I seem to have quite a few issues creating circular cuts and diagonal cuts - wavy lines created not smooth. I am convinced this is down to belt tension. I have printed some tensioning systems, but find that these cannot tension the belts enough. What solutions are out there? Pehaps a cam system that will allow to relieve tension overnight? Perhaps a rachet system. Any Ideas gratefully received
dual belt! any pics of what you are seeing? can be a few other things other than belts, like wheels too tight or loose pulley.
Gary Thanks for the reply Yes Dual belt. Wheels I have tightened until I cannot spin them easily. Here is an example - The curves are good honest!! Wavy2 by Marcus1 posted Jun 23, 2017 at 2:44 PM Wavy1 by Marcus1 posted Jun 23, 2017 at 2:44 PM Strategy is cut through leaving .5mm for finishing - run finishing to finished size 18000rpm @3600mm/min
if you are running dual belt the bottom belt is glued and no need for tension other than getting the part between the wheel and the pulley tight. Whats your DOC on the first pass? is it making the wonky parts on the finish only? can you post your cnc file?
Gary Dual belts yes - glued no I did read an article saying that there was no need to glue As to the DOC - 3.4mm 3 passes in MDF Finish full depth
The file does look real good, i pulled up the g-code in my UGS Your feed rates are real fast but might be ok, maybe i run too slow! What does it sound like? do you hear the endmill digging in and chattering? Regarding glue or double sided tape, IMO makes it worth while or tension is an issue.. and the belts still allow deflection then, although it would be double the resilience in theory. BUT Unless you have about 0.5mm of something in-between the lower belt and the rail there is a bit too much slop between the belts. The way i did mine worked very well, but i'm not sure its a great way as it took me three tries to get it right. I used 0.6x5mm carbon strips under the belt glued with rubberized CA (could use rc car tire glue) it bonds very well to the belt (it's permanent, belt is destroyed if you try to pull it off) the carbon makes the distance perfect. Then for the ends i just have end-caps screws holding the ends down. An easier way is the double sided tape easy to find 0.5mm thick tape. (all of this is in my build ) also curious what your Z looks like do you have a C-beam Z or a 2060 standard Z, router mount solid? cheers Gary
Gary No noise from the cutter - smooth, it is a surprise when I take the board out and clear the cuts that I see this finish. with the dual belt - if you glue the bottom belt down, do you just interlock and clamp together at each end? I have the standard OX Z axis and have printed to router mounts to give support all the way up and reduce any "swing"
Marcus, yes you just interlock and hold down the ends so they can't move around. The reason why i say it took 3 tries.. 1st) i used too much glue, made a mess, not fun cleaning CA off aluminum even with acetone. 2nd) Flipped the gantry, i got it down clean but i didn't pre-tension the glue down belt at all. 3rd) For the Y's i glued down one end about an inch, clamped it at that end then applied the rest of the glue and pulled tight (probably 5-10 lbs-force) before setting the belt into the glue, then clamped that end. That worked great although i have no issues with any of them. this is how i would do it next time as well. I'll be cutting some half inch mdf this weekend maybe i'll run your file, see what i get. Gary
Gary - Thanks for that. Just been reading your build, some great ideas in there! Could you take a picture of what works for you in Mach 3 - especially the General config! I need to eliminate the error and it is compounded when it could be the Cad elements created, the code generator, mach 3, or the machine!!!
