Reddit mentions: The best linear motion products

I have a Maker select. It's my first and only 3D printer so my review compared to others is unreliable.

Here's a copy/paste of a review I did on it about a month ago. It's long but detailed with links:

I will give you my background before my opinions. As everyone has different goals, opinions, and experiences.

I got my printer near the end March of this year. I have something like 2500m of filament run though it, and no idea how much print time.

When I received my printer, my test prints failed and I was pissed. But this community helped improve my Cura settings and started producing usable parts. I then went nuts and printed out a BUNCH of mods. This is by far my most favorite thing. There's always something I can print to improve the quality of the prints.

THe down side is I went too far and got to a point where I couldn't produce anything of quality. So, 2 weeks of tweeking and researching later I'm printing in PETG with beautiful quality and very minimal visible layers.

My most recent project in PETG:
http://i.imgur.com/sVf7S2D.jpg?1

So, now to answer your question...

> How do you like your Maker Select?

I love it. It allowed me to buy a cheaper printer (One of the cheapest at the time @ $350) that produced amazing results. It also has upgrades you can purchase or print to improve the quality, so investing smaller amounts over time to make it better and better. I highly recommend it to anyone who is starting because it does require tweaking which forces you to learn and understand how exactly 3d printers work. A major plus was that this community has a lot of Maker Select users for support, which was a MAJOR plus for me.


As of today, I've purchased the following upgrades:

• IKEA enclosure - $115
  
• LEDs for Inside enclosure - $25
  
• MK-9/10 Extruder Gear - $9
  
• Micro Swiss All Metal hot End - $50
  
• Micro Swiss Lever - $18 (Totally not necessary, but Micro Swiss's support was AMAZING to deal with, and I wanted to support them so I purchased this as well.
  
• Misc. M3 and M4 Screws, etc. - ~$25 in total between Amazon Orders and Lowe's for things needed for mods.
  
• New 40mm fan because I broke the blade on the one I had. There are cheaper ones than this. - $14
  
• 50mm blower fan - $8
  
  So, in the last ~3 months I've spent an additional $264... Oh god, don't tell my wife! All are totally not necessary, mind you. The only thing I'd 100% recommend you do are print out the following to mods:
  
  DiiiCooler along with buying the 50mm blower fan. There are cheaper options out there, I just wanted it faster so I bought it through Amazon to get free 2 day shipping.
  
  z-Brace - This is key, and will run you maybe $15 worst case scenario to get enough M4 screws and the threaded rods.
  
  Edit: Forgot a couple more things I bought.
  
  
• Lowe's glass - $4 for 2 pieces of 7.9"x7.9" glass
  
• Borosilicate Glass - $12 - Amazing adheasing with PLA and ABS. Don't use it right now, though because I'm printing in PETG and I read on here that PETG eats borosilicate glass.
  
• Lithium Grease - $7. When I changed my bearing blocks, I had issues with sticking so I purchased some of this to help smoothing out the bearing movement on the polished rods.
  
• 3D print removal tool - $5. Printer comes with a larger scraper, but I needed something a bit more fine (thin) and this thing is perfect.
  
• Spare bearings - $13 because I broke one of them when swapping to 3d Printed bearing blocks.
  
• Digital Calipers - $18
  
  That's another $59, so $323... I have a problem. again, 95% of this is NOT NECESSARY. I'm just addicted to modding.
  
  

Sounds like a cool project, probably more suited to the hobby CNC subreddit: /r/hobbycnc , but I'm still happy to throw in my 2 cents here.

Instead of building up trucks with threaded rod / bearings / nuts, and using an aluminum tube for your linear motion, I would highly recommend using off the shelf linear bearings and shafting. The proliferation of the hobbyist DIY CNC / 3D Printer segment has flooded the market with cheap linear motion components. It's still going to be a bit more than your proposed solution, but I think it would be worth it - you'll save yourself a lot of frustration and end up with a better performing solution, even using the cheapest off the shelf components. Something like these, for example:

• Linear Bearing
  
• Linear Motion Rail
  
  For the gear rack / spur gear: Do the individual "blocks" the louvers are attached to need to move independently of each other, or can they all move ganged? I'm assuming you need the independent linear motion, but just in case you don't, it would be much cheaper to use one motor to turn a single leadscrew that runs the full length of the machine axially and have a nut on each "block".
  
