I’ve been trying to troubleshoot a surface texturing issue for several weeks. I accidentally noticed the pulley had wobble, but thought it was the stepper motor at first. Nope. It’s the pulley.
Wow .26mm of disparity is a lot for such a crucial part. It may not be a high end printer. But seriously? At $280 USD I’d expect the pulley to be tighter tolerance.
That sounds about right. QA is expensive and time consuming, so it’s left up to the customer. This applies to every single part in the supply chain.
If you want a set of mitsumi linear rails for real precision applications, it’s going to cost just as much or more than that printer.
This is not a “buyer beware” rant, but the buyer should know they aren’t paying for consistency or precision. I am basically saying that for these printers to work reliably and with proper precision, you need to tear them down yourself and inspect each bolt.
I buy cheap Chinese stuff all the time, but my process is to tear the product down and find where costs were cut and look for any serious dangers.
Svol is well known enough that you should be able to get replacement bits for free. Or not. It’s a crap shoot, TBH.
I think with a lot of import products you need to be aware that you’ll be doing the QA and will in fact be working on the parts / product to get it to where you need it to be.
If you have the skills and the tools $280 + $3 for an unfinished pulley plus some time on the lathe or mill can still be worth it. I know this is asking a lot from a customer and maybe this particular example of a printer is not the best, i. e. it would totally be possible to manufacture this part within specs at cost, but I think the general notion still holds true.
you’ll be doing the QA and will in fact be working on the parts / product to get it to where you need it to be.
Absolutely. Unless a person wants to spend thousands of dollars on push button solutions that cover every imaginable use case, customization is the way to go.
For solid machines, the customer should already have an idea about what parts need to be modified. If a machine was advertised to mill a widget at +/-20% tolerance, cool. If you want to spend $500 more on a custom pully to get withing 5%, awesome. Precision is expensive and customization is niche.
For cheap machines, everything is generally ravaged by bean counters at every level of design and manufacturing. As long as people understand this and can make repairs, that is sometimes OK.
While I feel OPs pain of finding a 2¢ part that was 0.3mm off center, I can only just shrug it off. A pseudo-premium 5¢ part or building a jig for a worker to test each gear would have been quite expensive and it would probably tack on $2-$5 to the end product price. ($2-$5 actually matters on sites like Amazon or Temu and could potentially cost thousands in lost sales due to product placement.)
Yeh a long time ago I bought a cheap sovol but it never really printed correctly above 60% speed and if the temp went above 230 it would reset to 175 making it unusable for a lot of filaments.
