Good news! My mate comes back from Mexico tomorrow and so things should get going on the MK 2 pump very soon. (once I've stopped playing with my new burners that is!)
Wow JVD, at those high revs your pump uses, the tube fails quite quickly! Is the tube silicone tube like the stuff we use, or is it special for that pump, as it looks to be black in the link. I am hoping that using silicone tube, and at my much reduced rpm of only 50 rpm the tube will last more like months, but we will only truly know after......err......months! Your pump makes the tube bend quite drastically around the rollers compared with squeezing it gently against an outer wall. My tube spec says it is ideal for use in perastaltic pumps, so my hopes are at least based on some sound info.
I will fit an hour meter to my pump so it's run time can get logged, and will keep my fingers crossed. Mind you, I've got to make it first!!!
How do you run your pump? Do you slow it down for variable flow rates?
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Wow JVD, at those high revs your pump uses, the tube fails quite quickly! Is the tube silicone tube like the stuff we use, or is it special for that pump, as it looks to be black in the link.
No - I replaced the tubing with food grade silicone tubing.
Quote:
Originally Posted by silverbrewer
How do you run your pump? Do you slow it down for variable flow rates?
I just run the pump at normal rates and use a valve to control the flow rate. Usually though, 2 GPM is not quite fast enough. I wish I could circulate faster.
Using a complete front drum with hub assembly including the tapered bearings then all you would need is a machined center axle that fits the two different cone bearing bores for a concentric mounting point for your roller spider to mount onto. Threaded axle with jam nuts for slight bearing preload. With the drum mounted on a bracket off the hub lug studs it would then be easy if you have the axle extended past the outboard side of the hub for a connecting means to a 90 VDC gearmotor with speed control. For holding the tubing in their channels or pockets machine oversize aluminum rings with the proper spacers, freeze the rings or use dry ice then install the rings. Once expanded into the drum remove the spacers between the aluminum rings these channels for your tubes to set in. Like you mentioned before, cut away what's needed to pass the tubing in and out of the drum which can just be holes in the channels angles into the direction of the tubing and radiused to prevent any tube chafing. building the pump body this way 90% of it is from a automotive breaker just pick the diameter drum you want, make the spider to your drum and rollers as well the aluminum rings. Surely those tapered greased wheel bearings will outlast a lifetime of use going from 1,000 pounds plus loading to almost zero bearing loading just rotating. This is how I would build one as there are many drums available at 12" ID and smaller, my lathe can only swing 12" for the aluminum tubing support rings. I would build it to allow for grease seals at both ends of the hub.
One could conceivably reverse the brake drum and keep it bolted to the truck axle permitting the truck to power the pump. The truck transmission would give you the added benefit of speed control. A diesel rig would probably be the most economical to operate.
JVD, Just in case you don't know this, you CANNOT close off the flow of a perastaltic pump like you can on the March type pumps. When you throttle back the flow, you need to provide somewhere for the restrained flow to escape, like back to wherever it came from via a return route fitted somewhere between the pump output and your restricting valve? If not, then your pump will over pressurize the tube and that may be the reason you are getting tube failures. To reduce the flow you should reduce the rpm, or change the tube for a smaller diameter bore, or throttle the output but provide a feedback route.
Catt 22 :- The thought of leaving the brake drum connected to the vehicle had not actually occurred to me! Do you lot (over there) realize how much we have to pay for fuel over here!!! It's a bloody good job my car averages 107 MPG to work, with 70 MPG around town. On good days it gets over 120! My record is 125.3 ( Note :- That's our gallons in a 2001 Honda Insight Hybrid )
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Just found this thread and I am impressed. I am also inspired. I've done a good bit of work with miniature peristaltic so I know a little bit. I also have access to good CAD software and am pretty good with it. I will see what I can come up with this weekend if I have some time and post it on the board. I've got tons of ideas spinning in my head.
Nice to have another CAD savvy person on board! (the other one isn't me by the way)
What is it with Austin? Every other brewer on this forum seems to live there! Does Texas have some massive beer tax, or is it just a town with lot's of sensible people
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Blessed are the "cracked", for it is they who let in the light.
Well, one, we have a big beer drinking community with several local microbreweries and brewpubs who are involved in the community and we also have several really good beer bars. The culture in Austin is very focused around going out to eat and going out to bars. We also have one of the best LHBSs in the country. Aside from that, the people here are just generally awesome.
If anyone needs any help with any CAD work, I'd be glad to oblige. I enjoy doing it.
On the throttling the pump thing, you could throttle the flow to the intake of the pump, and as someone pointed out a while back that would just cause the tube to flatten if the pumps flow rate outstripped the actual supply. Still not good, but not too damaging either.
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Blessed are the "cracked", for it is they who let in the light.
On the throttling the pump thing, you could throttle the flow to the intake of the pump, and as someone pointed out a while back that would just cause the tube to flatten if the pumps flow rate outstripped the actual supply. Still not good, but not too damaging either.
How about a different hose with thicker walls so you have a smaller id and therefore less flow?
-OCD
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