  Assuming you need the independent linear movement, your use of a gear rack is a good solution. You mentioned wanting to use NEMA17 motors but were unable to locate a gear that would fit on the 5mm shaft. McMaster has brass spur gears with the DP and PA to match your rack with a .1875" bore, however they're brass, not stainless:
  
  
• 7880k31
  
  You'd obviously have to ream the bore to fit a 5mm shaft, but that shouldn't be much of an issue. If you can't live with brass, and you can't find a 32DP 20° spur gear with an appropriate bore elsewhere, you could always turn down a bushing to press fit on the 5mm motor shaft to make the larger bore spur gear work. If you're not paying for your time to make the bushings, the material cost for that is going to be a lot less than the price delta between the NEMA17 and NEMA23 steppers.
  
  Also, if the "blocks" are moving independently of each other, you probably want to put limit switches on them to prevent them from running into each other and trashing your steppers / gears / whatever else.
  
  Lastly, I'd try to avoid using the 2x2 wood stud for that structural component. Structural timber like that is terribly unstable and not dimensionally accurate at all, I can see it causing you issues - take a look at 80/20 aluminum extrusions for those structural components. They're obviously more expensive than wood, but you can find good deals on eBay (the actual manufacturer of 80/20 even has an eBay store where they sell surplus / off cuts / scratch & dent / etc.: 8020-Inc-Garage-Sale)
  
  Anyway, hope some of that is helpful. Like I said, looks like a cool project, and I think it's certainly achievable, even without taking any of my suggestions on board. Oh, and BTW - nice looking rendering you made there!

Short version- it's probably cheaper to buy a 2nd robot vacuum, unless you go total DIY route.

Medium version- Unless the hallway is an outside hallway (IE one of the hallway walls is on the outside of the house) you probably aren't wasting any money heating it. If the hallway is surrounded by heated rooms, then the hallway itself won't bleed much heat except maybe through the ceiling and that's probably to another apartment.

Long version: Locking and unlocking doors is fairly easy. Unlatching doors is a bit harder- motorized doorknobs aren't really a common thing so you'd need an electric security strike plate. That would probably require cutting out a lot of the door frame to mount it. Then you have the issue of actually opening and closing the door. It has to open and close with enough force that it pushes the latch through the strike plate, but also should have some safety mechanism so it can't cause any harm to a human or pet. That's one reason why automatic door openers (like you see at the supermarket) are quite expensive- you need a powerful motor but you also need a bunch of sensors to stop the motor before it does any damage. Those things are quite expensive and require custom mounting. They're also fugly- this is the smallest most attractive one I could find and it's $530. You could use something more like an automatic gate opener but that's still $289.

If you were to do this, the DIY route is probably the way to go. The strike plate is easy enough, you can get that on Amazon for $23. That just needs 12vdc to unlock it. The opener is the harder part. You'd probably want something like a long stroke linear actuator. Alternatively you could make something using some gears and stuff- there are a few ways to do that.

But when you put all this together, you are still spending a good amount of money. Even if it's just $100 (which I'd put as the absolute bare minimum for this) how long will it take you to realize $100 worth of energy savings vs just leaving the hallway doors open?

I have the same printer. This is what I used. The print quality improvement was amazing.

5mmx8mm Flexible Shaft Coupling


Lead Screws

You'll have to change the steps per mm for the z axis. I wasn't able to flash the firmware with the board the printer comes with. I hope you have better luck with yours. I just upgraded to a duetwifi board. It cost more than the whole printer. lol

Also, when you put the shaft couplings on, make sure on of the set screws is on the flat part of the motor shaft so it locks it down good.

Consider two alternatives to drawers:

• Pegboard in front of the workbench, like http://i.imgur.com/Y7r5V7H.jpg
  
• Under-workbench pegboard slideouts: http://i.imgur.com/uV7SEtL.jpg
  
  I find that seeing all my tools is helpful, though I did build drawers (ha, in middle of some remodeling now so everything's a mess, including the right drawer.) If you want heavy duty drawers that close nicely, you'll probably want to just focus on finding heavy-duty drawer rails that you like and go from there.
  
