Most likely your bearings are seized to the shaft. May I get on my "Soap Box" and plead my case not to buy or fix you oil free pump? Please buy a wonderful oily, slick, lubed scroll pump?

@@Philat4800feet absolutely, soap box away! Is this the one they refer to as the Premium Oil pump? This option has definitely been playing on my mind. I may opt for an oily, slick pump AND get the rebuild kit, assuming one is available, just for the experience (and aggravation!) of rebuilding it myself. Thanks for taking a look.

You have covered your bases. Here's some thoughts: Where the "epoxy plug" is located I don't know why HR would use a hard cement. I had a leak at the wire harness. I found a food grade silicone and applied it under low vacuum so the vacuum would help pull in the sealer. It fixed it. One potential leak would be a cracked weld. That would require NDI work such as a penetrating die inspection. I believe HR has a five year warranty on their chamber. I placed a vacuum micron gauge on top of my vacuum pump. I placed a 304SS tee with the gauge coming out the side and the hose coming out the top. If you have a shop that makes hydraulic hoses, they would have all the JIC fittings. Another thought is using different air fresheners to find your leak. Use them one at a time, in different locations, under vacuum and then smell inside the chamber. Place some towels inside the chamber to capture the scent.

@@Philat4800feet A new update to my freeze dryer. 1. I turned the tray holder upside down "unplugged" and ran the freeze dryer and within 5 minutes my visual screen turned upside in a mirror image. I turned it off unplugged restarted and the image was still a mirror image. I turned the tray holder right side up "unplugged still" and within about 5 minutes the visual image corrected itself. Go figure that one. That is a real head thumper. Upon testing the seal around the door, I saw where the gasket touches the front of the machine on the hinge side so I A. Put toilet paper inside around the rubber door ring and brought the vacuum to around 1300 mtorr then sprayed food dye around the outside. Result. No Leak. B. I then cleaned it all and brought the vacuum to around 1500 and sprayed soap water all around the door seal. No bubble seen inside the chamber however when I release the drain valve and pulled the rubber I saw bubble coming from the foam located behind the rubber seal in the area of the bad welds I have noticed. It appears my chamber is leaking through the welds.Most of the bad welds are near the front within 8" or so. This mean I must take the foam off the tank in this area and test again spraying soap water on the outside of the tank on the weld areas. This still does not clear up why that without the tray holder I can get down to 346 mtorr within 30 min. Well at least one leak has been discovered. I still plan on testing the vac sensor as you instructed on your video. You have been so much help brother. Any advice going forward would be welcome. The unit was purchased in 2018. 2018+5=2023

Yup. You might want to record (weigh) the amount of water taken out so you don't water it down later on.

There really isn't a way to control vacuum amount in candy. Candy contains either No water or very little water. In food the vacuum is controlled by heating the food and releasing water vapor. this decreases the vacuum (sublimation). The vapor is frozen to the chamber wall or is sucked into the pump. Candy just heats up to a liquid or near liquid and the high vacuum boils the liquid and pulls apart the soft parts of the candy (such as skittles).

An infrared camera would work best, but they can be pricy. Remember, you can't over dry.

Where did the cheese come from? Store bought?

@@Philat4800feet yeah we got the pre-sliced Costco w/ 4 separate flavors. Each one left grease and the slices weren’t that thick

Better luck with shredded cheese

It's more like minute rice.

I bet your frustrated. I would be and have been. Using a Hg/in gauge will only give you a rough measurement of vacuum. At my altitude the best I can get is 25 hg/in. You need to think metric in this case, it's almost like thinking backwards. you need 1/2 mm of vacuum. See this video to help you understand: kzfaq.info/get/bejne/es18pbCemrGtl5s.html First of all you need to find out what your vacuum pump will produce in microns at the pump's inlet, then at the end of the hose. It sounds like you have covered all the bases of finding leaks. If your pump can go under 500 mtorr and you have no leaks, then you may have a software issue. What software are you running?

@@Philat4800feet I am running v5.0.23 The unit is a large. I purchased it in 2018. It has mostly always given me problems with vacuum. There is one thing that is very strange. When I close the door, there is NO solid visual ring. The ring touches the glass and shows only on the hinge side until I latch it and it disappears. I have adjusted it both ways to no avail. I cannot get that side to show the ring. I purchased a new door seal but nothing changed. I even all but removed the hinges so that the door is just barely hanging on, turned on the vac pump and pushed the door until the vacuum pulled it to. It still did not achieve vacuum. It is like the drum has been ground uneven. I do not know how to test for that. When the vacuum pump stops the vacuum changes fast like there is a major vacuum leak. So it could be the drum. I put a straight edge on the door and the door shows about 25 thousands or so bow. I turned the door around inside out and ran it but the seal acted the same way and could not achieve a vacuum. Concerning the gauge. I bought it because it had mTorr reading on it. It reads 35 mtorr at the pump and 40 mtorr at the drain valve.

