Scratch Build – In Progress Teybers Rotary Single Stage

cleaned up evap on grinder...

 

Not really necessary to braze with an interference fit. The OD of the inside piece is slightly larger than the ID of the outside piece; by heating the outer piece and cooling the inner piece you should have just enough clearance to press them together, but when they come back to room temperature you'll have a nice tight joint between them.

 

ah nice. Submerge it in acetone/dry ice and then let it heat up. Man nice idea guys! Will definately do on my next evap

 

The governing equation for figuring out how much you have to heat/cool the part is:
dT = d / (a * D)

d = diametric interference
a = Coefficient of linear expansion (for copper = 9.3x10^-6 in/(in*F))
D = diameter (ID of shell, OD of core)
dT = temp difference (from ambient)
note: when cooling (dT is negative) then d is negative


assume you design for a given interference (i.e. 0.005 in) = d_actual
you want to have a clearance (for ease of assembly) = c
then: d_actual + c = d_total = d_shell - d_core

 

Lol I love the evap. Looks like you've got a wee bit too much brazing there. No matter though, it should clean up well enough.

 

Based on the pic of the braze job, I'd venture that you're not heating it up enough; to get a good weld you have to heat the metal up until it's a nice cherry/orangey red, then use the brass as a filler.

 

yup! I wasn't using my oxygen acetylene torch, because i have yet to get a good flashback arrestor. Got a victor torch coming in the mail with built in arrestors and check valves, so next braze adventure will be with the o/a and using 15% silver brazing rods.

Regards

Rocket: thanks man! yeah i batched (messed up) the braze job, but luckily it looks like it will hold pressure...

 

What were you using to braze before, just butane? Oxy-acetylene should greatly help with heating up the piece enough, just be sure to protect yourself when using a torch.

 

yep; a propane torch doesn't produce nearly enough heat to to brazing; Mapp gas, maybe; Oxy-Mapp actually works quite well for small stuff (I don't have the cash or space for an oxy-acety rig ATM)

 

I was using mapp, started off with oxy/acet and too small of a tip, but switched because i didn't feel safe. I don't think propane will even start to melt the brazing rod, but when brazing an evap you need oxy acet or at least oxy mapp and a torch stove under it...
Radodrill: do you have a oxy/mapp setup? Only reason i got my oxy acet was because you kinda need one to braze evaps. I plan to braze a lot in the future... PM me if you want my oxy mapp setup.
Had some spare $ so i got a load of new tools;
supco vg64 vacuum gauge(around 175$)
bacharach flaring, swagging, and cutting set (has a ratchet swag: was 70$ for set but cheaper then any quality swagging tool i could find)
90 degree tube bender (15$)
Various fittings(10$)(for vacuum pump to 3/8" manifold)
baby tube cutter (10$)
victor mixing chamber (torch)- 75$(190$ but i got it new on ebay... crossing my fingers it works)
a 50' reel of 5/16" copper tubing
And some other small things. can't wait
regards

 

Yes I do have an Oxy-Mapp torch

The major advantage to the oxy-acety is if it's used on a regular basis, the fuel is significantly less expensive when purchased in cylinders rather than buying the equivalent amount in little bottles for the oxy-mapp; also oxy-acety can be used for larger (i.e. thicker) pieces of stock

 

ah, i just sold a 20cf oxygen cylinder... I know someone with an oxy/mapp who just bought a adapter, and uses an oxy tank. Saves quite a bit of money. It costs me 2$ more to fill up my oxy tank then those damned bernzomatic little things lol. (20$ for acet(10cf), 10$ for oxygen, 20$ for argon, 15$ for 60cf of nitrogen...)

Hope to get some work done this weekend... just small things

regards

 

Finally a long overdue update! Still have a lot to do, and will post another mini update tonight. (p.s. in first golf tourny of season today shot 39 )
Here is where i am right now:

Spent a lot of time on that u-bend on suction...

Evap looks better IMO. Will grind it more and still gotta finish it up with oxy/acet. I tried with map again and was just globing, thought it would save me lots of leak saving time to just wait.

here are some pics of my brazing. Only 2 sloppy joints, and thats at compressor discharge and condenser. Both because they were moving lots of heat. I hope i didn't damage the compressor. The plastic over the electrical melted and made a mess lol. Compressor was fairly warm but i went over it with a cool towel, and had the electrical connections in opposite direction of flame.

A nice joint this bronze flexline is a breeze to braze! say that 10 times fast.

Best braze in the sytem ATM... Look how purdy she is...


Sorry for long overdue update. Im getting a lot of tools in about 45 minutes from ups... ill take a pic then.

Regards

 

Nice work there

 

thanks ratchet!

got a package in the mail tonight. Ordered wrong fitting for 3/8" to my vac pump though
First off, sorry for terrible pics. All items i got new. I have a cheap source for hvac parts (230$ for fluke 52 dual input eh)

Supco vg64 vacuum pump

Drewmesiter recommended that i get a clamping swag... not the hammer punch type. I ignored him and immediately regretted it. Found this for 70$ which i think is a steal. It includes a tube cutter, A swag and a flaring kit. (a swag which you actually clamp in tubing...). Also got a midget tubing cutter, Various fittings, a 90 degree tubing bender(already have 180), and various other things...

Regards

 

Way to go Teyber!!! You do very well young lad, indeed!

Looking forward to read more about your journey into the phase change realms
Sat here (at the job, sheeesh) reading the whole worklog, I'm actually feeling sad now as I reached the 'end' of this worklog - I hoped it was completed.. But anyway, now I can sit and wait for 'next set of pictures' as the rest of you dudes do

I don't know enough about phase changing to help you a lot, but if there's something, rest assured that I'll be there helping you! I do, as much as you and the dudes in here, want to see your project fully finished!!!!

Happy modding, tooling, grinding, benching - whatever! Just do it with style, and remember - SAFETY FIRST!

/Frido

 

awesome to see this stuff getting built

 

Thank you very much! yeah unfortunately it will problably be some time before you see the end of this thread... We will see though!

Thanks!

Good news! my jigsaw broke!
Will try to pick up a new one tomorow. Any recomendations? i always have good luck with hitachi. Looking to spend about 50-75$.

Regards

 

heres a couple pics




I am retarted folks. I had a suction line in (smaller one, not one for my build) and started brazing. Not really thinking, said "o ill braze the suction line in as well" i brazed the suction very close in,(to close to cut). Afterwards i was so mad at myself. So i decided. Just to make this into a suction line, and build meself a new evap for my build. This looks purdy though methinks

Sheesh i need some more cap tube. I used my only .031" on this. I need a 50' or 100' role of the stuff.

Regards


P.S. suction to evap is leaking pretty bad. Ill fix her up once i get oxy acet going...

 

Notes:
1) Got a new jigsaw today! couldn't justify spending 100$ on the hitachi when the one i got is 55$, as mine is more powerful, has a tooless toolchange, has a laser, and a side grip. Pretty happy, ill post pics soon.

2) Got a lot of progress on the condenser shroud. ill post pics tonight

3) Still havn't ordered the new bandsaw blade. i can't find out what size it is! anybody have any idea, its the one from harbor freight?

4) suction/evap joint is still leaking pretty bad. I know i shouldn't, but i stuck the entire thing under water and blew as hard as i could and bubbles where coming up. yeah i guess its a pretty big leak (victor where are yoU!)

Regards