/mini_ball_transfer_units.html (http://www.alwayse.com/en/products/mini_ball_transfer_units.html)
3MM http://www.holo-pack.com.tw/en/profile.jspx?no=A06001 (http://www.holo-pack.com.tw/en/profile.jspx?no=A06001)Having the main ball made out of delrin instead of steel might nice too. I wonder what difference there would be practically, for trackballs of different sizes/materials.
I wonder how smoothly these balls spin... I wonder what these cost, buying like 3–50 units at a time.They don't list a friction coefficient but if I can extrapolate from another manufacturer's material, I'd say it'd be somewhat lower than Teflon, and that's including all three bearings. I'll report back pricing after I've communicated with the OEM.
Having the main ball made out of delrin instead of steel might nice too. I wonder what difference there would be practically, for trackballs of different sizes/materials.I'd say stainless steel would be the best option for this due to longevity (and the price isn't too different it seems).
I’d be really curious to try to find some slightly grippy material for the main trackball ball (but ideally not something that attracted dirt/grime), assuming it could be found as a fairly dense, uniform, precisely spherical ball (or it would also work to e.g. have a metal ball coated in something slightly grippy). As long as the ball transfer units spin without much friction, increased traction against fingertips would be I think a big advantage.That's a really really good idea. Since there is no sliding a semi grip surface is now a possibility. The surface needs to be able to have a moderate change from grippy to slick depending on speed... as a thought, the surface of my MX518 would be perfect actually, or the surface of my Nexus 5. They are made out of special types of plastic however, which I feel would drive the cost up quite a bit. I think sticking to an aramith ball for now might be the best option as any coatings we could apply would probably not be perfectly spherical enough.
By the way, the guys who make those Aramith balls might have better suggestions about trackball balls:
http://www.preciball.com/index.php/en/links.html
A ceramic ball?! Won't that be prohibitively expensive? Are you planning to have the size match that of a standard billiard ball?most places don't make them in 2.125", but you can get 50mm (2") pretty easily. One place goes up to 70mm!! O_O
Alwayse has not reported any developments to me concerning sending sample units for testing. I'm wondering if their silence implies they are no longer interested in the situation. I'll report back if anything changes.
Actually the two sensors can be placed and oriented almost anywhere on the ball and you can capture full 3d rotation. For optimal accuracy you probably want them in some specific alignment though. This paper suggests that you get better numerical stability if the two sensors are at 90° to each-other http://3map.snu.ac.kr/courses/2001/cg/lecture/trackball.ps but I think their analysis seems a bit simplistic.I think we should "throw away" any unneeded data and forget about added accuracy. Those sensors are good enough for me!
Is the enclosure designed for a 57.2mm ball? Did they tell you how much bulk purchase would be? of that enclosure?Its for 2.25" ball. They have no discount for bulk purchase.
You might want to design some sturdy mounting studs for the container, that way this system could be used with just about any outer housing shape/design as long as the housing has the holes for mounting the container.Good idea.
I put data files for testing only at: https://github.com/hanya/btutbIs the enclosure designed for a 57.2mm ball? Did they tell you how much bulk purchase would be? of that enclosure?Its for 2.25" ball. They have no discount for bulk purchase.QuoteYou might want to design some sturdy mounting studs for the container, that way this system could be used with just about any outer housing shape/design as long as the housing has the holes for mounting the container.Good idea.
I uses trackball in left hand, so I would make left handed one for mine.
What?? 2 1/4th is a very common size. The older Kensingtons, the CSTs, the dt225...Just re-checked: my mistake.
It's the same size as most billiard balls so it's easy to find quality replacements at decent prices.
Watching this closely, love older trackballs but all the current models on the market are uncomfortable for me to use.What is uncomfortable about them?
@Synnöve - I have two older (off white) CST Trackballs if you would like them for testing and building your model. PM me if you are interested.Will do!
Watching this closely, love older trackballs but all the current models on the market are uncomfortable for me to use.What is uncomfortable about them?@Synnöve - I have two older (off white) CST Trackballs if you would like them for testing and building your model. PM me if you are interested.Will do!
Keep in mind it's a 50cm (2") ball.mm*
Keep in mind it's a 50cm (2") ball.For prototyping, I’m not too worried about the precise ball size, as long as the ball is a nice weight, smooth, and very spherical. Any design I make shouldn’t be too hard to adjust to fit a slightly bigger or smaller ball.
