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Help/suggestions needed for mounting Goto HEQ6 mount to existing steel pier


Orion

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https://www.dropbox.com/s/n8b8pe4r7omsfv5/20140420_142305.jpg

https://www.dropbox.com/s/seko1vryfs6gct9/20140330_155935.jpg

https://www.dropbox.com/s/eyzxxaz42yl94gd/20140330_155926.jpg

I am currently trying to decide what to do in the form of upgrading my old equipment to something modern which I can use for astrophotography, controlled by laptop.

The photo shows a Fullerscope mk2 mount covered in weather bags. The equatorial mount (mains synchronous 240v RA and Dec motors controlled by a hand help VFO) is attached to a steel pipe pier concreted into the ground to a depth of about 1 foot or more (in roughly 1x1.5x1.5 foot block).  The pipe top is modified to accept an insert and the equatorial mount. The pipe is either 4 or 4.5" OD but I can get accurate measurement later.

If I replace the mount with a modern equatorial mount, I need help in knowing how to attach it to the existing steel pier.   I have been thinking of considering getting a GOTO HEQ6 which should be capable of taking my existing 8.75" f5.6 reflector (which is housed in a glass fibre tube of approx diameter 10 inches).

If the HEQ6 mount can be bought without tripod, then the mount would need to be attached to some kind of adaptor and the adaptor attached to the steel pier.

I'm not mechanical so I need help in actually doing the work or having it done. I have seen some examples of observer's preparing observatories which show steel piers which have some kind of round flange or square attachment with 4 bolts. Sometimes the attachment looks like two flanges (plates) one on top of each other. I assume the 4 bolts are for adjustment for polar alignment. But I know the heq6 mount itself has adjustors to do the whole polar alignment, so I'm not sure if the 4 bolts are to tweak that polar alignment or for something else - such as simply a way of attaching the mount to the pier but such that the bolts make some provision for keeping the mount level with the ground.

I assume that the adaptor that connects to the steel pier could or would need to be welded on  and to as level as possible.  Then the standard heq6 mount is connected to the adaptor (presumably bolted in the same way it would be connected to the tripod legs?). I assume the adaptor would need lugs to accept the heq6 mount.

I then plan to add the 8.75" reflector to the heq6 and have a guide telescope attached (not sure what but assume an acromatic ST80). 

I would then house the kit in a plastic shed with a hole cut in the base to allow the shed to go around the steel pier base. The part of the base that is cut out will be added when the telescope is not in use (to limit moisture from the ground). And the door closed.  I could weigh down the shed with a sandbag or two - e.g. in case of wind.

To remove the shed, I open the door and push off the shed to clear the scope.  To help pushing off the shed,  I thought about getting some wheels or low castors so it can be pushed/wheeled over two wood runner tracks made from wood sunk into the ground. The reason for castor would be so I would be able to sit inside the shed as a warm room controlling the scope from inside but the scope would be outside.

The idea of castors was such that the weight of me inside the shed would not put stress on the base - the base would be flexible enough to still contact the grassed ground. But I'm not sure if it would work. Wheels would allow the shed to move easily but I wouldn't be able to sit inside it several inches off the ground - especially with part of the base cut out to accept the steel pier. It would just flop under my weight.

I plan to photograph the top of the steel pier to show its dimensions for anyone that can help.  Because there was some time spent on engineering modifications of the existing mount and pier, I feel a bit sad that it needs to be made redundant to allow a way forward for a mount that is far more usuable and productive.  But ive got nowhere with the current mount (not controllable by modern pc. The vfo unit would work by manually peering at a guide star in a cross hair and making incremental adjustments- something I don't fancy doing when modern methods have replaced that).

One other thing that comes to mind is, when the adaptor is welded to the steel pier,  if I were to move to another permanent location, what do I do?  Does the adaptor have to be sawn off, or the bottom half left on the steel pier and the top half removed and relocated elsewhere?  (leaving the steel pier in the ground redundant).

I think I can get welding help but if not, can anyone help or know exactly what to do?  I can't picture what such an adaptor would look like and whether they are commercially available to accommodate exactly what I was aiming for. There must be heq6's mounted atop steel piers rather than on tripods. I have not asked this question to someone like FLO who may know - and I could approach them.

I have not bought an heq6 (or neq6) yet because I am still considering options. Originally (and still am) I was considering an heq5 with 80-102mm apo frac and st80 guidescope - that system being lighter weight than an heq6,  and portable for dark sites on occasions when I might take it out.  But if I get an heq6, it would be limited to being permanently sited on the pier, housed in the plastic shed (with or without the 8.75" reflector attached. If it could clear the shed doors, then the reflector could stay on the mount, with a bit more weather proofing of the scope).

