MadModder

Ever have one of those Hokey-Pokey days? The days you take one step forward, one step back, then two steps forward? Today was one of those days.

It started out well enough, I got pilot holes drilled every place in the Y axis leadnut plate that needed a hole. Four of the nine holes were locations that needed to be tapped M3, so I just used the M3 tap drill for all the pilot holes. I needed an 11mm hole, actually I need 10.5mm but a little wiggle room isn't going to hurt. I ain't got no metric drills, what I've got are a set of number drills and a set of fractional drills from 1/16" to 1/2" - by 1/64" increments. So far that has fallen well within the tolerances of my gub-mint contracts. Anyhew, I got the big hole drilled, so I could check the leadscrew alignment with the leadnut plate.

Annnndddd.... It didn't fit as planned. I needed to move the plate about 2mm closer to the Y axis extrusions. Which meant that in addition to being too short, the plate is now also interfering with the mounting bolts for the Y axis rails. Oh Happy-Happy Joy-Joy! There IS a silver lining though, I had a proven hole layout, I knew what needed fixing, and I knew how to fix it. The second time you make a part really is faster than the first time, practice makes perfect I guess.

I knew that there was no way on God's green earth that I was going to be able to drill and tap four M3 bolt holes with everything on the rails, so I came up with a work-around. I took a careful measurement of the distance from the edge of the leadnut plate to the edge of the bearing plate, and clamped the leadnut plate in place. After carefully removing both plates, they were transferred to the vise where a transfer punch was used to mark the center of one hole - didn't want to push my luck. After drilling and tapping the hole M3, I used the M3 bolt to clamp the leadnut plate in place to mark the other hole. Rinse-lather-repeat and all the holes in the Y axis bearing plate are now drilled and tapped.

That just leaves the M3 hole that needs to be drilled and tapped in each of the far side Y axis bearing blocks. Back to the machine to partially reassemble the Y axis bearings and bearing block. I didn't need to put EVERYTHING back together, I just needed the far side bearings blocks tight enough that they wouldn't move when I slid the bearings off the rails. I took the side plate off the nearside of the machine, slid the Y axis close to the end of the rails and removed the near side bearings, setting them aside. I was then able to remove the rest of the Y axis assembly from the rails, clamp it firmly in the vise, and use a transfer punch to mark the hole locations for the M3 bolts. I then removed the bearings from the plate, covered the bearing openings with tape to keep the swarf out, and drilled and tapped the holes for M3 bolts. I then started putting this part of the machine back together - for what I hope to God is the last time.

Anywho, this is what the Y axis looks like now.  (vtsteam - I'm usually too lazy/busy/forgetful to remember to take pictures.)

Like I said, the offset leadscrew makes the plate look a little goofy. Everything is just loosely assembled right now, and since I took the side plate off I'll need to align the rails to the bed again. That's not the actual leadnut, I need to build the anti-backlash nut and the leadnut plate together as an assembly. The four M3 button-heads hold the leadnut plate/leadnut assembly to the rest of the Y axis assembly so maintenance will be fairly easy.

Thank you.

I agree the sharp edge and narrow contact area for the balls is a potential concern for future wear.  For the time being I'm just being careful not to wind them up with a torque wrench, just nip them.  I suppose the cyanoacrylate will help spread the load a little as well.   Another approach I've seen is to have a machined 'V' groove to locate and align the runners.

Having spent the afternoon depthing and measuring, it seems to have done the job.  To fit the barrel arbor I made a couple of press on adapters with larger coned sockets.  These are partially reamed 4mm but left the taper lead in of the reamer at the end so they wedge onto the end of the runner and thus saved me having to make an extra pair of runners with larger sockets.


Ian

I spent most of the day double and triple checking the 3D model against the machine as it currently sits, and found a couple of discrepancies - those got corrected. Last week I picked up a piece of 1/8" x 1-1/2" x 48" HRS barstock, only it was 1/8" plate that had been sheared to 1-1/2" width and I'm OK with that. The problem is that for some reason I had modeled this as 34mm wide and it actually measures at 38mm. I fixed the model, but then I had to be sure that everything was in the proper location. which is not as easy as you'd think. The leadnut plate is centered on the Y axis bearing plate, but the leadscrew is not centered on the plate. While I'm changing a LOT on this machine, I tried to move the minimum amount of hardware from its' original location as possible. When I changed the original Y axis 2020 extrusions to 2040 extrusions, I used the original mounting holes as my starting point. I also kept the original location of the Y axis leadscrew, this was not without consequences. By a happy coincidence the centerline of the leadscrew and the centerline of the Y axis rails all align vertically.

