Sr-90 P MJkzz not worth it

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Nestor
Posts: 7
Joined: Mon Jun 18, 2018 4:27 pm

Sr-90 P MJkzz not worth it

Post by Nestor »

Hi.
I would like to publish my bad experience with the SR-90 P lane purchased at MJKZZ. I send you two videos where it is clear that the lane is of poor quality and it is impossible to stack images even at 3 x. I do not understand why the company advertises that it is capable of expanding up to 50 x. It is flatly false and a hoax. The skate is of poor quality and does not carry a recognized brand. It is Chinese generic brand. Its market value is $ 8. That is the reason why the SR-90 P does not work properly. The lane is perfectly constructed and its manufacture is very correct but it uses a small and poor quality skate. I thought before buying that MJZZ rode HIWIN or THK skates. I have realized that it is not like that and I have been terribly disappointed because the SR-90 P is not exactly cheap.

https://vimeo.com/275381869

https://vimeo.com/275334882


greetings to all
Tenerife ( CANARY ISLAND-SPAIN)

rjlittlefield
Site Admin
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Joined: Tue Aug 01, 2006 8:34 am
Location: Richland, Washington State, USA
Contact:

Post by rjlittlefield »

The videos seem compelling. But we have had other reports from experienced stackers who did not indicate such difficulties. I'm wondering if this is a QA problem.

Have you contacted the seller?

--Rik

Nestor
Posts: 7
Joined: Mon Jun 18, 2018 4:27 pm

Post by Nestor »

rjlittlefield wrote:The videos seem compelling. But we have had other reports from experienced stackers who did not indicate such difficulties. I'm wondering if this is a QA problem.

Have you contacted the seller?

--Rik
Hi Kim,

After a lot of talking with the seller, in the end he agreed to return part of the purchase money. The problem is that he never recognized that the lane went wrong from the store.
With the refund I have changed several skates and the problem is not fixed so I conclude that it is a design problem.

To prove and verify that a lane has quality and precision it is necessary that when stacking with Zerene or another program the functions of correction of movement in the stack are deactivated.
Many times our lanes are bad and we do not find out if we let Zerene fix the problem ...

I simply wanted to make my story public since it is IMPOSSIBLE for that lane to stacked at x 50 as the seller states.

You can not make those affirmations when they are not real.

regards
Tenerife ( CANARY ISLAND-SPAIN)

zzffnn
Posts: 1896
Joined: Thu May 22, 2014 1:25 pm
Location: Houston, Texas, USA
Contact:

Post by zzffnn »

Nestor wrote:
rjlittlefield wrote:The videos seem compelling. But we have had other reports from experienced stackers who did not indicate such difficulties. I'm wondering if this is a QA problem.

Have you contacted the seller?

--Rik
Hi Kim,

After a lot of talking with the seller, in the end he agreed to return part of the purchase money. The problem is that he never recognized that the lane went wrong from the store.
With the refund I have changed several skates and the problem is not fixed so I conclude that it is a design problem.

To prove and verify that a lane has quality and precision it is necessary that when stacking with Zerene or another program the functions of correction of movement in the stack are deactivated.
Many times our lanes are bad and we do not find out if we let Zerene fix the problem ...

I simply wanted to make my story public since it is IMPOSSIBLE for that lane to stacked at x 50 as the seller states.

You can not make those affirmations when they are not real.

regards

Nestor,

Could it be that your entire unit has quality control issue? Or damaged during shipping?

Why not wait for seller to replace your entire unit, before posting such damaging forum post? If you pay with Paypal, you can easily file claim under "item not as described" and you are most likely going to win if you can prove it. Paypal protects buyer almost unfairly, in most cases, these days. Such damaging forum post does not seem fair, if not well proven.

To be fair, experienced forum members have used products from MJKzz before and like them. You are a brand new member and your very first post is "xxx MJkzz is not worth it". Probably too harsh too quickly?

I am not saying this was what happened. But to be fair, if you take this to a small claim court, you may have to prove that you have not damaged the unit yourself and that you are not associated with a competitor of MJkzz. And MJkzz can sue you under defamation, if he choose such.