That rules out the pump. Sounds good. Doesn't the drum come with a 5 year warranty? Have you had any contact with Harvest Right on this problem before 2023? I think the problem could be the drum to door gasket seal

I paid my 45.00 and they have my data. I have not discussed anything with any person at this time. I contacted them in 2022 about a vacuum leak but did not find the Divit until now. I will tell them when they contact me. Waiting you know. I tried putting tar in the gap but it did not change anything. Not sure what to try. I am hoping they have an idea.

Sorry, way over my head. I use a fan to defrost.

No. Any contamination, if there is any, is in the pump, and it remains in the pump. It can't travel backwards to the FD.

Is 135 the maximum the temp will go?

So the screen shows no vacuum at all? If you go to the function test, and run the vacuum pump for 15 minutes does that screen show vacuum?

I don't recall saying that. I can't think of any foundation that would support that statement. For the iron powder to migrate into the food, either the OA would need to be ripped open or the food would need to be really wet.

@@Philat4800feet Ok, thank you for responding.

Glad to help

I can't remember, but most of my batches are around 24 hours with the following setting: 0 freeze point 0:00 extra freeze time 130 Temp 12:00 extra dry time I prefreeze all my food. and prefreeze my FD

That come close to what I do, but it's dependent on your settings and how you prep your machine. I do the following: I prefreeze my food for 48 hours (rock hard frozen). my settings are: 0 freeze point 0:00 extra freeze time 130 temp 12:00 extra freeze time I prefreeze my freeze drier for 0:50 minutes and put my food in 10 minutes before the cycle starts.

At 5600 feet the air is thinner. You will be able to freeze dry your food a little faster. If you are going to use your FD food within 3-6 months I would package them in ziplock bags. If your food is for long term storage I would use an OA and store in a cool dark place. If you can, I would vacuum pack your food.

@Philat4800feet thank you. I actually trust you more than anyone else on KZfaq.

Strange. If you have a Home Depot nearby, you can pick up filters there: kzfaq.info/get/bejne/bJiUfN2o05abdok.html Usually, it's the first couple of cycles that takes extra time to filter. Is there any particulates in the bottom of the top part of the pitcher?. If this keeps happening, let the oil stand in a quart jar for a couple of days to let settle, and pour off the top into the filter pitcher. Place the bottom oil into another jar until filled, and when ready, pour off the top of it. Make sense?

@@Philat4800feet yes, that makes sense. I know there were never any particles in the bottom of the jar. The filter we have that goes into the jar that the oil from the pump goes in actually has a screen in the bottom of it now there is one or two particles in that screen, but as I said that, I didn’t see anything in the jar. But I’ll give that a try thank you for your help. And no we don’t have a Home Depot close to us just to Lowe’s. Thanks again.

The sealer I have came from Harvest Right and has been rebuilt twice (seal replacement). It works fine. A good seal is when you can see the imprint of the teflon fabric in the seal. There are several sources for OA. see link below: kzfaq.info/get/bejne/abWEqpeYrtCzYqc.html

Then you would know of the basic principle known as "oil canning". How many pressure vessels are square? Yes, I did talk to them. The vacuum pump is oilless and has a history of problems. This fact comes from a reliable source from the manufacture. The cube is the second attempt to enter the freeze drying market.

@@Philat4800feet Did you even read my reply?? If the walls are reinforced, which they are, a square can be stronger than a circle that is NOT reinforced which tells me there is a lot more Engineering that was done on the Cube. Who is your 'reliable' source?? They didn't tell you something simple like the pounds of ice it could handle or the exact gap difference between the rack and vacuum chamber?? Really? The term 'oil canning' is used by shadetree mechanics and your lack of critical details support this. Please get backing facts. The oilless pumps they use do NOT have a history of failing. You say 'the' vacuum pump, what pump/manufacturer are you referring to? The only pump they have had fail as of yet had an internal bearing issue and was within the first few months of use which makes sense because if there is to be a mechanical issue it normally happens within the break-in period of the pump (in high quality pumps that is). In fact they have 2 pumps in their research facility in which they absolutely ABUSE and neither pump has failed in 4 and half years. Did your 'reliable source' inform you of that? If youre referring to the oilless units sold by Harvest Right, yeah those are some off brand junk that have a horrible track record. Where are your sources that you are quoting from that says the Cube's oilless pump has alot of failures?? Do you even know the German manufactures' name?? Your 'reliable source' seems to know as much as you do about these machines and I HIGHLY DOUBT your source works for the Cube from the lack of details.

Basic engineering principles will always support a pressure vessel of a spherical design. Why start with an inferior design? The moisture coming from the freeze drier and entering the vacuum pump is acidic (PH scale). Without the protection of oil it will be a matter of time before bearings and machine surfaces begin to corrode. Not all moisture is trapped on the chamber wall. Only an inline cold trap would prevent this. No home freeze dryer uses a cold trap. Oil-free vacuum pumps are a bad idea and shouldn't be offered, or used by, any freeze dryer manufacturer.

