Dob Trolley for dummies

[Mr niall]

Hello there

Thought I would share my trolley building experience for those interested. The very important caveat to this is that there is nothing particularly innovative or complicated in this creation. This is particularly important as I am almost completely inept at anything related to DIY and am bound to fail. In fact, an excellent tag line for any company trying to bring a DIY product to market would be something along the lines of "so simple even Niall can do it". This is more a David and Goliath story about someone who beat very very short odds to create something really quite simple and easy to build despite a track record collapsing barbecues, doors that don't quite stay closed or reach the floor and fences that shudder and fly away at the slightest hint of a breeze. In 2010 my last minute recreation of the ISS using toilet roll tubes, tin foil, an empty cling film box and white emulsion actually attracted quite a lot of attention due to the fact it was unanimously agreed my 6 year old son had completely built it himself... Still an award is an award...

The other (in reality the biggest) consideration is cost - this whole thing cost me £18 to build using stuff I had lying around but even if you had none of it you could do it for less than £30. And it is 100% rock solid too which is a massive consideration when your telescope is your only "nice thing just for me".

The absolute easiest way to build this would have been to get a sheet of 18mm or thicker plywood and plonk wheels in the corners. But this was unattractive for two reasons; thick plywood is expensive £20-30 a sheet and - more importantly it still isn't really thick enough to provide a good anchor point for the wheels.

So I went with the classic "T" shape, with a scrap piece of wood I had lying around from a (failed) guinea pig house (they could get into the house but not out, long story). And I used the feet underneath as recessed mounting points so the dob wouldn't be inclined to slide off the trolley. This is attractive as it only requires one piece of wood and two 90 degree cuts (woo), even better is the fact that the 90 degree cuts dont have to be perfect; if you get them slightly wrong you can just wiggle the wood around until it seats and THEN mark out the final hole to cut for the third foot. If you look closely you'll notice my T shape isn't perfectly perpendicular cos this is what happened to me!

But importantly - no funny angle cutting required! As a man who has managed to cut himself so deeply he required stitches for the following - 1) trying to screw on a solar panel 2) Opening a tube of silicone sealant 3) Cutting a carrot; I am wisely not in possession of a cross-cut or table saw. Hand sawing only!

For info; A 2.4m 68x38mm batten from Wickes cost about £2.45 so that is considerably cheaper than thick ply. 

Wheels - I went with castors rather than pneumatic wheels, which I wouldn't have chosen ordinarily but did for the following reasons. 1) Despite actually having two 10" pneumatic tyres in my possession, I didn't have an axle. Getting hold of something suitable, and appropriate mountings, was going to be another £10 to £15 as I didn't have anything suitable in my armoury. 2) It would make it so wide that it wouldn't fit through my patio doors (which is a much bigger issue!). I easily managed to acquire a set of 4 125mm rubber wheeled castors (spend extra on rubber wheels it makes a huge difference to the noise and damping), 2 braked, 2 unbraked - for £15 including postage. I went for the biggest I could get as I have an 90mm lip to bump over to get the dob from the house to the patio. But you could save a fiver at least if you didn't need to go this big.

Construction - not much to say here; just held together with stuff I had in my armoury.  It occurred to me that the cross brace probably didn't need to be massively strong as most of the weight would be in the corners, but I did anyway; a single 100mm wood screw braced and wood-glued in place and then 4 angle brackets to prevent any side movement. I drilled 3 separate 32mm wide recessed holes for the dob feet to fit in, and a shallower one to clear the screw on the underside of the dob that secures the spinny base to the platform base. Into those recesses I glued a rubber disc from an old car mat - and then covered the top in some expanding PTFE from a previous failed project.  I took care to make sure that the depth of the holes was such that the dob base would compress the expanding ptfe tape but the feet would still sit at the bottom of the recesses.

The only snag was that the wood would have ideally been about 5mm wider due to the width of the castor feet but I made it work like a true Rockstar! Shockingly I didn't think to measure the width of the castor feet relative to the width of the wood before I started. But considering I once removed the entire Targa top of a car only to find out the replacement seals and mounting screws I had purchased were completely wrong and I had no way of re-attaching it despite the fact that rain was forecast that afternoon (and boy did it rain - the rest of that afternoon was like a bad episode of the A-team crossed with the blooper reel from Scrapheap challenge) - gives you an insight into the kind of "attention to detail" we're dealing with here.... Additionally the long piece over hangs slightly with an 18mm whole drilled through for attaching a handle / pull rope at a later date.

Couldn't really be simpler. But works nicely. The biggest unexpected bonuses are that the eyepiece sits at 1.7m at zenith now - which is fab as I'm 1.8m tall so its much more comfortable! Additionally the extra time and money spent on rubber feet, the rubber discs under the dob feet and the expanding ptfe strips means the whole thing is completely silent and there are almost no vibrations anywhere in travel, which makes nudging the big beast around even more of a pleasure, even at high magnifications.

So apologies for a long and frighteningly boring tale that, in essence, describes a man sticking two pieces of wood together; but honestly there are people out there like me who really don't have a clue when it comes to DIY and constantly fail despite our best intentions and desperately envy those of you who can do this stuff! Hopefully this may be of use to someone out there someday.

 

Edited June 23, 2019 by Mr niall

[Paul73]

Good job Mr Niall. Here’s my effort.

Paul

[MarsG76]

Very nice.. the wheels are nice and big.. I added wheels to the base of my Dob, but admittedly they're slightly too small and are a pain on the grass.