I think the setup described would allow me to use my existing 8.75" reflector for AP with a DSLR (thro the scope or piggy backed); and as a visual instrument with the goto control allowing more productivity (I've done enough star hopping and it was too time consuming to find objects).

I assume an heq6 would take my 8.75" with a guidescope. But I think I would need a set of cradles that would fit onto the heq6 mount. My existing cradles may not fit the heq6? But it's probably a minor issue.

If my 8.75" scope won't be usable for AP, I would then think about an apochromatic 80-102mm frac for the heq6 housed in the shed. But I can't see any reason the 8.75" would not be a good scope for AP.

I am still considering the additional option of a goto heq5 with 80mm apochromatic frac and st80 guiderscope. But that setup would not be housed in a shed (tripod legs would not clear the shed door for a permanent siting). But instead, it would be portable and placed in the garden with controlling leads into a warm dining room or equivalent.  Or in the worst situation, just use that setup outside.

Any help will be greatly appreciated

Thanks

Derek

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Derek, sounds good.

I'm no expert on any of this, bit some thoughts until someone who knows what they are talking about comes along.

The two mounts i think you are toying between are the:

HEQ5

NEQ6

The names are odd and i have no idea what the letters mean, and why they just don't keep the naming simple.

I suspect if you want to mount an 8" newt, AND guiding set up, you need the NEQ6 else you'll be pushing the limit (or over) with the HEQ5. The AZEQ6 (which i have) is lovely, and i think has a slightly higher payload capacity than the NEQ6, and already has some belts inside, and much better altitude adjustments, and encoders, but second hand they are going for £950 or so compared to £650-750 for the second hand NEQ6.

You can get pier adaptors which can convert something odd into a mount connection (no idea of the terminology). Graham would be able to make you something i'm sure.

You can buy steel piers, altair astro sell them, and again you can screw on the top an adaptor for your specific mount. There are pillars too which are like piers but can stand alone and not necessarily fixed to the floor.

I know nothing about the sheds, sorry.

Good luck.

Jd

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hi Derek,


i think if your going to do astrophotograpy and you can afford a neq6 then that's the mount to use, carrys more weight than a heq5 so you should never need to upgrade the mount again.


next the pier, if the metal pier you have already is fairly thick then you should be able to weld a metal flat plate horizontally onto it then another above separated by M12 bolts then a puck mount as surgested by James above which will need bolting to the top plate,


please see my pier build as it might give you some ideas,


http://www.robslack1.webspace.virginmedia.com/Pier%20Build.htm


then a st80 with a cheapish guide camera is the only other thing you`ll need to get going,


use eqmod to control the mount, excellent bit of free software and if you using active usb cables you could sit in the house or somewhere warm while your imaging, really simple to do, i know i did it.


as for a roll off shed to cover the scope i would have a word with Ron, he has done something very similar with his set up.


Edited by red dwalf
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Hi

Rob and James. Thank you for your help. It's these kind of replies that is helping me to learn.

I cant remember the thickness of the steel pier. It's a piece of steel gas pipe. Ill get thickness and report back so you can say if it's thick enough. I'm not sure of what precision adjuster exists on the neq6 for e/w adjustment. My existing mount has an insert tbat sits inside the pipe and the mount sits inside that. The mating faces are something like bronze and greased. With a steel bar screwed into tbe mount, I can use it like a periscope handle and move the mount east or west with incredibly smooth precision - possibly a tenth of a mm. It might be possible to retain that to accept the neq6, I dont know. I hope that the e/w adjustment on the neq6 is fine and smooth. Thinking it was on a tripod, I thought the e/w adjustment might have involved physically lifting the whole mount and tripod to rotate it e or w. But if it was on a pier, then the only way to move it e or w would be to rotate the mount. So I assume a nice smooth adjustment facility exists. But if you imagine the way a periscope rotates, that's how my equatorial rotates for polar alignment. The n/s adjustment is poor though - one course polar nut without any micro ajustments - loosen the polar night and I have to just crack it or else the whole mount can come down several degrees.

I saw something very similar to the adaptors in one of your links, sold by Billetparts but I couldn't see how tbe bottom plate of the adaptor could be attached to the pier. I now need to photograph the actual mount so you can see the insides (underneath the mount cap that takes the equatorial).

I will follow up suggestions. This type of help will get me more productive in starting some kind of action plan once I see where I'm going.

I would still consider an heq5 for portable applications but if the neq6 gets me there with my existing 8.75" NR, then I would be productive quite quickly. I'd possibly need a new focuser such as a motorised one or a lockable manual focuser. My current one was made by Ron Arbour, and is a 2" low profile focuser based on a helical screw. The main potential problem with that is, to fine focus, the camera would rotate whilst turning the helical focusser. But once focus is done, it can be locked and the camera rotated to any angle 360 degrees rotation (without changing the focus position). This focusser might still be a decent one.