@@Philat4800feet The statement "Oil-free vacuum pumps are a bad idea and shouldn't be offered, or used by, any freeze dryer manufacturer" is just insane. There are SPECIFIC oilless pumps designed SPECIFFICALLY for the food industry. I would agree if your statement had included "Just any oil-free vacuum pump is a bad idea". All I'm going to say is in high quality pumps, designed for this specific use, there are special anodizing coatings which are applied to the rotor surfaces that protect said surfaces from such acidic exposure. The bearings are SEALED which protects them as well. That's why there is little chance of contamination. You might want to contact a high quality pump manufacture before you give 'internet' reasons as to why an oilless pump shouldn't be used. Your assumption that all vacuum chamber designs that aren't round are inferior. Yeah, that's ridiculous.. This conversation is going no where. NASA uses SQUARE and other odd shapes for vacuum chambers, I guess they are ignorant as well. It is stated that the Cube is square because it is more efficient by not having as much wasted air space between the square rack and a round vacuum chamber in other dryers- once again read the available literature. Main point - don't trash someone else's design based on so called 'reliable sources' in which you cant even name. All of these points you make are 'internet talking points'. I talked with 2 engineers of the Cube and learned more facts about it in 5 minutes than you have in this entire video. No one is arguing that square is stronger than round when the same materials and construction methods are used. Even a middle school student knows this. The problem is that you dishonestly apply YOUR assumption to the Cube's engineers assuming and dishonestly implying that that's how they designed and built it - using a middle schooler's skillset and level of education along with an inaccurate animation which is totally false and misleading in reference to the Cube's construction. Conversation done.

If it's the main o-ring HR has replacements gaskets

I do this. My oil is always clean. I have sent oil samples into the same lab that @Philat4800feet uses and the particulate counts are low. I use a thermal switch to turn on the pump that circulates the oil through a filter and oil cooler. The filter has a water trap and I have never had any water accumulate in the oil trap. I use a Premier Pump. I had to tap the drain outlet with 1/8" npt and drill and tap a hole in the tank to return the filtered and cooled oil.

@@richarddavies6657 wow that is interesting. I was just going to program a small Arduino to set a small pump to circulate the oil every so often. Why cool the oil? I would think a warm oil would lubricate better.

I think changing the oil after the batch is good enough for me

You are a hardcore freeze drier.

Unknown. Not sure what that would do to the proteins when frozen.

Sorry to hear your woes. It sounds like the check valve, inside your pump, is allowing oil to seep out and back to the chamber. Is this correct?

Which vacuum pump do you have?

@@Philat4800feet Hi, i have the green pro pump.

How good are you with your hands? Can you take apart the check valve, clean it, inspect it, and put it back together? and then clean the chamber, rack, hose, etc. with isopropyl alcohol 70%/30% water? I want you to get everything really clean and let it air out overnight.

@Philat4800feet Hi Phil, well I've already done all that, less use alcohol when cleaning everything. I've washed out the chamber and hoses several times, cleaned the rack well to ensure no oil residue. I run a batch of veg and get oil floating on top of effluent water. Means oil vapor is getting into chamber, and hence on my food. All my finished products get a horrible smell after a month or so even when vac sealed in glass, kept cool and dark. I suppose it's from the oil, no other explanation. I looked for a check valve but can't find one to match the not so typical connections on these units. Thanks.

For those who run their FD a lot, it may not be a problem. The concern would be those who run their FD perhaps monthly and let the oil idle for long periods of time.

I changed oil in my freeze dryer every 20 batches using the Robinair oil! I ordered a gallon of Black Gold and was going to start using it because of all the moisture problems, my oil looked like that stuff Phil was just showing, I never got to try it, the pump failed on the last batch! The new pump is in route. I will take Phil's advice and change every cycle! and use the Black Gold. Total batches on that pump was 163 or about 5,215 hours with a average o 32 hours a batch

I recommend Black Gold. How did your pump fail?

@@Philat4800feet I know I asked you recently what oil you used and I bought a gallon.It failed on the electrical side, it started and ran for a couple of minutes and stoped then it started again and ran a couple of minutes and quit! I unplugged it and plugged it in a different outlet to make sure it wasn't the Harvest Right problem It has gave me fits with water in the oil, when I would change it the oil was nasty and would never separate , I only ran about 163 or so batches, but I don't know how long these pumps are supposed to last! I have the premiere pump.

I live on the Gulf coast where we have high humidity. I built a room just for the HR and put in a Air Conditioner I am also going to put in dehumidifier in there also!

Very good

I don't think so, because it's more of a vapor.

Yup, I'm sure there's a better way. Blue Alpine has their filter inside the chamber. Simple and elegance.

If there wasn't any innovation we would be driving model T's. If HR doesn't innovate, they will be a footnote in the history books of freeze drying.

What's F/R?

HR went from a 300cc to a 700cc around 2022. an OA will stop working once the oxygen is depleted. OA's will not add moisture to the food contents of a mylar bag, but how do you prove that to someone who has made up their mind? If there food went squishy it's because it wasn't dried enough.

What's the highest temp will it get? You can still do candy if you have a oven: kzfaq.info/get/bejne/qtOjibpp1a-xaGQ.html Play around with it