Keep in mind it's a 50cm (2") ball.mm*
I think we could probably get away with substantially bigger ones and still have them fit just fine, so if there’s any price difference for buying in bulk, we should just go with whatever is cheapest.
If you roll one of the ball transfer units along a wooden surface, it’s definitely loud, but I don’t think in practice screwed into a housing and spinning against a typical trackball it will be especially loud, or at any rate not any louder than the P&G trackball’s ball bearings. Figuring out how to plan a few little pieces of sorbothane into the design might help with any noise though.I agree that if it's screwed in to a sturdy housing with some dampening material installed, it should yield acceptable results.
I’m still not sure whether I want to use 2 sensors or 3, or exactly what shape I want to make the final housing. I’ll probably make some plasticine models in a week or two (sometime after KeyCon), but I’ll try to bring some kind of simple cardboard mockup to KeyCon if anyone who’s going wants to get a feel for the ball transfer units. Overall, I’m pretty optimistic about the project.Look forward to seeing your mockup and hearing feedback from others concerning the feel of the units. Why would you need more than two sensors?
This was my reaction as well, though I'd clarify that it's important to make sure the support balls and internals are stainless steel for longevity's sake.I’m pretty sure the Delrin ones would work too. Remember, the trackball is much lighter than the loads these ball transfer units are designed to support, the motion mostly rolling, not scraping, so there should be a lot less wear than with any existing trackballs.
Watching this closely, love older trackballs but all the current models on the market are uncomfortable for me to use.What is uncomfortable about them?@Synnöve - I have two older (off white) CST Trackballs if you would like them for testing and building your model. PM me if you are interested.Will do!
i think your mockup doesn’t leave as much of the ball exposed as I’d like. For a 2-d trackball it’s probably fine, but for a 3-d trackball it’s a huge advantage to be able to grip as much of the ball as possible.
Along with maybe being able to use larger ball units and/or plastic ones, I also think we should try the other model type of Alwayse ball units. That is, try 11-MI-05-13 or 11-MI-05-15 (is carbon steel vs stainless steel going to matter for us?) instead of the 11-MI-05-17. The few millimeters of extra overall size aren’t going to be a dealbreaker for us, and because they seem to use larger helper bearings, I suspect they might spin even smoother. Also, the longer metal bolt might come in really handy. I don’t think there’s any disadvantage for us in picking the flat top instead of chamfered-top kind.
After KeyCon I’m going to try to get the laser sensors hooked up to a Teensy 3.0 and see if they will usefully track the surface of the ball (it’s a smooth glossy black ball; not sure if that’s a good surface to track on or not). If I can get that working okay with one sensor, then I’ll start trying to design a housing I like. I’ll probably try to CNC cut it out of hardwood, and at some point integrate it with a keyboard.
That’s right, I want to measure the full 3-dimensional rotation of the ball. Internally to the trackball firmware, I want to at some point in the logic have the last time increment’s rotation stored as a quaternion. Then it’s possible to take this quaternion and process it to back out the amount of rotation about any arbitrary axes.i think your mockup doesn’t leave as much of the ball exposed as I’d like. For a 2-d trackball it’s probably fine, but for a 3-d trackball it’s a huge advantage to be able to grip as much of the ball as possible.When you say 3D I assume you're talking about the up down & side to side axis but with the addition of twist?
I brought the ball transfer units and trackball in my super classy cardboard housing to KeyCon, and everyone agreed: super smooth!
I brought the ball transfer units and trackball in my super classy cardboard housing to KeyCon, and everyone agreed: super smooth!
this it? looks nice
so is there no sticking/skipping on really small movement?There is a bit of “scratchiness” for small slow movements. I’m not sure if this is inherent, or just something to do with my flimsy cardboard mockup, or perhaps something that could be improved by using different ball transfer units.
and do the balls stay a little smooth after longer use? no dust collecting inside the units or anything?This is impossible to tell before building a real housing and using the trackball more extensively. I’m guessing they’ll last pretty well.
so is there no sticking/skipping on really small movement? and do the balls stay a little smooth after longer use? no dust collecting inside the units or anything?
There is a bit of “scratchiness” for small slow movements. I’m not sure if this is inherent, or just something to do with my flimsy cardboard mockup, or perhaps something that could be improved by using different ball transfer units.
