I have been advised to post this for the information of other Takahashi owners with a 2.7" focuser. (Mine is a TSA120)
As can be seen in the attached image, this focuser is worn away on the saddle that holds the spindle shaft and that is tensioned by a plate with two screws.
It is such a simple mechanism that it is hard to understand how this wear could occur in such a short time with little use by both owners.
Also intriguing is the black outline around the worn area...who and when did someone take it upon themselves to outline the effected area?
Was it Quality control?
This fault has been brought to the attention of Claude at AEC and he is as horrified as I was.
Claude has been marvellous and is sending images and info to Japan for advice, as the warranty is not transferable.
I used the scope without a problem at Qld Astrofest with manual focusing only.
It was only after fitting a custom JMI motor focuser and having problems with getting the focuser to work that we dismantled the focus mechanism and discovered the wear.
The scope serial number is 130163 which means it was a 2013 model.
If you own a focuser similar to this, it may be beneficial to have a look and see if there is similar wear.
May I stress that the previous owner had no knowledge of this problem when the scope was sold and absolutely no inference should be made that he is at fault in any way.
I hope this post is of help.
regards,
Phil
Last edited by Clancy Lane; 04-10-2014 at 10:04 AM.
Reason: delete unnecessay info
Hard to tell from the photo that there is excessive wear. What is the picture showing?
Electric focusers often travel out more easily (with gravity) than against.
Isn't that more a comment on the electric focuser not having enough grunt or a slipping fitting if you say you could focus manually easily?
Electric focusers have a bush that fits the shaft of the focuser. In the case of Robofocus there is a standard brass bush and it often does not match some scopes so you can get a wobble and it will fit rotating to some degree. You can order from Robofocus the exact right bush (shaft diameter exactly the same rather than the grub screws screwed too far in to close up the too large a diameter bush). That makes a night and day difference. How is it with the JMI in this regard?
Phil, I did not say the focuser was stiffer than normal, I said it was stiffer than I liked it to be, and asked if it was possible to slacken it off. The email reply I got from Japan suggested I send it back to them to change the type of grease in the focuser, or alternatively fit a micro-focuser (which is what I did)
His opinion was that the black line could indicate that a fault in the focuser casting had been noticed during assembly and the casting was then further machined in an attempt to rectify the fault.
We then loaded up the focuser with the reducer and the STF8300.
Using the manual control, the focuser moved outwards smoothly.
When moving inwards, the focuser would bind, severely, if further out.
I am sending the focuser to Claude for appraisal and rectification.
So far, from all the replies I have received, mine is the only focuser not performing as it should.
I concur with what Phil has reported. I hypothesize there lays a problem with the teflon tensioning pad on top of the drawtube - it is either deformed or cracked. White scoring/abrasion marks are evident in the sandblast chrome finish to the drawtube at the top under the teflon pad. No attempt was made to remove the focuser from the PTA to check, and nor were the 3 factory lacquer sealed tensioner grub screws tampered with.
The teflon pad would seem to be thrusting the drawtube to some extent. It would appear that the trailing section of the teflon pad (that closest to the OTA) is pitched DOWN (and the leading edge vice-versa), allowing free outward travel (and slipping under weight despite the lock screw being ALMOST cinched locked), but binding inward travel.
I believe this to be a simple fix or replacement. If it were my telescope, I would attempt this myself, but it is not, so that is not my call.
I DON'T think the remedied pinion cradle in the casting has any effect on this whatsoever, but Takahashi may have forgotten to re-adjust the 3 tensioning grub screws AFTER their QC remedial work. I believe the onus lies squarely with Takahashi.
I have a 102 and have had it for 7 years. It has done numerous automated imaging runs I the last 3 years and does not exhibit that sort of wear or damage. It got loose about 6 months ago but still was focusing until it got so loose that it slipped totally. Even then it did not get that worn.
In my focusor there is not Teflon, so I don't know where that comes from.
believe it or not we have a complete spare focuser for a TSA120 ... we put a feather touch on ours. It's currently packed in a box to move house, but if you need a replacement in december let us know and we can come to a deal.
believe it or not we have a complete spare focuser for a TSA120 ... we put a feather touch on ours. It's currently packed in a box to move house, but if you need a replacement in december let us know and we can come to a deal.
Can I ask why did you change what I thought would be a pretty good Tak focuser for the Feathertouch and did you notice much difference? Cheers
Sorry to hear your woes. Hope you get it fixed soon. After much research I bought my first Takahashi last week - a Mewlon 250CRS. Last night I used it for the first time & it's electric focuser doesn't work.
I'm sure it's sheer bad luck but after 18 years of coming from a Vixen (VC200L), this definitely isn't a good introduction to a renown brand.
At least you are close to the source for rectification but it is going to take some time as they inform me they are very busy with repairs.
Maybe Takahashi needs to update their Quality Control inspection methods before the scope leaves the factory.
At one time, in my role as warehouse manager for Roland Musical Instruments, every item was unpacked and tested prior to shipment to retailers around Australia....in 3 years not one item was returned as faulty on receipt by the retailer.
On the other hand, I have probably purchased about 20 scopes over the years and I think I can say that everyone of them had some fault that needed rectification.
I even bought a Canon 60Da that had an ant's nest in the flash unit!
The joys of electronic units - one reason I won't automate anything! I keep all mine purely mechanical and shy away from anything that has electronics as standard issue.
None of my Taks has any mechanical issue that I can see or feel. Here's fingers crossed the incoming TSA-102S is trouble free...
Sorry to hear your woes. Hope you get it fixed soon. After much research I bought my first Takahashi last week - a Mewlon 250CRS. Last night I used it for the first time & it's electric focuser doesn't work.
I'm sure it's sheer bad luck but after 18 years of coming from a Vixen (VC200L), this definitely isn't a good introduction to a renown brand.
Ok this isn't reassuring. I am/was contemplating a Mewlon 300CRS but had reservations because of the negative reports regarding the focusing system which also plagued the CCA-250. I thought they had fixed the problem.
And before the lynch mob get on the band wagon this is not a dig at Takahashi...all my gear (FSQ-106N, FSQ-106ED, Mewlon 250, NJP, EM200) is or has been Takahashi.
Ok this isn't reassuring. I am/was contemplating a Mewlon 300CRS but had reservations because of the negative reports regarding the focusing system which also plagued the CCA-250. I thought they had fixed the problem.
And before the lynch mob get on the band wagon this is not a dig at Takahashi...all my gear (FSQ-106N, FSQ-106ED, Mewlon 250, NJP, EM200) is or has been Takahashi.
Argh, I'll need to retract my statement. It turns out that the electric focusing system needed a +/- "reset" and a fresh set of batteries (seems the shrink wrapped batteries supplied were under voltage).
After I mailed Yama-san of Starbase Akihabara, he recommended me to try that and it worked. Unfortunately my astronomy weekend was over and only managed to test it when I got home.
Faith restored with Takahashi again, faith in myself, down the drain.