I'm due to see the heq5 at Martyn's but not yet arranged. Ive seen Kim's azeq6 but cant remember its adjustment facility.

The bolts that Rob mentioned. Are they just to connect the top and bottom plates only and not to use to tilt the top plate (inc mount) relative to the bottom flat plate? (I.e., not for polar alignment)?

Thanks fellows

Derek

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PS. I've just read Rob's web link showing the photos of the mount pier adaptor. It all looks good. Can't say I understand all of it though with not being mechanical. But the clear photos are very informative. Rob - you mentioned operating from the warm house. Would this still be possible for me - my dining room is probably about 6 -6 foot fence panels from the scope pier. I heard long leads don't work well? But there is always the option of the shed as a warm room (providing it CAN be made warm).

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Derek

These are the upgraded azimuth (e/w) and elevation (n/s) bolts on the Neq6 which most people use:

u2uruny9.jpg

The ones left and right (angular bolts) are the elevation bolts, and you can only see one of the azimuth screws ( the round one) as the other is the other side of the mount. The action is fairly smooth as they rotate to allow you to polar align; the elevation bolt moves a joint within the mount head, the azimuth bolt rotates the mount head on the puck (the blue thing below), using the upright peg as a leverage point:

na4e7ute.jpg

As rob suggests, and i'm no engineer, you should be able to weld a flat top plate onto the top of your pier and use that to bolt on another plate above, which would be home for the puck or maybe an extension tube then the puck:

uda3y3e6.jpgretupeje.jpg

But again don't rely on my half baked knowledge on this topic, rob is much more knowledgeable on this as he has been through it all and got the t-shirt.

I am using 15-20 foot active USB leads and don't have any problems, and use a 20 foot ethernet cable to use my handset from my conservatory (my warm room) as i've not yet stepped up to using eqmod. My data transfer is rapid frame rate planetary stuff and it works ok, so i guess (and it's only a guess and you should talk to the computer people like stephen, leigh, daz etc) about using longer active cables or more than one active cable to transfer longer exposure images and mount controls and guiding changes etc if you plan to be 6x6ft away.

Jd

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you can buy 5 meter active usb cable, active cables boost the signal so don`t loose it over a long length, you can daisy chain up to 5 together making 25 meters in total or you can buy them in one long length but as a single cable they are alittle more expensive the longer you have it of course.


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James and Rob

Thanks for these photos and info. It's great help. I was looking at a £250 plastic shed today. But the base is very thin material, so wouldn't take any weight standing or sitting in it if it was raised even an inch by castor wheels. The base would just slump. Also, if a cut was needed to go round the pier, the base of the frame at the door would also have to be cut, which would weaken the frame. I wished I knew mechanics! I'm going to go to Wymeswold tonight so might see you.

Derek

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Hi Derek, I have a 'roll off' obsy, a wooden one and although I cut a 'U' piece out for the pier, I made a small flap to close behind the pier to keep it's integrity. Just open the flap, push the shed away and 'park' it (it's on rails!) then close the flap again until finished observing/imaging!!


Going tonight if you want a chat about it?


 


Ron


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Hi Derek


The solution to your problem is simple and straight forward.


If you send me the measurements of you steel tube I can make you an adapter that will fit into the top of it.


All you will need to do is drill 3 holes into your tube to match the fixing bolts holes in the adapter I will supply.


Of course I will need to know what mount it is going to fit as the EQ5 and EQ6 are different.


Graham


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  • 2 weeks later...

Hi Derek

The solution to your problem is simple and straight forward.

If you send me the measurements of you steel tube I can make you an adapter that will fit into the top of it.

All you will need to do is drill 3 holes into your tube to match the fixing bolts holes in the adapter I will supply.

Of course I will need to know what mount it is going to fit as the EQ5 and EQ6 are different.

Graham

Graham

Sorry for the delay. Thanks for this. I need to photograph the top of the pier and make measurements. I did this some years back but can't find the photos that show how the thing goes together. If I find them, I'll be able to send or link to dropbox.  My present mount has an excellent E/W motion, very smooth. It would be a pity to loose that part because it would be another way of adjustment for polat alignment - in addition to the existing polar alignment facility in the NEQ6 - which I don't have experience of, nor understand whether the NEQ6 adjustters are course compared to the existing adjustment on my mount.  The steel pier has part of the inside wall cut away making it's wall thickness reduced. Now, I don't know if that thickness would be OK for welding a plate on top or whether it would have to be cut off.  But the present mount actually sits inside the steel pier tube.  I must get this kit photographed so all can see. I am still toying with an HEQ5 or an NEQ6.  The HEQ5 would not be OK for an 8.75" reflector, but an NEQ6 would.  But it would not be portable. An HEQ5 would be portable, but I would have to buy something like an apochromatic 80mm ED to go with it.

