Due to issues with my machine I have recently upgraded my mk1 30x30 from a LB to the SLB. I have also replaced all my V-wheels and added auto backlash adjusters. My machine is calibrated and squared but after I run my roughing pass on Gsender when the machine returns to XY 0 it is off about 3.5mm on the Y axis for some reason. Now when I adjusted my y axis back to the original work zero that I had marked it was still way off the roughing pass. Please Help!
Is this a repeatable issue or did it just happen one time?
If it just happened once, or a couple times but off by different amounts, it could be that something is a little tight somewhere and it lost some steps during a Y move. I’d double check the V-wheel tightness to make sure one isn’t too tight and I’ve recently started using a dry lube on the lead screws to help with any friction there. I 3D printed my regular style anti backlash blocks and they needed the lube, at least at first, but I don’t think it could hurt even with the Sienci ones. I’ve been using Blaster dry lube with Teflon but I’m sure there are others that would work. I like something that dries clear. I wouldn’t recommend a wet lube as sawdust is likely to stick to it.
One other thing that can cause excess friction on the anti-backlash nuts is if they are a little crooked. Sometimes they are just a little crooked and will work fine in the middle of the machine travel but bind towards the ends. I believe this is because the lead screw has less ‘give’ at the ends. To fix this jog close to an end, loosen the mounting bolts, jog back and forth slowly a couple inches and then tighten the bolts back up.
Things change under load but all you really can do to check before cutting, that I’m aware of, is jogging at max speed and listening/looking for problems when doing that. You can even turn up the max travel rates for testing before carving. I recently got a SLB and turned the max travel rate from 4000 to 5000mm/min and the acceleration from 750 to 1000. I wouldn’t keep them fast until you aren’t having problems when cutting at the original values though.
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@5Belz What are the “auto backlash adjusters” that you added? Are they the newer spring-loaded Sienci adjusters? If so, Sienci has posted on here and in the blog about a break-in routine that should be run with them. I agree with @_Michael , something is binding.
Hey Michael
Sorry I’ve been trying to figure this thing out and learning a ton at the same time but my time to work on it is limited so it’s been a process.
Yes I have adjusted and readjusted my vwheels. They do feel a bit tight on the top but if I loosen them then the bottom wheels feel loose. My lead screws move freely with no binding detected. I will definitely grab some dry lube.
So after I posted my last question about the xy zero being off the touch plate there was a comment made that made me realize that the xy wasn’t off after the cut but before. So yes it is a repeatable issue and is consistent every time I use my touch plate to xyz zero. I have checked my calibration over and over and movements are dead on. I’m struggling to keep my y axis square but after running multiple movements yesterday I’m hoping that I have that dialed in but probing xyz is still a mystery.
Hey @gwilki
Sorry I missed your reply. Yes the adjusters are the new sienci Spring loaded adjusters. They seem to be working well. I believe my issue may be more firmware or software related than hardware although I’m still not ruling it out. With no prior experience as to how these machines should react it’s tough to know if I’ve adjusted everything correctly or not.
If your struggling to keep the Y axis square that would indicate that something is causing the Y motors to not stay in sync as I’m sure you know. Whether something is binding or it’s a motor/wiring/control board problem I don’t know.
I was just thinking since Sienci recommends a break in for the spring loaded adjusters that maybe running the surfacing program in gSender would be a good way to do it. If only the Y axis is giving you trouble you could use the the raster style (back and forth) and switch the direction so the mill goes back and forth on the Y many times as it goes across the X once. Run it with the spindle/router off and up in the air. If you want to break in both X and Y you could use the spiral option.
At least that way you could automate the break in. I would stay within earshot in case it binds up but at least you could do something else close by as your time is limited.
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What issues were you having before the upgrade? I was reading the thread again to see if I missed something and now I’m wondering if the old issues are fixed or if the old and new problems are possibly related in some way.
Hey I’m glad you suggested that because it means I’m on the right track and am thinking in the right direction.
Yesterday I made sure my y rails were dead square, I readjusted all my vwheels, made sure my lead screw couplers were all tight and then ran a surfacing program through gsender. I then put a 1/8” bit in my router and jogged the length of my spoil board up and down the y axis 2”s apart and then back and forth on the x axis 2”s apart. I then put a 24” construction square on the lines to see if they were square and they weren’t or at least it seemed. I then decided to use a little math and took my mm ruler and ran up the y axis (on a cut line) and made a mark at 700mm then across the x axis at 600mm. I did the math and C was exactly what was supposed to be.
At that point my head hurt so I had to walk away. I’ll look back into it when I get home from work this evening
My initial issue I think was mainly due to a flat spot on a vwheel on the x axis that caused it to bind up and bounce around. The difference between my first surfacing and yesterdays was night and day.
Most of the old issues were caused by a flat spot on a vwheel but that hasn’t stopped the machine from going out of square.
A flat spot in a wheel would suggest that is was sliding instead of turning so maybe you are running them a bit too tight.
You should be able to turn all the wheels by hand. The top wheels on the X will turn harder because of the weight of Z axis.
I have a Makita router so this might change if you have something heavier but my Y wheels carry the weight on the back set of wheels. The weight is so far back the lower front wheel has more pressure on it than the top front.
When spinning the Y wheels by hand on my mill the resistance from lowest to highest is:
- lower back
- upper front
- lower front
- upper back
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Ya I bought the machine second hand so I’m guessing the guy before me was running them tight. I just got home from a 15hr day at work but when I get home tomorrow I will use your info and see if I can dial in the v-wheels a bit better.
Thanks again for your help, it’s much appreciated.
@5Belz FWIW, I’ve had good results on my LM 30x30 Mk1 by putting a wedge under the gantry plate before trying to set the top wheels. I figure that getting the weight of the X rail and the plates off the wheels is a good thing. So, I simply put a wedge between the spoilboard and the gantry plate. I slide the wedge in until the bottom wheels are where I want them to be. Then, I simply adjust the top wheels down snug to the top of the Y rail.
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Thank you Grant. I’ll give that a try this evening.
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