I’m stumped. Long story sorry but I need help.
I was trying to set the a/b belt tension using both the GT2 device and sound and here’s what I found. The belt adjusting screws were wildly different from side to side before I touched anything. Left side was almost all the way in (loosen the belt), the right side was 25% out (tighten the belt).
The two belts had way different tension as you would imagine (left side was in the double digit Hz mid 40s, right side was above 110 Hz). I tried adjusting from where they were and got the tension near the same but never could get it exact.
After getting the belts as close as I could, the x/y axis was out of adjustment, I had a gap at the back on one side. So followed the tutorial “SV08 AB shaft synchronization and belt replacement and adjustment tutorial”.
I loosened the belts as much as possible and tried adjusting the AB shaft per the tutorial but no luck, it appeared the belts were still too tight, so I removed the belts where they attach to the toolhead, then I could adjust the shaft to touch on both sides per the tutorial.
As soon as I reconnected the belts (3 teeth exposed on both sides) the shaft again had a space but on the left side.
One other thing. As I move the X/Y carriage back and forth the gap appears to shift from the left side to the right. I mean when I set the distance on the pulleys center to center on the left side to 150mm there is more than 150 on the right but when I move the carriage all the way to the rear, the gap is on the left.
That is where I am at the moment, help please
Is your main frame square? Measure diagonals (top, mid, bottom). Are they all the same?
No the measurements are different.
TOP measured diagonally from the “sawtooth” outside edge of the extrusion:
Z1-Z3 = 752.47 mm or 29.625 inches
Z2-Z4= 755.65 mm or 29.75 inches
Mid and bottom have the same measurement between the center screw holes for the enclosure (none installed) and just on top of the AB frame for the bottom Z was about 10.
Z1-Z3 = 696.925 mm or 27.438 inches
Z2-Z4 = 698.5 mm or 27.5 inches
Should be the same both diagonals. Can’t “square” a gantry to a parallelogram.
I understand. Based on a suggestion from the SV08 Facebook group, I’m going to try and square the frame. Basically loosen the bolts, square up the frame then tighten the bolts while trying to maintain square. Could be an interesting experience. A question though, why couldn’t Sovol put a procedure like that in the manual when your first assembling the machine.
Also, I’m a little suspicious that this out of square was known at the factory, otherwise why are the belt tensions so different?
belt tensions were so different BECAUSE printer got bent after they were set.
I assume the extrusions are bent. I’d leave everything tight and pull 2 to 4 till it springs back to square. Bar clamp or rachet strap. Go slow don’t want to overshoot.
I have a hard time believing the tensions are wrong because they changed when frame was bent. Reason I say that is the settings on the tension adjustment screws. One is all the way in and the other is 25% out. The belt attached to the screw that is all the way in cannot be loosened. If the belt was tight because from is bent, adjustment screw would be where it was set
Update:
I got the frame square, same diagonal measurement z1-3 and z2-4 and the AB carriage now has not gaps rear or front.
I still have the same problem with the belts. The X-axis belt (left side as you look at the machine), is much tighter than the Y-axis belt and X cannot be loosened. The adjustment screw is all the way in. On the GT2 tension measurement device it shows 2.5 and sonically it is in the 157 Hz range.
The Y axis belt measures 1.9 on the GT2 device and right around 110 Hz. Y adjustment screw has plenty of adjustment left in both directions.
I wonder is a slightly longer X axis belt would fix things
I can’t see why you couldn’t add 1 “notch” at the anchor. I know threading them is a PITA but I’d have to pull both belts and stretch them out side by side. Those belts are hella tough but they can be stretched.
While your at it double check all the rollers. bolts are tight, rollers roll free?
I could move the belts so they have 2 teeth rather than three. I don’t have to unthread the entire belt to do that. The ends are at the back of the tool head. I’m not ready to pull the belts completely yet. I’ve only had the printer since the middle of March. Do you know the uninstalled length for the belts?
I don’t have the belt lengths
Is there any possibility 2 rollers got swapped? The difference in size would be about the same offset as you have.
Tooth side of belt ALWAYS goes on a tooth roller
Flat side of the belt ALWAYS goes against a smooth idler.
@sovol3d
Hi,
Could you give us the reference of the belts of a SV08?
Thanks in advance
I’ve been in communication with Sovol. They advised to remove the belts, make sure a/b (x/y) carriage was square to the gantry. It is now.
After I removed the belts, it will be a PITA putting them back in, I measure them against each other, one of them is 3.4mm shorter than the other measured with calipers. The short belt is probably the one that I could not adjust properly.
I am going to provide all the data to Sovol including pictures and a video and hopefully they will provide a solution.
Lay the belts out side by side, notches up. Do the teeth line up between the 2?
If the long belt is stretched you should see it in the teeth. If the teeth line up one of the belts was cut to the wrong length.
If the reinforcing cord layer is “right” the belt should break before it stretches but…
Sovol is sending belts? Rolls of GT2 belting are available on Amazon but you need a length to cut to.
3.4 mm bothers me as GT2 belting cut halfway between the teeth should always be a multiple of 4mm
On the SV08 wiki there is a set of instructions to change the a/b belts and on youtube https://www.youtube.com/watch?v=7n_p33_o6dQ there is a tutorial video. I used both. I found a length in the Wiki in red. It is Belt Model: 2GT W:5.7mm L:1880mm*2. a little weird I wonder if a 6mm belt would work.
The YouTube video shows the demonstrator installing the belts in the little clip that holds them to the toolhead pointing out four teeth protruding from the clip.
The teeth check shows all teeth aligned. Both seem to have been cut short. I measure the long belt at 73.938 inches, converts to 1878.025mm. Probably why only 3 teeth were protruding from the clip at the toolhead.
Funny, I almost posted the Wiki link a few hours ago…but figured you probably looked there already.
I’m sure generic 6mm belting will fit. Sovol does some strange things at times custom machining parts that are available in bulk at commodity prices (nozzles in particular) but the belting is very generic.
It’s why I often post this link.
The doc is not often read.
Update: Sovol support has agreed to send me replacement belts since both of mine are short. Just don’t know how long before they ship or how long shipping will take.
They sometimes will send out a shipping email.
It wouldn’t hurt to email them back & ask for a tracking number.