NGT-18 Buggy

buggy

The NGT-18 is a great scope.  But, it is heavier than heck (about 260 lbs) and it is not real convenient to break it down into lighter pieces.  Mirror & cell weighs around 75 lbs, the tub & ring assembly weighs another 80 lbs or so.  Mash you fingers under the tub weights, which are threaded and hold the mirror cell in, and you quickly lose interest in breaking it down on a regular basis.  I used to wheel it out in the driveway on a simple dolly and it worked well, but I had to move numerous items in the garage to get the scope out.  After a while, it rarely saw photons except when we went to a star party.  We moved to a new location and now have the space to keep it fully assembled and ready to go.  It takes about five minutes to wheel it anywhere in the yard.  The buggy works so well even my wife can move the scope.

What's that?  You say I have the JMI wheelbarrow style wheel set for the scope?  Yes I do, and they work OK on hard surfaces.  The wheels are narrow enough they sink right into the typical lawn and are a real pain in loose dirt.  Also, you have to dead lift the handles and drag/push the scope around.  Real hard on my back anymore.  Then you have to remove the handles or keep banging your shins on them all night.  Several folks that own these scopes replace the wheels with larger balloon tires so they easily move across most surfaces, but you still have the dead lift of about 100 lbs, and the handles are in the way unless you remove them (sit on the ground, use a 9/16 socket).

My goals in building a different wheel system were:
    #1  No lifting
    #2  Easy to move across any surface
    #3  Keep the footprint as small as possible
    #4  Tool less and quick to separate the handle  (no more banged shins)
    #5  Fast.  No setup, assembly, etc.

frame

The frame of the buggy is simply constructed from clear pine.  I debated using a good hardwood, but nothing here requires a stronger wood than pine.  Factor in the cost of a hardwood and pine won out.  The feet on the one end are sized so the buggy sits level. 

wheel

Harbor Freight is your friend for this kind of project.  The wheels cost about 1/3 of what Lowes & Home Depot wanted for them.  I am sure they are a lower quality, but since they won't see a lot of mileage they should last forever.  The 10" wheels on the buggy have a bore of about 5/8" so a steel rod, four washers and two cotter pins make up the axle.  A simple dado in the frame locks the axle in place. 

 I was concerned that the bearings were sloppy enough that the scope would require some kind of stabilization, but once I put the full weight of the scope on the buggy they turned out to be fairly stable.  Whack on the scope and the vibrations go away in a couple seconds, aim the scope by hand and it has very little wobble while you are searching.  

bolt

I cut some 3/8-16 all-thread rod to make the bolts to hold the scope on.  The scope base has 3/8-16 t-nuts swaged into the bottom to accept the factory leveling jack screws.  I could of just ran a 2" bolt up through the buggy into the t-nuts, but I feared that the t-nuts may pull out of the base when moving the buggy over uneven ground.  Running the all-thread all the way through and putting a lock nut on top of the scope base eliminates any danger of the t-nuts pulling out.

angle iron pin hole

A piece of angle iron provides the quick attachment for the handle assembly.  The holes are drilled 1/2" so there is enough slop that the handle has a large range of motion up and down while remaining in the holes.

pin detail

The pins are simply a 3/8x4" square u-bolt.  I cut the threads off of one end and attached the bolts using a nut on the other end.  I added wood arms to keep the u-bolts aligned, and to prevent the bend in the bolt from passing through the holes in the angle iron and jamming.

8 inch balloon tire casters are used on the handle assembly (once again try Harbor Freight).  I thought of using one wheel, it would be easier to maneuver in tight areas, but feared one wheel may have enough load that it would want to sink into softer ground.

dolly

So, to easily maneuver the scope around in the shop a simple three caster dolly was built.  It fits between the wheels on the handle assembly.  I just set the small dolly on the floor, pull the buggy frame over it, lift and pull away the handle assembly

dolly

handle axle

dado

I did not put any kind of leveling on the buggy.  My experience with the scope is it doesn't really care if it is perfect.  Neither do the digital setting circles.  Just so it kind of looks level.   Adding jack screws to the four corners would be simple to do if I ever feel the need to add stabilization or leveling.

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