The man himself! Thank you very much. Its an awesome tool and it should help a lot of people. :)

They are so frustrating. A few times I’ve used them without any issue and other times it’s like they don’t register the strums. The mk4 build was kind of my last straw.

Using these apps made me dread touching my belts or doing anything that needed me to mess with the belts. Now I don't care with this tool. One of my favorite tools

The apps are worthless outside a quite room. Just try them while a couple other printers running.

The readout on the meter is based on the deflection of the belt which comes directly from the sin component of belt tension and the spring constant. Since we can definitely assume small angles here, we can say that the output of this tool is linear with respect to belt tension. So a 1.2x increase in desired frequency will correspond to a 1.44x increase in tension as read by this tool

Thanks buddy!! Haha at least this is a relatively small one. I know that all too well though 😂. The ever growing list.

lol they were sold out when I went to buy mine. I had to wait a week or two for a shipment. They seem to have been gaining popularity for some time.

Kit it is I guess 😅

Thank you :)

How do they deal with it?

@@Valintone they just have a simple spring putting a predefined amount of pressure that's equal to both idlers, you lose the idler, move the gantry around so it moves around, then lock the pulley again.

Thats a really interesting idea. I could see having idlers on the two outer teeth helping it to "slip" into place. It seems to lock in pretty well with the tap and after using it once or twice you get the hang of it but I like this idea. I think I was being a little anal with the positioning. The instructions make it seem like as long as you have 150mm of belt your good. I am probably carrying over a bit of the need for precision from the strumming method.

Rollers would probably help, but i guess then you would need to have the plunger part on an airbearing too, as that thing is sticking to the walls inside the outer shell and can't move freely in and out... In all seriousness tho, this is not a super high precision tool to begin with, so no need to overengineer to the whazoo. It's good enough to give you a decent idea of how tight or loose your belt is, and that is fine. If you need to have super precision, build a tensioner wheel with a load cell, so you can actually measure the force in static as well as dynamic load to really see what happens to the belt when a motor starts to jerk on it.

​@@ModBotArmy the belt must be allowed to slip at the two anchor points as there is actually a deflection in the belt caused by the middle probe-- you do not want the belt to stretch between these two points but rather allow more belt to come in to account for that deflection. if there is high friction at the two anchor points, then the tension will be higher inside the anchor points than outside (the true belt tension) because of this deflection. tapping the tool allows this slip to happen by overcoming static friction at the anchor points, ensuring that you are measuring tension for the whole 150mm rather than just the length between the anchors. i'll do the above comment better by saying that the probe itself should also be a free pulley (not possible for this application, but a 1mm steel dowel would be perfectly ok). that way the tool can be inserted, spring released, and the entire thing be free to run up and down the measured area to allow the entire belt inside the tool's area to equalise in tension to the rest of the 150mm. but this is starting to get unnecessary in terms of cost when at the end of the day an elcheapo tool like this is already overpriced as it is (see Ali for a $5 version using an electronic depth gauge which is superior). regarding 150mm, the voron specs do stipulate the recommended 2.2lbs +-10% for AB and 2.65lbs +-5.7% for Z, beyond which the % deviation will indicate a tension too high or too low. because the tension in that span is proportional to the length according to the 3 point flexural test methodology, that means you should keep your span measurement error within 5.7% or 10% of 150mm. that means you have 8 to 15mm allowance before your tardiness becomes an issue. in any case, 10% or 5.7% are arbitrary anyway. in other words, it's not really important if you get 150mm down to the millimeter but you should try to minimize the error because that's all you can do before you leave the rest to the tool. in principle though, you want the belt to be as long as possible to increase your error tolerances. note that the tool itself will introduces an error on its own because it applies a deflection to the belt which increases the tension in the same belt it is trying to measure. in practice, 150mm was probably chosen because of several good reasons and i will list a few: 1) you can measure this with a 6 inch ruler 2) this is roughly where the toolhead would be in the center of a voron 350. 3) the tension of 150mm will give a strumming frequency that is not too low (doesn't strum) or too high (attenuates too quickly to be measured). 4) anyone who subsequently makes a tuning guide will pick 150 for the sole reason that voron did it first.

Early in development I did have a version that used a stack of small 6m OD bearings for the outer pegs . While there was a very slight improvement for speed in acquiring the measurement the end results were the same. For the release candidate I wanted to keep the BOM and assembly as simple as possible to make self-sourcing and assembly easier and more accessible.

@diyshift Since nothing is turning very fast.I don't think the device would need full-fledged.Bearings just using 3 d printed rolling bushings would be good enough. I'm sure using pet g would be quite slippery enough for such pushing's.And it could even be a little snap fit or something over a ridge to the bottom of the pegs so no hardware to secure them. small details can improve operational dependability, even though you didn't have problems it's possible a less savvy user or a tired user of the product might not think or remember to settle the device on the belt, so if you can eliminate the need for such conditional operation the user experience will become more favorable.

