K-Tec

Help needed with Seben telescope collimation

  • Posts: 89
  • Thank you received: 12
hi looking for a bit of advice a friend of my has a seben telescope i think it is a 114 model and he had it stored away for a while he recently took it out of storage and wants to start using it again . i tried to collimate it with a laser collimater but when i turned it on all i seen was a red blob on the primary mirror where a sharp dot should have been the primary looks ok in the collimater but was wondering if the secondary is out as i tried to focus on a star and could see nothing . the lenses are not the greatest a 25 and 6.5 plossol with a weird looking 1.5 erecting eyepiece and a 2x barlow any ideas would be helpful thanks
9 years 1 week ago #97575

Please Log in or Create an account to join the conversation.

  • Posts: 9637
  • Thank you received: 544

Replied by Seanie_Morris on topic Re: Help needed with Seben telescope collimation

Moved to Observing Equipment forum
Midlands Astronomy Club.
Radio Presenter (Midlands 103), Space Enthusiast, Astronomy Outreach Co-ordinator.
Former IFAS Chairperson and Secretary.
9 years 1 week ago #97585

Please Log in or Create an account to join the conversation.

  • Posts: 8851
  • Thank you received: 237

Replied by dave_lillis on topic Re: Help needed with Seben telescope collimation

Hi ,
Are you sure that your collimator isnt one of the barlowed types?, they give a circular blob instead of a dot,
see
www.cameraconcepts.com/barlowed%20laser%20collimation.pdf
Dave L. on facebook , See my images in flickr
Chairman. Shannonside Astronomy Club (Limerick)

Carrying around my 20" obsession is going to kill me,
but what a way to go. :)
+ 12"LX200, MK67, Meade2045, 4"refractor
9 years 1 week ago #97586

Please Log in or Create an account to join the conversation.

  • Posts: 89
  • Thank you received: 12

Replied by astroman145 on topic Re: Help needed with Seben telescope collimation

hi dave the collimator i have is an astro professional model bought of stephen in ktec it shows a clears dot when i,m collimating my 200p dob but when i tried the seben it just showed a blob . my mate is bringing it up tonite and i,ll try or mabye torture myself trying to collimate it .but judging what i read on the forums seben are not the best scopes anyway but i,ll try me best he,s had the scope a few years and is interested in getting back into it again have to keep he,s interest going or else persuade him to get a new scope . by the way interesting article on collimating i,ll try that next time on the dob thanks again val.
9 years 1 week ago #97587

Please Log in or Create an account to join the conversation.

  • Posts: 187
  • Thank you received: 39
hey Val,
Are you sure there is nothing in the focuser?really sounds like there is a barlow somewhere over there.It seems odd that a lazer would have that much distortion bouncing off a mirror.How does it look on the secondary?Unless your secondary is miles off and the beam is hitting somewhere in the corner of it and by some odd chance it reflected on the primary?
9 years 1 week ago #97588

Please Log in or Create an account to join the conversation.

  • Posts: 89
  • Thank you received: 12

Replied by astroman145 on topic Re: Help needed with Seben telescope collimation

hi martin to be honest it looks like a blob of red light on the primary but the primary looks ok in the collimator i think it is the secondary and maybe the the focusing tube as its a bit longer than normal i,m having a good look at it this evening let you know how i get on thanks val
9 years 1 week ago #97589

Please Log in or Create an account to join the conversation.

  • Posts: 8851
  • Thank you received: 237

Replied by dave_lillis on topic Re: Help needed with Seben telescope collimation

Hi,
The length of the tube of how far the focuser is racked in or out wouldnt make a differance, my laser beam travels about 16 feet down and back up my scope and its still a dot.
The only other thing I can think of is that your secondary is soooo badly collimated that the laser beam is hitting the scopes tube wall on the way to the mirror and what youre seeing on the primary is some sort of distorted reflection of the beam off the scopes tube....
Dave L. on facebook , See my images in flickr
Chairman. Shannonside Astronomy Club (Limerick)

Carrying around my 20" obsession is going to kill me,
but what a way to go. :)
+ 12"LX200, MK67, Meade2045, 4"refractor
9 years 1 week ago #97591

Please Log in or Create an account to join the conversation.

  • Posts: 245
  • Thank you received: 96
It could well be that the Seben has a spherical mirror, and what is, effectively, a barlow in underneath the focuser.
This could be causing the problem.
I dont have any spherical mirror scopes in stock here, so unfortunately I cant check for you.
Stephen Kershaw
Ktec Telescopes Ltd
085 - 228 8692
This email address is being protected from spambots. You need JavaScript enabled to view it.
www.ktectelescopes.ie
www.facebook.com/ktectelescopes
www.twitter.com/ktectelescopes
9 years 1 week ago #97594

Please Log in or Create an account to join the conversation.

  • Posts: 8851
  • Thank you received: 237

Replied by dave_lillis on topic Re: Help needed with Seben telescope collimation

hi,
do let us know when you've got it figured out, it'll be interesting to read whats happening there. .
Dave L. on facebook , See my images in flickr
Chairman. Shannonside Astronomy Club (Limerick)

Carrying around my 20" obsession is going to kill me,
but what a way to go. :)
+ 12"LX200, MK67, Meade2045, 4"refractor
9 years 6 days ago #97602

Please Log in or Create an account to join the conversation.

  • Posts: 89
  • Thank you received: 12

Replied by astroman145 on topic Re: Help needed with Seben telescope collimation

hi sorry dave my mate still has,nt dropped up the scope yet the usual distractions he says " life well mostly the mrs " i,ll keep ye informed of what happens thanks
9 years 4 days ago #97615

Please Log in or Create an account to join the conversation.

  • Posts: 89
  • Thank you received: 12

Replied by astroman145 on topic Re: Help needed with Seben telescope collimation

sorry its been a while getting back to ye all ,my friend finally decided to drop up his telescope last nite it is a seben big boss 150-1400 model. i found out why i was getting a big blob on the primary while collimating it turns out it has a built in barlow lens in the focusing tube i took it out and hey hey i got a dot it was way of so i had a job of collimating it that was after i spent an hour trawling through numerous sites finding why it was there and also finding out there a bit of tat and according to one fella good for making a light or maybe a plant pot out of.i,ll try and take it out next clear nite and see how it goes and let ye know.
8 years 8 months ago #98747

Please Log in or Create an account to join the conversation.

Time to create page: 0.050 seconds
Powered by Kunena Forum