Sugaring the modern way DIY Maple Syrup Reverse Osmosis (RO) system

A half dozen friends have asked me to share my Maple Sap Reverse Osmosis setup I use sugaring each spring to make delicious Maple Syrup. This year I decided to take some pictures and put a blog post together with relevant information for them. Originally I decided to see how cheaply I could put together a small batch process Reverse Osmosis setup for removing water from the Maple Sap I collected. In this version it has been upgraded with UV Sterilization. I am able to remove about 75% of the water with this set up, which translates to an enormous energy savings versus boiling. The best part about this system, is I set it up on a timer which I let run for the amount of time it takes to reach the maximum concentration of sugar.

I actually worked out the energy costs, and ROI last year but can’t find my notes on it. Here’s some quick calculations to show the value of this system. Sap is 98-97% water, you need to boil off most of that to get syrup which has to be 66+%. The latent Heat of boiling at atmospheric pressure for water is 8133 BTU/GAL if we assume 8.35 LB/GAL and take the steam table value rounded to 974 BTU/LB @ 212°F (100°C). Using this RO system saves about 6100 BTU per gallon of raw sap processed. If you use use propane, that’s equivalent to about 0.28 lbs of Propane burned if you have 100% efficiency (which does not happen in boiling but let’s be generous). Consider it can take up to 40 gallons of sap to make 1 gallon of syrup, you are saving 11.2 lbs of propane fuel which amounts to quite the $$ savings per gallon of syrup.

You can see a process flow diagram of my system outlined in the image below. It consists of an inlet that I move from either fresh sap tank to the filtered concentrate tank depending on if I’m adding more sap or trying to increase the sugar concentration. The inlet passes through a UV sterilization unit with a UVc bulb to kill any bacteria, yeast, etc. The UV sterilizer needs to be in front of the pump as the operating pressure of my system (~80-90psi) is higher than the UV sterilizer housing can handle (60psi max pressure). Priming is a bit of a pain with this set up, but once primed it works well.

Ensure you put your Reverse Osmosis Membrane in correctly. In my housing the membrane installs like this. Also check which of the ports is which in your system

The pump then pushes the liquid through a 1 micron filter column followed by a reverse osmosis membrane before returning the concentrated sap to the concentrate tank. Pure water is the waste in this system. I use it for my humidifiers in the house rather than dump it down the drain or outside. As it is purified water you can drink it, or use it however you would like. It seems a waste to dump it down the drain.

Process Flow Diagram of DIY Reverse Osmosis for batch process of Maple Sap to remove water before boiling it into Syrup

I used the following items from Amazon in building my system. In addition to this list of components I used you will need to source some 1/4″ water line, and 1/4″ push to connect fittings. In addition you will need some buckets, or containers to hold your sap. I keep my purified water for use in my humidifiers. You can run the pure water waste line directly to the drain or outside if you so choose.

Aquatec CDP 8800 high flow Pressure boost pump 8852-2J03-B423 100GPD – 200 GPD RO reverse osmosis booster pump 24VAC 1/4 and 3/8
https://www.amazon.com/gp/product/B00A7ZV2GO/

Geekpure Ultraviolet Light Water Filter– UV Sterlizer Water Purifier (6W (0.5-1GPM)) https://www.amazon.com/gp/product/B07FPGCWQX/

Malida Water Pressure Gauge Stainless For Aquarium Meter 0-1.6MPa 0-220psi Reverse Osmosis System Pump With 1/4 https://www.amazon.com/gp/product/B0124FAV6Q/

Pentek 158117 1/4″ #10 Slim Line Clear Filter Housing https://www.amazon.com/gp/product/B003VT79VA/

Aquaboon 6-Pack of 1 Micron 10″ Sediment Water Filter Replacement Cartridge for Any Standard RO Unit | Whole House Sediment Filtration | Compatible with DuPont WFPFC5002, Pentek DGD series, RFC series https://www.amazon.com/gp/product/B01M0MIPUE/

1/4″High Pressure Needle Valve Thread Female Stainless Steel 316 J13W 160P https://www.amazon.com/gp/product/B00NBI3EEC/

Reverse Osmosis Membrane Housing with 1/4″ Quick-Connect Fittings https://www.amazon.com/gp/product/B00CCMNOSE/

HiKiNS Reverse Osmosis Membrane 100GPD for 5-Stage Home Drinking RO Water Filtration System 1-Pack https://www.amazon.com/gp/product/B0795R3NG3/

Pressure gauge on Maple Sugaring DIY RO system
Close the valve until you have a pressure in your system that is just under the maximum your membrane can handle. This will help push the water molecules through the membrane. You can see when your filter becomes plugged as the pressure drop between the two gauges will increase.