  Anyhow, from what you described as your workbench, you could potentially mount the built drawers like so: http://i.imgur.com/0pDnUjw.png - the framework there keeps the shape. In lieu of using brackets, you could screw + glue pieces of wood to preserve your surface. Mind the weight, of course, because that'll definitely require some bracing.

Judging by this image it looks like the legs use 2 connecting rods each. The rods connect to an extension just behind the joint, perhaps you can call it the knee and the rods the "tendons". I'm not certain as to what's under the covers, but I would guess a small linear servo could push and pull the rods enough and quickly, depending on the maximum torque needed and the extension length. This 2" linear actuator travels at 3.15"/sec, which could accomplish what the videos show. The weight limits are 11lbs, 22lbs, or 33lbs for these motors, one in each leg.

Going back to the image, the spacing of the rods on each side of the knee is exactly the same space that the linear servos provide, if the bars were on each side of the servo rod. The rod includes a hole perpendicular to the rod which a connection bar can go through. This can be a simple metal bar with holes for cotter pins on either side. The tendons would connect to this bar, attaching them to the servo/actuator.

It's also possible that they're using a motor with an offset extension that drives the tendons. When the motor turns, the offset arm pulls or pushes the metal bars, causing the leg to move. The limitation is that the distance of travel is defined by the diameter of the gear or arm attachment. Since the legs are relatively thin, I am guessing it's more in the linear servo or actuator category.

The joints that attach to the body are most definitely a standard motor, not a linear servo.

This video shows the range of motion in the joints, and better angles.

I haven't see those before.At $200 for all axes, that could be pretty good. You still may get the deflection in the centre of the x that is sometimes talked about because of the heavy tool head but still a pretty good financial compromise.

I don't know how much the openbuilds rail upgrades cost in total is though but this is certainly cheaper in terms of time and effort doing the upgrade.

I would suggest waiting on the ballscrews until you are going to build a bigger machine, a lead screw like this with a diy anti-backlash nut would save a fair bit a money and might work better with your motors. Aluminum and MDF could make a frame solid enough for what you need, I would suggest looking on youtube and seeing what others have done.

If you want to build out of aluminum this and this might be a good place to look for ideas and materials. I haven't bought anything from them myself, but it looks interesting.

What are you planning on using for a motion controller? linux cnc, GRBL?

Where about are you located?

Oh thank god Reddit is back up! Okay, I think a good bet might be these: https://www.amazon.com/OTRMAX-4-Piece-Longer-Bearing-Bushing/dp/B01MXTYSVL/ref=sr_1_2?s=industrial&ie=UTF8&qid=1498657770&sr=1-2&keywords=lm8luu as it is the correct size and has good reviews.

> It also probably has end of range limit switches - one can but hope.

It does, it says so in the description.
For my application it needs only to fully extend and fully retract, nothing needed in between. But you're right it is overkill for this project, I'm going to see if I can find something less powerful and cheaper

For example, this one is cheaper:

https://www.amazon.com/Heavy-Linear-Actuator-Stroke-Lift/dp/B00HYE82Y6/ref=sr_1_19?ie=UTF8&qid=1495649762&sr=8-19&keywords=actuator+14+inch

It says "Built-in clutch prevents over-extending and over-compressing."

Is that the same as a limit switch or different?

If I was going to make a beetle crusher, I'd probably get something like this and strip as much weight from it as possible. I'm not sure it would be competitive- if you settled for just grappling and put the extra weight towards better drive it'd probably do better. But that's what I think it would take to get through the top armor of most beetles.

That's an interesting product. We had an old Velux skylight and replaced the entire skylight when the motor broke and replacement parts were too hard to find. That chain's a cool piece of work, as it can extend a large amount and retract into a small package. Skylights are on a hinge, not a slider, so all a motor has to do is push up was the weight of the skylight, and not have to overcome friction in the sliding frame. The Rollertrol product says it can do about 20 pounds of force.

