2 inch Focuser upgrade options for a VX8? Baader diamond steeltrack/similar priced products.

[ONIKKINEN]

The time has come to change the stock ACU-2 focuser to something more appropriate for the heavier astro cam. With a DSLR i wasn't bothered by stability, but now i can quite easily feel my imaging train move if i grab the camera. If i tighten the compression ring with pliers, the camera stays put but i get weird edge effects on one side of the image which could indicate pinching of the comacorrector, so not a good fix. I also notice that the clamping mechanism while with a compression ring is only applied from one side, and has some play in it. I worry that this shifts my camera off center and causes collimation issues. I have had different results with the same collimation, and i am certain the primary cannot move under gravity enough to warrant this. Before jumping on the expensive-collimator ship i want to upgrade the mechanical parts to remove issues one by one. I am not concerned about the possibility of motor focus, as my setup is never left unattended so i don't really need motor focus.

I am also not worried about the exact hole spacing, i will just drill new holes which is easy to do on the soft aluminum tube.

I was looking at the Baader diamond steeltrack :https://www.teleskop-express.de/shop/product_info.php/info/p8215_Baader-2--Diamond-Steeltrack-Newtonian-Focuser.html

Conveniently priced and looks competently made. Boasts "virtually unbreakable" this and "zero shift" that, but often this is not true. Any opinions from users?

There is also the TS UNC-V power at a slightly lower price, or the TS monorail at cheaper still. The Moonlite 2 inch crayford is also around this pricerange, but with the baseplate comes out as a good bit more expensive. Any opinions?

[johninderby]

I can recommend the Baader Steeltrack focuser. Beautifully made, nice and smooth and no slippage. Next best thing to a FeatherTouch R&P focuser. The TS monorail is poorly made compared to the Steeltrack and does seem to wear out quickly. The Stedltrack handles a heavy load better than the Moonlight. BTW Moonlight no longer makes regular focusers but only motorised ones now.

I’ve got a couple of the Steeltracks and can’t fault them. One is the older version and works as well as new with zero wear. 

As to how tough they are bought a scope that had been in a fire intending to use it for parts. The Steeltrack on it was seized solid and had scorch marks The  focuser was filled with soot and ash and being soaked by firehouses didn’t help. Cleaned all the parts up and after reassembly the focuser worked perfectly. 👍🏻

Edited November 6, 2021 by johninderby

[Captain Scarlet]

I have owned the TS Monorail. It was terrible, the fine focus had lots of "bounce" to it, it was not "direct" at all, I found it unusable. I upgraded to a Baader Diamond Steeltrack, and now I own 3 of them, one on my VX8, one on my Helmerichs 12" carbon tube, and an SCT one on my Intes M603. They are superb. People's main objection to them is that they usually require new holes to be drilled in the tube, but you clearly have no problem with that. However, your VX8's tube is itself also quite flexible. I bought an air-conditioning-duct ring for my similarly flexible-tube Skywatcher 200p, and that also made quite a difference to local stiffness.

Cheers, Magnus

Edited November 6, 2021 by Captain Magenta

[ONIKKINEN]

5 minutes ago, johninderby said:

I can recommend the Baader Steeltrack focuser. Beautifully made, nice and smooth and no slippage. Next best thing to a FeatherTouch R&P focuser. The TS monorail is poorly made compared to the Steeltrack and does seem to wear out quickly. The Stedltrack handles a heavy load better than the Moonlight. BTW Moonlight no longer makes regular focusers but only motorised ones now.

I’ve got a couple of the Steeltracks and can’t fault them. One is the older version and works as well as new with zero wear. 

As to how tough they are bought a scope that had been in a fire intending to use it for parts. The Steeltrack on it was seized solid and had scorch marks The  focuser was filled with soot and ash and being soaked by firehouses didn’t help. Cleaned all the parts up and after reassembly the focusers worked perfectly. 

Well i don't plan on setting my scope on fire, but good to know its well made. TS monorail is off the list, then. The last thing i want is to replace a focuser with a similar one.

[ONIKKINEN]

5 minutes ago, Captain Magenta said:

I have owned the TS Monorail. It was terrible, the fine focus had lots of "bounce" to it, it was not "direct" at all, I found it unusable. I upgraded to a Baader Diamond Steeltrack, and now I own 3 of them, one on my VX8, one on my Helmerichs 12" carbon tube, and an SCT one on my Intes M603. They are superb. People's main objection to them is that they usually require new holes to be drilled in the tube, but you clearly have no problem with that. However, your VX8's tube is itself also quite flexible. I bought an air-conditioning-duct ring for my similarly flexible-tube Skywatcher 200p, and that also made quite a difference to local stiffness.

Cheers, Magnus

Thanks for the heads up, TS monorail is off the list.

As for the VX8 tube problem, that clamp thingy was exactly what i was going to do if i see tube flexing or an additional tube ring. Right now its hard to say what is flexing, but the focuser is definitely part of the issue. I saw someone post a picture of the clamp thingy and seems an easy cheap fix (could have been yours?). I could also see myself just ditching the tube for a helmerichs carbon one, but thats a project for another time.

