Replacement HEQ5 tripod legs

The HEQ5 comes with 1.5" thin-wall steel legs. For purely visual work these are fine as long as you can stiffen them with a lower brace which you can make if you have access to a the shop tools. A better option would be a pier but I think that tripods are better if you are dragging your scope around from site to site. The best way to go if you are buying a replacement would be to get a good wooden tripod such as a Takahashi or AP which is a VERY expensive proposition. Or you can do what I did and make some new wooden legs for your HEQ5. HEQ5 on mahogany tripod Wood Selection The best commonly available woods to use as far as I know are be red oak or mahogany. Better yet would be Sitka spruce but it's not common and very expensive. I decided on the mahogany and bought three boards planed to my requirements. Initial preparation The HEQ5 doesn't have a solid tripod leg attachment point like the Taks or other Synta mounts but has two 'ears' that stick out and the steel legs attach between them. This means that you'll have do some milling to the wood to get it to fit if you want the full width of your new legs to come into play at the attachment point. I enrolled (actually dragged kicking and screaming) Dave Rubenhagen, machinist extraordinaire, in the project. He used his end-mill and a large cutter to round one end of each leg; you'll probably want to use a router table with a 3/4" roundover bit. Then he found the centre of each board's width and milled in two .300" x 1.700" slots .788" from the centre on each end. These slots fit the 'ears'. After 1/2 of the board was rounded over and the slots cut the legs moved to the wood shop. Legs with milled slots In the wood shop The next step was move the boards to the table saw to rip them lengthwise to just over the final width of 2.75" and then cut them off to 43". A jointer brought them down to final width and any 'warts' were cleaned up with a hand plane. When this was done, the legs were moved to the router table and a 3/4" roundover bit was used to finish rounding the top of the legs and a 1/4" roundover bit was used to finish the bottom ends. Legs test fitted on the tripod hub More milling Next the outside wood at the top end has to be shaped so that the tripod can fold. This was done by making a scale drawing of the ends of the legs in my drawing software then creating templates of the needed cuts out of paper. These were placed on ends of the legs and used to mark them allowing us to set up the wood in the end-mill to do the needed milling. Two cuts are needed. One is a 30 degree angle cut and the other relieves .300" of wood the remaining depth of each slot. The process went quick. Dave setup a series of stops and plates on the end mill and did one leg. When the cuts were verified each leg in turn was placed against the stops and milled. Then the legs were turned over, the fences and stops reset and the mirror image on the other side of each legs was done. For the bolt to fit through some sacrificial wood was placed into the slots and an 8mm hole was drilled through the legs across the length. I bought M8x80 stainless steel bolts. Legs milled and fitted to tripod hub The adjuster holes I wanted legs to be able to be levelled so a scheme was come up with to add an 'adjuster' to the bottom of each leg. To prepare for this a two diameter hole was put in the bottom of each leg. The setup to bore the holes (we had no horizontal boring tool) was a bit Rube Goldberg. The metal lathe was pressed into service, Dave took apart one of the tool holders and made a clamp that would hold the leg tight. We used three metal blocks, two thicknesses of scrap aluminum and a hunk of cardboard to bring the leg to the right height so that the hole would be in the same place then bored the hole. We started with a 1" Forstner bit for 2.1" and then a 7/8" Lee Valley Greenwood bit to deepen the hole to its 4" total depth. Once this step was done the cutting and milling was finished so I sanded and finished the legs with three coats of Spar Varnish. The adjusters The adjuster itself is a 6" length of 5/8" stainless steel threaded rod that turns in a brass fitting which would be pressed and glued into the bottom of each leg. Dave machined the fitting .010" undersized then knurled them. This brings the outside of the 'diamonds' to just the right size for the hole. The threaded rod was cut to length with one end profiled on the lathe with a conical end. Dave then machined and knurled a brass locking nut for each fitting and some nylon washers to go between the fitting and nut. Adjuster fitting and threaded rod (nuts not shown) Adjusters in place Spreader pressure plates The Synta spreader (if you're going to use it) has sharp ends which will dig into the wood causing unsightly dents and dimples. These should be rounded slightly with a file. Then make yourself some pressure plates from aluminum or (better) brass. These should be about 2" x 2" square with some counter-sunk screw holes. Screw them in place with nice brass screws. You'll find that with these plates it's hard to have the legs 'centred' on the spreader. Take some 1" nylon bar and cut some 'rounds' at an angle. They should only be about 1/3" deep from the bottom to the top of the round. Then drill some small pilot holes through the brass plates into the wood. Then some larger holes through the brass. Now find the centre of your nylon rounds and drill the larger hole through these and countersink on the top of the round. Screw and glue (epoxy works) these into the centre of the brass plates. You'll have a nice pressure plate and the legs will properly centre on 120 degrees. Brass and nylon spreader pressure plate Lower brace I moved the lower leg brace from the steel tripod to the new wooden tripod. To attach it to the wood I purchased three screw-in rifle sling swivels and positioned them so that the legs, when spread, do not put pressure on the outer parts of the wood at the tripod end but keep the legs from spreading too far. Lower leg brace Performance The mount with the wooden legs and the Celestron anti-vibration pads damps in under 1 second if you give the scope a tap. If you tap the legs it twitches once and stops. On a cement pad without the Celestron pads a scope-tap damps in just over 1 second. On softer ground the performance without the pads would be better. Is the performance better than the steel legs? Yes. Is the performance enough better to justify the cost? Yes, again; but only because they look so darned nice =) Total cost of this project The mahogany cost me $120Cdn. This was dimensioned and planed. If you have access to the tools you can get the wood for about 1/2 the cost. The brass stock cost $55Cdn and the stainless steel threaded rod cost another $25Cdn. The QD sling swivels were $11Cdn and the various nuts, bolts and other hardware cost about $15Cdn. This is about the price of a Celestron CG-5 tripod but is much nicer. An Accessory Tray If you wish an idea for an accessory tray you can look at the one I made by clicking here. Note on function At a recent star party my scope was setup on a very un-level paved path. One of the adjusters was cranked out 4.5" with just 1.5" inside the fitting to hold it. The scope was stable, no vibration and damping in the 1 second range. Materials list Three mahogany boards planed to 4" x 1.5" x 46" 12" of 1.5" brass round stock 5/8" stainless steel threaded rod 1/8" brass sheet, enough for 3 2" x 2" plates 1 1/2" of 1" nylon bar Three 5/8" nylon washers Six 1 1/4" stainless steel M8 washers Three M8x80 stainless steel bolts Suitable finish (Urethane, Spar Varnish etc.) Three QD sling swivels (screw in type) Ten feet of 3/8" aluminum C-channel Six 3/8" chain master links Scrap of 3/8" aluminum plate Library of suitable curse words Tool list Metal lathe End mill Table saw Band saw Jointer 5/8" tap 17/32 drill bit Router table with suitable bits 3/4" roundover 1/4" roundover Lee Valley 8mm HSS long brad drill bit Lee Valley 7/8" Greenwood bit Lee Valley 1" Forstner bit Hack saw Files and sandpaper Files Dimensions of the foot of the leg Dimensions of the adjuster fitting Dimensions of the tripod hub end of the leg Spreader pressure plate Back to the HEQ5 Project page Back to Ozzzy's Astronomy pages