this is a place to throw out longer-term ideas for them to use when the injection molds they purchased need to be replaced
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for the top/bottom anchors:
consider having a few different sizes for different routers.
I managed to lean the partially assembled machine wrong and snapped the bolts out of one of the anchors that hold the lead screw covers. There is no reason why that portion needs to be so thin
Itâs good not to have to worry about finding the right length bolt for every location, but having bolts that are long enough that they can push the lock-nut out of the anchoring hole so it spins is a pain. if you make the anchor holes deeper (or the part where the screw is thicker), then this canât happen. I ran into this both anchoring the verticals to the ends and tightening the router clamps.
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For the arms:
make the spools/arms a larger diameter. Currently the arm against the router and the spool against the arm are going to be wear points. With a larger diameter there would be room for bearings (even if they are balls that you drop in rather than commercial bearings). It will be interesting to see how long everything lasts (may I suggest that you hook one to the cealing and hang a weight on the belt and just set it cycling, extending/retracting for a few weeks to find how it wears over time??)
note that the belt does not need to exit in line with the motor shaft if that makes things fit better with a larger spool.
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for the cap:
Iâm finding the tab shields on the ethernet cables are catching on the cap and bending up, making it hard to get at the connector tabs to remove them. please give just a little more room, or better still, make the cap flat rather than curved over the ports so that the cap doesnât stick out further than the ports.
(and in an electronics refresh, see if you can run the motor power through the ethernet cable as well and have the motor plug into the encoder board, that would make it easier to reposition the controller board)
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I agree 100% itâs a little annoying how those catch there. Iâve seen that too.
With regards to cables and cap, Iâd appreciate a design update that leaves wires less exposed. Especially at risk are the wires that power the motors. Not so much when the maslow is running though, More like when it is manually lifted turned stored. My first thought was to create a bigger, umbrella style cap that protects the wires but leaves room for the arms to move. Running power through utp as you suggest is a beautiful solution as it removes a lot of wires from the construction.
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The non linear bearing âtowersâ could be held together by a single bolt /nut running the full length of the tower as this would mean you had the ability to easily separate the 2 clamps and 4 spools
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The leadscrew from the stepper motors will pass through there, no?
Yep was thinking a mild redesign though that gets rid of the 3 small bolts in the middle - probably wasnât clear âŚ!
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Ah I think I understand, it would need to be a longer bolt though, right?
Very good idea, I would really like to be able to run the router off the top of
the lead screws for bit changes and storage.
David Lang
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Instead of the two plastic towers to the top of the guide rails being solid,
make them be two pieces (the top piece can include the cap for the guide rails)
and instead of 6 small nuts/screws holding the two parts together, have them key
together with a single bolt holding them together. That bolt could potentially
run the full length of the tower, giving it a very solid reinformcement
see how the usaadesign guy puts screws through his printed parts to make them
stronger https://www.youtube.com/@ussadesign
David Lang
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Another suggested improvement. Have threaded inserts molded into some of the parts, especially the base/sled. A rule of thumb for self-threadingh screws into plastic is that you can assemble and disassemble them an average of three times before the âthreadsâ are ruined. Metal threaded inserts remove this problem, especially the molded-in type. EVen in cheap consumer goods you will find them used for parts that are expected to be removed and replaced frequently, like battery access covers.
Threaded inserts are also much stronger and superior for high-stress connections like motor mounts.
Adding these would require changes to the molds, but the changes should all be steel-safe, so easier than they might be.
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WFD wrote:
Another suggested improvement. Have threaded inserts molded into some of the parts, especially the base/sled. A rule of thumb for self-threadingh screws into plastic is that you can assemble and disassemble them an average of three times before the âthreadsâ are ruined. Metal threaded inserts remove this problem, especially the molded-in type. EVen in cheap consumer goods you will find them used for parts that are expected to be removed and replaced frequently, like battery access covers.
Threaded inserts are also much stronger and superior for high-stress connections like motor mounts.
Adding these would require changes to the molds, but the changes should all be steel-safe, so easier than they might be.
Are there any screws that thread into plastic? I thought that they all go to a
nut or other metal part? (into the motors)
David Lang
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There are self tapping screws for plastic but the threads cut in aggressively and you generally canât assemble/disassemble something multiple times without having to repair the area the screws tap into.
silo0623 wrote:
There are self tapping screws for plastic but the threads cut in aggressively
and you generally canât assemble/disassemble something multiple times without
having to repair the area the screws tap into.
I know they exist, but I canât think of anything on the maslow4 that isnât going
into metal threads
David Lang
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What about the screws that mount into the sled? Do they all have nuts? Including the vacuum adapter (sorry if this is a false alarm but I donât have a maslow to look at yet.)
The do all have nuts. I agree that threading directly into plastic is a bad call since it wears out quickly.
That being said I think that your idea of using inserts is not a bad idea at all. Assembling with the nuts can be a hassle. I didnât go with inserts because I donât have enough personal experience with them to know how strong they will be in given situations, but long term I think we might add something like that.
WFD wrote:
What about the screws that mount into the sled? Do they all have nuts? Including the vacuum adapter (sorry if this is a false alarm but I donât have a maslow to look at yet.)
Yes they do.
David Lang
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Bar wrote:
That being said I think that your idea of using inserts is not a bad idea at
all. Assembling with the nuts can be a hassle. I didnât go with inserts
because I donât have enough personal experience with them to know how strong
they will be in given situations, but long term I think we might add something
like that.
It would drastically simplify assembly if you didnât have to fumble with the
nuts and holding them in position to get the bolts started in them.
There are a lot of places that would work well. It is going to depend on how
much plastic there is around the screw, and what the price is for the inserts
and installing them.
Yes the nuts are a hassle, but of all the problems weâre having, getting the
machine initially assembled is not near the top of the list.
David Lang
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