Full disclosure: I am biased. I have worked with MJkzz before and I think he is very kind, careful, knowledgeable and beyond professional. I personally would not hesitate to buy from him.

lonepal
Posts: 322
Joined: Sat Jan 28, 2017 12:26 pm
Location: Turkey

Post by lonepal »

Hi;

I purchased a controller from mjkzz and he is a very polite and professional man.

It is not good to blame a person before trying to solve the problem first and like zzffnn said you are a new member and your first message is written to blame an equipment maker, this looks weird.

You should prove that you are right before writing such a hot blaming message.

I am not biased, this is my opinion.
Regards.
Omer

mawyatt
Posts: 2497
Joined: Thu Aug 22, 2013 6:54 pm
Location: Clearwater, Florida

Post by mawyatt »

I have a version of the SR-90 that is part of MJKZZ Stack & Stitch System I purchased some time ago, but don't think it has the PR-90 Precision version rails. I discovered awhile back with the SR-90 that this rail does have some backlash and wobble but not so much as to prevent useful stacking at reasonable magnifications.

A simple technique that can help with rail wobble and backlash is "Off Axis Loading" (do a search here for details). I found the Stackshot, Wemacro and MJKZZ SR-90 rails all benefitted from this technique. The Stackshot and Wemacro rails are a different design than the SR-90 and have support guides in two places to the side of the rail screw and support the screw at the rail end, the MJKZZ SR-90 has a single support guide below the screw and does not support the screw end I recall (at work so can't look). {Edit, I'm home now and can confirm the SR-90 does not support the screw thread from the end.} The SR-90 actually had slightly less backlash but more wobble than my Stackshot and Wemacro rails.

I think for precision high magnification work one should look to more precision rails, like the THK-KR20 and possibly THK-KR26 types. I use the KR20 and can say they exhibit almost no rail backlash or wobble. Others have experience (they can report as I don't have the KR26) with the KR26 which is a larger, heavier KR type. These KR types show up on eBay, sometimes at reasobaqle prices. MJKZZ offers a mod kit for these KR types.

The THK-KR20 rails work with the superb Stackshot Controller (which works with Zerene user interface), Wemacro and MJKZZ controllers. All that's required is a custom cable assembly from the controller to the 2 phase 4 wire stepper motor.

Anyway, hope this helps with some reasonable expectations from various macro rails I have experience with.

Best,
Research is like a treasure hunt, you don't know where to look or what you'll find!
~Mike

Nestor
Posts: 7
Joined: Mon Jun 18, 2018 4:27 pm

Post by Nestor »

mawyatt wrote:I have a version of the SR-90 that is part of MJKZZ Stack & Stitch System I purchased some time ago, but don't think it has the PR-90 Precision version rails. I discovered awhile back with the SR-90 that this rail does have some backlash and wobble but not so much as to prevent useful stacking at reasonable magnifications.

A simple technique that can help with rail wobble and backlash is "Off Axis Loading" (do a search here for details). I found the Stackshot, Wemacro and MJKZZ SR-90 rails all benefitted from this technique. The Stackshot and Wemacro rails are a different design than the SR-90 and have support guides in two places to the side of the rail screw and support the screw at the rail end, the MJKZZ SR-90 has a single support guide below the screw and does not support the screw end I recall (at work so can't look). {Edit, I'm home now and can confirm the SR-90 does not support the screw thread from the end.} The SR-90 actually had slightly less backlash but more wobble than my Stackshot and Wemacro rails.

I think for precision high magnification work one should look to more precision rails, like the THK-KR20 and possibly THK-KR26 types. I use the KR20 and can say they exhibit almost no rail backlash or wobble. Others have experience (they can report as I don't have the KR26) with the KR26 which is a larger, heavier KR type. These KR types show up on eBay, sometimes at reasobaqle prices. MJKZZ offers a mod kit for these KR types.

The THK-KR20 rails work with the superb Stackshot Controller (which works with Zerene user interface), Wemacro and MJKZZ controllers. All that's required is a custom cable assembly from the controller to the 2 phase 4 wire stepper motor.

Anyway, hope this helps with some reasonable expectations from various macro rails I have experience with.

