Advice about Juwei 17 - Forums

Topic starter

Apr 17, 2025

Hi, I am very interested in purchasing this mount, has anyone measured the periodic error?
Is the height adjustment mechanism precise enough and not wobbly?
Thanks to everyone who will share their experiences of using this mount.
Clear skies
Carlo

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Astropimmy

Apr 17, 2025

Hi Carlo,

I all depends, but out of the box without making any changes in phd2, I am getting 0.3-1.4 periodic errors based on how well I am polar alignment, how strong the wind is andthe angle of my target as I got a lot atm around 85degrees. Regardless, if I get it properly polar aligned I am always getting great numbers close to or under 0.5 and have no issues with 5 minute exposures. Overall I am really happy with it and I cannot recommend it enough. Have a look at my pics on here, they have all been taken with this mount.

I hope this helps a bit.

Kr,

Pim

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Alex Fedorov

Apr 17, 2025

Hi Carlo,

Take a look at the screenshots. There is a periodic error, but it's manageable if you are polar aligned well. I am getting my RMS about 0.5-1 arcseconds. The result is quite consistent. 5-6 mins exposures cause no issues at all with guiding (I use OAG though).

Azimuth and altitude knobs are tight enough to keep overall alignment error under 20-30 arcseconds. There is some backlash in the altitude knob, not critical and controlable.

Strongly recommend the mount. A great value for money!

CS,

Alex

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Jan Erik Vallestad

Apr 17, 2025 · Edited: Apr 17, 2025

The mount works well enough, I don't have anything very bad to say about it. I don't find it as stable, robust nor well made as my AM5 which is a natural competitor (spec wise, not price). But it does well. Th only real gripe I have with it is that its made up of cheap, low quality components on the inside. There have been a lot of broken boards and bad wiring from what I've seen in the community (both CN and FB). I had the same experiences after six months of use. My mount suddenly stopped working and I had to replace the board and the cables.

As QC isn't the best you may get a copy that develops a fault quicker or slower, but you have to account for this to happen at some point and be willing/comfortable fixing it yourself. Warranties are also not something you can expect. I had to buy all the replacement parts which ended up costing about 1/4 of the mount (including pier extension - before tax). Which is quite expensive, and if you have to do this once or twice you may have been better off getting a better made mount. After six-eight months now I also see surface rust building up on bolts/screws, the CW rod etc. So there is also a lack of anodizing.

I'm not trying to slate it, because I have it and I do love it. It's just important that people understand that they are buying lower quality components. It's cheap, and there is a reason for it. Other than that, great piece of kit mostly.

I've mostly used it with my C8EHD which is a bit over the edge for what the mount can handle FL wise IMO. Here are my images so far. It's been going well mostly, but it will not guide at 0.5 stable. It will for periods of time (pointing right up is not affecting this number too much) but mostly it will hang around 0.5 to above 1. Which is no good for long FL imaging, but more than good enough for medium sized telescopes.

As for PE I haven't measured it but I have noticed that I absolutely need to guide mine with very fast exposures. I usually do 0.5 or 1s max, but anything higher and I start noticing periodic error building up and eventually ruining subs because it doesn't get corrected fast enough.

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ArvitZ

Apr 17, 2025

I use the Juwei-17 as my main workhorse for around 10 months now and am lucky to only share most of the good experiences mentioned above.

Sofar my electronics and mechanics has withstood the heavy usage holding my RC 8" setup surprisingly well, but I would not go with much heavier setups personally.

Asides from the intrinsic periodic error of probably every harmic drive I did not have any new pain coming from a smaller GEM.

Depending on your desired setup to pair with the Juwei-17 I think @Jan Erik Vallestad and me already tested the worst case in terms of weight and guiding performance. You can take a look at my images for reference aswell, but my resolution is most likely limited by the bad seeing of my balcony rather than the mount guiding performance.