In operation, the input from the raw sap tank, and it all passes through the system at least once before entering into your concentrate storage tank. This filters out any solids on the first pass, and sterilizes the sap with the UV sterilizer. The one needle valve in the system is used for concentrate flow control. Decreasing the flow rate through the valve increases the pressure going into the filter and membrane. The increased pressure drives the water molecules through the membrane further concentrating your sugar solution. You want to run your system a bit below the safe operating pressure for your membrane or other weak link in your system. The concentrate is recycled through the system until pure water no longer drips out of the waste line. I find I can get to ~9-10% sugar content with this system.

DIY Reverse Osmosis for batch process of Maple Sap to remove water before boiling it into Syrup
Priming your system at the start of the season can be messy, especially if you forget to open the valve and bleed your pressure before disconnecting something. Make sure you use your setup somewhere a bit of water on the floor won’t hurt anything.

A quick note note on startup. RO membrane columns come with some preservative. Flush 10-15 gallons of fresh water through your system. Additionally, membranes operate differently at low temperature. So if like me your store your sap in an ice cave you build in a snow pile during the depth of winter, you want to let it come to 50Fish for processing, it will work much better than at 32-45F.

We are using water with electricity, make sure you use a GFCI on your system. My shop doesn’t have one, so I use a GFCI extension cord to ensure any shorting through the water trips the power. Safety is important when playing with AC line voltage. Be safe!

I hope this helps you with your own setup. Remember, you need to keep all these things clean. I wash and dry my system for storage, replacing my filter and column every season.

Building a Gantry Crane lift

While restoring my Bridgeport Series I milling machine I reached a point where I needed a gantry crane to lift off the largest component from the mill. I shopped around online but could not find exactly what I wanted/needed in terms of size and capacity. This unavailability lead to me building one. Building yourself a gantry crane has the big advantage of being exactly the size you need. I wanted mine to be able to lift 2 tons safely, and fit with only an inch or so to spare inside my shop’s ceiling.

Drawing of the upright with dimensions. I used 0.120″ wall square steel tubing for the upright construction.

Harbor Freight does offer a reasonably affordable Gantry Crane. With a 25% off coupon you can get it for just under $600. I went and measured it to see if it would meet my needs. You can see my photos of measurements taken on the HF gantry crane in the gallery below. Turns out it would need a lot of modifications to be useful to me. I decided it wasn’t worth buying it to modify as making one would be less work and less money out of pocket.

After CADing up my proposed design, I went to my favorite steel supply shop Cohen Steel to purchase the necessary materials. All of the upright tubing is 0.120″ wall square tube. I ended up getting a short 4ft cheap W8x13 beam from their drop rack saved myself money. I plan to buy a 9ft beam length in the future to use this gantry crane to lift heavy things into the back of my truck.

CNC machining the mounting threads into the Gantry Crane Top Beam.

I machined the top brackets for the uprights as well as the beam ends on my CNC mill. The beam machining was a bit ridiculous, but I was lazy and this was the easiest way. You can see that most of it is hanging off the CNC mill’s table in the photo above. I had to pull the vise to do the machining.

This is the mounting plate drawing for the top of the uprights.

Above is the drawing for the mounting plate on the top of the upright. It’s certainly possible to make one of these with just a drill press and carefully center punching and laying out the hole locations. I used slots in my design as I will likely use different beam sizes when I go to a longer beam. I wanted to leave some wiggle and adjustment room to make assembly easier. The big hole in the bracket is there for alignment. I plan to weld locating rings or disks onto the ends of the beam to aid in assembly. The design of the upright mount is is such that I can add an extension to raise the beam height in the future if I need an extra few feet. Bolt on extensions are a lot easier than going for a telescoping upright design.

CNC milling the top upright mount brackets to secure the beam in place.

About the only trick I used in this build was tack welding the corners of two 0.25″ thick upright top mounting plates together before machining. Doing both at the same time saves some setup and machining time. If you look carefully you can see the tack welds in the corners. I later rounded the corners by hand and removed the tack welds separating the plates.

There was a lot of cutting on my band saw, grinding with different wheels, and welding to build this, but not a lot of tricks outside of being careful. WIP pics in the gallery below for your viewing pleasure.

When you are working long hard 16 hour days, trying to get a job done in a weekend, you make mistakes. I was working fast, and so focused on getting the base cross piece perfectly square that on the second upright I ended up knocking it off center. Thus the two sides are not exactly the same. In function this doesn’t change much, however it does irk me to have made this mistake in my exhaustion.

