Jump to content

Stargazers Lounge Uses Cookies

Like most websites, SGL uses cookies in order to deliver a secure, personalised service, to provide social media functions and to analyse our traffic. Continued use of SGL indicates your acceptance of our cookie policy.



  • Content Count

  • Joined

  • Last visited

Community Reputation

11 Good

About izakimak

  • Rank

Profile Information

  • Location
  1. Davies and everyone else. Sorry this has not been updated for such a long time. I have a good excuse ..... I nearly died :-). Puts a bit of a crimp on things. Maybe as this year goes on I'll get back up to speed on the project. Still have a large hole in my garden for the foundations. Kind regards.
  2. One bit of snow and we have a game of "name that can crash". Anyway, price for 10 piers being made work out at £216 each.
  3. On my way home. Allegedly the prices have been emailed. Give me an hour and I'll post them.
  4. Your correct there. Good to do away with them completely. As long as the pier is pretty much level, I may fix the mount in such a way that there is no gap between the plates. This would allow removal by separating the plates. Best of both worlds. However, if the foundations of the pier sink one side I can then use the bolts to level the top plate. Remember that the mount is designed to work level and with a balanced load, but I can't see a couple of degree's or a bit of odd balance being any real issue. Still awaiting prices by the way.
  5. Price ... I'm seeing the engineering firm today (for other things as well as this). Height is 670mm from the bottom of the base plate to the top of the top plate (cunningly named that one). The adaptor plate is a futher 55mm from the top of the top plate to the top of the adaptor plate (this obviously can be changed with longer bolts).
  6. Take a look at version 2 (all measurments are below are approx, and don't account for any painting). Extra holes in the base. All plates are now 12mm (thanks Steelfixer). Base plate 400mm diameter. Top plates 222mm diameter. All holes are 16mm. Just need to decide on how to approach the mount adaptor. ZAKALWE - your correct, to much worry about things that have an incredibly small chance of happening. I have a simple belief ref "over engineering", it doesn't exist. You either are being wasteful or, in your mind, covering the following to what you are happy with. 1: The pier should be strong enough to exceed to breaking point of things attached to it, plus someone walking into it. 2: Then be stable if it, or things attached, do have some external force applied. 3: Then "look" right, you have to have confidence in what you are using. To be honest, my scope on a 50mm post probably wouldn't collapse, but might be a bit "flexy". Just my thoughts.
  7. Hi Gina Certainly would be cheaper. I want to be able to remove it, otherwise concrete in cardboard would be the way to go.
  8. Good morning everybody. Quick call to the engineering firm (they start at 6am) for a little more clarity. The 150mm square tube gets the extra benefit of the corner material. Measure across opposite sides we get 150mm (as expected). Measure from corner to corner and we get over 200mm. If we take the perimeter of the square tube, with 10mm radius corners, the perimeter is 583mm. The round tube is 471mm. We need to use a tube of 185mm diameter to pretty much match the square section. Assuming that either round or square tube is used, perimeter is king. Rectangular material would be very good on one plane and very bad on another, so not recommended. I found that Pier Tech use square section. Look at their site and the Pier Tech 4 system. Massive unbalanced scope at a serious angle of dangle. That's how it's been explained to me. In general, round is a bit cheaper, looks better and, for the same result, is not as wide when measured across extremes (150mm diameter, square section os over 200mm corner to corner). Square is better (diameter to width) in flex and welds, brackets easy to weld on, looks industrial (not good) and will be a bit bigger from corner to corner. One thing we haven't mentioned is wall thickness. Thicker is better, but you try and lift a 1000mm x 150mm x 150mm solid steel bar!!! However, at the other extreme, would you mount your gear on a tube with 0.7mm thick walls? No thanks. Mine will have 5mm walls and 2 people to carry the final assembly. One of the most important things is cost. I'm fortunate that they use 150mm square tube all the time. This makes it much cheaper. If I was to buy and cost not an issue, I would go for large diameter round. If you can source large size scrap material, go for it. As for the pier to concrete bolts, nearer to the tube the better if using 4. The extra outer 4 that I will use just maximises the base to concrete clamping. Make a scale model of this pier out of paper or thin card and then blu-tac it to a table. A quick push around will show the base flexing. I come from the time of Blue Peter! The guy on "Cludy Nights" has produced a good article. I love the bit about not hitting things with a hammer ..... so true. Here's the next issue .... what to fill it with? I'm going to use the spray/expanding foam as it's not dense and will protect the interior from corrosion (along with paint). I've read that anything unsupported (e.g sand) will turn the pier into an upside down pendulum. It will have a low frequency "ring" which could take a long time to settle. Got to go to work now.
