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Workshop too cold and want to make something

Stirling engine kit

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Ajohnw18/01/2016 12:17:36
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I wanted a lens for something and with postage costs just had to buy something else so went for this

**LINK**

Which will need translating. The kit can be bought from their UK agents

**LINK**

I will be interested to see if it does run backwards stood on a cold can of beer,

Some astro people might find the site interesting. eg Want a 450mm fl guide scope, no idea if it would work out. Or fancy a 60 or 70mm finder but don't fancy the cost. As with finders these lenses will probably need a stop in the tube to restrict the field of view.

I should add given how they have to pack some of the things they sell their postage costs are very reasonable.

John

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Neil Wyatt18/01/2016 15:44:35
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Thanks for that John.

Lots of fun bits for pocket money prices. A cheap way to achomat lenses, mirrors or even solar film for a 70mm scope!

Neil

Ajohnw18/01/2016 16:15:34
3631 forum posts
160 photos

I wondered about the cardboard steam engine. Maybe next time. Steam's separated from the cardboard from a quick read.

I have built the spectroscope kit as a trial for that particular type and to check some design maths out. I had the bright idea of using super glue. Fine if things are pressed down in exactly the right position. It would have been better to use something that could be unstuck and maybe leaving a bit of space for something stronger if needed later.

Immediate thoughts was Super Pritt but which now seems to be called Power Pritt.

They are the only source I know of for cheap achromats and the large ones were probably destined for finders.

John

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Michael Gilligan18/01/2016 16:30:23
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Posted by Ajohnw on 18/01/2016 16:15:34:

They are the only source I know of for cheap achromats and the large ones were probably destined for finders.

.

John,

If you don't know them already, have a look at SurplusShed

Postal arrangements are very reasonable ... After buying, they tell you what it would cost to ship, and you can cancel the order if you don't like the shipping cost.

MichaelG.

Ajohnw18/01/2016 16:38:26
3631 forum posts
160 photos

I've used Surplus Shed several times Michael. One trick which believe it or not can save money is to ask them to ship things separately. That sometimes results in all being below the import limit so no vat and better still no tax collection fee - that can vary a lot at times. Not sure why.

sadI understand the limit is now £15. It was £18 and had been for a long time so really aught to be £30 plus.

Last time I ordered off them was the optics for a Bath interferometer. Easily the cheapest for the items needed but also a small surplus Edmond's lens of Ebay.com. That can often also be a cheap source of optics,

Why a Bath - final check on a telescope mirror when I get round to actually making it.

laughI'd be more interested to know if any one else will be ordering the kit.

John

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Edited By Ajohnw on 18/01/2016 16:46:03

Michael Gilligan18/01/2016 17:02:19
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Sorry I bothered mentioning SurplusShed then, John

Yes, the HMRC threshold is now £15 and:

  • It's their choice of exchange rate [I think it's supposedly when it arrives in the UK]; which may or my not be what you got at the time of transaction.
  • If you do go to £15.01 They apply the VAT to both the purchase price and the shipping !!

No, I won't be ordering the cardboard Stirling Engine kit.

MichaelG.

Edited By Michael Gilligan on 18/01/2016 17:03:36

Neil Wyatt18/01/2016 17:23:05
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I've ordered a 50mm x 184mm achromat, which will be ideal for making a finder.

Will return again, probably for Baader solar film and I rather fancy making a 70mm reflector just for the fun of it.

Neil

Ajohnw18/01/2016 19:13:14
3631 forum posts
160 photos

That's what life should be about Neil most of the time when it's possible - fun.

If you make the reflector you could be the only person around with a quartz over coated mirror.

One thing to note on finders. I have had several and all of the ones that are any good and don't show any chromatic effect have a baffle well down the tube with a hole in it. I think it does 2 things. Reduced the field of view and also and probably a lot more importantly increases the F ratio number - the entire lens will  still contribute to the image. The magnification calc is still the same as it always is, I'd base that around what 50mm finders usually offer which I think is around 8 or 9x

laughI might be teaching my grandma to suck eggs but just in case. I'll measure one up if you come to grief if you like.

John

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Edited By Ajohnw on 18/01/2016 19:24:26

Ajohnw18/01/2016 20:11:08
3631 forum posts
160 photos

surpriseI must get a life laugh. Just measured one. 50mm and focal length could well be 184mm. I measured it at 182. The lens cells screw on for focusing and has a locking ring. The baffle is approx 96mm back from the mid point of the lens and has 1" hole in it that might be 25mm. The hole edges should be very thin.

The baffle is very probably in the same place for right angle finders. It should be possible to scale the sizes for bigger lenses with longer focal lengths.

Somewhere to start anyway.

One other thing I can add. The size of the image the eyepiece views is 15 maybe 16mm dia.

