130p Heritage Focuser

[Holliday]

I've seen a few threads about this and the general consensus is to use some PTFE tape to improve the focuser. I've tried this but the tape gradually comes off and also when using my webcam, trying to focus whilst the webcam spins is pretty tricky. (I realise the heritage isn't the choice of scope for imaging).

But having just seen non-turning helical focuser's, I just wondered if the 130p Heritages could be replaced with something like http://www.ebay.co.uk/itm/191503427260?_trksid=p2060778.m1438.l2648&ssPageName=STRK%3AMEBIDX%3AIT if the thread sizes were the same would it just be a simple case of swapping them out?

[happy-kat]

That looks very interesting.

How does that focus I can not see anything to turn to adjust focus, perhaps I need to look again.

[happy-kat]

You have reignited my mission to replace the focuser.

http://www.365astronomy.com/1.25-Non-rotating-Helical-Micro-Focuser-with-T-thread-and-0.05mm-Scale.html

I have sent a question.

[Holliday]

You have reignited my mission to replace the focuser.

http://www.365astronomy.com/1.25-Non-rotating-Helical-Micro-Focuser-with-T-thread-and-0.05mm-Scale.html

I have sent a question.

Ah excellent, will be interesting to see their reply.

Just measuring the thread of the focuser on the 130p now and it seems to be about 44-45mm so can't see it being a straight swap, so I assume some tinkering would be needed.

I've also seen people adapting old camera lenses into helical focusers which might be a possibility.

[happy-kat]

I will try to measure it later with my micrometre to see out of interest what it is, I am liking the thought hugely of that one in the link.

[happy-kat]

My concern is that the unit would sit the eyepiece to high to reach focus though I guess could just push the trusses down to compensate.

[Holliday]

My concern is that the unit would sit the eyepiece to high to reach focus though I guess could just push the trusses down to compensate.

"Telescope side thread is 31mm with 0.45mm pitch.

Internal diameter at telescope side: 27.5mm"

Just measured an eyepiece and pretty much got these measurements. So maybe it'd be possible to hold the new focuser in the current one via the 2 screws? And if distance is an issue, maybe shorten the female thread on the telescope to allow more inwards travel?

[happy-kat]

Would rather drop the trusses then cut anything, might reduce the focused stability/strength if it were smaller.

[Holliday]

No idea what went wrong with the formatting above, apologies. Copy any pasting text doesn't seem to work well.

 

[happy-kat]

I am not sure about this one, the Heritage the naked focuser opening is 45.1mm which looks to be way bigger than the 31mm suggested for the telescope mount part of this replacement idea.

Also I think 10mm of focus travel is not enough.

Off looking for toehr ones now.

I actually already own the 135mm Helios lens in this thread.

http://stargazerslounge.com/topic/193010-low-profile-non-rotating-helical-focuser/

[happy-kat]

I am toying with the idea of a step up ring to use to mate the focuser to the Heritage barrel.

[happy-kat]

Going to pursue using and old lens I have two I could consider already.

[Holliday]

Going to pursue using and old lens I have two I could consider already.

Let me know how you get on. Might keep an eye out for a cheap lens eBay to try and adapt if it goes well.