However, the leadscrew's horizontal centerline is 3mm below the horizontal centerline of the 2 rails. This leads to an asymmetrical and somewhat goofy looking leadscrew plate. I've got the layout done on the plate and got the holes center popped. I've even got it cut out, filed, and sanded. The layout lines on the Y axis bearing plates match with the layout lines on the leadnut plate. I'm going to drill an 8mm hole for the leadscrew and make sure that's in the right spot before I do anything else. That'll give me a chance to possibly fix it if I did make-a-da-boo-boo. There's not a lot of wiggle room in some areas, the model shows that I SHOULD have about 8-9mm of clearance between base of the Y axis rails and the leadnut plate. The problem is that I didn't model the heads of the mounting bolts for those rails. I've got MAYBE 2mm, but clearance is clearance Clarence.

Sorry for well and truly raising a thread from the dead - but at least it's the right time of year for such things!

Having need for a depthing tool and liking the simplicity of this design, I decided to have a go myself.  In the absence of detailed drawings I've needed to sketch it out myself, hence the reason for necro-posting to add some dimensioned drawings should anyone in the future have a similar need and come across this thread.

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I went with 4.5mm balls in 4mm reamed holes (no countersinks or chamfers!)  with 6mm balls in 5mm holes for the hinges.   I also roughly cut out the 'C' shape of the frames first to let any stresses and distortion out of the metal, then machined to shape and again unclamped to let it relax before then drilling and reaming all the holes as the last step so they should all remain true to each other.

The adjustment has a half-round 'nut' which sits in a similar half-round groove on the inside of the one plate, with the end running in a short vertical half-round groove on the opposite side:

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If I wasn't too careful slackening off the adjusters the flippin' balls would drop off their seats.  I fixed this by fully cleaning all the parts then assembling and clamping the runners in position before using a wooden stick to add a small drop of cyanoacrylate glue down the hole behind.  The ball is blocking the hole and is held in position by the runner, so the glue is just going to tack them in position without the risk of preventing them sitting down accurately into position.

I haven't tried it in anger yet, but just setting the arbors together for this photo seems to suggest it's going to do the job for me just fine.

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Ian.

At first, a list of currently existing AI types: https://www.geeksforgeeks.org/artificial-intelligence/types-of-artificial-intelligence/

Some of them I find to be rather questionable, as they are basically used to replace human workers at corporate, and pretty much at all possible levels nowadays.

But I'll concentrate on 'generative AI, which is used for video processing in this post.

There are more and more Youtube channels, that have only AI-generated content (also called as AI slop). Some of those channels can have quite a lot of views.

Some "history" channels spew out plain false and made-up stories, with grayscale images/videos. So of course they must be authentic, right?

When there is a 'human looking host' speaking, something is missing; it can keep talking for 30 minutes or more, but it doesn't have human factors involved, like clearing throat, or change its posture.

Another sign of using AI is the use of artificial film grain, pretending that such videos have some credibility. Yes, they may make a lot of money for their creators, and that seems to be the only motive for such 'content creators'. I guess some kind of automated process is used to create them.

I've watched numerous of those videos on certain channels. Although the content and subjects may appear to be interesting, there are some kind of repetitive patterns, that I can't explain or fully understand, but which tells me that there are not a real human(s) involved in such videos.

I could make a long list here, but instead an example of another kind of videos: 3I  atlas - what a jolly good subject to create countless AI generated channels and "content". And don't ever forget to use superlatives in those video titles.

At this point, one subject, where the AI is not always successful, is to create videos of persons who then may have six fingers, or other weird glitches (especially if the 'creator' is sloppy and lacks any talent).

But enough of negative sides of AI.

The other side can be hilarious, when the videos are processed with skill. like this (they are called 'deepfakes') from 'Ctrl Shift Face' channel:
_https://www.youtube.com/watch?v=bPhUhypV27w

There is another channel as well, but as it's politically oriented, I think it may not be suitable to mention it here.