So I took the belt driv out of an old HP plotter to use for my belt mod on my MKI. Everthing is installed and it works but Iam having trouble putting te correst info into EMC2 t get the travel on the Y gantry crrect. Basicaly it's jsut a math poblem but fo some reason I can't figure i out.

The motor hs a pulley with 24 teeth that runs a belt to a pulley that has 60 teeth. The 6 toth pulley has a 41 tooth pulley mounted drectly on top of it that drives the belt that's attaced to the gantry. The belt on the gantr has 12 teeth per inch.

I would assume that I can put in 24 and 41 for the pulley and lead screw settingsin EMC2as the 60 tooth pulley and the 41 tooth pulley that actually drves the gantry both turn at the sam rate as they are fixed on top of each othr. Then for te pitch I am putting in 12 teeth per inch on the belt/41 teeth on the pulley (.2982...) for my pitch value. The problem is that when Iput these values in and jog th machine the software says it has gone a longer distance than th actual measured ditance traveled by the gantry.

Here are a few pis to help this makemore sense. Ignore the 43 on the front, I counted wrongthe first time and came up with 41 when I recounted

Any help greatly appreciated. When I dismantled the machine to put in the belt drive I also changed the rods for the Z gantry to 1/2" and pu in brass flange bearings. It looks like I'm going to beable t get a ton of speed ot of it once I get this straigtened out. I also am strngly considering rebuilding th Z gantry to mount a Rigid trim router in it, just for fun.

The Phlatprinter has bee great and I learned a ton about CNC from it. I am actually starting to build a Joe' 2006 righ now as well that will have full sized router in it for woodworking.

TIA,

Odi9 Attached files

 

Never mind, I figured it out, just took a while!
Odie9

 

You know, Odie9, I never bothered with the calculations when I calibrated my machine. What I did was for the first run I commanded it to go 1". I figured what ever will happen, 1" must be a safe distance. Even a rough measurement gave me a close enough starting point and the second run was safely done at 5". Saved me a lot of headache trying to make the calculation.

 

Thanks guys. I'm running EMC2 though. Do you know if there is way to do a calibation in it like there is in Mach3? I think that this was kit #19 that Mark and Trish sold so it's been a long time since I really did anything wit the software as far as setup. I know back when I set it up originally TV Casuality was a huge help, I ddn't really know what I was doing. He gave me the number 0.089.... to put in for the X lead screw pitch number, I never even really thought about how he came up with it. Last night when I was scratching my head trying to figure out wha to put in so that thegantrywould stop slamming into the side of the case Irealized that the pulley driven by the motor belt was basically the same as the pulley on the end of the X pipe and the pulley on to ofit with te gantry belt was basically like the X pipe itself. Then I tought bout it a litle more and figured out that that .089 number was 1/the circumference o the X pipe. So I divided 1 by the circumference o that top pulley and everything started working. Magical stuff that math! I can' believe it took methree hours to figure it out!

Thanks again for the replies.

Odie9