We have a collection of telescopes here at OA, one of which is the Dwarflab Dwarf 2 smart telescope, which is well loved by many. As a grab n go scope it is pretty much unbeatable in terms of portability.
Unfortunately our poor Dwarf 2 just upped and died on us, it wasn't the electronics, rather it was the plastic base that gave out, in a really strange yet catastrophic way.
The Dwarf had been stood flat on a table as usual and having picked it up to start setting it up for an evening of imaging, lo and behold the entire base is loose and dangling by some black wires. As you can imagine there were several moments of confusion, followed by a 'what the hell?!'
This unit had been used in alt-az and eq and was around 18 months old and as we're based in the UK it hadn't seen a massive amount of use due to the amount of cloud we get.
Being a member of the Dwarf 2 Facebook group we did what most people do and posted images in the group asking if anyone else had suffered the same issue, it felt it was necessary to ask as this type of break was nothing like the original base plate issues that were rife in the early batches of Dwarf 2's and resulted in the bottom of the base being glued at factory.
Interestingly there were several comments from other members on the thread who had suffered the same type of failure as shown in the pictures, equally interesting was that some had suffered the failure without having used their D2 in eq mode at all. So eq or alt-az seemed to make no difference.
Dwarflab were quick to reach out and offered a resolution which was greatly appreciated by us, Claire is fantastic. However the resolution unfortunately still meant that our little D2 was still dead.
So we decided to attempt to fabricate a replacement base that would be stronger and after a few tests we were happy that we were heading in the right direction.
There have been many tweaks to our design since starting work on it and we are now at Revision 12 and feel that it's ready to be released.
So the R12 replacement base for the Dwarf 2 has been designed to be printed in PETG-CF, a carbon fibre reinforced filament, and below are what's required in order for you to repair your Dwarf 2 base (using the OA D2 Base replacement):
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It does require that you canibalise the failed D2 base.
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You will need to pull the original base apart in order to remove the USB cirtcuit for use in the replacement base. Due to the original base being glue together this will destroy the original base. Make sure to pry the base apart at the end without the USB port in order to avoid damaging the USB circuit and cables!
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When removing the cables from the USB-C circuit you don't need to remember which one came from which socket (although it helps) as each connector will only fit a specific socket. Both removal and re-insertion should be gentle, if you're forcing it then it's in the wrong socket or upside down.
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The small M2 screws from the original base should also be kept. These are required for re-mounting the circuit and attaching the cable brace that comes as part of the new base.
- There are 2 bearings around the centre stand of the original base which are required and can be pryed off gently with a small flat head screw driver.
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You will also need 7 x M4-14 hex cap bolts.The cap section should be 7mm wide and 4mm deep and can be found on Amazon. Here's a link to some appropriately sized bolts https://amzn.to/4ex3uE7
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Looking up inside the bottom of the Dwarf 2 you will see a hex bolt holding on the remains of the neck of the original base. This bolt is very tight in no small part due to the fact that it appears to have been hot glued in place during assembly. You will need an appropriately sized hex driver to remove this and apply some degree of force to remove it. You will need to reverse this step to fit the new upper part of the replacement base
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Now that you have the bolt from the neck out you will need to keep the bolt assembly and take note of it's assembly. Where each washer goes is important as there is a split bearing in this which forms the clutch of the Dwarf 2 base.
So once you have everthing above you can start to re assemble the new base. This begins with making sure the cables are removed from the usb circuit and then fed through the hole in the neck of the new base. The neck walls are thicker and the opening is only just large enough to pass the largest connector through in order to strengthen the neck.
Once that's done it's time to re-attach the USB circuit to the cables and bolt the new upper part of the base back into the Dwarf 2. DO NOT TURN THE DWARF UPSIDE DOWN TO DO THIS!. The last thing you want is the washer that sits on top of the assembly above falling into the Dwarf 2 never to be seen again, that will either be the end of your repair attempt or the beggining of trying to further strip down your Dwarf 2. In either case, not good! This is possibly the most tricky part of the re-assembly. You'll need to make sure that the cables are flat and not twisted as they feed through and offer the new upper base, bolt assembly and washer up to the main body of the D2 while the bolt assembly is on your hex key and you're taking up any slack in the cables as you feed this back in to the body and fix it in place. It may take a few attempts (and a few choice words) but it isn't that bad or that complex when you've tried it a few times. You'll also notice in the photo above that I forgot to put the circular bearings back onto the neck, so I had to remove the cables put the bearings on and then re-thread the cables, don't forget the bearings first!
With the bearings on and the USB circuit re-attached to the cables you should have the below image. That's the most difficult part out of the way!
Next you will want to attach the USB-C circuit to the bottom part of the base and clamp the cables using the cable brace.
As you can see this is simply mounting the USB-C circuit using the M2 screws you saved when you were caninbalising your original Dwarf 2 base.
Now it's just a simple matter of ensuring the cable slack sits up inside the neck as you attach the lower base plate to the upper base plate using the 7 M4 - 14 Hex Cap bolts.
Those of you with keen eyes will notice that the bottom baseplate in the photo above is different to the base plate in the render. The photo was taken with the Rev 9 replacement base, while the current Rev12 base uses a 3/8 16 mounting thread with an open top, this means that you can reach the clutch assembly inside the Dwarf 2 with your hex key to adjust it without the need to constantly be removing the lower base plate. Just be carefull not to completely undo it accidentally or pinch the cables with your hex key when seating it into the clutch bolt.
Testing tracking on the Sun after first assembly.
Calibration marks.
So there we have it, our D2 is back up and running and stronger than ever with it's new base. We will be selling the replacement base, but will only be making it to order with the price likely to be £14.99 that will be with the 3/8 16 brass mounting insert but without any Dwarf 2 specific hardware, just the PETG-CF (Carbon Fibre) base plates and cable brace.
We will also be making the STL files available to the community for free (with the option to buy us a coffee, it'd certainly be appreciated!) as a download from our website.
If others intend to 3D print and sell this model the only stipulation that we have is that the OA logo remains part of the model and that you charge customers no more that £/$14.99 GBP/USD for it excluding postage, which should be more than enough to cover running costs for this item. All rights to this model will remain with OA.
If you've read this far then thank you, you'll find the relevant links at the bottom of the page.
Clear skies!
The Rev12 base with the 3/8 16 brass insert mount.
