An Affordable Modular Rotary Evaporator

Alright, got new bearing today and ran some trials! Results are in and two more pictures were taken. I was actually surprised the rotary evaporator beat out the vacuum distillation in all of the trials. Though it was close where there was more solvent per surface area.


This is it, The project is done.

Edit(woelen): Removed uploaded file, it is replaced by newer version on request of smaerd, which can be found near the end of the thread.




[Edited on 25-5-14 by woelen]

Thanks for letting me know I'll try and put them in another way
Does the PDF work?

Edit(woelen): Removed uploaded file, it is replaced by newer version on request of smaerd.


[Edited on 25-5-14 by woelen]

Quote: Originally posted by smaerd

I think this is actually the last one

The design is still holding up and working fine . Hasn't been used a tremendous amount of times but has removed some liters of solvent now of several varieties. If I had to improve on this design here is what I would do and may very well do in the future. Have to comment and say how refreshing it is to want solvent to be evaporated under mild conditions and 10 minutes later be back at work.

I would use a servo motor to drive the rotor. I would have a thermostat going into the bath. I would use an arduino microcontroller to read out the bath temperature and an LCD to display this information as well as the RPM's. I figure it would cost another 60 dollars or so but would provide very similar functionality to a commercial rotary evaporator without too much more work.

[Edited on 18-5-2013 by smaerd]

A couple suggestions

Hi there,
Really, a very nice and ambitious project. On that theme, well done.
Now, a couple suggestions.

You've clearly identified the biggest challenge in this project, and that is the rotary vacuum joint. Unfortunately, it is the weakest part of your write up. I've looked through countless (as in...."too many to bother counting" ) pdf's that you've uploaded, and not one of them actually shows the connection to the distillation column with the clear tube. You come close, but no cigar!

So, I'd suggest the following. First, get a moderator to delete all but your final version. I suspect more than a few have download some, but not all of your files. The second point would be to include a photo of the link between the condenser assembly and the teflon ball joint as it attaches to the aluminum tube.

Finally, it would really add to your instructable if you actually diagrammed, in a linear fashion how all the parts fit together (including the vacuum line and the ground glass flask that goes into the water bath). Ok, if you really want to polish it up, replace that out of focus picture of the teflon/ground glass joint adapter! I think I see some o-rings....but I'm not sure

Anyway, please don't take the above as anything but constructive criticism. I think you've accomplished a lot.

Oh, the following patent refers to the Yamato Scientific version of a Rotovap sealed joint. Very interesting. US005919339 dated July 6, 1999

My experiences with Rotovaps go back to my grad Chemistry days in the early 1980's. This may be a way more modern version.

Nitrous

I agree with Nitrous, The vacuum joint is not clearly defined at at, yet it is the most critical aspect of the design. It would be super nice if you posted a close-up picture if it!
That being said am really liking what you are doing here, I have been thinking about building a rotovap for some time and your document is definitely going to help!

Keep up the good work!

Hey Nitrous2000. Really sorry I will request a moderator to get on that. I will take a picture of the connections and diagram it more appropriately. It still is running to this day. I have to admit the vacuum seal is not perfect and the set-up is kind of crude. There is definitely a better solution but mine was to take the ground glass ball joint and 'mate' it with the teflon ball joint using some faucet grease to create a seal. A ring-stand clamp holds the ground glass ball joint into place I'll work on that either today or tomorrow.

Edit - Okay asked Woelen if he would be so kind as to remove all of the attachements except for the final one. I have a bad habit of editing things a hundred million times .


Edit(woelen): I removed all uploaded versions, except the last one. For all other versions I placed a remark in the message, telling that there is a newer version.

[Edited on 25-5-14 by woelen]

Hahaha, That's amateur science for you. A list of never ending projects. The trick is to start them while another project is nearing completion. Things do get done and before you know it you'll be so consumed in things you are still working on that you won't even recognize how much you've built/accomplished. At one point I didn't have a lab bench, or cabinets, or glass-ware aside from 10 test-tubes and some mason jars. It takes a life-time to build a lab from the ground up, and the Work is never finished.

Any dope can buy equipment, but it takes a hobbyist to turn that equipment into laboratory. I've spent the last what, 5 years cultivating my work-space and life-style into something formidable and there's miles to go. When people post pictures of their laboratories it's hard not to appreciate all the sweat and effort they put into it.

So many unspoken and under-noted achievements have been made by this community . It's the projects people don't talk about that are the most interesting. That's kind of what makes it fun though right? Excited to see what 2015 has in store for us all.