Fitting a Baader Steeltrack focuser.

[bosun21]

Can someone please give me a few pointers on the fitting and centering my Baader Steeltrack focuser? I bought this recently and it's actually used but in excellent condition. I don't have a template for the base which makes it a little more difficult. I want it to replace the single speed focuser on my 250 Flextube go to dobsonian. I have watched a video on YouTube showing the base plate corresponding to the existing holes in the inner portion allowing the outer fixing holes to be marked and drilled. Unfortunately they don't match up in my case. Obviously the positioning is crucial and if anyone can help with some pointers  i would greatly appreciate it. Thanks.

 

Edited March 15 by bosun21
Typo

[bosun21]

Anyone?

[StevieDvd]

Is this the video?

Looks like the 4 screws are just to hold the plate in position for you to line up the plate with the tube hole.  Are you using the same 4 holes as the video (i.e. the elongated ones)?

Otherwise you need to do the same alignment but with another method to hold the plate in place whilst you drill/mark the new holes.  Or make up a cardboard template and tape that to the tube and drill through that.

Hopefully, someone here may have swapped the focuser for a Baader one on the same scope.

 

[bottletopburly]

I fitted a Steeltrack to my 200pds and holes didn’t match , make a  paper card  template I wish I had , and measure what the focuser center is before dismantling  , I just used the elongated holes , I got light leakage on the base which I plugged using black foam , excellent focuser though .

[PeterC65]

I've considered upgrading to the Baader Steeltrack but decided against it as the installation seems unnecessarily complex.

As I understand it, the inner elongated holes in the Steeltrack base are just to hold the base while you mark out the OTA for drilling of the new holes. You then use the new holes with the outer rods to attach and adjust the focuser.

I was very surprised that the Baader Steeltrack was not just a direct replacement for Sky-Watcher focusers, like the Astro Essential focusers are for example.

One thing that did cross my mind was whether the inner alignment holes could just be used to permanently attach the Steeltrack, ignoring the outer rods (and probably their adjustment function).

 

[bosun21]

Thanks for your replies. The holes don't line up with any on the Steeltrack focuser so I can't use that method. I think I know of a way forward with this so I'll post how I get on. It's good to know that some fine movement can be done by manipulating the fixing rods once in position. Thanks again.

[Tomatobro]

A long time ago I fitted a steel track to a SW MN190 and like others have commented nothing lined up hole wise. From what I can remember I placed strips of masking tape around the hole and lined up the focuser using a collimation cap in the focus tube to the secondary. While holding it still I then marked out the position of the base plate onto the masking tape.

The tape had the benefit of not letting the drill slip when starting the holes.

[bosun21]

2 minutes ago, Tomatobro said:

A long time ago I fitted a steel track to a SW MN190 and like others have commented nothing lined up hole wise. From what I can remember I placed strips of masking tape around the hole and lined up the focuser using a collimation cap in the focus tube to the secondary. While holding it still I then marked out the position of the base plate onto the masking tape.

The tape had the benefit of not letting the drill slip when starting the holes.

That's along the lines I was thinking of. I was going to use a concenter to position it correctly and held in position with Blu Tack which will allow for small changes in position. Mark and drill accordingly. I wonder which telescopes they actually fit out of the box.

[Tomatobro]

Since my last post I went through my phone pictures as I have a habit of taking pictures of each stage but although I have some with it installed non are of the actual process.

Looking at the pictures it does look as in you have some leeway on the longitudinal positioning post hole drilling but not much side to side. The side to side is not so critical as the mirror can be rotated to suit. On that basis the actual hole positioning is not a s critical as it would seem. Just make sure you mark and drill in the plate slot centres so you can raise and lower the focuser as required.

Edited March 15 by Tomatobro
spelling

[StevieDvd]

Not having done a swap of a focuser on a dob myself but brain-storming a solution I had the idea of using 2 templates to get a good alignment.

• Create a template of the current SW focuser (A) note the position of the screw holes & centre cut-out
• Make a similar one (B) for the Baader - make allowance for the tube curvature
• Centre the SW template on top of the Baader one so you can use the 4 holes of the SW template to align the Baader template.  If the cut-out on each is the same size then a simple alignment, if not then you would need to find the centre of each cut-out to align with.

Though I expect someone may come up with a better/simpler solution if they've actually done the deed themselves🙃

[Flamidey]

All you need really is to make sure the plate is centered over your existing hole.

• Measure the distance between the opposite elongated holes on the plate.
• Subtract your existing focuser hole's diameter.
• Divide by two.
• Make a mark at that distance from the extremity of the hole, one on each side.
• Trace two parallel lines through these marks. 
• That gives you the line where the center of the elongated holes on the plate should be.
• Pick a spot where the plate seems centered. 
• Mark the center of the elongated holes on the tube.
• Drill 4 screw holes on those marks. 
• Mount the plate and adjust to center perfectly.

Edited March 16 by Flamidey

[bosun21]

On 15/03/2024 at 17:34, bottletopburly said:

I fitted a Steeltrack to my 200pds and holes didn’t match , make a  paper card  template I wish I had , and measure what the focuser center is before dismantling  , I just used the elongated holes , I got light leakage on the base which I plugged using black foam , excellent focuser though .

I now have the focuser fitted and centered, along with collimation. What did you use to block the light leaks? I was thinking of some sort of spray foam (black). Any recommendations?

[bottletopburly]

1 hour ago, bosun21 said:

I now have the focuser fitted and centered, along with collimation. What did you use to block the light leaks? I was thinking of some sort of spray foam (black). Any recommendations?

I used the firm black foam that the focuser came in , see image 

[Flamidey]

1 hour ago, bosun21 said:

I now have the focuser fitted and centered, along with collimation. What did you use to block the light leaks? I was thinking of some sort of spray foam (black). Any recommendations?

I use simple electrical tape. 

[bosun21]

Completely finished with the focuser changeover now. I have taped the redundant fixing holes and used black foam to completely eradicate any light ingress. What was initially frustrating at the start with nothing whatsoever lining up as they miraculously seem to do on the YouTube videos. I'm pleased as punch with the final outcome. 

 

Edited March 29 by bosun21
Add photos

[Stu]

1 hour ago, bosun21 said:

Completely finished with the focuser changeover now. I have taped the redundant fixing holes and used black foam to completely eradicate any light ingress. What was initially frustrating at the start with nothing whatsoever lining up as they miraculously seem to do on the YouTube videos I'm pleased as punch with the final outcome. 

 

Looks great, they are excellent focusers. I have one on my incomplete 12” truss dob project which I will sort out one of these days!

[PeterStudz]

4 hours ago, bosun21 said:

What was initially frustrating at the start with nothing whatsoever lining up as they miraculously seem to do on the YouTube videos. I'm pleased as punch with the final outcome. 

From my experience (OK, limited to many on here) I think that these couple of sentences could apply to all areas of astronomy. And not just DIY.

All looks great and well done!

Edited March 29 by PeterStudz

[Piero]

Looks very good! Enjoy your new focuser!