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....

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.

hi,
do let us know when you've got it figured out, it'll be interesting to read whats happening there. .

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

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.