Author Topic: Re-Create the DataHand - Thumb cluster under development. Project 75% done.  (Read 221625 times)

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Offline JesusFreke

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Re: Re-Create the DataHand - Thumb cluster under development. Project 75% done.
« Reply #750 on: Wed, 11 September 2019, 01:35:32 »
datahand: around 28.5mm
lalboard: around 27mm

Offline RSanders

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Re: Re-Create the DataHand - Thumb cluster under development. Project 75% done.
« Reply #751 on: Wed, 11 September 2019, 09:34:36 »
It appears to me that Datahand is not for people with medium/small hands, I`m saying that because the thickness of the switches and distance between the clusters/switch assembly will force the user to uncomfortably spread fingers to touch the center/down switch or pinky/left and index/right.

For example my hand is 7 inch long, measuring from wrist joint to tip of the middle finger, according to the pictures and measurements I found about DataHand, I would not be able to use the device comfortably.

Part of the challenge is to make the 5 way switch no bigger than 1 inch width/height and keep it serviceable. People with extra small hands... sorry, having Michael Jordan`s hand size would solve lots of design problems

@RSanders or anyone that own a DataHand, do you happen to have large hands/long fingers ? And thank you all for posting pictures of the original device.

The keymouse... the trackball version is $500+..., the mouse version is not even worth talking about, you cant destroy your shoulder constantly moving half pound piece of plastic on the desk...

For that money you can get a cheap 3d printer for $150, micro switches max $20, one roll of filament whatever color you want $15, soldering iron, wires/solder/flux $40, teensy $20

And you can customize it, modify the 3d file and print parts as you please, make modifications to fit your need, hang in there, we`ll get this :)



I will have some additional measurements for you shortly beyond what has already been posted. Regarding hand size, the measurement from the base of my palm where it connects to the wrist to the tip of my long finger is essentially identical to you, i.e 7”. In my opinion, smaller to mid sized hands would have an easier time with the DataHand than someone with large hands and correspondingly thick fingers, mostly as relates to accidental/incidental key activation. What you may have been missing from not having access to an actual unit is that the PCB to which the key wells are attached is fully adjustable in the x, y, and z plane using the two numbered dials pictured (for adjusting distance of left and right corners of the PCB in relation to the palm pad) and the thumb screw pictured for elevation (one on each side of the unit for independent elevation of the left and right side of the PCB). The PCB is not visible as it is protected by what amounts to a rubber dental dam. The rotational position of the PCB board has a big impact on comfort, at least for me. It effectively reduces the horizontal distance with which you were concerned between the fingers. It is much easier to curl the fingers towards the palm than it is to spread them, as you have observed.  On mine, the left hand PCB is rotated counterclockwise slightly and the right hand one is rotated clockwise slightly. Tenting is also important. On the left, my pinky is lower than my pointer finger. On the right, same thing. To avoid unnecessary reaching and other contortions to activate keys, I requested tall keys for all except the south directions, as described below. The best way to describe this is for most west or east movements, I very slightly move the finger in question towards the west or east while at the same time very, very slightly pivoting my entire arm (forearm, wrist, hand all as one unit, pivoting more or less on the elbow or whatever is being supported by the arm of my chair) in that same direction giving just enough movement to the finger to activate the wanted key without activating any of the other west or east keys at the same time.  I added pads as needed to further decrease necessary travel, as specified below. It is important to note that, while the original design was intended for multiple users (each user making note of their respective dial settings or thumb screw settings), a properly and extensively configured DataHand, like mine, is a very individual thing and once set up "just so", it is not easy to convert all the adjustments, key heights, palm pad size, key padding, etc. over for another individual to use.


The rubber palm pads came in two sizes, small and large.  I personally use the large. The base unit also came with North keys tall and South West East keys short. I requested tall keys for all except the South direction as I had problems actuating the west and east keys otherwise, especially at speed. I also requested the oversized thumb up keys as I kept missing them at speed. Of note, I am slightly slower on a DataHand than on a regular flat keyboard, where I was timed by a temp agency at 120wpm in my prime.  I was closer to 80 to 90 wpm on a DataHand.  This is due to reaction times being faster if your fingers are hovering over keys as opposed to being in physical contact with them prior to activating your finger to activate the key.  At one point I was working with DataHand engineers as I was outpacing the processor when switching between NAS mode (numbers and symbols) and normal as well as switching from typing a capital letter followed immediately by lower case. The unit would keep typing all caps even though I had released the shift key because I was typing too fast for the processor to catch that the shift key was no longer depressed. Same with NAS, I would type a number, release the NAS key, and numbers/symbols would continue to be output as I had outpaced the processor. For most typists this is probably not an issue but for a, at the time, high output medical transcriptionist, it was a big deal.  Now I don't have to type that fast or for as long so I don't worry to much about speeds. The issue was never satisfactorily resolved other than to limit the string of all caps to one cap after the originally intended cap or one number/symbol in addition to the initially intended number/symbol. Editing still became necessary so it really wasn't a fix as far as I was concerned.  I just learned to slow down when shifting between lower case/upper case and when typing in medication dosages (switching rapidly from numbers to letters). Even with a slightly slower speed on the DataHand, my output actually increased as I did NOT need breaks while using the Datahand. On any other keyboard, including Maltron and Kinesis, I still need periodic breaks as discomfort does develop when using those, just not nearly as quickly as when using a regular flat keyboard.

