Chriske

We developed a very (special) test to see how strong these printed tubes really are. And with success I might say. The first test was a load of 75kg and a second was about 95kg. There was no deformation at all and the three parts could be screwed loose without any effort after the test. This is our very special setup...🤭

One of the printed versions of this Delmarva Schief project will look like this. The printer of this builder only allow 180mm high prints. So the secondary tube needs to be printed in a few parts and connected with threaded inner rings. He already printed and tested a few parts and it is incredibly strong and stiff. Each of the inner connecting rings has it's correct baffle on board. That makes these parts even stronger. Together with the special zenith prism it will look like this. It is the one I drew and posted here earlier. Maybe, just maybe he will draw his own. I'll ask him...

I need to make some time to print that focuser....sigh...! This very moment I'm busy building a Delmarva Schief. A few others of my ATM team join me in that quest. At the same time I'm building, together with another team, a 'full scale' model of Wall-e. And I'm also working on a 1:33 scale model of SLS Block1B Crew. Just finished Printing all parts of the Solid fuel boosters ready to assemble. When aal is done I also build SLS's LUT. The complete assembly will be almost 4.5m high. But hey, I'll reserve one of my printers to print your designs. So go ahead and post that latest Helical(STP)

Meanwhile a 'special' laser collimator(yellow) is in the making. The laser beam is not in line with the eyepiece, it is with the rest of the scope.

Because this Kutter has a tilted focal plane the eyepiece needs to be tilted 3°93 forward. For this I designed a special Crayford focuser in which a zenit prism is integrated. I also need to construct a special lasercollimator to compensate for that tilt. A regular laser collimator is useless in this scope. Laserunit not yet in drawing, only the red beam. The black tube is in fact the 'eyepiece barrel'. Because of the optical design I cannot rotate that barrel in it's Crayford. I probabaly will add a notch of some kind so the barrel is fixed in its correct position. Same for the laser collimator. It only has one possible and correct way to be inserted in the focuser. It already has that notch in the drawing.

Still busy planning, drawing some more and already made a few testprints. As I said before I already have a wooden Kutter but the others need to make their scope. One more joined the group, so that leaves me with 1 set of optics. So in total : - a wooden will be made(mine) - a second one will make the tubes out of aluminium - a third will make a it's tube and wedge out a combination of wood, printed parts and a few sheets of acryl. - the last two will be (almost) 100% printed. Almost because internally the printed parts will be reinforced with smooth or threaded rods. So in the end these scopes will be as stiff and strong as the other versions. Except for the collimation bolts no other metal part will be visible in these two scopes, that is the plan.

I use(d) these brass backlash nuts all the time in my 3D printers beds. Recently I removed the smaller part and the spring of these units, because not working properly on my latest printer 300x300x500. I screwed a 1kg steel disk under the heatbed instead. Backlash problem solved.

I also have a idea to eliminate backlash on this focuser.

I take that as a yes...😉 And if my dual speed system is approved by you we call it Velical-C...

Thanks a lot..! I only need a proper name for your design. Credit where credit is due..! What about 'Velical' focuser..?...😁😉

It' only now that I see these printed rings are sold for 233€ ....😳. That is INSANE...! Did a simulation and that very same ring cost me about 2.5€ and on top of it I made it far more thicker then teleskop-express's ring. https://www.teleskop-express.de/shop/product_info.php/info/p14170_TS-Optics-plastic-tube-rings---made-to-measure-for-tubes-up-to-180-mm-diameter.html

I'll have try with your non rotating helical focuser if I'm allowed to...?

Vlaiv, have you considered adding a dual speed knob yet..?

If I may... A bit more travel, say 30mm (maybe even more) would be better imo. The eyepiece barrel OD is 36mm, the upper ring hole is 36.2, that might be a little bit tight. Glueing a few sheet of very thin copper should eliminate that roughness while focusing. Thickness about 0.05mm. Something like this.

Never mind, I just read from your last post : ...but when I designed the thing ...

one more question about this Helix focuser. Is it your idea and or is it some-once copy..? If I use this focuser in a concept I like(must) to tell other people who designed this nice little 'thing'. 😉

There's a extra ring, green in my assembly, what does it do..?

👍

😉

Another thing, I was able to open a few FC files, but there are to many, don't know which one to pick out of these list of 62 files Could you please convert the files I need to STP format and send me these instead..? Thanks

Well no, for this I need to install a very small nozzle, 0.2 or even 0.15 or so. I'm used to print very large things with big nozzles, up to 1.5mm, and fairly smooth I might say, but never tried to print very small things. It needs a complete other set of settings to print these small things compared to my usual work...

If you decide to use these I'll send a few. OD 18.5mm

OPITEC https://www.opitec.be/index.php?lang=3&cl=search&searchparam=catreal%3ATandwielen

These are very strong, Nylon. I always enlarge the holes to 5mm. 10pcs 3.85€

15€...???😳😳😳 I buy a set of 10 for just a few €s