A trackball and a conventional mouse can both be excellent CAD input devices. The difference is not the accuracy of the geometry you create: it is how you control the pointer, how much room you need on your desk and which arrangement feels natural to you.
Quick answer
Choose a trackball if you like the idea of leaving the device in one place and moving the pointer with your thumb or fingers. Choose a conventional mouse if you prefer familiar hand movement and don't mind reserving some desk space. Neither guarantees better CAD precision; accurate models come from snaps, dimensions, constraints and coordinates.
How movement differs
With a conventional mouse you move the whole device across the desk. With a trackball the device stays still while you rotate a ball. This can make a noticeable difference when CAD drawings, notes, books and other equipment compete for desk space.
Our contributor has used a Logitech M570 trackball for CAD for many years and now uses a ProtoArc EM04 at work. The biggest frustration remembered from conventional mice was the amount of clear desk space needed for repeated movement. That is historical personal experience: modern mice can use adjustable sensitivity, which reduces the physical distance needed for a given pointer movement.
Trackball vs mouse: at a glance
| Consideration | Trackball | Conventional mouse |
|---|---|---|
| Pointer movement | Rotate a ball; device stays in place | Move the mouse across the desk |
| Clear desk area | Generally little movement space needed | Some clear movement area required |
| Learning curve | Can take time after years using a mouse | Familiar to most users |
| Drag-and-drop | Depends heavily on button arrangement | Usually familiar button arrangement |
| Pointer sensitivity | Adjustable on many models | Adjustable on many models |
| Best for everyone? | No | No |
What does DPI mean for CAD?
DPI is a sensitivity specification commonly used for pointing devices. In practical terms, a higher setting usually moves the on-screen pointer farther for a given physical movement; a lower setting makes movement feel slower and more controlled. The operating system's pointer settings and any acceleration also affect the result.
That means modern mice can address part of the desk-movement complaint: raising sensitivity can reduce how far the mouse must travel. Trackballs can offer adjustable sensitivity too. Higher DPI alone does not mean a more accurate CAD model.
Buttons and drag-and-drop matter
Button position can be more important than it looks in product photographs. The contributor's first trackball, a Logitech TrackMan Marble, had an unfamiliar button layout that made drag-and-drop awkward. The later Logitech M570 and ProtoArc EM04 felt more natural, with buttons positioned much like a conventional mouse.
That is a reason to consider the whole device, not just whether its ball is thumb-operated or finger-operated. Try selecting, dragging, scrolling and using a middle-button CAD navigation action before deciding that a particular design suits you.
Comfort and the learning curve
Trackballs can be divisive: some users love them and others never get comfortable. A different movement pattern may require practice. Neither design is automatically better for everyone's wrist, hand or posture. Comfort depends on the individual, their working position and the exact product.
Our contributor now mainly uses conventional mice for browsing, Word and PowerPoint rather than CAD. This is not a recent hands-on comparison of modern mice; the current product options below are researched choices, not claimed personal tests.
Three products worth considering
Affiliate disclosure: The Amazon links below are affiliate links. As an Amazon Associate I earn from qualifying purchases. This does not change the price you pay. Prices and availability can change; check the seller's listing before ordering.
Logitech MX Ergo Wireless Trackball — adjustable-angle option
The original MX Ergo is a thumb-operated wireless trackball with an adjustable tilt and a precision-mode button. It is an older model, so confirm the exact listing, condition, seller and charging connector before purchasing. It is not the newer MX Ergo S.
View Logitech MX Ergo on Amazon UK (affiliate link) →
ProtoArc EM01 NL — another thumb-operated option
The EM01 NL is a rechargeable thumb-operated trackball with adjustable sensitivity and multi-device wireless connectivity. It is a different model from the ProtoArc EM04 used by our contributor, and we have not personally tested the EM01 NL. Check the exact product version and seller details.
View ProtoArc EM01 NL on Amazon UK (affiliate link) →
Logitech MX Master 4 — conventional mouse alternative
The MX Master 4 represents the conventional-mouse approach: the pointer is controlled by moving the device rather than rotating a ball. It is an option for someone who prefers a familiar mouse layout and adjustable pointer behaviour. It has not been personally tested by our contributor.
View Logitech MX Master 4 on Amazon UK (affiliate link) →
Which would I choose for CAD?
If a cluttered desk or repeated mouse movement frustrates you, a thumb trackball is worth trying. If you already work comfortably and efficiently with a conventional mouse, switching is not essential. If possible, give a trackball more than a few minutes before judging the different control method.
The two trackball products above are alternatives to investigate, not a claim that either is universally superior. We have not performed controlled accuracy, comfort or durability tests on these three featured products.
Read the first-hand experience
For the longer story of using the TrackMan Marble, Logitech M570 and ProtoArc EM04 in CAD work, see Are Trackballs Good for CAD? My Experience After Years of Using One →
Editorial note: First-hand observations refer only to the TrackMan Marble, M570 and EM04. The linked MX Ergo, EM01 NL and MX Master 4 are presented as researched shopping options, not products personally tested by the contributor. No performance ranking is implied.