Compression springs

[DanDare]

Hi,

I'm restoring a 10" truss tube newt and trying to get hold of some compression springs for a mirror cell and spider? I've had a look at a few web sites but they all have a minumum order spend (the lowest I've found so far is £15.00 + delivery)

I see that Screwfix do a box of various sized springs for £8.99 although no sizes are given and they don't look at all small enough for the spider.

Thanks for looking.

Roy

[The Warthog]

Oddly enough, I am shortly going to be involved in the same search for a 11½" mirror cell. Are you going with three or four adjustment points. I was going to use four, but did some thinking and decided three would work better.

[DanDare]

WH,

Its a three point cell I'm restoring, so the hard work has already been done. So far I've just had to drill a 2.5mm hole in each support and insert a slotted steel pin. I then drilled a slightly larger hole in the base of the cell which the pin sits in - this allows the support to pivot up and down but stops it from sliding away. (With acknowledgements to Barkis for his advice on this). Each support sits on a stainless steel slotted mushroom set screw. I'll give it a paint job in due course. I've attached a picture of the cell as it was when I first dismantled the scope. The supports where originally held in place by springs which had just about rusted away, but you can just see the remains of a couple.

From what I understand a three point cell is fine for this size mirror.

All the best.

Roy

[Milamber]

Try here...

Arthur

[G4YVM]

My 16" mirror cell looks like that and I have used three landrover valve springs. They cost me about 2 quid each if memory serves.

David

[DanDare]

Thanks for the replies guys.

Just had a quick look at the Brocott site Arthur and that looks promising.

[ZOG]

I also was going to recommend a trip to the local scrapyard to pick up some valve springs. Should be ideal for the job.

[DanDare]

Thanks Zog, I think I've sorted the ones for the mirror cell, now just looking around for some smaller ones for the spider/secondary holder.

Roy

[Astrokev]

Thanks Zog, I think I've sorted the ones for the mirror cell, now just looking around for some smaller ones for the spider/secondary holder.

Roy

Roy,

A long time since you posted, so no idea if this will "find" you!

I'm currently making a cell for a 10" primary. What size springs did you use ?

Thanks

[Steep]

Odd you should bring this thread back, I was in Aldi today and saw one of their specials just now is a box of assorted springs for £3.49 I think.

[Astrokev]

What range of sizes did they do? I imagine for a weighty 10" mirror the springs need to be pretty beefy to hold the mirror firm.

Thanks

[Steep]

Pass, pop in to your local one and have a look, they come in a clear plastic box so you can see them all before buying.

[Astrokev]

Just need to find an Aldi ;-)

[Tom How]

When I needed some springs for my telescope mount I went to RS because they were selling stainless steel springs

Hardware | Hinges and Brackets | Springs

I was worrieda bout spring steel springs rusting

[Tom How]

however, last time I made a mirror cell, I used a spring off one of those automatic garden gate closer thingies and chopped it up - very strong spring!!

Gate Spring Closer

easy to find in homebase, b+q etc and very very stiff - almost too stiff

[Steep]

The Aldi springs are very light compared to that garden gate spring, assuming a 10" mirror is as weighty as Astrokev says then I doubt they would do to hold one firm. Here's a picture of the compression spring types in the box anyway, there's lots of tension springs in the box too.

The image is big and 360k so I've linked to it rather than post it.

http://www.marnoch.org/galleryhm/springs.jpg

[blinky]

I ordered new springs for my F4 Newt from Bob's Knobs - although they are in USA I got delivery in under a week.

[haitch]

I'm sure I saw a thread on here about using landrover valve springs or something similar.