Should we make a Left Handed version Combimouse?

Here is a concept of what a Left Handed version could look like.

This is just a quick sketch and isn’t a definitive solution. It is presented for discussion purposes only. For example a left handed version wouldn’t have the right part being mobile with the big palm/grip rest.

Click to enlarge.

What do you think?

Consider the following:

15% of people are left handed.

50% of left handed people use a mouse in a right handed way.

If we did a special left handed version, the Function keys could be located at the top of the right unit which would be stationary.

It is very expensive to make a special shape. Ideally one design can satisfy the majority of users.

We would like to build an optimized left handed version but at his stage it is not economically viable for us.

Scroll solutions for the Combimouse

There is no ideal scrolling solution for the right hand Combimouse part.

On the earlier prototype a Scroll wheel was located on the left part but that is not ideal and will be removed.

Currently the thinking is to implement both the Gesture Scrolling and Click Scrolling methods as described in the first two solutions below. The third solution is likely to also be present.

Gesture scrolling by moving finger along surface of the Comma key

This is the same that is done on the Apple Magic Mouse and some Microsoft mice.

By moving your finger along the surface scrolling will happen.

This hasn’t been implemented yet on the Combimouse, but it is expected to work and is practical to implement even though it is fairly complicated. I did say it is practical to implement - that needs to be confirmed.

There is a disadvantage of this system as it is very sensitive and doesn’t give as much control as a scroll wheel.

The other disadvantage is that it is only available for Mouse Grip 1 and not Mouse Grip 2

Mouse grip 1


Mouse grip 2

Click scrolling

This has been implemented and works well. The disadvantage is that like the Gesture Scrolling method it doesn’t provide fine control.

One advantage is that works for both mouse grip modes.

During mouse mode, if the P or Semi-Colon is pressed and released, the unit goes into scrolling mode. If you move the mouse up or down from this zero position scrolling goes up or down. The further you move from the zero position the faster the scrolling. If you keep the mouse at a position away from the zero position scrolling accelerates quickly. This makes it easy to jump to the top and bottom of documents.

To get out of the scrolling mode, any key is pressed or you got out of mouse mode by stop touching the touch sensor on the right side of the unit.

Alternate Click Scrolling

This method was prototyped but is not practical.

If you were to press a designated key during mouse mode, scrolling would occur by moving the mouse. The problem is you need to keep moving the mouse for scrolling to continue. By the time you are finished scrolling the mouse has moved very far.

Pointing stick

The pointing stick as shown below has been considered. It wouldn’t move the cursor as it normal does - rather it would produce scrolling in the direction it  pushed. I discarded this option - I must confess that I can’t remember why. I think it was due the high power consumption.

One advantage would be that the same pointing stick  could be used with both mouse grip modes. It also doesn’t add significant mass far from the centre of gravity


Thumb Wheel Scrolling

This method has been suggested and is being considered, although it would seem that it probably is not a good solution.

The big advantage is that it is accurate and has good control.

Two scroll wheels located on the mouse grip as shown in the diagram below would be needed. Two scroll wheels would be required - one for each mouse grip mode.

One problem is that there there would not be enough space for the thumb between the Space key and the side of the side when using the top scroll wheel. In addition the height below the keyboard to house the scroll wheels is not sufficient. There is only 7mm available.

Another problem is that the thumb may not be suitable for continuous scrolling and may cause RSI - this is just a gut feeling and may not actually occur.


What’s it like using the Combimouse?

So, what’s it like using the Combimouse.

Having a mouse at one’s fingertips is of course is the main advantage and it is great. Often I sit back and say to myself after doing some nifty mouse action – Did that really happen? Wow!

As a mouse it works as well as a regular mouse.

I still need to implement a suitable scrolling mechanism. At the moment I am considering making the surface of the raises comma key a touch sensitive surface on which scrolling can be implemented as is done on the Apple Magic Mouse and some Microsoft mice. Someone has suggested a Scroll wheel by the right thumb grip - unfortunately there is limited space already for the thumb in the space between the SPACE and DEL keys. There wouldn’t be enough space for it to roll the wheel.

As a keyboard it works as well as a normal keyboard. Some keys have been moved. Some keys like the backspace and delete keys have been moved to very convenient positions. Unfortunately some keys have been moved to different positions – these are:

Back Slash, Forward Slash, Home, End, Page Up and Page Down.

I use my Combimouse full time (except when it is dismantled). When I do use my regular keyboard and mouse it is annoying to have to move my hand between the keyboard and mouse.

Combimouse Design Evolution

In this blog I will give you a brief summary of the Combimouse design history. I have made many prototypes over the years. At the time it was invented, technology wasn’t available to make it a reality. There were also difficult design obstacles to overcome.