I never had stability issues with a small counterweight using my 12kg rig attached to a solid tripod and their long pier extention. But always use a OAG with short guide exposure times aswell, but this does seem to be the case for most harmoic drives anyways. Guiding for up to 900s subs for my latest Abell 31 project worked very nice (editing is hopefully done soon)

After some time I also got their OnStep handbox, which is very nice in my opinion aswell. But obviously credit is due to the aswesome folks who have developed the OnStep software!

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Kerry Werry

Apr 17, 2025 · Edited: Apr 17, 2025

I own 2 and one has given me problems initially but the vendor replaced parts no cost to me other than shipping. Now trouble shooting was a pain due to language barriers and time zones but the vendor I bought from did step up.. I get pretty good guiding 0.5 to 0.7 Dec and RA usually.. I run the mount with small refractors and a 6" Richie Chretien and I don't see much difference between the two.. Onstep has a few quirks that are covered in threads. All in all I'm happy but I would so if you have no DIY skills then I would be cautious about buying. FYI the Aliexpress vendor was LittleLight store

Jan Erik Vallestad

Apr 17, 2025 · Edited: Apr 17, 2025

ArvitZ:
I use the Juwei-17 as my main workhorse for around 10 months now and am lucky to only share most of the good experiences mentioned above.

Sofar my electronics and mechanics has withstood the heavy usage holding my RC 8" setup surprisingly well, but I would not go with much heavier setups personally.

Asides from the intrinsic periodic error of probably every harmic drive I did not have any new pain coming from a smaller GEM.

Depending on your desired setup to pair with the Juwei-17 I think @Jan Erik Vallestad and me already tested the worst case in terms of weight and guiding performance. You can take a look at my images for reference aswell, but my resolution is most likely limited by the bad seeing of my balcony rather than the mount guiding performance.

I never had stability issues with a small counterweight using my 12kg rig attached to a solid tripod and their long pier extention. But always use a OAG with short guide exposure times aswell, but this does seem to be the case for most harmoic drives anyways. Guiding for up to 900s subs for my latest Abell 31 project worked very nice (editing is hopefully done soon)

After some time I also got their OnStep handbox, which is very nice in my opinion aswell. But obviously credit is due to the aswesome folks who have developed the OnStep software!

That's good to hear! There must be some QC issues going on as I know many have had them running for up to a year without seeing problems. At the same time there seem to be many having the opposite experience. I forgot to mention that I have mine mounted on a EQ5 steel tripod to increase stability. I've resorted to work with bin2 in post to work around the guiding not being good enough. To be fair though, I'm not sure that my AM5 would deliver around 0.38" on average at 2000mm either. Which is where I need to be at with my pixel size and not using the reducer. In good seeing the AM5 is at 0.2-0.4 but on average I think 0.5-0.6 is more realistic when seeing isn't that good. So it would perhaps still require bin2.

Kerry Werry:
I own 2 and one has given me problems initially but the vendor replaced parts no cost to me other than shipping. Now trouble shooting was a pain due to language barriers and time zones but the vendor I bought from did step up.. I get pretty good guiding 0.5 to 0.7 Dec and RA usually.. I run the mount with small refractors and a 6" Richie Chretien and I don't see much difference between the two.. Onstep has a few quirks that are covered in threads. All in all I'm happy but I would so if you have no DIY skills then I would be cautious about buying. FYI the Aliexpress vendor was LittleLight store

You're in luck then it seems! My SCT has been on it outside since last august/september. I'm not sure how many effective hours I've gotten out of it yet though. I used the same vendor but did not get any parts on the warranty. It's also where I bought my new board from, which cost around 170-180USD I think. So in the end I could have gotten an AM3 for the same price, and probably much less hassle. So I think you're right. The Juwei is only a viable option if you are prepared to not get any refund/warranty (even though some do get it) and if you are comfortable tinkering/patching cables, swapping boards/connectors etc. The vendor himself said that the electronics was cheap and known for getting faulty, so IMO they should be issuing new electronics to everyone who have issues. They are communicating very well I think, and seem accomodating, but not responding to warranty claims in my experience.

In comparison my second hand AM5 has been running flawlessly for years without breaking a sweat. Yes, it does cost a lot more brand new - but for the general public it would be a safer choice.