You could look at "linear actuators" which can provide hundreds of pounds of force. Here's one that does 330 pounds: https://smile.amazon.com/ECO-WORTHY-330lbs-Tracker-Actuator-Multi-function/dp/B07H73VZGK I've been planning to use a linear actuator to make a video projector come down from the ceiling and hide away between uses. The trick on designing with these is that the distance they can extend is less than the length of the unit, in other words, the extended length is less than twice the contracted length. It might be able to open the window part-way, but not all the way open, unless the actuator was built into the wall above or below.

The rollertrol product is shown placed right in the center of the window to apply the force in a balanced manner.

If you had an actuator at each side, you'd have to make sure they stayed in perfect sync. If you used a product like: https://smile.amazon.com/WindyNation-Actuators-Connectors-Momentary-Maintained/dp/B07957BXR4

you could have a problem because whichever side needed more force would get slowed down, potentially making a sliding window bind up.

If you're going to replace the rods, you should really consider upgrading straight to lead screws. I replaced the m5 rods on my Prusa i3v with 8mm leadscrews and saw a pretty noticable increase in print quality. They'll help make your printer more rigid and have less backlash, giving smoother and more consistent print faces.

You can get relatively cheap ones off of amazon that will be a serious upgrade over threaded rods: https://www.amazon.com/Drillpro-400mm-Lead-Screw-Printer/dp/B017AR5QBS

I am trying to teach myself about using low level logic to switch higher current devices. So here is the project. I am building an automatic door opener for my brother's chicken coop using this 12" actuator. You reverse the polarity to drive the arm in/out. It was very nice out today in the Boston area so I decided to free-hand my project design rather than sit inside ;)

Here is my drawing. I need to know what other stuff I need to add to protect everything. I know that I need some resistors from the arduino pins so I don't draw too much current. I think I also need some pull-down resistors on the actuator-feed relays, or would this be the job of a capacitor?

Edit Here is a reference to the automotive relay I am using.

Thanks in advance!

WINDYNATION 12 Inch 12" Stroke Linear Actuator 12 Volt 12V 225 Pounds lbs Maximum Lift (Includes Mounting Brackets) https://www.amazon.com/dp/B00P4U556U/ref=cm_sw_r_cp_apa_DF-qzb74JZBBW

I also used the Firgelli feedback actuator on a different project a while back. It is double the cost, but the feedback would have been great for this build.

Mine printed fine for a couple months until I got lines like those.... I bought a new lead screw on amazon for about $10 and it’s been printing fine ever since.

https://www.amazon.com/dp/B017AR5QBS?ref=ppx_pop_mob_ap_share

This is the one I bought.

This picture is inland PLA printed at 220 C at various speeds - 60 mm/s on the left to 10 mm/s on the right.

Like most Wanhao i3 pluses, my y axis bearings started going, so I replaced them with these LM8LUUs. I got a lot of ringing. Tightening the belt didn't seem to help. Adjusting print speed and acceleration work, but only with extreme values - the printer was printing fine at 60 mm/s print speeds before the swap, and now I can only get rid of the ringing at 10 mm/s. Similar with acceleration values, originally printed at 1000 mm/s^2, and can get rid of ringing sub 200 (the picture is all 800 mm/s^2). Obviously this is not ideal. I'm out of ideas, but am wondering if this could be a problem with the bearings themselves at this point - that is, if I should replace the bearings again.

the ultimate solution is to upgrade to linear railings like these

​

Here's a video of mine in action

3D Printer Linear Ball Roller Bearing Slide Block Comgrow https://www.amazon.com/dp/B0728J3J9K/ref=cm_sw_r_cp_api_fMhMBbRK4R04A

But before you buy try again with what you have, only slightly hand tighten all the bearing blocks and then while sliding it back and forth, slowly tighten them to make sure it still slides beautifully

linear rails can be had reasonably enough. They offer superior accuracy and stability, and if installed properly, last a long long time.

Amazon has a new brand that hasn't got many reviews yet but man that price. been watching them to see how it plays out.

For homemade purposes, there are better options than real linear bearings. A wheeled "cart", spring-loaded to ride on a track, will work just fine and can be made cheaply. You can also use heavy-duty drawer slides.

Have you looked at the Shapeoko? They are using rolling "carts" on angled tracks.

also, http://www.amazon.com/Linear-Motion-Length-Chrome-Hardened/dp/B002BBJ0CA/

Pretty generic Not super high quality, but a big improvement over the bearings my printer came with. They were rough.