To further decrease necessary finger travel, I also requested the rubber adhesive pads to put on all the nswe keys and the thumb keys, most of which have long since deteriorated and have been replaced by industrial strength adhesive loop side (not hook side) Velcro.

The duct tape visible was me being lazy and not bothering to remove some deteriorated rubber pad for replacement with loop Velcro. I may get around to it at some point. The mostly missing (a warm thank you to the nighttime cleaning staff for that "modification" which essentially turns it into the original stock thumb up key) thumb up key is directly opposite the duct tape and, as it is only needed to toggle back to “normal” mode, it is not too much of a bother to pause a moment and reach a bit to actuate it when needed so I have not bothered cobbling together a replacement. If I were still in a high production medical transcription environment, I would have fixed it by now.

The intact right thumb up key is included for comparison only.

Thank you for your thoughts on the keymouse.  I will avoid for the moment. 
« Last Edit: Wed, 11 September 2019, 12:36:52 by RSanders »

Offline RSanders

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Re: Re-Create the DataHand - Thumb cluster under development. Project 75% done.
« Reply #752 on: Wed, 11 September 2019, 10:03:59 »
Each pod is 1" in external diameter with no overhang beyond the pod by the keys unless they are being actuated.

I am listing measurements based on the right hand side referring to each key well by letter, A, B, C and D with A being pointer finger, D being pinky.

For all practical purposes, A and C are directly across from each other with B being 4/10" higher than an imaginary line between A and C with D being 4/10" lower than the imaginary A - C line. While A and B appear to be more or less radially oriented the same (might be a very slight rotation clockwise for B compared with A), C shows more of a clockwise rotation from B and likewise, D shows more of a clockwise rotation from C.
Distance from center to center of down keys:
A - D = 3 and 1/10"
A - C = 2 and 1/10"
A - B = 1 and 1/10"

The tops of the tall key caps are 3/10" higher than the top of down key. The tops of the small key caps are 1/10" higher than the top of the down key.

Down key total travel distance is 1/10"

Inner diameter (where the finger goes) assuming tall keys and no padding is 7/10"

NSWE key travel is, depending on how high up the key you measure (lever motion, not linear motion like the down key), approximately 1/10" per key. Given the pods are 1/10" apart that makes sense.

I am eyeballing this as best I can without relying on a digital readout as I discovered this morning my work caliper battery is dead and my purely mechanical precision caliper is at home.

I couldn't really tell from the images already posted, does your design account for over-travel prevention similarly to the DataHand, i.e. the plastic "fence" around all four key wells?

On reading your issues with translucency potentially affecting the IR sensors, that reminded me of the time I tried to use a DataHand in direct sunlight. It did not go well, for obvious reasons. At first I thought I had a system failure and was quite relieved when drawing the blinds solved the issue. The device has to be used away from any strong direct light sources, otherwise the IR sensors get overwhelmed and no key input is possible.


« Last Edit: Wed, 11 September 2019, 11:05:33 by RSanders »

Offline JesusFreke

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Re: Re-Create the DataHand - Thumb cluster under development. Project 75% done.
« Reply #753 on: Wed, 11 September 2019, 12:13:05 »

I couldn't really tell from the images already posted, does your design account for over-travel prevention similarly to the DataHand, i.e. the plastic "fence" around all four key wells?



Each key well has a back that provides a positive stop. It also has a little groove that mates with one in the key to prevent the keys from sliding out when you press them, since they're not held in mechanically, only magnetically. (makes for much easier cleaning/maintenance/replacement!)



Offline RSanders

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Re: Re-Create the DataHand - Thumb cluster under development. Project 75% done.
« Reply #754 on: Wed, 11 September 2019, 12:33:37 »

Each key well has a back that provides a positive stop. It also has a little groove that mates with one in the key to prevent the keys from sliding out when you press them, since they're not held in mechanically, only magnetically. (makes for much easier cleaning/maintenance/replacement!)


Thank you for the explanation. That design may very well be an improvement on the original, assuming there are no issues with the overall weight of the keys vs the magnets. The DataHand overcame this by using a VERY thin/delicate stalk and a more or less hollow key cap, the weak point being right where the stalk push fits into the key cap, as was demonstrated by the nighttime cleaning staff when they broke off my "N" keycap.... On the DataHand, the inner keys themselves have the travel self limited by bumping into each other. The outer keys have their travel limited by the "fence". Since any excessive pressure on the part of the user is directed from the keycap directly to the "fence" or to another key that is relatively resistant to moving in a particular direction, there is usually no danger of the thin stalk/cap combination being damaged, nighttime cleaning staff excepted, of course. Removing the fence allows all of the external keys to be completely levered away from the central down key allowing for removal and cleaning. The internal ones are a bit more of a pain as the well itself has to be removed to allow the keys to rotate away from the down key completely for removal and cleaning.  Fortunately, I have only ever had problems with the "external" keys sticking as removing them for cleaning is much easier than the inner ones that bump into each other.  I have found that PCB-safe electrical contact cleaner sprayed around a key usually does the job as well without having to open up the mechanism for thorough cleaning and without negatively affecting the IR assembly.

