Disclaimer (TL;DR accepted):
All of this is observation and crazy made up theory with no claim on truth!
I did a lot of (extensive) ‘weight and balance’ tests with my new sled. I’m holding back, because i don’t trust my observations yet, due to the weightless 8mm acrylic base. As far as i can remember, it was @blurfl that tested distributed weight with bad results, but wasn’t that with brackets? With quadrilateral the twist angle around the Z of the sled is part of the math (we measured the distance from the bit to the centre of gravity in Y direction in an attempt to get that right).
With triangular, I can tell that a long ‘pendulum’ weight down the middle does not work well (tested).
A drag (bottom friction) is introduced that can be compensated with raising the chain mounts, but who wants that
1 of the simpler tests i did was:
- Dry run horizontal along the top of the sheet with the top of the sled at same height as the sheet edge (full sled on the sheet). The same mirrored at the bottom. With a sled balanced in the middle of the sheet (i mean putting a rod horizontal under the sled in line with the raised bit and it does not tilt in any direction), moving from left to right shows a slight drag at the top (top falls behind/top-friction), while left to right at the bottom shows a slight drag at the bottom (bottom falls behind/bottom friction). If your sled shows top-friction at the top and the bottom, your chain mount is to high. Opposite, if it shows bottom friction on both runs, your chain mount is to low.
I used almost a complete roll of double sided tape and tested a series of ‘flat steel arrangements’ in various combinations. What i ended up doing was to put the sled on the table and put a rod under it in X direction in line with the bit and shifting the 2 outer weights i have upwards until the sled balanced on the rod. I do have weight down in the centre, what i believe still keeps the sled level. So does the upside down ~V i did with the outer weights i guess.
Compared to my overweight ~16kg Bosh GOF2000PE setup, i was able to cut the chain mount height more then half with this ~8.5kg (might not be enough) sled. With a steel base i could have done better.
With 16kg i could go down to a frame angle of ~9° before seeing the effect that there was not enough force in Z direction for the bit to go in. With 8.5kg i’m back to 15°. Tweaking all this variables is quite a task.
Lighter weight is better for future speed.
How can we motivate a larger group to upload their Maslow-specs and cut the same file so the collected data would help big time? Does it already fail because similar calibration results would be a must? Several attempts from various members failed till date, as you would need lager numbers than a handful to get usable results and conclusions.
Respect if you made it until here
Kind regards from the turning to dried meat (55°C/131°F expected next week), Gero
Edit: Bar’s first original for memory