[Ron Boggs]

For two to go out nearly simultaneously and with one getting far less use...I can't help but wonder about conditions during use.
Are you shooting fishing scenes in very sandy conditions? Though your lenses are water and dust sealed, sand grains in the outer focusing rings perhaps?
Do you sometimes leave the camera on in your vest or kit so that the motors may become engaged for a prolonged period? Yeah auto shutoff, but if the af button or shutter button gets touched at each bump while driving...?
Strange coincidence for two dead motors...

The good news is how inexpensive new motor repairs are. So a pro lens gets repowered and returned with a new warranty for under $200. If it's a once a decade deal, great price!

Just a note...machines wear out and break down. The more you use it the more you can be assured that the machine will break down from time to time. This might be an example of "wow, dude, you shoot a bunch in the course of a year." I own a bunch of * lenses and many have been back for "tune-ups" or "overhauls" or "fixes" during the past couple decades of hard use and hard travel. I don't blame Pentax for that at all!

It's an imperfect world, pay for the repairs and move on with your life...no big deal.

PS Pentax repairs tend to run on the inexpensive side compared to the other brands...

[iflyfisher]

Russell -- Great suggestion. I am pretty certain my credit card offers double warranty Still concerned about how long the repair will last.

wtlwdwgn -- I did send Ned a polite message that expresses my disappointment in the quality of these lenses. I think he needs to know there are people like me and you that have had both lenses fail.

Ken

[reeftool]

For two to go out nearly simultaneously and with one getting far less use...I can't help but wonder about conditions during use.
Are you shooting fishing scenes in very sandy conditions? Though your lenses are water and dust sealed, sand grains in the outer focusing rings perhaps?
Do you sometimes leave the camera on in your vest or kit so that the motors may become engaged for a prolonged period? Yeah auto shutoff, but if the af button or shutter button gets touched at each bump while driving...?
Strange coincidence for two dead motors...

The good news is how inexpensive new motor repairs are. So a pro lens gets repowered and returned with a new warranty for under $200. If it's a once a decade deal, great price!

Just a note...machines wear out and break down. The more you use it the more you can be assured that the machine will break down from time to time. This might be an example of "wow, dude, you shoot a bunch in the course of a year." I own a bunch of * lenses and many have been back for "tune-ups" or "overhauls" or "fixes" during the past couple decades of hard use and hard travel. I don't blame Pentax for that at all!

It's an imperfect world, pay for the repairs and move on with your life...no big deal.

PS Pentax repairs tend to run on the inexpensive side compared to the other brands...

Are you serious? If sending a pro lens in for a new focusing motor every couple of years is acceptable, then fine, it's your money. As for me, I have to save for months for a new high quality lens and I expect it to last a while. True, stuff does break. Buying higher end lenses comes with the expectation of better build quality and longer life. You mentioned decades of use from your * lenses. Many people are only getting a few months and with light use. For those of us without large wads of disposable cash sitting around, SDM lenses seem to be something to stay away from.

[iflyfisher]

Well my emails and calls to Pentax finally resulted in a call from Pentax. I was assured that the failure rate on SDM lenses is actually quite low and over the past several months very few SDM lenses have been sent in for repair. I was told that the cause of the failure isn't directly known, could have been a bad batch of motors or who knows. The individual didn't want to speculate. However, Pentax agreed to waive the repair charges and asked CRIS to expedite the repairs but to do a very thorough job of repairing and testing prior to returning the lenses. I didn't really get a good answer to my question as to how well the repair will hold up. Pentax felt the lenses should work well into the future, but I was told to keep Pentax apprised of any future issues I may have with the lenses following the repair.

I am still very disappointed that the two lenses failed (and no I didn't drag them through water or sand. The tele zoom had seen only limited use). I'm also annoyed that I have been trying to get the body and lenses working since July. But I am very pleased Pentax is standing behind the lenses. I hope the repaired lenses hold up to years of service!

I'll try to keep the future posts more upbeat!

Thanks everyone.

