Hi there,
my name is armin, and i bought a used lr3 and i am totally now to this.
As the lr3 was shipped via parcel service i came in parts.
I have now managed to place the mechanic on the table, the belts are also fixed on the table and now comes the question:
If i push the lr3 on one side it slightly moves forth and back…is this a normal behaviour which stops when the motors have power on?
It does not look promising at all, also some parts cracked because the pla seems to be brittle…i replaced them with asa…
The board which came with it is arduino and i plan to use estlcam…but currently, i am a little worried if this is just a waste of time?
I need to cut hardwood, time would not be an issue, it can work slowly but should be precise…
thanks for your input…
Yes, that is normal, but the amount of movement can vary quite a bit depending on what materials the XZ and YZ plates are made from (aluminum is stiffest, printed is least stiff), and infill density of the end strut braces.
The amount of movement also depends quite a bit how long the gantry is (the same angle of deflection over a longer distance will be a greater amount of movement).
Once the belts are attached and the motors are engaged, there should be very little movement.
Editing to clarify -
The printed parts are fine, especially to get started. You mentioned that you will be mostly cutting hardwood. After drawing your first crown (see the documentation), I suggest making several practice cuts in air, then styrofoam, and then a softer wood (pine?) to start with, so you can get familiar with the machine and all its nuances.
Because you will eventually be cutting hardwood, and you mention that precision is a priority, you may find that you want to upgrade to milled flat parts (XZ Plates, YZ Plates), and possibly a stiffer set of struts to increase overall rigidity. I cut all of those parts out of aluminum after assembling my LR3 equipped with just printed plates, but many people here used MDF or acrylic. Your machine should be capable of doing all that. But for now, just get it working and learn how to use it.
Can you let us know some more details about your machine (width of gantry, size of X rail tubes, etc.), and maybe some pictures? We’re happy to help you get this machine working for you!
Well, i was trying to replace the belt tensioner for x, because the old one was broken. I printed asa, petg, and pla…i am not able to manage getting the belt inside, without breaking the part? i already did expand holes in the slicer…?
Issues like stringing can cause headaches getting the belts through the slots, as can very small calibration issues.
I push a tie-wrap through the slot several times back and forth to clear the path a bit. If necessary I punch a small hole in the tie wrap and near the end of the belt, wrap a very thin wire (strip off the coating from a twist tie) through the hole and through the belt, and use the tie-wrap to pull the belt through the slot.
Hi Bartman, well, the parts are perfectly printed, the slot is just too small, if i take the belt in double, the thickness is 3 mm.
This may be the wrong belt, but that is what i have got…
i will try to work out with editing the part…
i will keep you posted.
Can you take a picture of what you are doing? The little nub in the middle of the tensioner can be broken off, it just has to be there so the belts can’t slip out.
Yes, i just measured the original file and the slot is 2 mm.there are two ways to get the belts back, one is to push the belt back in that 2 mm slot or guiding the belt above the little nub and secure it by just screwing the tensioner on the plate. i have tried both options, first one, the little nub always breaks, because 2 mm slot cannot cope with 3 mm total of belts, the other one fits, but the belts cannot be tightened properly. i will try to increase the slot to 3 mm and see if this works…
SMALL adjustments until the part fits. If you make a 1mm thick square with a few different hole sizes, grab your calipers and adjust until the hole is correct, it doesn’t take long and you don’t waste much filament.
Welcome back. 
The little nub in the middle of the tensioner can be broken off, it just has to be there so the belts can’t slip out.