You may find the following URL of interest: http://daveola.com/Pages/Stuff/DataHand/Cleaning/
« Last Edit: Wed, 11 September 2019, 12:39:28 by RSanders »

Offline JesusFreke

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Re: Re-Create the DataHand - Thumb cluster under development. Project 75% done.
« Reply #755 on: Wed, 11 September 2019, 13:07:33 »
Oh, I've thoroughly disassembled and reassembled my datahand quite a few times :). I had reverse engineered the PCB and wrote my own firmware from scratch for the "stock" at89c55wd that the datahand uses, and then replaced that with a teensy (firmware) (for better USB support), with a hacked together wiring harness/adapter for the 40pin DIP socket.

The firmware for the lalboard (which I still need to release, ugh. If anyone is waiting on that, feel free to ping me) is based on that teensy firmware.

But anywho, I always found it a pain to disassemble it -- even just taking off the fence to get at the keys/clusters, etc. Hence, I hardly ever cleaned my datahand :). I love how easy it is to take out any of the keys on the lalboard - it makes it so much more convenient to clean, and so I'm much more likely to.

I haven't had any issues with the side keys breaking, although I have snagged and broke the thumb mode keys that stick up a couple of times. But it's a simple matter to reprint and replace them. I make sure to keep a small stock of them on hand, haha.

The only occasional issues I've had with the side keys are crap getting stuck in the key well, causing the key to stick or not fully press, or the magnet coming loose from the key stem, which is easily solved with some CA glue.



Offline RSanders

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Re: Re-Create the DataHand - Thumb cluster under development. Project 75% done.
« Reply #756 on: Wed, 11 September 2019, 13:44:33 »
Very nice. Disassembly has always been a pain and I try to do it as little as possible.  Speaking as a former research engineer, your attention regarding ease of preventive maintenance and part replacement is very good to see. Dale Retter (https://www.linkedin.com/in/dale-retter-35441a19/)  would be pleased, I think to see all that everyone here has accomplished. Once complete, is the intent to have an open source DIY model for this project or has any contact been established with Dale regarding potentially releasing a re-created DataHand under a sustainable business model?

Offline JesusFreke

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Re: Re-Create the DataHand - Thumb cluster under development. Project 75% done.
« Reply #757 on: Wed, 11 September 2019, 14:03:08 »
Once complete, is the intent to have an open source DIY model for this project


... yes, it already is :)

lalboard.com


Offline RSanders

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Re: Re-Create the DataHand - Thumb cluster under development. Project 75% done.
« Reply #758 on: Wed, 11 September 2019, 15:07:49 »
.
... yes, it already is :)
lalboard.com

That just made my day. Thank you for forwarding the link.  Now I have a legitimate reason to purchase a 3d printer as well as a great off-season project to work on with the high school robotics team I mentor.


Offline iso

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Re: Re-Create the DataHand - Thumb cluster under development. Project 75% done.
« Reply #759 on: Thu, 12 September 2019, 11:52:55 »
Thank you both for the images/measurements.
The way I designed the cluster switches will allow about 10 degrees of movement, the top part of the switch is gonna be detacheable and can be reprinted different size to be as close as needed or away from the finger, the lever itself is gonna be a separate piece too, the longer the lever arm, the easier to push the button (longer travel)
Main switch assembly can be detached from the plate without desoldering, easy to clean it with little bit of compressed air.
If I can manage to find the time some soldering is gonna happen next Friday.

Offline JesusFreke

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Re: Re-Create the DataHand - Thumb cluster under development. Project 75% done.
« Reply #760 on: Thu, 12 September 2019, 12:00:53 »
The way I designed the cluster switches will allow about 10 degrees of movement

That sounds about right, I think my design has 12.5 degrees of movement for the side keys.


Offline RSanders

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Re: Re-Create the DataHand - Thumb cluster under development. Project 75% done.
« Reply #761 on: Thu, 12 September 2019, 13:11:05 »
Thank you both for the images/measurements....easy to clean it with little bit of compressed air.

You are most welcome.

I have found that in addition to compressed air, a minimal amount of a good quality non-conductive electrical contact cleaner with a lubricating component does a great job on the key mechanisms when (cough) aerosolized soda (cough) or other build-up gums up the works.  Saves the bother of disassembly and, given the age, the very real risk of breaking something critical. I am pleased to see the current iterations take into account ease of maintenance/repair, something DataHand just didn't do very well, in my opinion.  You can imagine how stressful it was attempting to swap out all the short key caps for long ones in the west east direction on the original. After breaking several following their directions, I ended up sending it back and having them do it. Swapping out the firmware chip was much easier by comparison.