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jmdl101

Apr 17, 2025

Might be one of the earliest users of the Juwei-17, at least in the US, March of last year. Mine is still working great, using it any time I have a clear night. These days I have my RC8 on it and it guides well enough for round stars at almost any exposure length, tested up to 20 minutes so far. I also have the J14, but I would recommend the J17 over it.

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Jan Erik Vallestad

Apr 18, 2025 · Edited: Apr 18, 2025

Might be one of the earliest users of the Juwei-17, at least in the US, March of last year. Mine is still working great, using it any time I have a clear night. These days I have my RC8 on it and it guides well enough for round stars at almost any exposure length, tested up to 20 minutes so far. I also have the J14, but I would recommend the J17 over it.

Keep in mind that round stars has nothing to do with sampling. Mine are also round at all exposure lengths, but seeing and RMS performance determine whether your sampling is good or not. Over-sampled images do not look good which is why they need to be downsampled / binned in post. Just a very important notice to give it more context

To figure out your own ideal sampling use this.

The facts still remain though. I know several people have had good experiences, you included - but I know equally many have had issues and they have mostly been related to boards/electronics which the vendor has said is of poor quality. So buyers beware, do not buy thinking it has the quality and finish of more expensive mounts. They are cheap for a reason and you might luck out, or you may not. If you don't it can get expensive.

Though to be fair, I use mine in fairly harsh environments. Temperatures vary from +20c to -20/30c during astro season from fall to spring and I keep everything outside most of the time. Sometimes, during bad weather or non-use periods, under a roof or in an un-insulated shed.

jmdl101

Apr 18, 2025

Jan Erik Vallestad:
Might be one of the earliest users of the Juwei-17, at least in the US, March of last year. Mine is still working great, using it any time I have a clear night. These days I have my RC8 on it and it guides well enough for round stars at almost any exposure length, tested up to 20 minutes so far. I also have the J14, but I would recommend the J17 over it.

Keep in mind that round stars has nothing to do with sampling. Mine are also round at all exposure lengths, but seeing and RMS performance determine whether your sampling is good or not. Over-sampled images do not look good which is why they need to be downsampled / binned in post. Just a very important notice to give it more context To figure out your own ideal sampling use this.

The facts still remain though. I know several people have had good experiences, you included - but I know equally many have had issues and they have mostly been related to boards/electronics which the vendor has said is of poor quality. So buyers beware, do not buy thinking it has the quality and finish of more expensive mounts. They are cheap for a reason and you might luck out, or you may not. If you don't it can get expensive.

Though to be fair, I use mine in fairly harsh environments. Temperatures vary from +20c to -20/30c during astro season from fall to spring and I keep everything outside most of the time. Sometimes, during bad weather or non-use periods, under a roof or in an un-insulated shed.

My sampling is 0.71"/px with the imx571 at 1100mm, right in the green for my typical skies. I also agree that some mounts have had issue, mostly all easily corrected, but also at the speed of shipping parts from China.

I would still describe the J17 and J14 as commercialized DIY project mounts that run on the open source Onstep project firmware. The strain wave gears, saddle, and actual box all seem to be without any issues, everything else is easy and cheap to fix. There's at least one user designing custom boards now and the FYSTEC E4 also fits inside the J17 box. I wouldn't recommend them to someone who isn't comfortable with a soldering iron, or at least comfortable with learning how to use one.

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Jan Erik Vallestad

Apr 18, 2025

Jan Erik Vallestad:
Might be one of the earliest users of the Juwei-17, at least in the US, March of last year. Mine is still working great, using it any time I have a clear night. These days I have my RC8 on it and it guides well enough for round stars at almost any exposure length, tested up to 20 minutes so far. I also have the J14, but I would recommend the J17 over it.

Keep in mind that round stars has nothing to do with sampling. Mine are also round at all exposure lengths, but seeing and RMS performance determine whether your sampling is good or not. Over-sampled images do not look good which is why they need to be downsampled / binned in post. Just a very important notice to give it more context To figure out your own ideal sampling use this.

