5-Part LongMill V2 Impromptu Assembly Video Series

Hey guys!

In case you didn’t see, I’ve just finished putting up a 5-part follow-along video series showing the LongMill V2 assembly process as a supplement to our existing online assembly instructions. Filming these assembly videos was very impromptu and completely unscripted since I’m still in school full-time for the next month and I managed to only cut out a 2-day window that I could come in and record everything, but I’m still very happy with how it turned out and I hope that you all find the pacing nice and the content informative and understandable.

As a bonus to the existing LongMill users, I also blocked off a nice chunk of time in the fourth video to show how to properly set the rotation of the eccentric nuts so that they’re clamping down on the rail with an appropriate amount of force. Between the second video and the fourth one, I also mention how to install the anti-backlash nuts and how to properly tension them :+1:

All five parts are already out and available for you to watch, check it out!

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Love the t-shirt!

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As someone about to start putting my V1 together, any areas where this would lead me astray or can I largely us it as well as a reference?

The primary area I can think of is that on the V1 the ‘arm’ on the Z-axis assembly is plastic rather than the steel that we switched over to for V2, so as you go through the assembly videos you’ll see me being more nonchalant about laying the assembly onto its back arm since I know that the steel can take it; however if you do this with V1 then the arm could certainly snap. Main advice here: be very aware of the plastic arm.

The layout of the packaging is also much different between V1 and V2, so it would be best for you to look through the list here: https://sienci.com/dmx-longmill/unboxing/ in the “LongMill V1 Unboxing” tab a little ways down the page while I talk about the components in the first video.

Other than these things, I’m quite certain that the assembly process is exactly the same :+1:

Is there such thing as a V1 to V2 upgrade kit? I haven’t kept up with the changes. Since I haven’t put mine together, could I buy a small kit and make it a V2 or are the changes too material?

Andy blog post here talks about the changes which were made to go from V1 to V2:

https://sienci.com/2020/02/18/a-list-of-common-issues-and-how-we-resolved-them-on-the-longmill-v1-and-how-we-improved-on-our-machines-for-v2/

Most of the changes were process/QA related or were fixes that we implemented to make assembly and packaging easier on our end. The only noticeable improvements made for the end user is the steel vs. plastic ‘arm’ (which really only comes into play during assembly), the longer motor cables, and the improved control box (where the primary improvement is the ability to now fasten it down easily). There were a handful of other smaller improvements which primarily are to your benefit during assembly such as the new LongMill wrench and better hole clearances.

So I suppose to answer your question, we don’t currently have a V1 to V2 upgrade kit, nor were we planning on implementing once since 100% of the machines improvements were towards making assembly easier, but not towards changing how the machine performs. I think the only thing we’ll be selling is the new control boxes as well as the new LongMill wrenches.

Thanks for the detailed response. Makes sense.

So other than securing the controller, no other change to the box? Hmm, I wouldn’t mind a longer cable set, is that do-able? :slight_smile:

Haven’t reached a conclusion on that yet between myself and Andy. Seems we didn’t order many spares and getting more would take a while under the current virus situation. For now I’d make the assumption that they won’t be available since I don’t link making promises that I can’t keep. Will update you if a decision is reached :+1:

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Understand. Wago connectors it is then. :slight_smile:

Good videos, will help in my build for sure!

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Very well done,Chris. Where were you when I was building mine? :wink:

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Video has been great so far. Have the XZ Gantry totally build and the nuts fit in to the feet. Hopefully will finish and get it moving tonight.

@chrismakesstuff one tiny piece of feedback is to be clearer about which M5 bolts are for retaining the route grip to the Z backplate. It was hard to see which ones and I used the medium length ones and couldn’t understand why they weren’t going in. It was late, I was tired, and my impact driver was the wrong answer… it sheared the top off one of the bolts.

Other than that, most things were pretty easy to understand. My main suggestion would be to keep refining the packaging and labeling of the parts. And also to let people know both the requried # of a given bolt or nut etc as well as the supplied number. I only had 11 of the expected 12 M5 nuts. Still not sure if it is an issue. It seems like you did an awesome thing and included 2+ extras of most of those parts. Which is brilliant, because one or two have rolled under things in the shop already… :slight_smile:

Had to go out and resupply today. Things have changed a lot in the past week or so. Staff at Home Depot are behind plexiglass here now. Staples staff almost all had masks on. Costco all have gloves on, and most customers have masks, few staff did but the other day no staff I saw had masks so even that is changing.

Big line-up and waiting to get in to HD and Costco. 1 in 1 out kind of thing.

On the upside, I did discover my local HD has something they call “Russian Birch” but only in the 2’x4’ area, and I only noticed it by accident. Apparently they stock it in both 1/2" and 3/4" in my store. I bought some for the first wave of projects.