Best,
Hi Mike,

Indeed, all these lanes have unwanted movements and we believe that it is due to bad design. They use a very small skate (MGN 9) and it is not a recognized brand such as Hiwin.
This morning I got a fourth skate with his china rail (MGN 9) and we put it on. Finally we get stacked to 10 x without problems.
Anyway, I've asked Korea for a second-hand ticket (SKR 20) that I hope will arrive soon. I will make the relevant adaptations and I believe that this will be the final one.

regards
Tenerife ( CANARY ISLAND-SPAIN)

mawyatt
Posts: 2497
Joined: Thu Aug 22, 2013 6:54 pm
Location: Clearwater, Florida

Post by mawyatt »

Nestor wrote:
mawyatt wrote:I have a version of the SR-90 that is part of MJKZZ Stack & Stitch System I purchased some time ago, but don't think it has the PR-90 Precision version rails. I discovered awhile back with the SR-90 that this rail does have some backlash and wobble but not so much as to prevent useful stacking at reasonable magnifications.

A simple technique that can help with rail wobble and backlash is "Off Axis Loading" (do a search here for details). I found the Stackshot, Wemacro and MJKZZ SR-90 rails all benefitted from this technique. The Stackshot and Wemacro rails are a different design than the SR-90 and have support guides in two places to the side of the rail screw and support the screw at the rail end, the MJKZZ SR-90 has a single support guide below the screw and does not support the screw end I recall (at work so can't look). {Edit, I'm home now and can confirm the SR-90 does not support the screw thread from the end.} The SR-90 actually had slightly less backlash but more wobble than my Stackshot and Wemacro rails.

I think for precision high magnification work one should look to more precision rails, like the THK-KR20 and possibly THK-KR26 types. I use the KR20 and can say they exhibit almost no rail backlash or wobble. Others have experience (they can report as I don't have the KR26) with the KR26 which is a larger, heavier KR type. These KR types show up on eBay, sometimes at reasobaqle prices. MJKZZ offers a mod kit for these KR types.

The THK-KR20 rails work with the superb Stackshot Controller (which works with Zerene user interface), Wemacro and MJKZZ controllers. All that's required is a custom cable assembly from the controller to the 2 phase 4 wire stepper motor.

Anyway, hope this helps with some reasonable expectations from various macro rails I have experience with.

Best,
Hi Mike,

Indeed, all these lanes have unwanted movements and we believe that it is due to bad design. They use a very small skate (MGN 9) and it is not a recognized brand such as Hiwin.
This morning I got a fourth skate with his china rail (MGN 9) and we put it on. Finally we get stacked to 10 x without problems.
Anyway, I've asked Korea for a second-hand ticket (SKR 20) that I hope will arrive soon. I will make the relevant adaptations and I believe that this will be the final one.

regards
Hi Nestor,

I wouldn't say the MJKZZ design is "bad", maybe just different than other rails (mostly single guide vs. dual guide and no screw end support) and maybe has some weakness that you've pointed out. I've found with the SR-90 has more wobble but a little less backlash than other rails mentioned. It's good you've found a skate that improves the rail performance and can get you started on what you expect from the rail. Maybe you could describe in detail how you've helped improve the rail performance, so others can consider this.

You will be very pleased with the THK-KR20, this is a much higher precision rail. I know I have 3 (surplus) of them :D

They are based upon a machined extrusion for the guide sides and dual ball bearing guides, and have end screw support, so fundamentally a more precision structure. They also incorporate stage end safety plastic/rubber bumpers that help when crashing into the rail extremes, you get alerted with a loud noise! Don't ask how I know this :oops:

Your MJKZZ controller should work fine with the KR-20 as does the Stackshot & Wemacro controllers with the proper cable. I've used a 150mm long ARCA plate (fits perfectly) bolted to the bottom of the KR-20 to allow easy mounting. Just drill and tap 4 holes in the ARCA plate and bolt thru the KR-20 base from the inside of the rail.

Good luck and keep us posted on your progress.

Best,
Research is like a treasure hunt, you don't know where to look or what you'll find!
~Mike

mjkzz
Posts: 1681
Joined: Wed Jul 01, 2015 3:38 pm
Location: California/Shenzhen
Contact:

Post by mjkzz »

Nestor,

First, I should have stopped the shipment at the very beginning because there was something wrong with your address in DHL system. When I mentioned it to you, you went ALL CAP on me, yelling at me about not paying extra, etc, etc. So I used EMS which is 50% more expensive, my shipping company had to do something to get it shipped.

