Trident height

[mbunjes]

I saw an online shop that sold the 17HS4401s with a 350mm leadscrew instead of the 300mm from the BOM. is there a downside to getting an extra 5cm height ? Apart from 5 extrusions that have to be 50mm longer ?

[smirk]

3 hours ago, mbunjes said:

 Apart from 5 extrusions that have to be 50mm longer ?

Surely the acrylic panels need to be "longer" as well, and some trivial modifications to the printer.cfg config (it's the kind of thing I'd forget and then never get the benefit)?

I wouldn't, however, really see there would be an issue. Guess it's the whole point of the open nature of the Voron platform - it encourages experimentation.

From my personal perspective (if it was me doing it) I'd guess I'd focus on the cost/hassle of sourcing the "outsized" other parts plus the quality of the other stepper motors and their lead screws. I would also want to make sure the "longer" steppers were of the same spec/rating as a good equivalent stock  stepper, and the lead-screws had the same lead/threading (I speak from bitter experience of "assuming" that things would be the same ).

[mbunjes]

The sourcing is no problem, I already found them, the quality might be an issue, I don't know. They are only € 1.50 more than the regular size.
Don't know whether this is allowed but here they are :

https://www.hta3d.com/en/nema17-17hs4401s-tr8x8-350mm-stepper-motor-with-trapezoidal-spindle

The acrylic panels are my absolute last consideration.

[smirk]

There's a good chance I'm about to make myself look stupid here......I'm sure the cleverer members will save me. The advert doesn't give all the details I'd like to see to make a judgment. Unless I've missed it they don't explicitly mention "starts" for the lead screw so I'm not 100% sure how they get to the 8mm lead (i.e. 8mm of movement for a single turn). If it is really a "standard" 2mm lead with 4 starts(*) then I could see how they've got to a 8mm lead as a TR8x8 but I'm suspicious as they talk about 1/32 microstepping. In my mind, there's a chance they don't really have a great resolution, as it were. I would've expected to see TR8x2 (2mm lead) with 4 starts.

(*) To my mind more leads, within reason, is better than fewer.I did some experiments a while back with single start leads and 2-start leads and they just gave poorer results than 4-start leads. Someone once explained it to me as something to do with the number of points the (lead-screw) nut had to rest on/support it. Although that might be absolute nonsense

The prusa calculator is a useful tool for figuring out the possible resolutions on things like lead screws.

If it was me, I wouldn't buy those lead screws. As I say, I don't see anything wrong with a longer lead screw (depending on sizing all the other parts) but that is based on other factors staying the same (e.g. 4-start TR8x2 lead screws).

 

[smirk]

Apologies!

59 minutes ago, smirk said:

There's a good chance I'm about to make myself look stupid here......

Yup, I'm right.....I'm stupid. I could say I was being harrassed by a shouting child, but that would be mean. I was confusing my pitches and leads.

Looks like that lead screw is 4-starts, 2mm (pitch) which gives a "lead" of 8mm (starts x pitch). I think what confused me was their 1/32 micros-stepping. Most often I leave it at 1/16 which would equate to 400 steps/mm in old money (i.e. non klipper). Microstepping has it's uses but they're not necessarily accurate (I guess beyond reducing vibrations and improving accuracy that way)

Not sure if I'd revise my "I wouldn't buy those" comment, granted I'm an idiot and misinterpreted the figures but not having used the company I cannot attest to the overall quality of the product.

Anyway, I'll take a small bit of comfort form knowing that I was right (about being stupid) and say sorry if I've given you a bum steer.

[mbunjes]

I don't think you did, you made me realize the absence of information on the website. Although the steppers are the same as the ones in the Voron BOM (17HS4401S TR8x8) I wonder if I shouldn't be weary of the very low price as well.
I think I'll follow your sound advice and go for the LDO's

[claudermilk]

Back to the original question: None really. You will need longer vertical extrusions and new panels. I think it's the LDO Trident 300 kit that has longer Z motors allowing it to be 300x300x300 instead of the standard bom 300x300x250. Check Nero's build series (Trident named Big Papa Joey P since he used orange Prusament ASA).

Edit: I think I misremembered. Nero's Trident build was the 350 Fysetc (with issues). Steve Builds was the LDO kit: 

 

[mbunjes]

I've searched high and low but I can't find longer LDO's anywhere. I think I'll just have to give up on the idea.

 

[smirk]

That's a shame, I had a look at steppersonline (as they're on the Voron BOM) and they top out less than you wanted. Unless someone else can recommend a supplier. I've used E3D kit beyond hot-ends, in the past without complaint (never their integrated lead-screws though) and they seem to be 365mm according to the document (https://e3d-online.zendesk.com/hc/en-us/article_attachments/360016686878/Leadscrew_Motor.pdf).

In the past I've used some called "Iverntech NEMA 17 Stepper Motor with Integrated 400mm leadscrews" for a self-build printer, they're available on Amazon. Clearly a generic-brand/marketing-name (probably also sold as Happy-Song-Lala motors, or whatever). I haven't had any complaints with that printer in respect of the z-axis, in fact it was the machine I originally printed my Voron 0.1 parts on. Granted not having seen my Voron that's not much of a recommendation but I am happy with the resolution that it can achieve.

Anyway, good luck and enjoy the Trident whatever you opt for.

[claudermilk]

I don't think the LDO motors are available yet. Steve did the series to check the beta kit for LDO; IIRC he mentions a few times (and I think Jason @ LDO was in chat and commenting) that the kits are a couple of months out because of supply chain issues. 

If you can find a good NEMA17 motor with the right spec lead screw you should be fine. I think the spec is TR8x4 (2mm pitch, 8mm lead)? I'm not an expert on lead screw specs and it took me two tries to get the right POM nuts.

[Francois]

Pretty sure Jason from LDO said something about august/sept before the kits become available in Steve's stream

[mbunjes]

Thanks guys, I think I'll stick with the original LDO's. 5 cm isn't that much of a deal anyway.

[claudermilk]

IMHO the 250mm Z is plenty. Unless you have a specific need for that height it shouldn't be an issue. So far I have come nowhere near my max Z capacity. I have made good use of my full 250mm^2 bed space though.

[smirk]

1 hour ago, claudermilk said:

250mm Z is plenty

On reflection, I'd probably second that. That self-build printer I'd used those 400mm lead-screws for, I've never used the height. I opted for the height on. the off-chance I might (but I was a younger, more carefree individual back then). I never have used it, and to be blunt, it's more of a hassle (finding outsized lead-screw/stepper combos, having to make my enclosure extra-tall, etc).

[mbunjes]

Well, definitely not young, carefree maybe but you're right, I've never used my printers to the height limit either.