Ok, I got my 144s. I had a number of alternatives for mounting:
1) Joustmounts - $219
2) Aluminum machined sleeves - $240 approx.
3) TAP Plastics rings $220
4) TAP Plastics Joust knockoffs in acrylic ~$85
5) PVC Pipe ~$25
6) MDF cut rings ~$7
The requirements for mounting seemed much easier to understand once I had the lenses in hand and could see the problems directly. I was struck by what was a problem that should have a clever and easy solution. After going through a bunch of alternatives listed above, and reading what really elegant solutions others did, I was determined to come up with something simple, cheap and easy.
So, I went to the internet and researched PVC pipe standards. I found that Schedule 40 PVC 5" pipe (5.016" ID 5.56 OD) was amazingly close to what I neededfor a barrel that extended the full length of what had been the original mounting sleeve. I really needed about 4.87" ID and 5.43" OD (approximations). I was SO CLOSE. Then it hit me. Run a blade cut or two the length of the tube and it compresses down to very close to the right size. If the tube had a wall about 1/16" thicker it would be spot on. I think I will make that up with plumbers heavy tape between the lense barrel and the PVC.
The front of the lens mount for HD-8s is wider than the rear by about 1/2". To fill that gap I bought a Schedule 40 5" PVC pipe coupler and sliced off 3/4" rings. This also needed further mods. You slice about 3/8" out of the ring and compress it to fit around the smaller diameter PVC barrel. This material came with raised lines on the outside that had to be filed down to fit.
That brings me to the current state of the project. I placed the lenses in the 1208s/2 last night. Since I did not have the plumbers tape on the rear end and there was a lot of give. I was able to do the full set up but that brings us to the next challenge, the screw stays that hold the lenses in the lens mounts.
Here is my plan for today. The lens screws for these lenses have self tapping screws that work well in plastic. I am going to drill out the PVC pipe to accept these screws. I will mount the lenses with plumbers tape to solidify things. Once it is dark I will try the critical lens focus tasks and see how well the screws hold. The alternative would be to look for tubular washers that match the width of the lens screws and use the original holes. I really don't want to do that.
I will upload pics when I get a chance. Warning: They are NOT pretty. I don't have the proper tools to do the perfectionist job others have shown here. Cutting PVC with a Skillsaw is not very precise. I highly reccomend a band saw to get really clean cuts. Also, the PVC pipe looks dirty. I washed it but stuff gets in deep to the material. So the cuts are rough (though not critical). The most iportant thing is that it works, is easy to do and cheap.
Supplies: 5" PVC is is VERY hard to find unless you know where to look. Everyone stocks 4" and 6". It turns out that 5" is a standard for well casings. Find someone who does wells and you will find the pipe. If you are lucky they will give/sell you 18" so you don't have to buy 20'. The price is usually about $5/ft. The coupling cost me $18.
Some don't like this approach because they lose the mounts for the HD-8s. This means you can't seel them on eBay. Well, many have been trying to sell HD-8s on eBay with no takers. Who wants them? If anyone is going to want them is will be to replace scratched lenses. It is actually easier to sell them without mounts and have them just remove the adjustment screws on the set that is mounted, than remove the 4 hex screws on the mount. So someone can STILL sell them on eBay if you really think there might be a taker.....not likely....it is a market flooded with HD-8 lenses made orphans by HD-144/5 conversions.
Well here are the first pics. The original plan had two narrow rings, one 1X and one 2X thickness. I modified that to be a 1X thick sleeve just shy of the original HD-144 mount length (~4.3") with a 3/4" collar made from the 5" PVC coupler. I realised a couple of problems wit that. Mounting the lens set bolts, they need to be just under the surface of the lens mount slot to function and there would be more stability if the thick section ran deeper into the space. So, I recut another section of the couple ~ 1.75" wide.
Fitting brought new headaches of course. The HD-8 mount narrows slightly inside as you get deeper. The lens is widest at the front. This made for an excessively tight fit for a piece that is intended to slide. So I sanded the inner ring near the widest area which helped. I need to do more of that. I want to see how the blue lens focuses tonight. Last night I had problems with it and with the image on the tube. I thought it might be fungus but on inspection it looks really clean. So either the EM focus is off or I need to be really careful with the physical focus.
I have to buy another coupler to make two more wide rings (~1.75") since I used up a lot of the couple already making the 3/4" rings. These should fit better anyway since there is tapering on the coupler that is exacerbating the problem with the fit.
I plan to paint the edges black and probably use plumbers tape between the lens barrel and the inner sleeve to close any clearance issues. I will need to sand a bit more to make rotational travel easier for the main focus.
I said in my first post that it wasn't going to be pretty. If I had a band saw I could make much nicer cuts on the PVC. A belt sander or grinding wheel would have made cleaning the ribs off the outside a lot easier. But it is what is is so far.