Then, when you said the controller did not work, I offered you a FREE stand alone controller worth 100USD with FREE shipping because ##### happens during shipping. You took the offer and insisted on buying ANOTHER controller which you paid for it. I shipped both to you. This is all based on the trust I have in you. But to this date, I still do not understand why you would need TWO controllers for ONE rail?

AFTER both controller were shipped, you showed me those video, indicating something was wrong with rail, from the video, yes, it is bad and really bad to the point that it looks like it was tempered with. So at first you demanded money to buy a better guide rail, indicating your proficiency at working on things like this. Again for benefit of doubt, I agreed to offer you 100USD to get a new guide rail, I think that is pretty generous offer as the whole kit was only 275USD.

Then you came back asking me to ship you an Ultra rail free of charge. That thing costs twice as much as what you paid for, I do not understand if there is any shame of making such demand. So I refused and get very suspicious about the whole situation.

At this point, I do not think it is fair, so I asked you to ship all back to me and I will refund you in FULL. Why, because all indicators show you have the proficiency of modifying, fixing rails on your own. Another fact is in one of the message, you used the word WE, indicating there are more than ONE user. If I met your demand, you would end up with TWO rails and TWO controllers. Another reason I asked it back is to see what is going on, was it tempered with, was it really bad guide rail?

As I told Paypal, it is not fair to refund you in full without all things back. Paypal agreed with me but did refund 100USD back to you. I was surprised that Paypal did this, it only means you have requested and accepted what Paypal offered to you. So as far as I know, this is done.

From the all cap yelling at me at the beginning, threats to defame my rails like posting this, shameless demand for an ultra rail (in which case, you would end up with 2 rails with one being far superior one, 2 controllers (one you paid for)), I do not know what to say about you being a father of four as you later wrote about yourself and to which I did not reply as I think we are done. Sure, you might be mad at being blocked from joining my focus stacking group but again, as I told you numerous times, we are done in business relationship.

Nestor
Posts: 7
Joined: Mon Jun 18, 2018 4:27 pm

Post by Nestor »

mjkzz wrote:Nestor,

First, I should have stopped the shipment at the very beginning because there was something wrong with your address in DHL system. When I mentioned it to you, you went ALL CAP on me, yelling at me about not paying extra, etc, etc. So I used EMS which is 50% more expensive, my shipping company had to do something to get it shipped.

Then, when you said the controller did not work, I offered you a FREE stand alone controller worth 100USD with FREE shipping because ##### happens during shipping. You took the offer and insisted on buying ANOTHER controller which you paid for it. I shipped both to you. This is all based on the trust I have in you. But to this date, I still do not understand why you would need TWO controllers for ONE rail?

AFTER both controller were shipped, you showed me those video, indicating something was wrong with rail, from the video, yes, it is bad and really bad to the point that it looks like it was tempered with. So at first you demanded money to buy a better guide rail, indicating your proficiency at working on things like this. Again for benefit of doubt, I agreed to offer you 100USD to get a new guide rail, I think that is pretty generous offer as the whole kit was only 275USD.

Then you came back asking me to ship you an Ultra rail free of charge. That thing costs twice as much as what you paid for, I do not understand if there is any shame of making such demand. So I refused and get very suspicious about the whole situation.

At this point, I do not think it is fair, so I asked you to ship all back to me and I will refund you in FULL. Why, because all indicators show you have the proficiency of modifying, fixing rails on your own. Another fact is in one of the message, you used the word WE, indicating there are more than ONE user. If I met your demand, you would end up with TWO rails and TWO controllers. Another reason I asked it back is to see what is going on, was it tempered with, was it really bad guide rail?

As I told Paypal, it is not fair to refund you in full without all things back. Paypal agreed with me but did refund 100USD back to you. I was surprised that Paypal did this, it only means you have requested and accepted what Paypal offered to you. So as far as I know, this is done.

