I've had my lead for almost a year now and have done some great things with it. But lately things have been off to say the least. perfect circles are starting to look a bit wobbly. and nothing is spatially correct. I've been using aspire to generate gcode which I then load into openbuilds controller. the gcode looks as it should in the open builds simulator so i dont think its a code issue. I've made sure nothing is loose and everything is straight on the machine itself.. when i jog around everything seems to be in order so i dont get what the problem is. in the included pics its supposed to be 3 holes evenly spaced around a bigger hole. the 3 outer holes should have a smaller hold dead center in each. As you can see thats not whats happening.. any thoughts?
Hi @Campbellcastle We have to get this machine to sober up! Its hard to see but it looks like the Y axis is either loosing steps or is loose. It sounds like you have a lot of experience with the machine so when you say everything is tight I believe it. I would still fire it up so that the motors are locked and just give it a wiggle on each axis to ensure there is no play or slop where the lock collars sit against the bearings. If all is good there I would say since you have been using it for a while to check your wiring connections after so many times of going back and forth with out wire strain there is a good chance that one of the wires are cracked from bending so many times. Its a hard one to find so you will need to power down and check each motor wire. Pull them out and check they are making good connections.
So i checked the wires and rechecked all joints to look for a problems but still didnt find anything. The just for kicks I decided to tryout building some g code on open builds online editor. I made a few circles and cut them out. They came out almost perfect. So is it possible that something weird is going on in the vectorworks>aspire>openbuilds chain? I've included my possibly faulty g-code with this post.
Are you using the correct post processor (grbl-mm) from aspire? I looked over the gcode, seems to be in Inch (supposed to work, but some vectric users mention the mm mode Post plays nicer with Grbl) but other than that speeds looks good, very conservative Any major differences in aggression? (Depth of cut, feedrate, etc?) between the two tests?
OK so significant progress has been made on this problem. The first correction was the the inch / mm thing. That cleared up the spatial errors. But circles were still looking a bit wobbly. I noticed in a test cut a fair amount of play on the z axis plate. So I tightened it up and ran a test cut of four pocket circles. The first one was perfect, second was almost perfect, third wasnt great. fourth.. full retard mode. The wheels I had just tightened were already loose again.. What can I do to prevent that from coming loose so fast?
Campbellcastle, Replace your lock-nuts or use some blue Loctite. Also, make sure your flex couplers are good, sometimes they are loose or not set on the flat spot of the motor shaft and will jump around a bit. Flex couplers can be broken and it's hard to tell as they tend to stay together looking fine. The openbuilds leads are a bit smaller than 8mm and I needed to shim the coupler to lead connection to get a good grip on the lead, I used foil tape. Cheers Gary
