Tevo Tarantula Pro 2020 - calculate and calibrate your E steps!

Welcome back guys. Tech Nervous here. Today we are going to adjust the e-steps on the Tevo Tarantula and the way that we're going to do that is by going into Pronterface and running a couple of commands and saving those commands to the firmware on the printer in order to enable to print at the proper step rate. Now this is going to fix all sorts of problems for us including under extrusion and over extrusion so dialing in the proper step rate for your extruder is critical for having your machine running at top condition. Right, so as you can see we have our connection to the printer we need to actually connect via Pronterface here and then we are going to heat it up so we can move filament through the hot end. We're not actually going to be moving it through the hot end but the extruder won't push filament unless the hot end is hot in order to not break anything basically. So here's Pronterface. I'm on COM 7 we'll go ahead and connect. There we go. I had problems with my plug being plugged into the wrong USB port so COM 7 wasn't working for me so I just had to plug it back into the other one and we are in business. Now I'm going to heat the hot end. Set it to 210. I bet I'm not really too worried about it. I don't need to heat that. I just need to let this get up to temperature. And now that we are approaching that temperature you can see up here that we are just kind of focused on the hot end there. The part you're going to be looking at is where the extruder meets the Bowden tube so keep an eye on that. That's where we're going to be doing most of our work and in fact we can get a little closer here. Alright so now that I have the filament flush with the end of the extruder I'm going to tell the extruder to push out 100mm of filament and then we are going to measure how much actually comes out. Now if there's a difference it will tell me if I'm over or under extruding and we'll make a slight calculation and then some adjustments in the G code. So what we need to do is enter a command and it is the G1 E100 command. Take note that if you were measuring from the entry point of the extruder and marking 100mm in order to do it that way without disconnecting the Bowden tube you would want to add an additional F100 command in order to slow it down so it doesn't push it too fast for your machine to handle. Since we're not going through the hot end we're going to go ahead and just run it like this. You can see it spit it out fairly quickly. Alright so what I'm going to do here is take a measurement with my calipers after I knock this thing over and then struggle to pick it back up. Nope. There we go. Stay there. Alright so now I'm measuring the amount I actually extruded to see how close it is to that 100mm extrusion that I set in Pronterface and I'm just going to get right up against the extruder with my calipers there and measure the distance. It is easier to do if you keep one end in the extruder but you can cut it off and just measure it with the calipers as well. It's just a little bit more difficult. Basically what we're looking for here is the difference between what you told it to extrude and what it actually extruded. So if you extruded exactly 100mm good for you, your e-steps are calculated properly and your extruder is calibrated. However if you extruded more than 100mm you are over extruding and this can lead to blobs and squished layers, things of that nature. So an otherwise imperfect model. If you extruded less than 100mm you are under extruding and this is a problem as well as it can cause holes in the model, gaps in the printing, and really thin strings which offer really no support to build upon and a kind of frail and fragile sometimes wireframe looking model. So we are going to make an adjustment to get that right to 100mm and the way we're going to do that is by using a formula. Alright so I brought up a little sticky note here with the equation we're going to need. It is the current e-steps times the length of the extrusion versus the actual extrusion. Now the length of extrusion is that 100mm we tried to extrude and the actual extrusion is the amount we actually got. So we're going to plug a 100 in here as you can see down here and I am using 101 because I am over extruding. Whatever your measurement was from the amount of filament that extruded from the extruder after sending that last command you're going to put it right here. Then we're going to go in and we're going to have to grab the e-steps, the current e-steps and in order to do that we're going to hit M503 and on this line here where it says echo M92 there is an E and then a number at the end. Mine is 408, on the Ender 3 it's 96 I believe to begin with, maybe 98, but yours may be different. This is for the Tarantula Pro here. I'm going to go ahead and take that number and that's what I'm going to plug into my formula here. So then I'm going to get my calculator out and I'm going to do the math. So I'm going to do 100 divided by 101 that gives me .99 and then I'm going to multiply that by 408 which gives me 403.96. So I'm only going to go to the second value after the decimal here and we're going to go back and we're going to do a M29 command and then E for the extruder and then 403.96. You're going to enter whatever value you got from doing your calculation. I'm going to hit enter and it is sending it and then I'm going to do an M500 to store it. Now that I've done that it should be stored on the hardware on the actual printer itself so it will print at that e-step value no matter what and I can verify that by hitting M503 again. I'm looking for that line that says echo M92 and of course it didn't work. If you look here you can see that I didn't enter M92 I accidentally typed in M29 so we're going to go and fix that right now M92 E 403.96 and there it goes and now our M500 to save it then the M503. Alright now if you look here it says echo M92 and my e-steps are 403.96 so that is optimal that's right where I want to be. Now all I need to do is go back to the printer here which should still be at temp because it's still connected. We're going to pop over to the printer cam and we are going to again extrude 100 millimeters and that is our G1 E100 command. Let's try that again. There we go and now we are going to measure. We should have exactly 100 millimeters of filament. If it adjusted too much or didn't adjust quite enough we can simply run it again and the more times you do this process the closer it will get to that 100 millimeters but let's go over and see exactly how long it is. And there you have it. Our calipers are showing an exact 100 millimeters. These aren't digital calipers. You can get a little closer with digital calipers with the kind I am using. I am more than happy with the results and we are going to roll with that. So now you know how to calculate your e-steps. You can do this with any 3D printer that is an extruder machine and this is the simplest way to do it without having to wait forever for it to extrude that filament agonizingly long time because it is passing through the hot end. Simply remove the Bowden tube and measure from the end of the extruder. As always this channel is brought to you by these fine Patreon supporters. If you would like to support the channel on Patreon head over to www.patreon.com slash technivorous. 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