From the all cap yelling at me at the beginning, threats to defame my rails like posting this, shameless demand for an ultra rail (in which case, you would end up with 2 rails with one being far superior one, 2 controllers (one you paid for)), I do not know what to say about you being a father of four as you later wrote about yourself and to which I did not reply as I think we are done. Sure, you might be mad at being blocked from joining my focus stacking group but again, as I told you numerous times, we are done in business relationship.
Hello Peter,
I'm glad you answered me through the forum, because my last direct mails did not want to answer them. Why?.

The reason why I did not return the whole order was because the controllers at the end were good and I was interested because I recognize that they are very good and of great quality. In addition, returning the order supposed that he had to pay $ 85 on the return transport and was not willing to make that expense. For that reason I decided to accept the $ 100 refund and try to fix it myself.
In my last email I said that I am an honest businessman and father of 4 children to see that I am not a criminal. I have plenty of money to buy all the lanes I want and I do not need to deceive people. You in your emails indicated that I was cheating and stealing.
I know that it is hard to believe someone you are not seeing and I understand in part their mistrust ... I would have liked to have continued with you the business relationship because many people speak very well of you.

regards
Tenerife ( CANARY ISLAND-SPAIN)

Nestor
Posts: 7
Joined: Mon Jun 18, 2018 4:27 pm

Post by Nestor »

Nestor wrote:
mjkzz wrote:Nestor,

First, I should have stopped the shipment at the very beginning because there was something wrong with your address in DHL system. When I mentioned it to you, you went ALL CAP on me, yelling at me about not paying extra, etc, etc. So I used EMS which is 50% more expensive, my shipping company had to do something to get it shipped.

Then, when you said the controller did not work, I offered you a FREE stand alone controller worth 100USD with FREE shipping because ##### happens during shipping. You took the offer and insisted on buying ANOTHER controller which you paid for it. I shipped both to you. This is all based on the trust I have in you. But to this date, I still do not understand why you would need TWO controllers for ONE rail?

AFTER both controller were shipped, you showed me those video, indicating something was wrong with rail, from the video, yes, it is bad and really bad to the point that it looks like it was tempered with. So at first you demanded money to buy a better guide rail, indicating your proficiency at working on things like this. Again for benefit of doubt, I agreed to offer you 100USD to get a new guide rail, I think that is pretty generous offer as the whole kit was only 275USD.

Then you came back asking me to ship you an Ultra rail free of charge. That thing costs twice as much as what you paid for, I do not understand if there is any shame of making such demand. So I refused and get very suspicious about the whole situation.

At this point, I do not think it is fair, so I asked you to ship all back to me and I will refund you in FULL. Why, because all indicators show you have the proficiency of modifying, fixing rails on your own. Another fact is in one of the message, you used the word WE, indicating there are more than ONE user. If I met your demand, you would end up with TWO rails and TWO controllers. Another reason I asked it back is to see what is going on, was it tempered with, was it really bad guide rail?

As I told Paypal, it is not fair to refund you in full without all things back. Paypal agreed with me but did refund 100USD back to you. I was surprised that Paypal did this, it only means you have requested and accepted what Paypal offered to you. So as far as I know, this is done.

From the all cap yelling at me at the beginning, threats to defame my rails like posting this, shameless demand for an ultra rail (in which case, you would end up with 2 rails with one being far superior one, 2 controllers (one you paid for)), I do not know what to say about you being a father of four as you later wrote about yourself and to which I did not reply as I think we are done. Sure, you might be mad at being blocked from joining my focus stacking group but again, as I told you numerous times, we are done in business relationship.
Hello Peter,
I'm glad you answered me through the forum, because my last direct mails did not want to answer them. Why?.

The reason why I did not return the whole order was because the controllers at the end were good and I was interested because I recognize that they are very good and of great quality. In addition, returning the order supposed that he had to pay $ 85 on the return transport and was not willing to make that expense. For that reason I decided to accept the $ 100 refund and try to fix it myself.
In my last email I said that I am an honest businessman and father of 4 children to see that I am not a criminal. I have plenty of money to buy all the lanes I want and I do not need to deceive people. You in your emails indicated that I was cheating and stealing.
I know that it is hard to believe someone you are not seeing and I understand in part their mistrust ... I would have liked to have continued with you the business relationship because many people speak very well of you.

regards
I forgot to tell you Peter, when you mention that you do not explain yourself because paypal agreed to reimburse me $ 100, I'll tell you why they did it.