I will refer to the Old prototype shown below as “OLD”. OLD has a mass of 194 grams. The centre of gravity is located somewhere along the red line. This is what the Combimouse looked like in 2012.

The latest prototype (as of April 2013) is shown in the following sketch and has a mass of 74 grams. I will refer to it as “LATEST”. The centre of gravity is located somewhere on the red line. It is 120 grams lighter than OLD and lighter than most regular mice.

As a comparison, below is the Apple Magic which has a mass of 108 grams. The centre of gravity is located somewhere along the red line. It is 34 grams heavier than the Combimouse.

Originally with OLD, I thought that the palm grip had to be bulging. This was necessary so that it would fill the palm of the hand while using as a mouse. This was especially true up until a few years ago, when the right part was heavy and a good grip was necessary.

The problem is that this bulge made it uncomfortable as a palm rest during typing. As a palm rest it has to be flat and low. Also when I used to move my hand when typing I would bump into the large bulge and the whole unit would move.

On OLD, I was using AA batteries that have a diameter of 14mm. Also on OLD I wasn’t aware that height is an issue – I have subsequently discovered that the top of the keys must be as low as possible. The height of the top of the keys above the desk on OLD is 27mm. On Latest it is 14mm. So LATEST is much lower and that makes typing much easier.

In addition the mouse click keys are now much lower and better.

Apple started selling the Apple Magic Mouse a few years ago. I was surprised that it didn’t have a bulge to fill the bottom of the hand. They made it very flat and low. This is probably a compromise so that they can make the surface a flat touch sensitive surface for gestures. Apple supplies this mouse with all their Macs.

Last year (2012) I realized that if Apple can do this then so can I. I can now have a low flat surface for the palm rest/palm grip, which is ideal as a palm rest during typing. It is also good enough as a palm grip during mouse mode especially now that LATEST is light and doesn’t need a firm grip. This was a major breakthrough.

In addition electronics have reached a point where power consumption is very low. Today a common Logitech wireless mouse has over 1.5 years battery life. So the Combimouse, which has a relatively high current consumption, can use the lighter and smaller AAA battery. This makes LATEST lower and lighter.

Mass of Keyboard Section

It is critical to make the mass of the Keyboard section as low as possible so that it isn’t top heavy during mouse mode. Even 1 gram is a lot. Notebook Keyboard technology has slowly improved to a point where keyboards are very light.

In addition thin plastic walled devices are now possible allowing for a light Combimouse. One mm thick walls are now easy. This is mainly due to advances in mold flow analysis software, which occurred in the last few years.

This progress in technology makes a light design possible.

There are two main conflicting design obstacles that had to be overcome with the Combimouse:

  • Make it mobile as a mouse
  • Make it immobile as a keyboard.

Mobile Mouse

To make it mobile as a mouse it was necessary to reduce the mass and achieve a favorable center of gravity and low moment of inertia. What this comes down to, is making the mass of the keyboard section as low as possible. I have got it to a point where the area bounded by the Equal, Seven, Space and Shift keys is about 15 grams. This took a long time. I have been liaising with the manufacturer to check that this solution is manufacturable. They think it is manufacturable, but would need to use software flow analysis to confirm this and this costs money.

Immobile Keyboard

The problem of making the unit immobile as a keyboard was a difficult problem. Earlier this year (2013)I decided that I needed a radical change to solve this problem, as I wasn’t getting anywhere. I have now devised a solution. Unfortunately I can’t talk about the solution, as I will be patenting it.

After all these years it is a relief that this problem has been finally resolved.

As a result the Combimouse works well as described in the blog “What’s it like using the Combimouse?“.

The PC is dead - Touch devices are the future - No need for Combimouse?

The news these days is that “PC sales plunge as tablets bite“.

Does that mean that the Combimouse has missed it’s opportunity?

Do you have fewer computers in your home than you used to and would have less of a need for the Combimouse?

Or as the this article suggests is it that:

“The reason people aren’t buying new PCs isn’t that they don’t need a PC. It’s that, for the most part, they’re getting along just fine with the one they already have.”

and as this article says:

“Tablets and smartphones aren’t replacing PCs, says Sacconaghi, but they are likely “lengthening the replacement cycle” as they cut into some of the PC’s workload and make their replacement less urgent.”

Why not use Bluetooth - Question from Indiegogo

There was a question about using BLUETOOTH, but there is a problem – see below.
Bluetooth will have to come later. I need to check but certainly a few years ago it was expensive and difficult to implement.
The problem is that there needs to be interaction between the left and right units. For example when you hold the 2nd Fn key down on the left unit it enables alternative functions on the right side. These alternative functions include modifying cursor up to page up for example. Another alternative function is temproarily modifying space to back space. There are many others.

The left and right units transmit data to the dongle and the dongle can combine the functions described above.