I opened L-trac to see if there's any room to fit in 3 ball bearings with 3d printed frame.
The answer is no the bearing on the right side will overlap with trackball right key.
the scratchyness doesnt sound to bothering in the video.It was barely noticeable. I really really liked it and I'm a "trackball-bearing snob".
I opened L-trac to see if there's any room to fit in 3 ball bearings with 3d printed frame.
The answer is no the bearing on the right side will overlap with trackball right key.
I was thinking about that, and decided it would be a lot easier to just move that microswitch elsewhere in the case.
That said, the CST trackballs are not the best targets (though it would improve their most obvious flaw: the bearings)
I've been searching for a place to purchase the ball transfer bearings in 3mm or 5mm. If anyone finds a way to buy them, please let me know. I plan on revising my 3D printed trackball design to incorporate these. It looks like much good work has been done so far and I can share my models when/if they get done and work. It would probably take a 5-axis CNC to mill the socket properly, so 3D printing makes sense. I only have a 3 axis CNC and milling the pockets for the bearings in the sides at an angle would be the challenge...or just work those by hand?Hey John! Good to see you here again.
The only thing I can't quite figure out is why the need for two of my sensors verses one located right at the bottom of the ball. What does twisting the ball do for you? Maybe one located at the bottom for "normal" movements and one along the side to detect the twist?
I think it makes sense to incorporate some adjustment via set screws backing each bearing to achieve the optimal 2.4mm distance from sensor lens to ball. I know it was a booger to get all three of my bearing lined up to that distance when I made my trackballs. This also allows for centering the ball in the socket for any inconsistencies. There is only about 0.2mm of tolerance to this measurement from ball to sensor, so getting exact dialed in distance is key to a solid motion reading. I can imagine that getting two sensors along the side of the ball lined up at that distance would be challenging for sure.
I'm also giving serious thought to a Kickstarter campaign if I can get trackball design that I'm happy with that I can make more of in a reasonable assembly line (like casting the ball sockets and bodies). This will help us all get the benefits of group buying. I'm a fan of the thumb ball design, but not ruling out a center mounted option as well.
-John
I've been searching for a place to purchase the ball transfer bearings in 3mm or 5mm. If anyone finds a way to buy them, please let me know. I plan on revising my 3D printed trackball design to incorporate these. It looks like much good work has been done so far and I can share my models when/if they get done and work. It would probably take a 5-axis CNC to mill the socket properly, so 3D printing makes sense. I only have a 3 axis CNC and milling the pockets for the bearings in the sides at an angle would be the challenge...or just work those by hand?I’ve been very busy with random other stuff for the past month, but I’m going to try to start in on this again in earnest ASAP (and I’m sure emailing you with sensor protocol questions). I want to try to CNC cut it out of wood, on a 3-axis CNC router. I think I can do it by building some little jigs to hold the workpiece at 2-3 different angles so I can properly mill out the little pockets to hold the bearings and sensor. It’s going to take more elaborate setup than it would with a 5-axis mill, but I think it should be doable.
The only thing I can't quite figure out is why the need for two of my sensors verses one located right at the bottom of the ball. What does twisting the ball do for you? Maybe one located at the bottom for "normal" movements and one along the side to detect the twist?Personally I want to record the full 3-dimensional rotation of the ball, so I can use it for rotating objects in a 3-d environment (like a cad program or a data visualization or whatever).
It'd be hard to use in daily life, like for a volume control or scrollwheel or somethingKensington slimblade has twisting working as scroll wheel and it works exceptionally well IMO.
It'd be hard to use in daily life, like for a volume control or scrollwheel or somethingKensington slimblade has twisting working as scroll wheel and it works exceptionally well IMO.
The slimblades use a scroll ring around the side of the trackball: a much different design (that does indeed work nicely).Actually new Kensington Slimblades include 2 sensors and interpret twists of the ball as scrolling.
The idea on this one is to twist the trackball itself. You could use it for scrolling, but it'd also happen a lot when you're just moving the cursor around, making it a bad solution, imo.
Exactly. And in the 9 months of using it, it never happened when I didn't want it to, so it's definitely possible to implement. I think it just checks if there's any rotation (with some margin of error) around any other axis than Z, and if there is, it's interpreted as cursor movement only. (You can't move the cursor and scroll at the same time)The slimblades use a scroll ring around the side of the trackball: a much different design (that does indeed work nicely).Actually new Kensington Slimblades include 2 sensors and interpret twists of the ball as scrolling.
