Hi
Could someone post me a picture of the belt within the Y axis cbeam please? I'm trying to figure out clearance for an idea and id like to know how big the gap is between the pinion and the veritcal internal wall of the c-beam is.
Thanks

 

@sharmstr Thanks thats cool, appreciate it. i think there is a gap

I have an OX, modified, at the moment and have noticed how much flex there is in the y axis 20*80, which I have fixed. However, I'm looking at upgrading to a larger format with c-beam,using very long sections so i can do a full 2400mm work area. This with workbee plates (I like the double wheel idea) and c-beam for X looks like it will be worthwhile.

On my current Y-axis I have a 40mm*10mm flat bar bolted on the inside the whole length on the Y and it works great. I wondered if I could do the same, with thinner stock, inside the c-beam and with the workbee plates without interfering with the pinion gear.

So if you were looking at the cross-section of the Y axis, down the internal channel how much of a gap is there?

If i were to guess i'd say approx 5mm - the belt in the channel is the middle 6.773 but the gear would go slightly beyond that im just not sure what it is. if it leaves too little room then flat bar wouldn't add anything



Hope that makes sense.

Alternatively - is c-beam at 2600mm (ish) stiff enough on its own?- the workbee plates don't allow any intermediate supports.

Thanks
Ryan

 

That is exactly what I was looking for, thank you very much. I appreciate the effort.

The Red bar feels somewhat insignificant when shown like that so this is probably not a good idea, although the low profile bolts allowing a 40*5 bar would help. I think however that this would be far less rigid than the 40*10 that gave me the idea. So I'm not sure it stacks up.

I do like the modified Y plates by Antonio Pereira as anchoring to the table seems the best approach by far and with that Metalguru has me thinking about linear rails and a new approach altogether.

 

Has any one used 1/2 MDF instead 3/4 spoil board on the 1510.

 

Vibration Redux or 1 Step Forward, 2 Step Back!

After having this problem seemingly resolved, and the machine moving perfectly on all axes, we finally found time to surface our spoil board. We set up a 1" surfacing mill to a 0.02" offset pocket. It worked flawlessly until it moved to the rear 8"-10" or so. Then the vibration returned. Once it began, the position data was obviously lost to the controller. When it moved to the front, it skipped ahead, leaving an unsurfaced area of about 1.5". I stopped the run and checked the wheel tightness in the slots, as this seemed to solve the problem previously. I attempted another run, adding a second pass taking another 0.01" to correct any Z-zeroing discrepancy. The first pass ran well, but was slightly higher than the last aborted run. When the second (0.01") pass began it again messed up in the rear of the Y axis. I stopped the run and tried jogging without cutting. This video shows what is now occurring.

I believe the problem is that the wheels are binding, but I have the tightest as loose as the eccentrics will allow (see original post noted above.) The very helpful Mark Carew believed the problem was related to the driver board and was nice enough to send me a new one. As I had seemingly corrected the problem in the meantime and didn't want to waste a good board, I sent it back. (Wish I had installed it now! At least I could have eliminated that possibility.)

I would appreciate any ideas (or speculation) at this point. I'm starting to think desperate thoughts, like dismantling the machine to re-assembling the Y-axes.

 

I had the same problem it was the belt on the Y motor, I didn't put the tie on the belt and it came loose

 

I checked both Y-axes with a 3' aluminum level, top and side, but could see no discernible variance. I just made a test sign in the front 12" and it worked fine. I measured across the X and found maybe 1/32" variance around the problem area. With the power off, I ran it by hand for a few inches in the back and there was no noticeable binding. That baffles me, but it may be that the amount of force I use is overcoming the bind. As before, when I jog it through with the machine driver and provide slight assistance with my hand it stops making noise. Is the amount of power the motors are supplying too small to overcome some small amount of added resistance in the back? The belts seem tensioned correctly and are all zip-tied so they are not loosening, but is there wear on the grooves from the previous problems I had? Doubtful, but maybe I'll have to remove them and check.

 

Tomorrow I will try your suggestion of loosening one of the sides of the Y then run it back and see if that helps. Good idea.

 

I had something similar in my very first run. I saw someones' tip about adding the ties but thought that was more of a "long-term" thing. When I realized how quickly it can come loose I zip-tied it. My tension seems good now, and my problem is only in the rear foot or so of my Y.

 

When you say you re-squared the gantry what do you mean? Are you talking about loosening screws then squaring with a carpenter's square and re-tightening?

 

Thanks. I understand now.

 

I loosened my Y and jogged to the rear but no noticeable difference.

What I did notice is that when the power is off and I move the Y by hand I have no stalling. When I turn the power on, the left Y axis (right side in video taken from rear) is locked but the other side moves. (Somewhat hard to see the lockup in the 2nd video but I think you'll get my point.) Is this a driver issue? Motor issue?

You will also notice that the wheels on the top aren't turning when moved, but they are not locked up. The opposing bottom wheel is as tight as I can make it without over-tightening and possibly causing further binding. There is no rocking of either of the Y-assemblies. When this issue is resolved I will look at further re-adjustment but I want to err on the side of looseness for now.

 

It looks like you and @GrayUK were right! I connected my wire extension for the right Y axis with a small Dupont connector. As the chain started to bend, the wire at the base of the block was bending. I removed the connector and soldered the wires. Problem solved! Hard to believe that I missed this possibility! I never would have thought of it had you both not mentioned it. I ignored the old adage, "Start with the simplest things."

I did run my board surfacing successfully. I had one small problem, but it was on the X axis, so I don't think it was related. After I reset the job, it ran successfully. I do want to run some more jobs before declaring victory; I have at least learned that much!

ProTip for anyone experiencing this same problem:
-Stop the job at point of failure. Check your pairs for continuity at the screws. If you no longer have continuity in one of your pairs, LOOK NO FURTHER!