[Captain Scarlet]

15 minutes ago, ONIKKINEN said:

... I saw someone post a picture of the clamp thingy and seems an easy cheap fix (could have been yours?) ...

it could well have been:

[ONIKKINEN]

23 hours ago, Captain Magenta said:

it could well have been:

It was yours!

Seeing the focuser attached to the tube makes it look quite bulky, at least compared to my current very slim one. I will definitely need some reinforcement on the tube.

[johninderby]

Steeltrack on my old OO 14” dob.

[Captain Scarlet]

@johninderby what's that little peashooter-lookalike in your bottom picture? A laser?

[johninderby]

3 minutes ago, Captain Magenta said:

@johninderby what's that little peashooter-lookalike in your bottom picture? A laser?

It’s a polar scope as the scope had. StellarCat drive and Argo Navis.

[Clarkey]

On 06/11/2021 at 14:10, ONIKKINEN said:

was looking at the Baader diamond steeltrack

Another vote for the steeltrack. I have two and can't fault them. Both used for AP.

As stated above, the TS mono rail is very poor. Slips like skates on ice.

[ONIKKINEN]

1 hour ago, Clarkey said:

Another vote for the steeltrack. I have two and can't fault them. Both used for AP.

As stated above, the TS mono rail is very poor. Slips like skates on ice.

Just ordered one. Cant seem to find much negative experiences online, must be for a reason.

Question for owners: Versabase. Whats the function of that? Adjustable base?

[johninderby]

Here you go. 

 

Edited November 8, 2021 by johninderby

[Piero]

I also recommend the Baader Diamond Steeltrack. It has a robust and reliable design.  Overall, the focuser is much better than the more expensive Moonlite where the bearings roll on the aluminium drawtube, digging irregular lanes which cause a shift in the focuser axial alignment over time... 

The only disadvantages of the Baader Diamond Steeltrack, compared to what I consider the best focuser out there - the Feathertouch - are: 1) the weight, and 2) one single choice for the drawtube length. These two aspects might not be issues for you though.

[Captain Scarlet]

One extra thing. I myself have just fitted my Diamond Steeltrack to my VX8. Because the tube itself is a bit narrower than for example than that of the SW 8”, the pair of supplied shims is not _quite_ enough for the middle of the base plate to avoid touching the tube. I used some extra washers to lift it that extra 1mm or so.

[ONIKKINEN]

3 minutes ago, Captain Magenta said:

One extra thing. I myself have just fitted my Diamond Steeltrack to my VX8. Because the tube itself is a bit narrower than for example than that of the SW 8”, the pair of supplied shims is not _quite_ enough for the middle of the base plate to avoid touching the tube. I used some extra washers to lift it that extra 1mm or so.

Good to know. I expect to shim it anyway to properly center the focuser on the axis. My tube is slightly non-round so i have shimmed my current focuser with washers on one side to center the focuser on the secondary without having to adjust the spider to be unsymmetrically offset.

[johninderby]

Baader do the proper shims to lift the focuser base.

https://www.baader-planetarium.co.uk/shop/baader-1-5mm-strip-shims-spacers-for-bds-nt-focuser/

[ONIKKINEN]

Just installed the Baader diamond steeltrack on my VX8. I ended up having to enlarge the borehole itself since it was a bit too tight. It does fit in the stock hole but it chafes and who knows what happens when thermal expansion is taken into account? Just shaved a bit of the aluminum off and filed it smooth, not that big of a deal. Also of course drilled the holes for the attachment plate. Starlight deprived first impressions are very good, the focuser is solidly built and i doubt i could break it without considerable violence and misuse. No sign of tilt or flex of any kind whatsoever with a payload on it and the action itself is very smooth and not "springy" at all in the fine adjustment knob, unlike the one this focuser replaces. The weight of this focuser is also very similar to the stock one, so ill just see if i can get away with not reinforcing the tube with the clamp. I don't have an accurate scale but the old one was 0.8 or 0.9 kg and the BDS is 0.9, so i will assume pretty close.

On 09/11/2021 at 13:22, Captain Magenta said:

One extra thing. I myself have just fitted my Diamond Steeltrack to my VX8. Because the tube itself is a bit narrower than for example than that of the SW 8”, the pair of supplied shims is not _quite_ enough for the middle of the base plate to avoid touching the tube. I used some extra washers to lift it that extra 1mm or so.

Interestingly, i did not need extra shims. 1 shim per side was almost enough, but with 2 shims its easily enough.

Also i found out that i don't need to shim one side to fix tilt, since the focuser drawtube itself is adjustable in relation to the focuser body! The adjusting screws have plenty of room to play with and i was easily able to square it on axis using the drawtube up/down adjustment screws. Very welcome surprise to find this while browsing the user manual.

[ONIKKINEN]

A few nights out in -15 or colder temperatures i have noticed that the Baader diamond steeltrack becomes "springy" like the stock focuser in the fine motion knob. Its possible to work around this by carefully adjusting the friction screw to a point where it almost, but not quite slips but its a bit of a faff. It gets better once the entire setup has properly cooled to ambient temperatures, but during cooling i will have to keep an eye on the focus and adjust if necessary. Much better than the stock focuser of course, but if anyone is wondering how it performs in difficult situations i thought i would mention that its not perfect.

But in all fairness, nothing that is supposed to move seems to work properly in cold temperatures, so shouldn't be a surprise for someone who is used to that.