The idea on this one is to twist the trackball itself. You could use it for scrolling, but it'd also happen a lot when you're just moving the cursor around, making it a bad solution, imo.
http://brightcove.vo.llnwd.net/e1/uds/pd/1414329509001/1414329509001_1544858659001_819f15a3-3f7f-4362-9249-be454ab48957.mp4
Does anyone had the skills to write an operating system driver (MS Windows and Mac for instance) that would allow the settings of a custom trackball to be adjusted?What kind of settings are you talking about? I was planning on building a trackball into a keyboard and making the firmware support some amount of custom behavior via typing the appropriate keystrokes (e.g. hold down a specific modifier to give the trackball the behavior of repeating the previous keypress for each unit of rotation / repeat the 'delete' key for rotation the other way, or hold down another modifier key to turn the trackball into a volume knob).
There aren't enough trackballs on the market.
Also, forefinger operated trackballs are evil. I feel sad that there are only two thumb-operated models on the market, and they're both mediocre.
Somebody said Logitech hates thumb-trackballs, and sics their lawyers on anyone who markets one. If true, the entire patent system and anything tangentially related needs to die a fiery, painful death.
Can someone who likes thumb trackballs explain exactly where they want to position their thumb, and what thumb motions they’d ideally want to use to move the ball in each direction? Do current thumb trackballs get the housing shape right? What about the sensor position or interpretation of rotations into X/Y movements? Do they put the finger buttons in a good place? How many finger buttons could be supported on a trackball actually shaped like a hand? maybe 1-2 per other finger? (Or should the pinky not get buttons?) How big should the ball be?
With a totally custom-designed trackball, any arbitrary rotational axes could be interpreted as X/Y (would probably work best if the two axes were orthogonal, but that's not strictly necessary), and the amount of rotation required to move one pixel in each direction could also be different, if e.g. the thumb has an easier time moving along one axis than another.
I’ve only briefly used a thumb trackball, and didn’t really like it, but if it were optimized for the actual strength/agility of the thumb, along with a housing that fit the rest of the hand properly, I could imagine it being nice to use. (I still think the thumb moves really well along one horizontal-ish direction, and quite poorly in the vertical-ish direction unless you start moving the whole hand around, but maybe that’s just me.)
There aren't enough trackballs on the market.
Also, forefinger operated trackballs are evil. I feel sad that there are only two thumb-operated models on the market, and they're both mediocre.
Somebody said Logitech hates thumb-trackballs, and sics their lawyers on anyone who markets one. If true, the entire patent system and anything tangentially related needs to die a fiery, painful death.
I feel the same way. I really love thumb trackballs. I am using one at work and have done so for years. if you have to go across multiple screens and constantly select and drag things, then a trackball is arguably faster and easier to use (for me at least). People might also be surprised with the speed and accuracy with which you can use it.
Anyway, I really wish there were more options to choose from. Such a shame that there is barely anything else than the logitech M570. Which is surprising given that it is actually fairly popular. The only thing like it I have found is a rather unimpressive Japanese one.
I am inspired by passion of fellow hackers looking to play with some balls.
As to left-handed designs ... It's a valid consideration. Do the shops that 3D print, offer to invert the image? Same firmware, controller, parts, you'd just need to make everything be flipped left-to-right, and you'd have a left handed housing.
As to left-handed designs ... It's a valid consideration. Do the shops that 3D print, offer to invert the image? Same firmware, controller, parts, you'd just need to make everything be flipped left-to-right, and you'd have a left handed housing.
That can be done in about 5 seconds in software. It can be done either by mirroring the entire thing or scaling it to -100% in one direction depending on whether it is parametric or in a polygon format. It is trivial either way.
Flipping an axis in code is a simple as multiplying the results by -1. This can be done for X or Y.
I'm planning to make a modular ball socket that can be dropped into a custom shell for left, right or middle control. The shell would need buttons, but that isn't too hard.
