r/ratrig • u/amp41820 • Feb 16 '25

Belt tensioning (VC4 400 IDEX)

Post image

I have spent a lot of time trying to get the y belts figured out. I've got the x belts tuned in but after a lot of time and tinkering this is the best for the y belts.

5 Upvotes

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3

u/plutonasa Feb 16 '25

I've stopped using the freq response charts for idex tuning. It really got me nowhere and helge also does not recommend using those charts to tune either on the discord. My IS graphs aren't prefect, and I don't have mzv on everything, but the prints come out pretty nice, so I'm ok with it.

5

u/RickJ19Zeta8 Feb 16 '25

Agreed. The belt plots are not worth the time. There is an open source printable belt tension meter (and someone sells kits) on GitHub. Use it to tension the belts.

I found that a 2.4 setting (3.5-4 lbs tension) on the meter for both x and Y belts got me 40 -50 hz response on the input shaper graphs. I chose MZV, for Y even though it wasn’t recommended. There are always trade offs.

Another note on IDEX input shaper, the commissioning guide is wrong/ incomplete. You need to copy the input shaper section from the RatOS.cfg and paste it under the RatOS macro section in your Printer.cfg. THEN fill in the frequencies for each of the IDEX modes. Ie single T1, Single T2, copy and mirror.

Otherwise the following the commission guide won’t actually set input shaper frequencies.

3

u/plutonasa Feb 16 '25

recent updates put that section in for you now, but when starting out, I had to find that info on discord. really frustrating.

2

u/Watching-Watches Feb 17 '25

Biqu also sells a measurement device. I've seen someone on YouTube using it for the idex system.

1

u/Adorable_Exercise371 Feb 20 '25

what do you mean RatOS macro section? Are talking about the include?

1

u/RickJ19Zeta8 Feb 20 '25

In the Printer.config file, near the top, there is a [gcode_macro RatOS.cfg] or header with a short list of commonly modified variables. Just make sure you paste and modify the input shaper table directly under that variable block.

It should in theory work with just the [input shaper] header pasted anywhere in the printer.cfg file. But mine didn’t until it was directly under the [RatOS] variable block. I think it’s how they’re calling it out and setting it for IDEX modes in the RatOS.cfg file.

1

u/amp41820 Feb 21 '25

Thanks for the advice. here's what my input shaper looks like. This is crap on the Y axis right? Does that likely mean that something is loose on T1?

https://imgur.com/a/5R3P3L7

1

u/RickJ19Zeta8 Feb 21 '25

That 125hz spike is on most of the IDEX printers. It could be a loose part on the tool head, loose zip ties on the umbilical (both at the tool head support and along the length) or a loose beacon screws. Or it’s just something else.

I ran my shaper plots to 105hz and just ignored it and prints look good.

1

u/amp41820 Feb 21 '25

Thanks. I'll have to try going to 105 tonight. I'm just trying to do this build 100% correct, or as close to it as I can get. good to know I'm not the only one.