I agree. The best way would probably be to position the X-Y gantry in different positions and test the tension to see how much variability you get. If the tool offers a good degree of repeatability, and there is no mechanical issue with the printer, the tension should not change much with the different gantry positions.

Never seen or heard of a digital one. Got a name?

In theory yes, however, they have a built in semi automatic tensioning system so unless there is a specific reason that isnt working I would opt to just stick with that on the P1S.

The recommended values are with different belts, yes they are gates- but there are values for rf, epdm, gt3 (I believe)

Just relisted, the maker does these himself and pumps out a lot but the demand certainly outpaces supply :)

I just put some back in stock, we do restocks every week or two. We don’t pre-order because we like to deliver a high standard of service and when things slip so does the experience.

According to docs it does

@@ModBotArmy not gt3

Thats a great question. I didn't see an obvious answer or reason for this.

Durability over time. PLA will creep more under load, that tenioning spring is a constant load. But also it was designed and tested in ABS/ASA so using another material with different shrinkage properties could lead to tollerance issues.

@@ModBotArmy i have printed and assembled this few weeks before (great tool), i can try to print in PLA and compare it , but my guess would be model tolerances(gear meshing) compensated for shrinking of ABS a tiny bit of ABS durability (PLA change over time with stress forces)

PLA creeps under load, so this tool may not remain calibrated if printed out of that material. ABS is a lot better for long-term dimensional stability.

Every plastic creeps under load. PLA with the higher stiffness would probably be a better option imho. However, the tool should come with a mode to relax the spring for storage. Every torque wrech (with a few special exceptions) has to be untensioned before putting it back in to storage too, as the spring that sets the torque "creeps" over time too if it's constantly loaded, so your wrench would move out of specification faster if you always keep the spring tensioned. The fact that this belt tension tool comes with a calibrator is actually nice, as you know where the tool is just before you use it. With a torque wrench, you usually don't have a calibration tool that can test the torque before using it, unless you work in a bigger workshop that has torque references.

Do you have a link to the simple version you're referring to?

@SmrimpyMaster None of the belt tension testers on Printables measure a unit and value, so unless you’ve compared with a calibrated tool you have no idea if your particular print is within spec. As far as giving advice to the masses, this tool will be accurate for 999/1000 people that use it, whilst the same cannot be said about others. Edit: corrected 999/10,000 to 1,000

@@TheOfficialOriginalChad not the statistic you were looking for, i think

@@ejenda9909 haha yes thanks.

Most of the ali ones are just tire gauges/calipers. I have both that style and this printed one from west3d. On the ali one, the plunger is a sharp point instead of something rounder and more fit for the profile of the belt, which makes actually using it to get a reading difficult. There is no way to reliably "zero" it. There is no guide for calibrating it s that you can match deflection to a specific hz of tension. It seems like it should be better but in practice, the ali one is useless. The printed one is calibrated, can be re-calibrated easily, fits on the belts properly, and is easy to use. If the ali one wa more developed to overcome these issues, it might be the other pick. But as is it is hard to recommend.

The feedback I have seen on the Ali ones are horrible. Both from the quality of the tool/it arriving damaged, to it not working well due to the shape of the arms/prong on the tool. If you can find one that works well for you then by all means, but if its not reliable or repeatable then its worthless.

@@caramelzappa the ali ones have a bit too little area for the belt to grab onto as well, iirc by the reviews

I used them and having no problems, i think allot of people have a opinion about them without trying them. Digital always beats analog in measuring, only dummies think otherwise.

@@TheOneAndOnlySatan How do you reliabley "zero" yours for repeatability? How do you convert your measurement in MM to HZ? How do you handle the sharp point wanting to slip off the belt? I would love to make some use out of mine.

A quality one can be north of a thousand dollars. The feedback I have seen on the cheaper ones is awful. From just arriving completely damaged to not being suited to work with belts due to the point on the probe this one has been designed specifically to overcome these issues.

Are you referring to the apps that I mention in the video? Or are you talking about the digital Ali meters a few have mentioned?

An ad, for what exactly? The completely open source tool?

@@UloPe yes. The tool which is being sold. Do you have any idea on why there is completely zero comparison of the print results "before" and "after"?

@@paragongamecom2497 It's only being sold as an option for people that don't feel up to the task of assembling one themselves... I have no idea why there is no comparison but I would imagine because it's very difficult to see minute belt tension changes in print results in an otherwise well tuned printer.

@@UloPe my point exactly. Why to spend time on making a video and attract attention to a tool (sounds like an advertisement) and not show ANY influence of the tool to the print results. To me it is misbehavior. An attempt to make some positive impression not backed up by... Anything. Case closed.

@@paragongamecom2497 To me the point of this video is to show an alternative to using apps for getting proper belt tension. It’s well documented that improperly tensioned belts can lead to both poor prints and increased wear.