I also completed a Java app this weekend that allows for a GUI to control settings of my Teensy based trackball. It uses the virtual USB serial port to communicate with the Teensy. It stores the profiles in the microcontroller EEPROM, so they travel inside the trackball and survive the power being cut. At this point, looking at 10 custom profiles. Java App Screenshot: https://www.flickr.com/photos/8465641@N07/14937404399/ (https://www.flickr.com/photos/8465641@N07/14937404399/)
It looks like those Holo Pack bearings I linked previously cost about $4-$8 each in small quantities. The lower cost being all plastic and the higher cost being all stainless. I'll have to order them from Taiwan directly with a $100 minimum order amount and direct bank account transfer only (another $50 fee). I'll probably hold off ordering these to prototype until funding on the Kickstarter project. For now, I'll just stick with the metal nub bearings I'm using now to make the newer trackball version.
John
Designers: Please do not forget those of us who have an extreme preference for a non-thumb trackball; whenever I try to use one I cannot achieve the movements nor same level of dexterity.Yes, I prefer non-thumb, larger ball, etc. I'd be willing to try a thumb ball, but ultimately I think the traditional kind is better for me.
The friction of the units internal system might be higher than the billiard ball on the units. Where did you purchase them from?This one: http://www2s.biglobe.ne.jp/~quartier/pettit-ball-castor.htm
Has there been any discussion on using ceramic ball bearings over steel and polymer?
http://www.bocabearings.com/bearing-types/balls/ceramic-silicon-nitride-si3n4-series
I'm holding off on buying a CST or another Slimblade. Wanna see how this project plays out.
What would be the effort to send 5 different mouse buttons? Do you need driver support for that? Would it be possible to fool an existing driver?That shouldn’t be much trouble, once the firmware has a reasonable USB HID implementation. Sending mouse buttons, keyboard combinations, game controller inputs, or whatever else should be pretty straightforward. Figuring out the best system for configuring the firmware to do what you want is an interesting non-trivial problem, though. The user interface design part is the difficult problem here though, not actually coding up the mouse button actions.
Have you calculated the force being applied on the BTUs? A 52mm Ball will weigh around 100grams (tested a Logitech Marble FX ball), my relaxed Fingers laying on the ball add another 150grams. At the angle the BTUs are positioned, I figure you're pretty close to the max rated load of the Polymer ball type, especially if you consider additional forces from moving the ball.Which ball transfer units are you considering? The ones I got some samples of from Synnöve have a metal ball, and seem quite sturdy. I haven’t subjected any to long-term usage, so I can’t tell you for sure how well they’ll hold up, but I have high hopes.
Have you considered that the "natural" X/Y axis (the directions a user intuitively moves the ball to go straight left/right and up/down ) do not correspond to the physical X/Y axis of the sensor? Have you considered that the natural X/Y axis might not be perpendicular? I.e. are you planning to implement a translation from physical coordinates to actual mouse movement? Are you planning to add some kind of calibration to account for the different natural movement directions of different users? [...] Also, the way I use an ergonomical trackball, the actual center of movement (where physical movement and desired mouse movement would differ the least) is towards my hand - incidentally very close to where the sensor of the TBE sits ;)Absolutely. Personally, my goal is to use two sensors, and as an intermediate step compute the full 3-dimensional rotation of the ball at each timestep (e.g. as a quaternion). Once you have a precise/accurate measure of the 3-d rotation of the ball, it’s fairly easy to transform that to find the rotation relative to any particular set of axes, which means any arbitrary ball directions could be associated with X and Y (even with different sensitivity in each dimension if you want), when you want to use the ball motion to move a 2-d cursor.
PLEASE don't put a sensor underneath the ball - if you care about ergonomic design, you want the trackball to be as low as possible. Every mm of height adds bend+strain to your wrist and/or reduces the contact area of your arm, increasing pressure on your heel of hand. Also, if you need to translate physical movement to mouse cursor movement anyway, it does not matter where the sensor is placed.My personal advice would be to avoid flexing or extending your wrist at all if possible, keeping it in a neutral position, and also avoid putting pressure on the heel of your hand to the extent possible. Having your palm and wrist entirely in the air is the ideal, but resting it lightly on some surface is probably acceptable, as long as you’re not pressing down hard. Of critical importance is the height of your desk and chair, and the distance to the trackball.
How long do I have to keep typing these verification strings? Is there a number of posts after which you are no longer required to do it?
Why not duplicate the functionality of a single ball transfer unit as the trackball itself. You'd need to make an accurate housing for it, though. The basic idea is part spherical housing with internal diameter of ball + bearing size, with a rolled off edge. You put a bunch of smaller bearings in there and then rest the big one on them, with a number resting on the rolled off edge. As the big one rotates, the small ones unload at the rolled off edge and are free to move. With an enclosed space they will migrate to the other side where they are rolled under the big ball again. The sensors will have to be poisitioned above the ball rolling area, so it means you'd need two sensors to track all rotations. A pair of optical mouse sensors should work just fine.