  9. I've got some professional science applied to piers now. The engineering firm kindly simulated a pier of 1000mm (mine will be 700mm) tall. The simulation compared 150mm round tube and 150mm square attached to 6mm bases/plates. All based on thier lovely computer system that can simulate the stress on complete, large, multi component assemblies. Conclusion: Square tube outperformed round by about 30% in flex. Had to go up to over 180mm diameter round tube to get it to similar level. However, diameter/perimeter is your friend, and if you can go larger all well and good. When it comes to welding, the square tube was 20% stronger when attached to the base than the round. This is due to the larger perimeter that the welding acts on. As for cracks in the welding on the corners. They have never seen it happen. As they said, square tube of that size isn't square, it has radii on all the corners (5mm inside radius on 5mm thick material). Sharp cornered material, only welded on the corners, may have issues, but would be a silly way to assemble something. When I showed them the full assembly, with the adjustment plate/bolts (on top), they put it into the simulation. It showed that any adjustment system based on bolts through the top plates will cause a much greater uneven load issue than using square tube ever would. Keep the bolts close to the tube or flex in the plates will be worse. Also, keep the bolts and gap between the plates as short as possible. Plate thickness is simple, thicker the better. Base plate attachment to the concrete base was interesting. Bolts near to the outer edge allow the base to flex between the bolts and the post. Bolts next to the post allow less flex in the base plate, but still showed some. Using 8 bolts, 4 inner and 4 outer was a vast improvement on both of the other options. Bolts to use for pier to concrete and pier to plate, M16 is well "over engineered". Also, bear in mind I'll now be using 8 of them for the base. Now assuming the welds are "average" or better, they said they could attach this pier to the side of a building, and assuming the wall doesn't break, I could easily hang my car on it (E320 estate Merc). Now dealing with wind load, avoid beans! Seriously, if the wind is strong enought to break the pier/mount in any way, you wouldn't be outside imaging. Think of road signs, 1 or 2 three inch posts holding a large "sail" of a sign, and the only parts that break in very strong winds are the parts that hold the sign to the post. The strength issue is with the parts of the scope. The bolt holding the mount to the pier, dove tail, bolts holding scope to dove tail and scope rings will all break a long time before the pier. As for the loading cause by the scope (we assumed 50kg), it's straight down the tube. Again, I could park my car on it without issue and have no notable compression. Think I've covered eveything. The changes I will make will be 12mm (they carry 12mm as standard) thick plates, a slightly larger base plate to allow the 8 anchor bolts and modifying the mounting point on the actual mount to accept 4 bolts to hold it to the top plate. Price unknown until new drawings are produced.
  10. Hi Graham Thanks for the reply. Rain away, I'm all for getting it right in the first place. The worse job you have to do is put right what you got wrong. Been doing research on these piers and found that the material thickness on "off the shelf" units is less than mine. The Altair Astro unit (for 16" Cassigrans on an EQ6) is only 6 mm thick for the plates and uses 16 mm bolts. Their bolts are also further from where the plate meets the post, so this allows any flex to be greater. It uses a 6mm 325mm diameter plate for the base, mine is 8mm and 300mm. The fact they use ribs near the base changes the loading to almost a square tube effect. Regards Nigel
  11. Hi I'm going to get one of the attached made. 210mm diameter top plate, 300mm bottom/ground plate, both with 16mm holes for attaching. Both plates 8mm thick. Post is 700mm x 150mm x 150mm with a wall thickness of 4mm. All unpainted mild steel. Even I can use a paint brush! Two questions: 1: Good for an EQ6 with a Skywatcher 250px attached? 2: Anyone else want one, as getting several made at the same time would be cheaper per unit than one? If enough are interesed I'll get a bulk price. It should be easy to have a custom lenght of post made, but the plates/holes are the sizes above.
  12. Can be difficult to find the ones that do small jobs. Depends where you are, but Littler Co ltd. in Leighton Buzzard take on "saturday morning" jobs. However, it does depend on their current main workload.
  13. Have to agree with the bacon sarnies. With melted cheese. And onion. And a bit of brown sauce ........ Mmmmmmm bacon. Hot dogs work well.
  • Create New...

Important Information

By using this site, you agree to our Terms of Use.