Simple motorized barn door tracker

[hobsey]

I know I have my CG5-GT mount but that along with my scopes has been put away for a couple of months.

I was thinking about making a barn door tracker to have ago at some widefield photography as my DSLR doesn't get used half as much as it should do.

Do anyone have any good links to making a very simple motorized one? Or has anyone has any experiences making their own one.

Many thanks.

[smudgeball]

Hi

Not motorised, but you're welcome to a copy of my plans here

Regards

Neil

[hobsey]

Thank you very much.

I can see me making a manual one for now until I can find a simple enough motorized one or until I get the hang of widefield photography.

[hobsey]

Going to have ago at this one which Ronin gave me the link to,

http://www.garyseronik.com/?q=node/52

Having an absolute nightmare trying to find the right size gear spurs he has used in his build. There is a part number for its for a supplier abroad. 

[LukeSkywatcher]

I'd love to have even basic DIY skills and such, to make a simple manual barn door. Even as a kid, i got totally lost and confused when even attempting to do a Blue Peter project.

[hobsey]

I'd love to have even basic DIY skills and such, to make a simple manual barn door. Even as a kid, i got totally lost and confused when even attempting to do a Blue Peter project.

Believe me, I hate wood work. Everything I have made from wood has ended up in the bin as I loose patience but I will stick at this one.

If I can't get the motorized one going, I will follow this guide for a manual one,

http://barn-door-tracker.co.uk/

[smudgeball]

When I made the one in my link, I used an online article and totally missed the part about distance between hinge and adjusting bolt !

By a complete fluke I drilled the hole to within 5 mm of where it should have been, so got away with it.

But I'm generally in the get someone else to do it camp if I can get away with it.

Neil

[hobsey]

But I'm generally in the get someone else to do it camp if I can get away with it.

Neil

I am if I can get away with it but I also like the satisfaction of finishing something that works.

[ronin]

The gears of 16, 64 are to gear the motor down to 1 rpm for the motor he used.

In effect any 1:4 ratio should do.

This model boat hobyist does gear wheels and you can get a 15 tooth and a 60 tooth to gear it the same.

http://www.cornwallmodelboats.co.uk/acatalog/rb-gear-wheels.html

They do a 19 and 76 which is also 1:4

I am assuming that the ones given all mesh with each other.

Possibly safer to locate a motor first then get the gearing for it to get to 1rpm.

[hobsey]

Cheers Ronin.

I really don't understand ratio gearing, thats why I was trying to find the exact sizes that were used in the building guide. 

I spent about an hour and a half flicking from his suppliers webpage to uk pages looking at the specs sheets with no luck.

[hobsey]

Right, here is a motor that does 1rpm out of the box.

http://www.ebay.co.uk/itm/4W-1-RPM-CW-Replacement-Motor-Altai-G007ND-/321165529430?pt=UK_Sound_Vision_Other&hash=item4ac6f51156

Would you happen to know what size spurs I would need to keep it at 1rpm? 

[hobsey]

Forget that last post.

That motor is a 240v.

[happy-kat]

That design has the windy handle on the top and users an m8 bolt I bought an m10 for mine (when I get round to making one) and this design uses a barrel nut rather than a t-nut. Interesting to see a different design.

[hobsey]

I have spent all evening trying to find the correct motor and gear combination to make that electric one and its really starting to annoy the hell out of me, so I think I'm going to throw in the towel and make the manual one.

[ronin]

Tried looking for a suitable motor down in the low speed area and little luck.

Somewhere there must be one, just it is hiding well.

Any search I put in just turns up too many that are wrong and the Maplin site is appauling - for electric motor I get chain saws.

[hobsey]

Tried looking for a suitable motor down in the low speed area and little luck.

Somewhere there must be one, just it is hiding well.

Any search I put in just turns up too many that are wrong and the Maplin site is appauling - for electric motor I get chain saws.

Yeah, same.

I think I have exhausted my searching for this evening.

Its a shame that the part numbers he has quoted aren't universal numbers instead of dealer specific.

[hobsey]

I have just this second found this page, looks promising but too complicated for this time of night.

http://www.digikey.co.uk/product-search/en?FV=fff4000f%2Cfff80055&mnonly=0&newproducts=0&ColumnSort=134&page=1&stock=0&pbfree=0&rohs=0&quantity=&ptm=0&fid=0&pageSize=25

Will have a look tomorrow.

Cheers for the help.

[Lonestar70]

Hi Anthony,

Here you go,

4 RPM  6volt Geared Motor: -

http://www.mclennan.co.uk/datasheets/european/geared/1271.pdf

Motor part number = 1271-06-392.

Suitable Gears can be obtained here: -

http://www.hpcgears.com/pdf_c33/23.96-23.101.pdf

32 DP in Steel, Brass, Tufnol or Delrin... the latter are the white plastic type.

Hope this helps,

Best Regards.

Sandy.

[hobsey]

That's spot on, thank you very much.

I will have a proper look tomorrow as I'm on tapatalk at the moment and I will let you know how I get on.

[hobsey]

Hello, me again.

If I was to order up a couple of gear as close as I can to the original specs and the gearing/ratio is slightly off, say the rotation is fast/slow, do you think if I wire in a rheostat it would work for fine tuning?

[Lonestar70]

Why would you get close gears, when the correct 16tooth and 64tooth gears are readily available.?

Controlling motor speed may be desirable, since the speed will vary as battery voltage dropped, however this would be best done using a pulse width modulation (PWM) speed controller rather than a simple rheostat, which can be a quite coarse control.

Best regards.

Sandy.

[hobsey]

Why would you get close gears, when the correct 16tooth and 64tooth gears are readily available.?

I don't know, it was just a thought.

Are all 16 and 64 tooth gears all the same diameter then? Because doesn't the diameter effect the gearing?

[Lonestar70]

Hi Anthony,

I don't know, it was just a thought.

Are all 16 and 64 tooth gears all the same diameter then? Because doesn't the diameter effect the gearing?

Short answer... NO and NO.

The outside dia of a gear is defined by the Diametric Pitch of the gear (DP) so a 16 tooth gear of say 48DP would be considerably smaller than a 16 tooth gear at 32DP.

However, regardless of the DP the ratio of  a 16 tooth gear driving a 64 tooth gear (both of the same DP) would be the same 4:1 ratio... it is the ratio between the number of teeth on the gears which defines the ratio.

What would change would be the centre to centre spacing of the 2 gears if a different DP was chosen, or different tooth counts were used.

You must use gears of the same DP in order for them to mesh... a 48DP gear will not mesh with a 32DP gear.

The original gears specified for your project are 32DP, and they will be the same diameters as the originals regardless of where you get them from...therefore, you can use the same spacing for the gears as specified on your plans.

If you were to choose gears with a different number of teeth, or choose to use a different DP then you would need to adjust the spacing between the gear shafts to suit.

I would suggest you stick with the design sizes... it makes life easier.

Hope this helps.

Best regards.

Sandy.

[hobsey]

Oh I see, thanks for that.

In that case, I will order up the 16 and 64 tooth gears from the link you sent me last night.

Thank you so much for your help, gearing abd ratios gave always confused me.

Fingers crossed this goes well, I have until August bank holiday to make where I'm off to the Brecon beacons. So hopefully get some nice wide shots.

[hobsey]

Thanks everyone for your help but I don't think my D.I.Y skills and patience are going to be up to the job so I'm going to try and track down a table top EQ1 with RA drive.