There aren't enough trackballs on the market.
Also, forefinger operated trackballs are evil. I feel sad that there are only two thumb-operated models on the market, and they're both mediocre.
Somebody said Logitech hates thumb-trackballs, and sics their lawyers on anyone who markets one. If true, the entire patent system and anything tangentially related needs to die a fiery, painful death.
Hi guys,
Great work so far. I've been following this concept for a while now, here and on Deskthority.
I kinda ditched the idea of getting Kensington Slimblade, and ordered some Rexroth BTUs instead, so I may soon join in on the fun ;D
Just a question though: I see that most people use pretty heavy balls for their trackballs, which is kinda counter-intuitive for me. Wouldn't it be better to have a lightweight ball, with little inertia?
No luck with the printed transfer units. The small balls don't always spin in the housing thus generating different friction values which do not allow for a smooth motion. It might be related to the interior finish of the housing. Being 3d printed the walls are ridged and not smooth as they are with other manufacturing techniques. The hardness of PLA does probably play a role too.
I just tried a Logitech Cordless Optical TrackMan and there the ball encounters almost no resistance when you try to spin it from a stand still but it stops rapidly if you flick it. With my transfer units the ball encounters some resistance when you spin it from a stand still (results in a jerky start) but spins much longer then the logitech. I don't understand...
A USB unit just doesn't play nicely with phone/tablet use!As far as I know you can’t really use an external pointing device in a meaningful way on a phone/tablet anyway. There’s no pointer symbol on screen, and the mobile operating systems are designed around direct touch.
What would you do with a trackball hooked up to a phone?
1.
Minimizing the contact area is what i'm trying to do. At the moment I see no way of inserting something in the printed part (maybe some very small screws?). I also thought of printing a "real" BTU, with the 5mm ball sitting on 1 mm balls, but the printer I am using can't print that well and also I am missing the 1mm balls.
When you say you're molding your own ball are you referring to the actual ball? If so, why?
Have you tried the BTUs with a ball? How smooth is the movement? What model have you bought?
My printed BTUs are not providing a satisfying movement. The ones I printed yesterday turned up ok, the nitride ball could spin freely inside, but the friction is still too high. Probably a precision housing and better materials are required.
In the mean time I bought a m570 trackball and it is smoother but the ball is way to small and light for my novice taste. I only bought it to have something to benchmark against.
Mainly to get the right diameter (75mm), and to have it empty inside so it's light and has relatively low inertia.A dense ball is in general nicer to use. You want something dense and smooth and perfectly spherical. The point of the ball transfer units is to make the ball’s speed easy to control with your finger, regardless of the trackball weight. A heavier ball rolls more smoothly because the ball transfers work better under a moderate load. You also want a material which your finger sticks to just slightly. The balls that come with industrial trackballs are just about perfect (though they could benefit from being slightly grippier): I think it would take a lot of work to do better, and that would be basically impossible using common 3d printing technologies, which are imprecise with a limited choice of materials and terrible surface finish.
@GuilleAcoustic
Which BTU are you planing on using?
A heavier ball rolls more smoothly because the ball transfers work better under a moderate load.
I think it would take a lot of work to do better, and that would be basically impossible using common 3d printing technologies, which are imprecise with a limited choice of materials and terrible surface finish.
@sinusoid
I hope you succeed, but I fear it is almost impossible (with home/hobby tools) to obtain the same quality as an industrially produced ball.
The balls I am using in the printed transfer units are 5mm diameter so a printer with very good precision is needed in order to have complex models at that size. The one I have access to sadly isn't very precise.
As for your IRON MAIDEN, I fear for it's teeth. When you take into consideration the 200g ball and human hand + force exerted by operating the ball it might end up with a few broken teeth very soon. Also I think it has too much contact surface.
There are better ways of getting a load on a bearing than increasing weigh of the rolling element. Will show later.Superstition? I’m just telling you my direct personal experience playing with ball transfer units. I don’t claim any kind of omniscient knowledge though; maybe your ball units behave differently.
I think there is a tad bit too much superstition about trackballs, and not nearly enough experimentation.