John

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Edited By Ajohnw on 18/01/2016 20:35:24

David Clark 118/01/2016 20:26:28
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As well as the Vat on the parcel they include it on the postage and charge an £8 admin fee as well.

Ajohnw18/01/2016 20:46:24
3631 forum posts
160 photos

I've never been charged VAT on postage but have been charged more than £8 for admin. They should charge on postage so no idea why they don't always do that. Import duty is also possible on top of the vat, in fact I think it's added before vat when it has to be paid.

All stupid really. I asked a postman about it once. It seems that they get a lot in that has zero put in the customs value. However there is some indication that certain items are spotted when they go through customs and charged accordingly. Personally I don't mind the VAT but the £8 or more at times for sitting at my PC and paying the import duty and the £8 via a card electronically what ever it's value is really annoys me. It's all very treasure island Britain like many other sales related areas.

Then there are all of the parcels that come in from China that have $10 on them what ever is in it.

John

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Michael Gilligan18/01/2016 20:54:52
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Posted by David Clark 1 on 18/01/2016 20:26:28:

As well as the Vat on the parcel they include it on the postage and charge an £8 admin fee as well.

.

Very true, David

That was my third bullet point, but I deleted it before posting ... because Ajohnw appeared to 'know that already'.

MichaelG.

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P.S. ... For anyone who hasn't yet suffered this form of robbery : here is HMRC's guide

Edited By Michael Gilligan on 18/01/2016 21:01:35

Ajohnw18/01/2016 22:29:38
3631 forum posts
160 photos

This thread has gone a long way from Astromediashop goodies which is a pity really - not that they sell that much astro stuff really.

However people might find Michael's link rather interesting if they can find details in it concerning importing antiques. What I have found the past concerning HMRC's doc's though is that they are seldom complete and specific details may be hard to find.

Antiques - seems to be a good example of what may apply to one sector of society but wont to another.

I imported a 150 year old pocket watch from the USA once to restore. No chance of finishing until I have a furnace to make a new dial.

John

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Michael Gilligan18/01/2016 22:40:13
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Posted by Ajohnw on 18/01/2016 22:29:38:

However people might find Michael's link rather interesting if they can find details in it concerning importing antiques. What I have found the past concerning HMRC's doc's though is that they are seldom complete and specific details may be hard to find.

.

question

Michael Gilligan18/01/2016 23:00:18
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13781 forum posts
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John,

I really don't know why you suddenly raised the matter of importing Antiques, but perhaps this will be of some interest.

MichaelG.

Ajohnw18/01/2016 23:44:20
3631 forum posts
160 photos
Posted by Michael Gilligan on 18/01/2016 23:00:18:

John,

I really don't know why you suddenly raised the matter of importing Antiques, but perhaps this will be of some interest.

MichaelG.

I raised it because unless things have changed they don't attract any VAT at all. Also because I had a feeling that even if there were any charges HMRC's doc's in all probability don't mention what they actually are. I found out that they were zero rated at the time from some one in the USA who asked a USPS agent. The tax free aspect seemed to apply to all major countries in the west.

It's an area that might interest people who collect old microscopes.

Really from my experience if some one wants to know specific details about import taxes it's probably best to phone up and ask them. There may even be different rules for gifts and commercial samples.

John

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Ajohnw19/01/2016 18:22:24
3631 forum posts
160 photos

Just a note for any one who buys lenses from Astromedia. The lenses are coated as they state but that isn't immediately apparent. They are broad band and don't really have any colour at all. Some colour can be seen by looking at the reflection of a fluorescent strip light at various angles. This happens because the thickness of the coatings is what gives them the anti reflection property so at some angles it appears thicker as far as light is concerned and the surface will reflect.

surpriseSome one bought one and thought it wasn't coated. Actually I think it's a fairly high quality coating.

The other way to tell is to compare the reflection off them with a plain piece of polished glass.

John

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Neil Wyatt19/01/2016 19:00:19
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Posted by Ajohnw on 19/01/2016 18:22:24:

surpriseSome one bought one and thought it wasn't coated. Actually I think it's a fairly high quality coating.

What an oaf? eh

Ajohnw19/01/2016 19:38:57
3631 forum posts
160 photos

Actually Neil it looks like things can go wrong. I wanted a best form plano convex lens. The flat side is slightly curved. It's come and it's only coated on one side !

Not sure if that is a one off or normal for this lens. It probably doesn't matter for what I want it for and I have to bear in mind it costed £2.58. Knightoptical would charge me 10 times that plus vat and probably a ridiculous postage price. Cheapest on ebay around £21.

John

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Neil Wyatt19/01/2016 20:52:30
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Now trying to think of an easy route to a 2" tube without butchering my 50mm/300mm scope just in case I find a use for it (guiding?)

Probably end up paying as much for a bit of ally tube as the lens!

N.

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