Ken

[superfuzzy]

ken, that's good news

My 50-135mm is still going strong after 1+ years, and it's good to know that if worse comes to worse the cost is under $200 to repair. I've taken many shots with the lens and assume I have a good one.

[PentaxPoke]

Well my emails and calls to Pentax finally resulted in a call from Pentax. I was assured that the failure rate on SDM lenses is actually quite low and over the past several months very few SDM lenses have been sent in for repair. I was told that the cause of the failure isn't directly known, could have been a bad batch of motors or who knows. The individual didn't want to speculate. However, Pentax agreed to waive the repair charges and asked CRIS to expedite the repairs but to do a very thorough job of repairing and testing prior to returning the lenses. I didn't really get a good answer to my question as to how well the repair will hold up. Pentax felt the lenses should work well into the future, but I was told to keep Pentax apprised of any future issues I may have with the lenses following the repair.

I am still very disappointed that the two lenses failed (and no I didn't drag them through water or sand. The tele zoom had seen only limited use). I'm also annoyed that I have been trying to get the body and lenses working since July. But I am very pleased Pentax is standing behind the lenses. I hope the repaired lenses hold up to years of service!

I'll try to keep the future posts more upbeat!

Thanks everyone.

Ken

Nice job Ken. I am glad to hear that you were treated so well by Pentax customer support. That has been my experience as well. I have never had a problem dealing with their customer service, and they are quite responsive.

I disagree with the statement though, that "failure rate on SDM lenses is quite low." Low compared to what? I have had two SDM failures resulting in new lenses from Pentax, you have had two failures, how many other people on this forum and others have had SDM failures? When is the last time in history (for those of us that have been loyal to Pentax for decades) have you ever heard such a widespread outcry regarding a mechanical failure of a lens?

I completely agree with reeftool. When did we as quality lens consumers ever change our attitude to "oh well it is an electronic device, and I will have to pay $275 every couple of years to get it fixed." Not me! I have some 20+ year-old Pentax glass that still works like new. I refuse to spend upwards of $1000 on quality glass, that seems to be driven by subquality, lower cost micro-drives. That is a lot of money to me, and I expect it to last. The other brands only use the micro-ultrasonic drives in their cheapest lenses.

I have had enough of the SDM "russian roullete." I sold the latest DA* lens that was replaced by Pentax due to SDM failure (the one that if you stored it for more than a day, you would have to wake back up to life by constantly touching the shutter button, and gently turning the focus ring back and forth. No it is not the contacts!) and now I am SDM-less and life is good. I expect my remaining Pentax glass will last for decades, and my Limited, probably into the next century.

[kenyee]

Glad Pentax did the right thing and fixed your issue.
No way should SDM motors be designed to croak in a year or even five. I've never heard of Canon/Nikon users griping that their ring motors have croaked...only Sigma so far. Ring motors at least should last a long time because of their design which doesn't really use gears/motors...

[PentaxPoke]

Glad Pentax did the right thing and fixed your issue.
No way should SDM motors be designed to croak in a year or even five. I've never heard of Canon/Nikon users griping that their ring motors have croaked...only Sigma so far. Ring motors at least should last a long time because of their design which doesn't really use gears/motors...

Yes kenyee, but my understanding is that Pentax does not use ring motors. (I wish they did). They use ultrasonic micro motors.

At this link you can see a ring ultrasonic motor vs an ultrasonic micromotor. (Sorry for the C link, but this is the only place on the net I have seen them side by side.) The ring motors go around the lens body and can produce substantial torque. They are used on high-quality C glass. The micromotor design next to it, is small and must be geared into the lens drive. These are used by C on the cheapest lenses with internal focusing motors:

Canon USM Link

And another

Better side view

I have never taken apart a DA* lens to check, but have read in several places that Pentax uses the cheaper micro-usm approach to lens focusing. If this is incorrect, please correct me.

Most DA* lenses are certainly of an optical and build quality to deserve a ring-type SDM design assuming patents don't preclude it. My understanding is that the ring USM has been in service since 1987 so the technology must be mature by now.