Can't confirm these are the ones I got but they look like something Id buy, i just look for case hardened. If you dont have long lm8luus check those out too. And white lithium grease lube

https://www.amazon.com/Hardened-Chrome-Linear-Motion-Shafts/dp/B01LXAZFKZ/ref=mp_s_a_1_3?ie=UTF8&qid=1525048454&sr=8-3&pi=AC_SX236_SY340_FMwebp_QL65&keywords=8mm+linear+shaft

Here's where I got some really good LM8UU bearings recently, https://www.amazon.com/6pcs-LM8UU-Linear-Bearing-Bushing/dp/B008RIKN7W, it comes in a 6 pack for about $8 bucks

After doing quite of bit of reading, I went with these:

OTRMAX 4-Piece 8mm Longer Linear Motion Ball Bearing Double Side Rubber Seal Linear Bushing CNC Part LM8LUU https://www.amazon.com/dp/B01MXTYSVL/ref=cm_sw_r_cp_apa_5iPSBb8S68Y2Q

I'm pleased with them so far.

I bought these lead screws. Be careful because they will not fit by default. You will have to drill/dremel out the existing z-axis mounts where the original threaded rod brass nuts were to make these fit. These take M-4 screws while the old ones took M-3 so the holes will need to be enlarged on the carriage. It took about a couple of hours to mount it correctly. It seemed that everything the Geeetech came with was too small by a couple of mm. The 8mm spring couplers were not exactly 8mm so I had to purchase new 8mm spring couplers to get the new lead screws to mount to the z-axis steppers. You will also have to cut the rods shorter because these were 400mm. I also had to tap the M4 threads into the mounting nuts for these. this might not be required as yours might come tapped but I would recommend buying an M4 tap or a set of metric taps. These were a pain in the ass to install but they produced really top quality prints, anything better than I've seen come from my printer. I would say it's worth the bit of engineering to get them to fit. I mean that's what this hobby is about right?

I think one of these should work. The thingiverse mentiones 45cm long, which is roughly 17 inches, so I think a 16inch or 19inch should be fine without cutting.

https://www.amazon.com/Hardened-Chrome-Linear-Motion-Shafts/dp/B01LXAZFKZ/ref=sr_1_3?keywords=8mm+rod&qid=1566315274&s=gateway&sr=8-3

https://www.amazon.com/ReliaBot-Hardened-Chrome-Plated-Linear/dp/B07DPFH7HL/ref=sr_1_5?keywords=8mm+rod&qid=1566315497&s=gateway&sr=8-5

rods are original (7.94mm in diameter)

I think the bearings are the regular LM8UU ones

3d printer linear ball rollers work well. Decently cheap too.

​

https://www.amazon.com/Printer-Linear-Roller-Bearing-Comgrow/dp/B0728J3J9K

ACME thread leadscrew

https://amzn.com/B00OZJMX1Q

You could always just buy these and also get a saw. Alternatively, use this page, select the approximate size of your rod (in this case 8mm/251-498.5mm) and then enter the exact length you need in the "customize" section before adding it to your cart.

I've basically had this problem for about 2.5 years and have posted about it about 6 times, this was the first time anyone knew what it was.

Here's the changes/settings I've made:

EEPROM:

• X axis acceleration: 800
  
• Y axis acceleration: 700
  
• X jerk: 5
  
  Cura 4.2.1:
  
  
• Wall line count: 4
  
• Top Thickness 1mm
  
• Bottom thickness: .7 mm
  
• Print speed: 50 mm/s
  
• Travel speed: 120 mm/s
  
• Initial Layer speed: 25 mm/s
  
  Upgrades to the printer (apart from those already mentioned):
  
  
• Running on a RPi3 with OctoPi/Octoprint
  
• Got rid of the spring tensioners and used these instead https://www.thingiverse.com/thing:1784375
  
• New bearings: https://www.amazon.com/gp/product/B01MXTYSVL/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
  
• https://www.thingiverse.com/thing:1728482
  
• https://www.thingiverse.com/thing:1635585
  
  The rest of my settings tend to vary based on what I'm printing; and my retraction currently isn't dialed in.