Localy Built Dob EQ Platform/Table

[netwolf]

Iceman, agreed 1 and 5 are a little exesive. Howeve I think that we should at least be able to have the option to add a DEC drive later. So the design should have a manual method to tilt the platform up down, this can then me motorised later if need be.

See picture in this link for a manual way of tilting using the long rod on one pivot.
http://www.geocities.com/reaganjj/singleax2.jpg
Now same platform with Stepper added for this pivot.
http://www.geocities.com/reaganjj/stepplatback.jpg
Constuction notes for above platform.
http://www.geocities.com/reaganjj/

I would like to see a price around $300 or less if possible. The folks building these in the US have done them on $100-200 US budgets and less.
You can see there discussions and pictures etc on this Yahoo group.
http://groups.yahoo.com/group/eqplatforms/

One more item would be to look at a quick reset method.

[davidpretorius]

stepper motor drivers arrive next day or two, i have three or plans of platforms thanks to netwolf. We sell abrasives,airtools etc. So I have lots of contacts in engineering shops. I will show around over the next few weeks, get some quotes and see how we go.

The limit is $1000, I believe as we are then in the EQ6 price bracket.

I have also emailed hurst stepper motors in USA for pricing.



In my mind 4 models easily upgradable

1. Dob buggy
2. Dob Buggy with basic eq platform
3. Dob Buggy with
   1. ALT/AZ drivers, focuser or
   2. EQ platform with RA / Dec drivers, focuser
4. Dob buggy with EQ platform, ra/dec drivers, focuser & encoding.

IF built with stepper motors, then no need for dec, but if servos are used, then dec is needed.

[davidpretorius]

http://www.roundtableplatforms.com/images/Add_Pic_1.jpg
a piece of marine ply at 900mm wide x 2400mm long would be around $120. i will download some templates and cost it up. as long as you get the angles right for the 70 to 80 minute period, this version should be ok to mass produce.

http://www.equatorialplatforms.com/alumplt.jpg

again, it is the angles that need to be right, but the look doos not have to be pretty. i will cost out as well.

[Daring Dave]

I have discussed this thread in general with a mate who is a cabinet maker by trade.. Whilst he has no real interest in astronomy he said he might be interested in making the platforms for minimal profit if plans are provided.

He has a full workshop and obviously trade contacts for material supplies...

From looking at a few pix he reckon's they are 'dead easy' as long as the plans are OK.

[davidpretorius]

yes daring, i had talks with a aluminium and stainless fabricator today. I think i will be giving this a real hard think and then trying to bring the best of all that i have seen together as a package.

I will be posting some ideas later tonight for guys to pick to pieces in order to get a great cost effective result!

[iceman (Mike)]

Not sure if you guys have seen this link:

http://www3.telus.net/astrotel/astrotelpagefive.htm

Looks like a nice platform.

[davidpretorius]

thanks mike, the simplest design yet and very interesting. This has potential!!!

[netwolf]

Is anyone out there insrested in building on of these for me? If so could you PM me a cost for it? Has anyone built one for there own personal use?

[davidpretorius]

hey mate

http://dbpeckham.com/EP/Don-EP.htm

is the best description and explanation i have seen. I will be having a go at building this in next few months. I hope Mick Pinner will incorporate into his buggy or more importantly, i can adapt to his buggy and then also dec motorising.

I won't be starting for a few weeks though.

If the costs are looking ok, i am happy to make 2.

[netwolf]

Dave, I too was looking at this design with Dec motor added in. This would limit the need to mechanically change my dob. Where as with the Alt/Az motorisation, i would have to make significant mechanical changes not to mention iron out the electronics.

However With the Eq platform we still need a way to clutch the Alt/Az so they do not move while tracking on the platform.

This also leaves the door open to make Alt/Az changes later to the Dob when bigger budget becomes available.