mod a dob

[sparkyjon]

just thought i'd add a few of the mods i've done and will be doing as i go along ( probably going to be slow progress due to my broken ankle)

i knew about a few mods that help with the joy of owning a dob, as soon as i had my 200p a few of the local lads pointed me in the direction of the lazy susan mod, so i have bought everything i need for that and awaiting the build,

but while waiting i have added a few things,

a skywatcher auto focuser and a k-son rdf (telrad style) even takes a cut down telrad dew sheild.

next one was to add 4 x caster wheels two of them have brakes so it wont roll away when i take my eye of it.. very cheap and makes it so much easier to move around the garden and house.

the next one is the fan mod, at present i have only added a 40mm 5v fan in the dust cap , just to help with the cool down time, some may say it's not needed but i think the cooler the better.

these have really taken me minutes to do on each mod it's so easy and makes life easier (if it can get easier with a dob)

i also have a few more planned , the lazy susan will be done as soon as my gear arrives for it, i will document it, i have a 140mm 12v fan coming which i plan to install in the base so it cools the ota when in the upright position and doesn't effect the balance of the ota, and i will be flocking the inside as soon as i can get out there..

if anyone has any other mods that are useful and i have missed please let me know,

[swamp thing]

Nice one, you may wanna add a dew shield to your list, and seeing as you are a sparky. How about knocking yourself up a secondary heater.

[sparkyjon]

Heaters could be a plan. Dew shield yes i don't know why i haven't done one yet i did one straight away for my previous two scopes i have a mat here still.

[John]

Interesting stuff. Modding dobs can be great fun !

Does the fan on the dust cap push or pull the air ?

I have a small fan behind the primary mirror of my 12" dob but I've not used it so far. The scope seems to cool OK left to it's own devices.

[sparkyjon]

It blows air down the ota on to the secondary so cold air down the ota. Its all removable nothing is permanent. I can see why some may say its not needed but i had it spare so thought id use it.. Summer is coming and i store mine indoors.

[lennylovit]

center bush mod , when you fit the lazy you will need a longer bolt

[Rijidij]

Seeing as warm air rises, it might be more efficient if the top fan were to suck, rather than blow...

Also less chance of blowing dust and pollen, etc. onto your primary.

[sparkyjon]

Now ive installed the rear fan Im dropping the smaller fan its not needed the whole tube chills really quickly with the bigger 140mm fan running.

[sparkyjon]

wow these mods make a really big difference i've done the lazy susan mod and built the fans in ,although i'm taking the smaller one out, i will add pics of the fan mod and lazy susan mod when i get 5 minutes, time to flock it now..

[ZEbbEDY]

cool mods man, any updates?

[texaspete1973]

post some pictures of the 140mm fan john, you've got me curious now

[texaspete1973]

The dew heaters are a good addition too, Mr Fibble did a really good setup that he made

[houston]

I have setting circles on my 200p base and a wixey for the altitude. Makes it really fast and easy to find the fainter objects. Cheap and best mod i have done.

[michaeldurban]

I have done similar mods on my SW 10"

first the fan, on a template

Template cut out on some cheap plywood and spraypainted.

installed and ready to go, attached the cord to a variable

4-12V adapter.

then added a LZ bearing, with setting circle

and finally a simple digital inclinometer

added a telrad, new springs, flocked the scope and flattened

the focuser tube.

Works great !

[Avocette]

I am just in the process of removing a lazy Susan bearing from my 300p, and suggest you don't add one to your 200p if you haven't already done so! The 200p is quite light and runs well on three Teflon furniture sliders used instead of the white Teflon rectangles crudely stapled in place by SW. If you fit a setting circle you might still want the lazy Susan as the centre bearing, not to support the top part of the mount but just to centre the rotation and avoid the errors introduced by the bolt slop (see http://stargazerslounge.com/topic/205732-my-sw-skyliner-200p-additions-and-modifications/)

[Avocette]

Oh, I forgot the Turtle Wax coating on the undersurface of the mount where the furniture sliders rub (recommended by Reeny).