@Melanchrom the delivery Service was DHL Express
This is a faulty statementā¦ it is a special designed silicone pad designed to fill gaps between an IC and a heat sink like This. The silicone makes it not conduct electricity while still conducting heatā¦ the stepper drivers overheat with out them just like almost any stepper driver would overheat without a heat sink.
That said your fears are not unfounded. My understanding is they are dealing with a lead screw issue causing variations in movement speeds between linear modules. This seems to affect a large number of modules and would have similar implications as you have outlined. With the exception that it would not require a design change to correct.
Atom, Iāve said it before and Iāll say it again, your expertise is invaluable here! This is a little off topic from demanding that SM respond to whatās going and step up to the plate for being a respectable company, but do you believe the thermal transfer is adequate? If you really want to tickle my brain, do you know the Thermal conductivity? I actually designed my own computer with a full custom water cooling system and I calculated the heat dissipation of the whole system with error, so I am no stranger to thermal dynamics. I also designed the computer for a minimum 10 year service life given the average demand, temperature and data sheets of all components used, not to mention the hydraulic propertiesā¦
I have been a long time electric motor guy, mostly in high performance RCs and stuff like that, I have very often heard that having 2 motors tied together (such as is the case with the A350 for all axis) should be avoided because if the motors are not perfectly in sync (nearly impossible to do except in very specific circumstances) and there is no give (say with jack screws instead of belts) then the motors will fight each other to maintain their own step, causing binding, significantly more power draw, heat, and ultimately failure. Just saying, when the motors fight with each other like this, they become abnormally loud(say, just like many people complain about the Snapmaker). Every picture I see of SM testing the linear rails has been the rails with no load, I only imagine how things have undoubtedly changed since the machine has started seeing real world application. One last point of note, I am also very curious of the mechanism that transfers rotational torque to the linear rail, where are the pressure points and how much friction is caused, there is SO much to consider when it comes to this sorta stuff, which is exactly why SM should be maintaining open dialog with us!
Regardless of all things, Snapmaker owes itās supporters, community, and friends, an up front and honest explanation. Even if they sent me an email saying they need a few more months to rework the linear rails, I would be much more agreeable to that than complete silence. We are all makers and have alot to contribute, just as you have shown. The silence is just unacceptable.
Thx. Im looking forward to receiving my Printer. It is marked as being sent to Germany Last thursday.
@Melanchrom At the moment, customs seem to be overloaded with the heavy parcels.On this occasion in which corner of the world should the printer open it? Schkeudiz is slow to snore.
Yes based on what I have seen from taking apart my rails, they have a greater thermal dissipation then any other 3d printer i have seen. Assuming that the silicone pads are in place and of good quality.
I do not as there are different pads from different manufacturers with different specs, and I do not know what they useā¦ that said there aluminum heat sink is the aluminum extrusion so if that thermal pad is good it should have much more heat dissipation than the 1cm heating used as an industry standard.
Stepper motors are some what a unique caseā¦ because the motors are forced to discrete steps i feel it is easier to synch them. Also I would like to note that driving 2 motors off of the same driver for each axis is the standard for 3d printers. I do agree that having independent steppers for each is better. But it seems to be rare in this industry. I have not heard of it causing an unreasonable amount of wear on any part.
They use lead screws, do a quick Google search and you will find all the info on them you want, it is a good system but for this application it requires precise threaded rods. This is the source of the issue SM is currently dealing with. Apparently there supplier of lead screws has given them a product with to much variation in thread pitch and it is causing the paired rails to fight each other to the point that they skip steps. This is the āy bumpā that Iām sure you have seen posts about in the forum.
Lastly I agree with you SM communication is horrible and needs significant improvements. But that has been said over and over for months and nothing changes. So I have given up. As soon as I get my replacement parts so that I have a fully functioning machine I intend to sell it.
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So the lead screw itself is not precise enough for the product?
What size is it? I presume its a metric acme thread.
Not sure what length it is, havenāt taken my rails apart enough to get an accurate measurement.
And at least from what I have seen/read it seems like the screw pitch is consistent along the length, just not consistent from rail to rail. Also it appears to be a ābad batchā issue as the earlier rails donāt seem to have the issue only the ones shipped in the last couple of months.
im thinkin about taking my apart to fix this wobble anyhowā¦ ill let you know if its something easily obtained, i would imagine it would be something off the shelf im sure mcmaster has it unless its a custom thread or some dumb thing like that
If your looking to replace, when you buy a lead screw it comes as a pair the rod and the bolt piece, also to get consistency you may need to replace both in each pair of rails. Then you should be able to adjust the mm/step to get them properly calibrated. Let me know how it goes 
If nothing else this would be a really fun thing to benchtop. Weāve all thought about it, lowering the ratio with some very sturdy rails, raising the torque and slowly milling soft metalā¦ haha, Iām day dreaming now and WAY off topic. This has me thinking though, maybe itās time we compile our knowledge of issues and fixes in a single thread, much like a tasking list, but user generated. Then we can see who is working on what, progress, and what still is left to figure out. Probably a single tasking forum post that simply links to the post specific to that issue. Unfortunately I canāt really participate though as I have yet to receive my printer, but food for thought, I might build up a proper fix it channel for this poor bastard of a machine.
Although, at this point I am somewhat thinking it would be easier to just build our own version of the thing. At this rate Iām not sure what we paid SM for?
I am currently building my own cnc and will build a 3dp after thatā¦ the issue with milling aluminum isnāt the torque of the steppers but rather the rigidity of the frame.
@Atom, This just started popping up on FB. This is exactly what I feared was the case and why I said what I said earlier. Iām thinking every printer thatās out there now has a major deficiency and SM doesnāt know how to address it without it blowing up! Iām now seeing images of them even catching fire!
A few isolated incidents is one thing. Could have been poor contact of the thermal pad, or very harsh ambient air conditionsā¦ there are always failures, but I havenāt seen enough cases of failures with thermal pads to be concernedā¦ yetā¦ though anything is possible.
According to the people on that forum there are many more failures than thermal pads missing being reported. Either way, take a look at this, somebody disassembled theirs to check and I may be wrong but it almost looks like they have 2 driver ICās to their motor? Perhaps this is SMās first attempt to fix this, by having 2 ICās in parallel? IDK, either way take a look. Also I attached the major failure, rail on fire!
Therefore smoke alarms in the workshop! 
Interesting, I should have a few new rails on their way, I will take a look at them before selling the unit. But 2 drivers controlling 1 motor is not a good ideaā¦ drivers arenāt synced so they would fight each other. Hard to tell from the pictures but it seems like the damage isnāt around the ic but rather around the wiring. But that could just be the angleā¦ alas I do not use FB so I can not get any details beyond those posted here in the official forums.
Hi, may i know where to fill in the survey? i ordered my A350 on Aug and i never received any email about filling in a survey!
thanks
Ed
The e-mail was sent through backerkit and allowed to add the enclosure and some tools to your order. Title was: āResponse Needed ā Get your reward for Snapmaker 2.0 Preorder - EU - A250, A350ā
Not sure if they are still using backerkit for this. And if they are, if they have already sent those out for the more ārecentā orders.
You should check the statuspage (see this sticky: Pre-order shipping update (October)) with your order number.
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Thank You very much!
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