Hypersensing with THCAD - better way to do ohmic sensing

rodw wrote:
The hypersensing method we've devised (which thefabricator03 is not yet using) seems to have solved the problem and its in use by quite a few now on several different brands of machines.

I find it really hard to upgrade a machine used everyday for production. Its the same reason that mines and power stations have shutdowns which are week blocks were the whole place stops.

In the past I have had little things that stuff me up from not reading the instructions correctly or just wiring something wrong that takes time to fix. At the end of the year we shut down for six weeks so I will get the Hypersensing (hopefully) sorted then.

stivemaster13 wrote: tommylight, maybe I don't understand something. You mean that you regulate with PID a simple stepper motor Nema17 with 1500-2000 rpm?

Yes.
Have a look at the link i posted, there are some videos of the gantry moving at 55m/m with 1.8A Nema23 Sanyo-Denki motors with 1:3 reduction and 45mm/rev final drive. How many RPM does that make ?
BTW i did push it to 68m/m but it started tearing the belts.
All this is possible using LAM technologies drives powered by 1.2KW power supply (overkill) at 72V, they can handle 90V.

tommylight wrote: BTW i did push it to 68m/m but it started tearing the belts.

If you were to use rack and pinion and a quality planetary gearbox, do you think it would handle those speeds well and be reliable?

rodw wrote: Plasmac does something similar to what you suggest with the 12 volt threshold

Does it?

I have asked Phill to add a seperate THC hold pin to Plasmac for third party use but so far he has been unwilling to do so. That would make extensions like this much easier to implement.

There is a thc disable pin that has been available since June 2019

thefabricator03 wrote:

tommylight wrote: BTW i did push it to 68m/m but it started tearing the belts.

If you were to use rack and pinion and a quality planetary gearbox, do you think it would handle those speeds well and be reliable?

Would have to be very high quality ones, with rack and pinion the self induced vibrations might cause issues.
20mm wide HTD belts are good for up to 6m length when tightened properly, perfect for 3 to 4m. No belts with square teeth, they also cause vibrations, so you tighten them a bit more and they cause more vibrations !
15mm wide HTD3 or HTD5 mounted in a "servo belt" configuration will carry a 50KG gantry easily even at 6m length, but does require 2 belts per side.

Hmm just found this, it uses only one belt and a short looped piece ! Nice ! Oh cr@p, more to do ....

The difficulty comes from the fact that depending on the speed of work, the passage through the hole can take different lengths of time.

As for the lifter, I use far cheaper components that do not have to work in a mode beyond their capabilities. Motor with feedback that does not lose position. Tomorrow I will upload photos.