anigeek65 published a new build:

Read more about this build...

 

It wasn't to much of a problem Mark. I would get through one plate fine and the second would walk. Played around with various feeds and speeds. I did notice much like wood grain that my piece of aluminum would make the cutter walk depending on its orientation. Kind of strange. But all in all it taught me alot, hence why I am making the z as strong as possible. This axis by far is the most sensitive of these types of hobby machine. I think the X and Y always seem to be fairly safe from the week zone. Thanks for following.

 

Are these plates you made or plates purchased from open builds? All the plates I have purchased were fine but the plates I made for this build none of the eccentrics worked. I had to go with eccentrics everywhere. You will have to drill out the holes for the 6mm spacers and replace with eccentrics. This is how others are solving this problem. I kind of like it that way anyway. It give me more flexibility and adjustability. Cost more but I like being able to adjust each wheel independently. Hope this helps. Oh sorry I see the XL gantry plate from open builds.

 

Well I hope you figure it out. You could try my suggestion about the eccentrics everywhere but you could not return the plate. Maybe try one and see if this can solve you problem. Good luck.

 

Evan, thanks for the feedback. The back to back c-beam is incredibly strong. I tied the two c-beams together with several 2 hole joining strip plates. This plate is small enough that the v wheels pass by it, but tie the two beams together. It is much like having a I-beam and is very strong. I worry about the span of 1000mm for using 2 20x60 rails, plus I would not know how to keep them together and from separating in the center without the v wheels hitting something or from the rail twisting when pressure applied in the -y or +y. Also I now have a great place for the acme lead screw to run. I will eventually cover this with a bellows to keep chips out. As for the long fasteners, they don't seem to be a problem, I made provision for all my plates to add the mini v-wheels inside the c-beam rails if need be. I don't feel any flex or movement in them, but at the same time I have not cut aluminum with this. My biggest concern is the "Z" axis. That is the life blood of any machine and if not strong enough the end mill will chatter and grab and mess up the aluminum (much like the C-BEAM machine I used did to some of my parts. to solve this I will have a double plate on the z. It is not seen is this picture but I will have it done by then end of the week. As it is right now, when I grab the z axis at the spindle bracket I can hardly twist it. It will be even better after the second plate. The spoiler board is actually just my base to work on and support the wide foot print. I have 10 - 20x80 rails that I am going to lay down and bolt on and make a "T" slot bed. I have leftover 2"x2" angle I will cut and use for that. I probably wouldn't use that board as a spoiler board since it is laminated plywood and not very good for cutting on. I plan to eventually get a spindle and not the colt router I have.. but the budget is shot for now. Keep me up-to-date on you build. I will update this this weekend with the bed and new plate I hope. as you think more about your build if you have the $$ double plate your x, y, and z axis. Your machine will be much much stronger and this will also help keep the z axis from twisting when cutting aluminum. Which is the problem with the c-beam machine.

 

I am still working the bugs out now. I was using an arduino board now I using the xpro and the new high torque nema 23 motor from the partstore. If I run at 2000mm/min the motors skip.. or I call it speed up and slow down. I am sure it's a setting somewhere. Once I get the bugs worked out I will upload a parts list. It's not perfect it is still not as strong as I would like but I believe that the extruded aluminum will never be strong enough for longer x travel.

 

I have almost completed my build but have a question or need some input.
Super "C"-OX
I have lead screws that are 1000mm long on "X" and "Y, for the most part it runs pretty well but I have noticed that the bearings that I get from the parts store are not very accurate. I can move the screw up and down in the center hole meaning the hole ID is not very close the thread OD. when I travel I can hear clicking of the screw moving up and down in the bearing then the drive gets close to it.(not a deal breaker just annoying). I also have some whipping although not to terrible. My question is should I tear it down and reverse my plates so I can put the drive screws in tension instead of compression or just leave it alone and move on. (move the locking nuts to the outside.) I have seen others suggest this but I am not sure I want to do a complete tear down to accomplish this. Your thoughts...anyone? thanks in advance..
What do you think Mark Carew?

 

Interesting Rick, how do you suggest filling the gap?

 

Thanks for the feedback Barry, since you build always in tension, does you notice a noise reduction also?

 

I shouldn't have that problem, I have more than enough screw length to add lock washer at then ends on the outside.

 

Thanks for the link, I just ordered a set...still processing whether I want to tear it down or not though..lol

 

Here is an update. I order the thrust bearings that Rick talked about but I don't have them yet. But I went ahead and moved the bearings I had to the outside on my z axis because it was the easiest and I wanted to try it. Boy what a difference. The noise level is nonexistent. Can't wait to do all the axis.

 

Agree...that is why I have not gone to steel wheels from the parts store. It works fine the way it is now. I am about to post my final results of this build in a few days to show the pros and cons and where I think that eccentrics fail in these style of designs.