Upgrade to the Vegemite etalon tuner

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Merlin66
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Upgrade to the Vegemite etalon tuner

Post by Merlin66 »

Well, after almost ten years of use, my Vegemite etalon tuner has been "upgraded"
I replaced the "hand controller" lid with a SW electronic motor...extended the control cable (now 5mtr) to allow me to remotely control the etalon tuning from the office.
I now have control of focusing, scanning and etalon tuning from the office desk.
I had a few minutes (!!) of clear sky this morning, just enough time to image the proms....using the tuner allows the image on the screen to show immediately the impact of the Doppler shift, I could clearly see differences in intensities between the blue and red wing...pretty neat!
Original hand Vegemite control
Original hand Vegemite control
IMG_1544s.jpg (242.23 KiB) Viewed 3604 times
Vegemite_motor_tuner02.JPG
Vegemite_motor_tuner02.JPG (221.19 KiB) Viewed 3604 times
Vegemite_motor_tuner01.JPG
Vegemite_motor_tuner01.JPG (232.18 KiB) Viewed 3604 times
Vegemite_motor_tuner03.JPG
Vegemite_motor_tuner03.JPG (229.5 KiB) Viewed 3604 times
Martin (Q'land) is trialling a similar (but a bit more sophisticated!!) drive system on his set-up.

Recommended to all with front tilt tuned etalons......


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Re: Upgrade to the Vegemite etalon tuner

Post by MapleRidge »

Hi Ken...

The motorized tuning looks great!!!

I find this is almost a must, since the ability to work at a computer and reach the tuning dial is pretty awkward. I motorized my Lunt etalons years ago with unused JMI focus motors and can control them for desktop software. Really handy when I was using them.

Brian


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Re: Upgrade to the Vegemite etalon tuner

Post by Martin_S »

Ken, this is a great mod,thank's for all your help and advice on tuning etalons. As Brian says this is a must do mod.

Martin


H alpha : ,Skywatcher 120mm F8 open frame refractor, a tilted 2" 7nm H-alpha filter as a sub energy rejection filter, Baader TZ4 telecentric focal extender, Player One energy rejection filter, Combo Quark Chromosphere, Naked PST etalon for double stacking, ASI74mm camera
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Re: Upgrade to the Vegemite etalon tuner

Post by Merlin66 »

Martin,
Thanks mate!


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Re: Upgrade to the Vegemite etalon tuner

Post by Merlin66 »

Brian,
Glad you agree!
I would be interesting to hear from others who have adopted driven etalon tuner solutions.


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Re: Upgrade to the Vegemite etalon tuner

Post by Rusted »

Well done but, if you will forgive me for saying so, unnecessarily over-complicated. ;)

This little motor happily drives my 3.5 FT focuser while vertical on my 180mm.
It does so even with the hefty Lacerta 2" prism and ZWO camera attached.

The toothed drive belt slips remarkably smoothly on the FT's fine focusing knob.
This is a real boon when 4" of rapid focuser movement is required. Just spin the direct drive knob!
Most commercial focuser motors deny the user that freedom. [But I digress.]

The structured rim of the PST etalon is similar to a focusing knob and should drive well with a timing belt.
Much of the perceived friction in the PST etalon is from the rubber ring being squashed by the fingers.
Wrapping your adjusting finger and thumb into a circle removes the friction. As would a wrapped, toothed belt.

I just need to make a fixing bracket to fit the little motor on the sturdy AOK Swiss etalon adapter.
This would place the little gearbox motor very close to the etalon.
Without any of the shafting, bearings and drive wheels you have employed.
You could use a tube mounting ring on your scope to support the motor next to the etalon.
Ready for a belt drive and all under slow motion, software control.
Attachments
P1380499 rsz 600 focuser belt.JPG
P1380499 rsz 600 focuser belt.JPG (67.31 KiB) Viewed 3553 times


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Re: Upgrade to the Vegemite etalon tuner

Post by Merlin66 »

Rusted,
When you’ve achieved success....look forward to seeing your actual solution.
The PST tilt etalon is much stiffer than the tilt of an external etalon.
I speak from experience.


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Re: Upgrade to the Vegemite etalon tuner

Post by Rusted »

The mechanical advantage [ratio between the difference in diameters] should help.
If not, a larger radius is easily achievable by mounting a suitable ring on the PST Etalon band.
I'll be back! ;)


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H-alpha: Baader 160mm D-ERF, iStar 150/10 H-alpha objective, 2" Baader 35nm H-a, 2" Beloptik KG3,
Lunt 60MT etalon, Lunt B1200S2 BF, Assorted T-S GPCs or 2x "Shorty" Barlow, ZWO ASI174.
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