My whoops on this project, I didn’t notice it until way too late to fix it. Since it doesn’t affect the performance or use of the gantry crane, I left it to remind myself to be more careful in the future. This upright has the center post off center by about 2 inches.

Below is the picture of the gantry crane set up for the first time. I was pretty excited to get it together. It was late Sunday night and I still had a bunch of welding to do. I did a test fit without the top plate gussets or welds being complete to ensure it was going to work before I finished up the welding.

First test assembly of the Gantry Crane

For now, the uprights have a wheel on only one end. I used wheels from an old 4 ton jack I had scrapped a few years ago. You can see my water jet brackets and a fixed wheel test fit in the photo below. The axle is a piece of 3/4″ steel shaft on the Gantry lift. The screwdriver was just to hold it for photographic purposes. To date I have used my machine skates for the other side of the Gantry crane uprights in order to wheel it about under load. Eventually I’ll mount the spinning caster type wheels that you can barely see in the bottom left of the picture below to the other end of the uprights.

Test fit of the water jet cut brackets for the wheel mount. I designed it so I could tilt the upright and roll it about somewhat easily. Each upright is over 100lbs, not so heavy I can’t carry it around but it’s easier to be able to wheel them around.

For the lifting I have a 1 ton Chain Hoist and a Harbor Freight beam trolley. I regret using the trolley. I will eventually buy or make a static clamp type mount for the chain hoist. It tends to roll when in use, which I don’t like. Alternatively I may just make clamps for the edge of the beam to stop the trolley from rolling.

Beam trolley on the Gantry Crane, in use lifting the knee off the Bridgeport.

The gantry crane lifted the knee off my Bridgeport with ease. It allowed me to remove it safely, lifting it straight up slowly so I could ensure there would be no damage to the precious precision machined surfaces of the ways. You can read more and see photos about this first use of the gantry crane in my previous blog post: Bridgeport Milling machine Restoration: Part 3 Challenges of taking apart the mill

If you end up building a gantry crane and my post was helpful please share a picture of your project in the comments. I would love to see what I might have helped inspire you to build. Cheers!

Bridgeport Milling machine Restoration: Part 3 Challenges of taking apart the mill

A Series I Bridgeport is not all that heavy a piece of machinery, weighing in at ~2200 lbs. However, disassembly requires some careful handling as several of the individual pieces weigh more than a couple hundred pounds. The Knee is the heaviest, followed by the Ram. These two parts are too heavy to remove by lifting off the machine by hand, even with help. An accidental whoops with either could damage the ways or dovetails. You do not want to hurt these precision surfaces on your machine. Be sure to use safe rigging to lift heavy components. In my case I built myself a gantry crane to lift the knee, and used the knee to lift the ram.

Inevitably you will have problems getting something apart as part of your rebuild. I had several serious issues with mine. Long ago someone had broken the Ram Pinion Handle off the Mill leaving the broken stud threaded in the pinion. The Ram was very stuck in place from not having moved in countless years. I ended up pulling the Ram Pinion and using the old weld a nut onto the broken stud trick to carefully extract the broken threaded section. After letting the weld cool fully the broken stud came right out with a wrench. I will have to make, or buy, a new handle for the pinion.

Welding a nut onto a broken stud (if you are careful and good with your welder) is a great way to remove the broken section. This is a classic trick ,the heat burns off any varnish, thermal expansion must break siezed rusted bits, and the threaded section always comes out easily afterward. Use caution if into Aluminum, Magnisium, pot metals, etc. You can melt and ruin these metals quick if you aren’t careful with heat control.

The ram itself was very seized in place from minor corrosion. Thankfully my ram has some inner ribs evenly spaced inside the ram. One rib was not too far from the back of the column on the body. I used a 4ft heavy pry bar with a block of wood to spread the load on the metal. I was able to slowly wiggle the ram free by applying a large leverage force this way. I only did this after a week of soaking the ram joints daily with both PB Blaster and Liquid Wrench spray. It’s best not to rush these sorts of things, you don’t want to break your mill’s castings trying to free up a stuck major component like the ram.

Sliding the Ram off the machine onto a wooden support spacer after freeing up the ramwith a 4 ft pry bar.

I ended up using the Knee to remove the Ram after working it free. I built a wooden support box to gain the required height I needed. I used 2×8 lumber scraps to build a knee length support for the ram. This allowed me to slide it out onto the wood and use the z axis to get the height perfect and take all load off of the dovetails as I pulled it forward onto the wooden blocking. This went well, but I will put it back together using the gantry lift now that I have it.