-Jeff

PS - You absolutely did the right thing not speeding anything up. We can turn up the speed in YouTube if we want, but I really appreciate you diligently documenting every actual step. Very well done video.

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I watched the entire series and it was excellent. I have my machine at work but due to the corona virus I haven’t assembled it.
I think I’ll do a few things a little differently.

  1. First thing I’ll do different is use purple thread locking compound on fasteners that engage threaded holes in the aluminum extrusion.
  2. I’m considering making a flat spot on the ACME rods so the set screw in the motor coupler will better hold the shaft and use the thread locker on the set screw.
  3. I’m also considering using construction adhesive on the X-axis brace (30-30 Longmill). This would effectively make the two pieces work as one which would improve rigidity.
  4. You used the longer screws on the backlash nuts but pointed out the this would reduce travel a little. I think I’ll see if I can use the original screws intended and place the jam nut in the robot’s mouth. I’m not sure how this will work out but I think it’s worth a try, at least as an experiment.
  5. I’m going to investigate using a split collar behind the ACME nuts. I’m not confident in the set screws holding the ACME nut tight over the long term. At a minimum I will use thread locker on the set screws.
    It’s been a few days since I watched the videos so that’s all that comes to mind.
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Excellent ideas. Best time to do it is as you build. This past 2 weeks I partially dis-assembled my longmill and have rebuilt my table due to middle sag. I also switched from all plywood top to plywood and topped with 2 layers of MDF. After the table was done I re-assembled the longmill and thought about some of the things you mentioned. Mainly grinding a flat spot on the lead screws. When dis-assembling I couldn’t get the set screws out of the couplers. I ended up having to drill them out. I had to replace the couplers and ended up using solid couplers. That means the set screws contact the lead screw. I believe the provided couplers are compression couplers so the set screws just tighten the coupler around the lead screw. I personally think that would definitely eliminate slippage especially in my case. As for the backlash nuts I switched from the longer screws to the set screws with the jam nut. Picked up at least an inch of travel and don’t have to worry about the bolt hitting the front feet and messing up the backlash nut. Good luck with your build.

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Excellent suggestions from both of you. I had a few of the same thoughts, but actually more identified some of the issues without knowing how to resolve them. The idea of having a flat spot or similar for the set screws on the couplers to engage the acme lead screw sounds promising, although not sure how one would do this at home?

I followed Chris’ lead in the video and used the higher mounting point for the router collar but now that I have it together I’m wondering how you would lever lower it as the screws enter from the rear and it is impossible to get in there due to the limited space around the screw and the aluminum rails. Am I missing something? It would be great if a design revision somehow enabled the router holder to be moved from the front without having to take the X-axis off the machine.

I know the coupler has been changed once already to a different design, is there any feedback on how that has worked out versus the original compression design Bill and I have?

You just brought up another thought i had.
6. I might consider using two router collars to improve rigidity.

Jeff, on the router plate access screws. I had originally set mine up on the lower holes but decided to move it up to the top row. After giving it a good look I removed the 8 screws (4 on each side) from the router Z mounting plate to the linear slides and the screws from the backlash nut. Removed the router too. Then you have full access to the 4 motor mount screws. On re-assembly I put the 8 linear slide screws in first and then the 2 backlash nut screws. Just be sure not to remove the linear slide rail screws (no need to). So far no problems with it.

I too had to change which router plate mounting position. I chose to remove the Upper V-Wheels so I could take the entire mounting plate off. Remove the router first to eliminate the weight. It’s not perfect but I was able to move the mounting plate to my desired location. then just retention the Wheels and you’re done.

I also had a problem like Heyward in that one of the compression couplings, x axis for me, would not tighten onto the motor shaft tight enough to not slip. I used a bit of sandpaper between the shaft and the coupling to take up space and a bit of friction and all has been good ever since.

Good idea, if I run in to that again I’ll get out the sandpaper.

And thanks for the tip on accessing the router. I want to try to cut the PPE face masks that @gwilki included the info for in another link, but they use a 1/16th inch but and 1/4" or less material so I’m just too darn far away from it with the router in the upper position. For now I’m going to grab some extra pieces of material and just elevate the workpiece, but if I need to change the router I like your V-wheel removal idea.

Still having a heck of a time getting my wheel tension and set screw tensions just right (on the lead screw ends). Not sure what I’m doing wrong but have had multiple instances of loosening.

I just watched the video series. Well done!
I did notice two glaring omissions…
No Tragically Hip blaring in the background and no ever-growing row of empty beer bottles. How do you expect to get anything done properly without those work shop staples?

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