I asked them some questions via Kickstarter. I'm intrigued to see how / what they say in response.
"Hi, my name is ***** and I test table tennis equipment and post the results on YouTube as PathfinderPro - https://www.youtube.com/user/PathfinderPro
I am looking at expanding my equipment testing capabilities and am intrigued by the mobility of trainerbot. For the majority of tests I'll be firing a ball directly downwards from a given distance at a sheet of rubber attached to a substance with a COR rating as close to 1 as I can source. Trainerbot looks like an interesting option for launching the balls at controlled and consistent speed and spin rates at these sheets of test rubbers.
I have a number of questions about trainerbot please:
1. Can the feed mechanism still work if trainerbot is laid horizontally so it fires balls vertically downwards?
2. Trainerbot is currently cylindrical in shape which means if I lay it horizontally the chances are it will move (roll) and any movement will invalidate my test results. Are there any mountings on trainerbot to allow me to fix it in a horizontal position whilst in use?
3. I currently use a TT Matic 500 robot. It feeds balls by forcing them through foam rollers. These foam rollers wear out. You don't mention what the feed mechanism is, nor the life expectancy of the wearable parts, nor if it's possible to buy replacement parts should these wear out. I can't afford to invest in a product which might work great for a few months but then due to wear issues the feeds become inconsistent and spare parts aren't available. If you intend to sell spare parts (good source of secondary income for you), what type of parts do you expect to wear out, how easy will it be to replace them and what will the cost of spare parts be?
4. When choosing where to fire the ball, you select a section of the table in the app. When I've used the TT matic 500, the velocity of the ball and spin rates used will dramatically affect the accuracy of the ball feeds and where the ball lands (even an inch difference in landing point on the table can dramatically affect the outcome of results in rubber rebound tests). There will also be times when I won't be using a table (firing the ball directly downwards at the rubber). The power used to fire the ball in to a certain section of the table looks like it's using algorithms based on the standard size of table tennis table. If I meed to aim the ball at distances further away than 9 feet can trainerbot cope with this or is it limited to trajectories with a maximum distance of the length of a table tennis table (9 feet).
5. Is it possible to specify the actual spin rates of the ball and speed eg set 60rpm, 75rpm, 100rpm and specify the actual launch speed eg 50mph, 60mph. I need to be able to specify spin rates and speed of the ball so that I can then use high speed photography to measure the rebound speed and spin rates and angle or rebound. You reference customisable settings like 1-9 but exactly what do 1-9 equate to in real terms?
6. How accurate is trainerbot. If you fired 30 balls at each section of the table, what would be the dispersion rates ie in segment 9 would the landing point vary by 1inch, 2 inches 3 inches or more?
7. How does this accuracy vary when different makes and types of ball are used (plastic and celluloid). I've produced a detailed comparison of the plastic and celluloid table tennis balls and know for a fact that there are quite significant differences in size of these balls. How does trainerbot cope with these differences to ensure consistency of results, especially if two types of ball are mixed in to the 30 balls trainerbot can feed on?
8. How consistent is trainerbot in feeding the balls in terms of spin and speed. Is there much variance in a batch of 30 balls fired at a selected speed and spin rate? What is that variance?
9. Watching trainerbot move and rotate, the motion seems quite jerky which appears to impacting on stability (use without the stand) and could impact on wear and tear of the moving parts. Will you be looking to "smooth" out the movements of trainerbot by including something like dampening.
10. Will trainerbot work in the UK where the electricity power supply rating is different to the US.
I appreciate the cost of trainerbot is relatively low, and from watching your videos you seem to be targeting the casual club player rather than take on the big boy tt robots like the Butterfly Amicus range, but if I can't ensure consistency in trajectory, speed and spin rates even $379 becomes an impractical investment for me as I won't be able to use it for the purpose I'd buy it, testing other equipment.
As a suggestion, I really think it would be good if you could include at least some of this type of information in your promotional literature. At the moment you reference some other robots but the crucial information is missing.
Congratulations on getting your idea off the ground and into production, no mean feat. Fascinating concept and I really like your enthusiasm which comes across in your videos. I look forward to watching how your idea continues to develop in to the finished article. Thanks for sharing on Kickstarter and good luck with making your dreams a reality.
One of the other things I'd like to seem demonstrated is can it duplicate serves. When you look at the app, the landing zones are all on the far side of the table. It would be great if it can land the ball first on it's own side of the table to replicate serves, especially short spinny ones.