I ended up building myself a Gantry lift to remove the knee. I felt using the forks on my tractor was not controlled enough. I didn’t feel an engine hoist was going to fit in the space I had, nor did I believe I could lift high enough with the one I can borrow. Plus I’ve needed a gantry lift a few times in the recent past. I decided this was the perfect time to build myself one. You can see the full weekend build of the Gantry Crane Lift in the separate blog post where I share my designs and lots of build photos. It was a long weekend but I managed to complete it in just the one so I could keep moving forward on the Bridgeport Restoration. Sometimes it’s easy to get sidetracked or derailed on larger projects like this Bridgeport Restoration.

I was fortunate in removing the knee from the mill, the gibb came free easily. I have read this is a real headache for some restorations. Again, lots of penetrating oil soaking in here since I first got the machine was likely helpful. I sprayed it often and heavily for a few months. Pulling the knee with the Gantry Lift was safe, easy, and prevented any possible harm to the critical precision surfaces on my mill. I have no regrets building the tool to do this correctly.

The red arrow points to the one part I seriously struggled with removing as part of this rebuild. The stupid Z axis gearshaft clutch insert. This part is supposed to just slide out with a tight fit, I had to torch the hell out of it, apply gear puller bending forces, and hit it with a large lead hammer to free it up. It was glued in place by old cutting fluid or oils that had varnished into some sort of solid resinous adhesive holding it in place.

If you are familiar with restoring old machines or engines you will understand that no rebuild ever happens without something being so stuck you feel like getting it apart is beyond all hope. We have all been there. Those of us who rebuild and restore things often have been there many times. For me, on this Bridgeport restoration, it was the removal of part number 85 on the basic machine drawing (code number 2060079 ), the Gearshaft Clutch Insert. The lil bastard of a part(shown in the photo above) was essentially glued in place by old oil or cutting fluid that had varnished to a solid strong glue. After checking every possible online reference and looking for weird variations of Series I mills to ensure I wasn’t going to break this component with some judicial application of brute force. I applied a ridiculous amount of force with a gear puller, used a torch to make it glow red hot, and then hit it hard with a 3 lb lead hammer repeatedly. This was after several less brutal attempts at removing the stuck component, and weeks of soaking with oils, solvents, and so on.

Once I pulled the stuck Z axis clutch mount off the gearshaft that lifts and lowers the knee, the rest of the parts inside the knee came apart quite easily. The shaft bearings are quite good. I’m not sure if the oils dripping down on them has kept the grease soft, but these ones do not need to be pulled apart, cleaned and repacked based on how nicely they turn by hand off the machine. I removed all of the components off of the knee for the rebuild. The gears, nuts handles etc all will get cleaned, buffed, and oiled before reassembly.

Remember, when you are stuck, take a step back. Turn to the internet and find whatever images, videos, forum posts, and online friends you can to help you work through whatever is stuck. Don’t immediately go for the I have to cut it off or destroy the part brutal approach. While it’s true some times that is the only way, more often than not there is a trick that will get the job done. Step back, sleep on it, and then revisit the problem another day with a fresh perspective. If you do this , you can almost always successfully remove whatever bitch of a component that is being a real bear and not coming apart for you .

“Bridgeport Milling machine Restoration: Part 2 – rebuild reference materials

This page is for me, I have learned not to rely on the internet to keep a history of files and documents I might need in regards to restoration projects, as often sites are taken down and things lost. I will upload a few useful documents and store some links that are very helpful for anyone planning to restore or work on a Bridgeport Series I Mill.

One of the challenges of bringing a Bridgeport Mill home is finding a space for it in your shop. This was my originally planned, but it really did not fit or work with the rest of my shop layout. Not to mention I couldn’t fit my car in the garage any more with it here.

This is a section of PDF’s I’ve collected that have useful information

The parts diagrams in the manuals are priceless for knowing what goes wear, as well as understanding how things come apart. You will reference these drawings an awful lot in your Mill rebuild.

This section is a list of useful links to helpful rebuild information, and or parts suppliers.

Rockford Ball Screw kit: https://rockfordballscrew.com/ballscrews/kits/

All the Series I parts: https://www.machinerypartsdepot.com/parts_for_bridgeport

Hardinge Parts for knee mills: https://shophardinge.com/kneemillparts.aspx

The final resting place of my Bridgeport. In the end I had to part with a shelving unit and clean a lot of stuff up to make a large enough space for the Mill to operate fully. Moving this around is not simple. I will likely put it on a leveling caster type base after I strip and paint it.

This page will likely see a lot of additions as I finish up my rebuild, but I don’t plan to keep links current, if a link is dead let me know and I’ll test/remove it when I have a moment.