The facts still remain though. I know several people have had good experiences, you included - but I know equally many have had issues and they have mostly been related to boards/electronics which the vendor has said is of poor quality. So buyers beware, do not buy thinking it has the quality and finish of more expensive mounts. They are cheap for a reason and you might luck out, or you may not. If you don't it can get expensive.

Though to be fair, I use mine in fairly harsh environments. Temperatures vary from +20c to -20/30c during astro season from fall to spring and I keep everything outside most of the time. Sometimes, during bad weather or non-use periods, under a roof or in an un-insulated shed.

My sampling is 0.71"/px with the imx571 at 1100mm, right in the green for my typical skies. I also agree that some mounts have had issue, mostly all easily corrected, but also at the speed of shipping parts from China.

I would still describe the J17 and J14 as commercialized DIY project mounts that run on the open source Onstep project firmware. The strain wave gears, saddle, and actual box all seem to be without any issues, everything else is easy and cheap to fix. There's at least one user designing custom boards now and the FYSTEC E4 also fits inside the J17 box. I wouldn't recommend them to someone who isn't comfortable with a soldering iron, or at least comfortable with learning how to use one.

Yeah, 1100mm isn't too long so 0.71" should be within the acceptable range most of the time without needing to bin to get good results, I can totally see that! My sampling is 0.38" which is impossible to do with the J17, and most cheaper mounts, at least if not throwing away most of the subs. But bin2 seems to be ok as a compromise.

I think the price of a replacement board is far from cheap at almost USD175 (considering the price of the mount). But I agree that some of the work is fairly easily done, though also equally easy to mess up in the wrong hands. I think, even at this price point, the quality should be a bit better over all. Especially as the vendor has admitted that they are selling mounts with bad quality electronics (especially boards, wires and connectors) and that the faults people are experiencing are to be expected / well known. So even if the vendor might be a nice enough guy they are not being consistent about honoring warranties. Which is something important to consider for anyone looking to buy. I doubt anyone would accept this from any of the more reputable vendors out there.

Many who go looking for these will no doubt be looking for a deal. So yeah, I totally agree with you that its important to note that though they may work right out of the box without issues, these are DIY-based mounts unsuited for many. Though I doubt that they've commercialized a mount with only experienced DIY'ers in mind. That would be a very risky strategy at least..

I may come off as negative however, as I've said, I'm quite enjoying mine despite all the fuss and extra cost. I just think its important to bring both sides into the light to help people make informed decisions. Though I want to be balanced I may lean more towards the critical side, especially since people are often (almost) seemingly trying to sell it on the vendors behalf.

You've obviously lucked out with your copy which I'm glad about, while I got a worse one which has left me with some trust issues perhaps. So both POV's are equally valid and important I think!

Noah Tingey

Apr 19, 2025

If I might butt in with a recommendation:

I was an early adopter of the Proxisky mounts. I have their first model (the UMi 17), and I've been very pleased with it. Their customer support is very, very good. I've bothered their salesperson(?), Nokk, like half a dozen times and he's always been happy to help with my dumb questions.

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Jan Erik Vallestad

Apr 19, 2025

Noah Tingey:
If I might butt in with a recommendation:

I was an early adopter of the Proxisky mounts. I have their first model (the UMi 17), and I've been very pleased with it. Their customer support is very, very good. I've bothered their salesperson(?), Nokk, like half a dozen times and he's always been happy to help with my dumb questions.

Proxisky seems like a decent brand. But they're not really cheaper than the most established ones nowadays, as they have become pretty established themselves. Which is the one reason why people are actually considering the Juwei/Scorpio mounts, as they are still in the early phase. We expected to see the Juwei price rise a lot, but that hasn't really happened yet (not by much anyway). To me that's the main issue, we see more competition but they all seem to strive to be at the same price point or above.. That's where Juwei is doing a very good job so far.

IMHO: The Juwei mounts would have been infinitely better/more stable if they had just used good quality wires and components for the board. Hardly anything that would have made the mount that much more expensive I think.