Reserved for showing off my MKIII and it's first meal. It's not too early, is it? muahahahahaha

- Jeff

 

Well I checked the UPS tracking for the tenth time today, hoping it would bring good news but knowing full well that it would still tell me my MKIII was stuck in a sort facility just an hour's drive from my house. I'm here to say I had a pleasant surprise. Originally it had a rescheduled delivery date of 11/30, and it has said that since this past Wednesday. But tonight (12:30 AM, tomorrow really ) it gave me ANOTHER rescheduled delivery date of 11/29. So I will will my MKIII in my hands tomorrow afternoon .

First thing I'll do is inspect ALL of the wood parts (while keeping them separated into steps!) to make sure UPS didn't do a number on the boxes. Hopefully I'll have some good news to report as opposed to, IIRC, to kits with damaged pieces. Fortunately IF anything is broken I know Mark and Trish will send new ones out in a hurry

Just noticed my avatar changed to "Level 1 MKIII". WOOHOO! Not fair though - I could never be level 3 because the MKI and MKII aren't sold anymore, lol.

I'll see if I can get past the excitement and remember to take some pics during the build.

- Jeff

 

I've ran into my first problem. I'm on step three, inserting the acme rod into the the two bearings. Problem is, it doesn't fit! I've tried filing down the ends of the rods in case there were some burs, but i can't get the bearings more than 3/4 of the way on the rod...

- Jeff

 

Just tried filing the rods a little more, and now I'm able to get the bearings all the way on so that the rod sticks about a 1/4" out of the end of the bearing, but they still won't go any further. :?

- Jeff

 

Not the inside of the bearing! Just sand the outside of the Acme threaded rod! It will remove burrs which are preventing the threaded rod from slipping into the bearing.

Use a fine sandpaper grit like 400 and wrap the rod while running it back and forth a few times.

 

Thanks guyz, I'll give that a try. It was frustrating as I was sure they were mismatched parts :roll:

- Jeff

 

I'm using some 320 grit (finest I have) to gently sand the threads down and it seems to be working...just a few more strokes and the bearing should slide freely.

One more question so far. While working on step three I I developed a small crack in the MDF, looks just like a surface crack and it doesn't go all the way through. The wood does not flex at all at the crack. I didn't force it on the tabs any harder than the rest of the pieces, I guess I just pushed it at the right place to induce a crack. I've included a picture (hopefully the macro setting on my camera worked well enough for you to see it) of the crack. Let me know if you guyz think it will be okay. I would think so, as there will be plenty of support from other pieces around it, but what do I know!

- Jeff Attached files .jpg]

 

Thank you for the offer, Mark! I think I'm going to wait until I'm done with the build though, just in case there's anything else I need it could be done all at once. After my more recent problem I think there may be many more

The acme thread now slide smoothly onto the bearings. I slide the acme thread through one bearing, then screw it into the anti-backlash nut on the assembly with the four bearings, then through the other bearing and tighten the stop collars. One side of u-groove bearings fits nicely on the rod, but the other side is near a quarter inch off, and in order to get in on the track, the acme thread is must be bent quite a bit. I've tried tightening the nuts on the u-groove bearings first so that it is completely on the tracks and then screwing the acme rod through the second bearing, but it doesn't even come close to straight. What do you guyz suggest I try?

- Jeff[attachment=1]IMG_1049[1].jpg[/attachment][attachment=0]IMG_1050[1].jpg[/attachment] Attached files .jpg] .jpg]

 

Go back to the build video and watch it again closely... I think there are supposed to be two washers there instead of one.

I'm not in my shop to verify this, but I am pretty sure that is the case.

 

If it helps, I could take some video of the specific problem I'm having. I know it's kinda hard to understand my words, especially when I don't have the right terminology.

- Jeff

 

I watched the build videos again and there's only supposed to be one washer on either side of the bearing. You are right, though, on a different assembly the washer setup is one washer on one side and two on the other. On the assembly concerning me, two washers would the problem worse, anyway

For now I've moved on in the build and am currently on step 6, gluing the rods for the Y axis in place. Hopefully the acme rod deal will be sorted out soon and there will be an easy fix...

- Jeff

 

ooohhh yeaaaaaa, it's lookin pretty sweet already

So nobody else has had any problems with the acme rod feeding straight through the anti-backlash nut?

- Jeff Attached files .jpg]

 

With my Acme rod thru the lower bearing and the anti-backlash nut it didn't naturaly line up with the top bearing, but it was close. I didn't have to try very hard to get it into the top bearing, it felt like there was enough play in it to go there and it "looks" as straight as an arrow now.

 

I guess I might have to just try it out. Maybe even with a slight bow in the acme rod it will still screw in and out of the assembly freely. We'll see. It's just that I kinda need to get the assembly on in order to move on in the build

- Jeff

 

I'm on step 11 right now but I just couldn't sleep without knowing whether or not I had too much binding on my Z axis. First off, Crash, your video tutorials are excellent! Like you mentioned, you DO have a knack for these things. My y axis jogged around just fine, but the Z would only move a fraction of an inch before it the belt started slipping or the motor stalled. I tried tightening the belt a little more but still the same problem. So, I need to fix my Z...somehow. It's been a couple days since I last looked at it, so maybe tomorrow I'll take it off the rails and have a "fresh" look at it to see what's going on.

Apparently swapping the two gears (small gear on stepper, big on gantry) may help, but this will give me more torque at the expense of speed, correct? Even if swapping the gears worked, I'd rather figure out what's going on than apply a bandaid.

Thank you, guyz, for all your input so far. I'm sure I'll get through this with your help

- Jeff

 

Thank you for checking this out Mark. I'll take the gantry off tonight and try what you suggested.

As for the handle being locked in the upright position, I have to knock one end down at a time with my fist...that's how tight it is. The left side has worked it's way loose a little bit, but the right side must be smacked pretty hard. Hopefully things will work in over time. I have everything done so far except for the cabinet door. I'm missing two square nuts for the hinges but I should be able to find some in the garage or at Home Depot.

- Jeff

 

I had similar issues... I attributed it to having painted my MDF but what I did to solve it could work for you if you have a Dremel with a round sanding bit.

I think I used the half inch sanding bit but it may have been the 1/4" one, not sure now. In any event, I lightly sanded the tracks where the pivot arm bearings run up and down.

Then I added lithium grease to the bearing tracks and to the insides of the pivot arms.

It made a huge improvement and now my pivot arms raise and lower with little effort. You still have to exert some force to lower it, but it raises into position and locks very nicely now.

 

Mark,

I ran into the same problem that jkarnacki had where my bearings that position the zplate appear to be too high on the blocks and washes. When I assembled it yesterday, it went together causing a slight bow (about 1/16 inch at the center) in the acme rod. My solution will be to go out and find a set of washers that are about half the thickness of the ones supplied to go under the 4 bearings. This should work if I can find them. It appears that there may be some variation in the way all of these parts are going together. I don't know if it's because there may be an opportunity to snug some plate down more than you might, or if it could be caused by the paint on the two blocks that support the bearings that is raising them more.

Maybe a possible solution to those who are finding this variation would be to supply additional washers of varying thicknesses to allow the builder to fine tune.

I supplied a picture of my z axis block. The hight of those two bearings seems to be the issue for me. I am not having any problem with the alignment from left to right.

SlowBipe Attached files