 

I've also been thinking about the 8.75" f5.6 reflector on a NEQ6 for AP.  I remembered doing ray diagrams years ago and the fully illuminated cone of light at Newtonian focus (prime focus) was only about 0.25" diameter. One would need a fully illuminated cone of at least 1" to cover what was the minor axis of old 35mm film (24x36mm), or an equiv DSLR chip (I assume they are full size these days equiv to 35mm film?).  I'm not saying that there is no light outside of the diameter of the illuminated cone - there is but it's not 100% illuminated. This means, if we had a line of stars all of equal mag from edge of field, thro the centre and to the other side, the middle stars would be brightest and the outer ones would be less bright.  To get round that, the relative position of mirror and flat can be adjusted.repositioned to get a bigger fully illuminated cone. But only to a certain extent. The better way is to use a bigger secondary flat, which I have a 2.5" one but no suitable mount for it. The present flat is much smaller.  Of course, that's a side issue of using the NR for AP, but I thought I'd post it. The alternative is to abandon the NR for AP and to buy a refractor.  I don't know if refractors have the same fully illuminated cone issue as do reflectors. 

 

I'll be in touch on measurements, and discuss more.

thanks

Derek

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Hi Derek, in not sure why you believe the NEQ6 to not be portable? I put my neq6 mount head in a pelicase 1600 flight case and it is not difficult to put into the boot of my car to take to dark sites. I wouldn't rule out the NEQ6 just because it's a little heavier. Just my opinion :)

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Hi Derek, in not sure why you believe the NEQ6 to not be portable? I put my neq6 mount head in a pelicase 1600 flight case and it is not difficult to put into the boot of my car to take to dark sites. I wouldn't rule out the NEQ6 just because it's a little heavier. Just my opinion :)

 

 

Hi

 

I always used my old NEQ6 as a portable set up.  Everyone will tell you i used to carry it mount and tripod complete into the field together.

I am 5ft 4 ins and weigh 65kgs,  I did not find it bad at all really.  My current mount is heavier and I manage that OK too.

 

My 6 was just put in the boot as it was and other stuff packed around it.  Dont rule it out  as weight wise its not that bad at all :)

 

 

Sheila

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  • 5 weeks later...
Hi

 

I always used my old NEQ6 as a portable set up.  Everyone will tell you i used to carry it mount and tripod complete into the field together.

I am 5ft 4 ins and weigh 65kgs,  I did not find it bad at all really.  My current mount is heavier and I manage that OK too.

 

My 6 was just put in the boot as it was and other stuff packed around it.  Dont rule it out  as weight wise its not that bad at all :)

 

 

Sheila

Thank you Sheila. Sorry for the delay, have been busy, ill, busy, rest, holiday. I won't rule the 6 out. But if I get one, it's likely to go on an external permanent steel pier - hence the talks and questions about how to mount it on an existing ~4.5" gas pipe sunk in concrete. Hope the imaging is doing well. Not much dark at the moment though. Derek

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Hi Derek, in not sure why you believe the NEQ6 to not be portable? I put my neq6 mount head in a pelicase 1600 flight case and it is not difficult to put into the boot of my car to take to dark sites. I wouldn't rule out the NEQ6 just because it's a little heavier. Just my opinion :)

Felix. Thanks. Haven't ruled it out but looks too heavy for me. Probably go as a permanent mount and I might get something else smaller for dark site (or use your scope ;) ) Derek

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Hi Derek

The solution to your problem is simple and straight forward.

If you send me the measurements of you steel tube I can make you an adapter that will fit into the top of it.

All you will need to do is drill 3 holes into your tube to match the fixing bolts holes in the adapter I will supply.

Of course I will need to know what mount it is going to fit as the EQ5 and EQ6 are different.

Graham

Graham. Time goes so quickly. Been ill, busy, holiday, relatives visiting etc. I still need to get round to photographing my mount pier. Sorry about delay. I can rarely keep up these days. I'm still unsure of my f5.6 8.75" NR for AP with DSLR. I don't think the fully illuminated field projected at prime focus falling on the DSLR chip would be big enough with the small secondary mirror. The field would probably be less than 0.3" which means the rest of the chip would be wasted (it would receive light but not 100% from the whole main mirror, only a percentage. The %light outside the fully illuminated field falls off from the perimeter of the 100% cone. I think I'd have to get a bigger secondary, change the position (raise) of the primary (limited), shorter draw tube (already low profile) or combination. What do others do using a reflector? Is their secondary mirror sufficiently large enough to produce a fully illuminated field diameter at least equal to the chip major length (or even the minor width)? Derek

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