Paypal has known me since 2007 and we have made many transactions since that date, enough to know who I am and that I am not a delinquent.

regards
Tenerife ( CANARY ISLAND-SPAIN)

mjkzz
Posts: 1681
Joined: Wed Jul 01, 2015 3:38 pm
Location: California/Shenzhen
Contact:

Post by mjkzz »

Nestor wrote: I forgot to tell you Peter, when you mention that you do not explain yourself because paypal agreed to reimburse me $ 100, I'll tell you why they did it.

Paypal has known me since 2007 and we have made many transactions since that date, enough to know who I am and that I am not a delinquent.

regards
If you have such a strong case and you are so good why didn't Paypal grant you full refund? Paypal give you 100USD because I wrote it in the case presentation about offering 100USD to replace the linear guide rail.

For your accusation of using 8 USD guide rail, if the linear guide rail costs so little, why did I offer you 100USD, without your demand, when you told me you want to replace it? I could have offered 15USD. If I am scammed by my linear guide rail supplier, I need the package back so that I can figure out whether there was tempering involved or not, my supplier WILL NOT accept your words or videos as evidence if I accuse them of wrong doing.

And in the end, you did "fix the rail", so why the excessive demand of a free expensive Ultra rail with free shipping when you have 100USD offered? Why the two controllers?

If you are mad at me blocking you on FB or not replying to your last email and post such accusation, then it confirms to me who you really are.

Anyways, this forum/website is for professional discussions, not trade feuds or accusations, so I am done replying to you.

mawyatt
Posts: 2497
Joined: Thu Aug 22, 2013 6:54 pm
Location: Clearwater, Florida

Post by mawyatt »

Can we please move this "you said, I said" arguing off line or in private messages??

Let's just stick to the discussion of rail performance, figuring out things, and trying to help each other, rather than this bickering :shock:

Best,
Research is like a treasure hunt, you don't know where to look or what you'll find!
~Mike

mjkzz
Posts: 1681
Joined: Wed Jul 01, 2015 3:38 pm
Location: California/Shenzhen
Contact:

Post by mjkzz »

mawyatt wrote:Can we please move this "you said, I said" arguing off line or in private messages??
Mike, you are NOT a party involved, how do you know what I said is "you said, I said"? Your statement is highly subjective and diminutive. What I said are all in the Paypal case resolution and are on record.

In terms of bickering, Nestor made an one sided accusation and defamation, making baseless claims (using 8 USD linear rail, etc, he does not have my purchase order of linear rails). So I have the right to defend myself and as far as I know, I have NOT accused Nestor as fraud in public, nor in Paypal case resolution. Why? Because there is a possibility that the rail was damaged during shipping as it is in such bad condition that it is NOT usable. But the excessive demand of sending a FREE Ultra rail with FREE shipping made me think otherwise and refused Nestor's demand.

So I am kind of disappointed that you wrote such statement diminishing others without even slightest idea what went on.
mawyatt wrote: Let's just stick to the discussion of rail performance, figuring out things, and trying to help each other . . .
Isn't that what I said at the end of my last post? Had you posted this without the first part, it shows your objectivity and I think we can be in constructive mode even with accusative title.

mawyatt
Posts: 2497
Joined: Thu Aug 22, 2013 6:54 pm
Location: Clearwater, Florida

Post by mawyatt »

Wow, Peter getting defensive aren't we!! :oops:

Agree, I am not a PARTY to this on-line bickering!! Think most would like to understand what rail problems exist, if any, if they were caused during shipping, or is this normal behavior and is there a possible fix. We all can learn, INCLUDING YOU, from this episode and lets not speculate!!

I said can "WE" move this off line, this was not directed just at you but both, as in the "you said, I said" you both are arguing :shock:

I know you are disappointed in me, same goes your way!!

My goal, was and still is, to get to the bottom of this rail misbehavior, which we all will benefit from.
Research is like a treasure hunt, you don't know where to look or what you'll find!
~Mike

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