New/Re-build. Drop Deck Omen e-Chief (Dual VESC/R-Spec 63mm)

[sl33py]

hey there, I am considering the vacuum pump, I am actually molding many pieces but it's a pain to make the carbon fiber stick to the mold perfectly.

I used a clothes vacuum bag with a hover yesterday.. it was nice but it didn't kept the pressure. I want something more professional than this hover stuff which was a fail. Result is OK but impredicable.

I will also use it in my upcoming project with a CF deck.

do you have any thought on this one : http://www.ebay.fr/itm/3S-POMPE-A-VIDE-CLIM-FRIGORISTE-DOUBLE-etages-42-Lt-min-electrovanne-vacuometre-/190680830797?hash=item2c6576934d ;

it's 150 euros in France but I found this one in Italy, same price but has some additional pieces

http://www.ebay.fr/itm/3S-KIT-POMPE-A-VIDE-42-Lt-min-MANIFOLD-UNIVERSEL-MANO-CLIM-R410A-R407C-R134A/141563299536?_trksid=p2047675.c100005.m1851&_trkparms=aid%3D222007%26algo%3DSIC.MBE%26ao%3D1%26asc%3D20140620091323%26meid%3D19bb052efb784a7cbe200aded90855da%26pid%3D100005%26rk%3D1%26rkt%3D6%26sd%3D110769285183

I will have also to get the vacuum plastic bag and some additional sheets.

I would definitely skip the one with additional pieces. All of those pieces are specific to AC/refrigerant - in other words not very useful. The biggest pain of getting the pump setup to use was getting converters and the pump setup to go to a regular hose barb so i could run vacuum to my bag/table. The converters from coolant connectors is a pain and i'd avoid it. I ended up taking the whole threaded adapter out of the pump and replaced it with a standard NPT fitting to go to my vacuum gauge and hose barb.

Another thing - 42 (L / minute) = 1.483216 cubic feet per minute. 1.5 CFM is pretty slow. I don't think i'm using my pump efficiently at this point, but i wouldn't want a slower pump unless it was significantly less expensive. For ~$150 i think you should get a faster speed pump 3/5/+ CFM. (70-100L/min)

I have found that correctly sealing the membranes with butyl tape was the best way to keep vacuum pressure on the part. If you shut off the pump for a minute and listen while you feel the edge of the membrane/tape - it's usually pretty easy to hear and find the leak.

what membrane and other materials are you looking to get?

 

[whitepony]

cheapest way for a reuseable vaccum mold/press might be http://www.roarockit.eu/shop/en/13-thin-air-press

was thinking about ordering one, but my laminating plans are on hold, too many other construction sites right now.

 

[sl33py]

cheapest way for a reuseable vaccum mold/press might be http://www.roarockit.eu/shop/en/13-thin-air-press

was thinking about ordering one, but my laminating plans are on hold, too many other construction sites right now.

I would skip the roarockit kit after watching it used by Freshair (check out his build here

He said it was really difficult to get everything into the bag. Might be practice and it might be easier with one of the larger bags they offer? He got it done and it looks great, but maybe he'll chime in and see if he suggests that kit.

 

[sl33py]

okp - I thought i saw you ask about another pump you found online. Looks like you deleted the post.

I would avoid any "kit" that includes the manifold and hoses. All of those hoses and connectors are going to be useless for your needs. The hardest part setting up the pump is getting adapters from the coolant connectors to a standard hose barb. I used 1/4" NPT with 1/2" ID hose barb for the hose i have. If you have smaller hose w/ 3/8" ID or 1/4" ID hose obviously it will depend on what you use. I finally removed the threaded in adapter from the base of the pump entirely and found the thread type to go to NPT for the rest of my connections. A pain. Several trips to the hardware store before i got it sorted out.

Just a word of warning. If you can get an adapter from the coolant connectors directly to a hose barb you'd be setup and working, but i wasn't able to find those. At least my experience - it might be easier and i just made it more difficult (not the first time).

GL!

 

[okp]

thanks for the feedback, I deleted the post because I noticed that you already said that such vaccum pump has many stuff which will be redundant for our use.

most challenging is of course to get all the stuff connected.

I ordered the peeling films, vaccum plastic bag and I am now looking for the pump (the same one in 70L). I noticed that an expensive version of the same pump is sold with a on/off switch pressure, which means that when the pressure is dropping for any reason, it automatically re engage the pump to remove the air and keep it at the good level.

it leads to my question.. as soon as you do the vaccuum to remove the air... do you keep the pump connected (I assume no as by default it would continue to remove the air and get hot)

 

[bandaro]

it leads to my question.. as soon as you do the vaccuum to remove the air... do you keep the pump connected (I assume no as by default it would continue to remove the air and get hot)

Depends on the pump and bag. If you have no holes obviously you don't need the pump, but a perfect seal can be hard through all the fittings/used bags. I run my pumps continuously without a hitch, but some will overheat. The TAP system mentioned earlier is hand pump so obviously not continuous. If you can, keep it running, but be aware of the temperature. always disconnect it when off, they will leak.

 

[sl33py]

it leads to my question.. as soon as you do the vaccuum to remove the air... do you keep the pump connected (I assume no as by default it would continue to remove the air and get hot)

Depends on the pump and bag. If you have no holes obviously you don't need the pump, but a perfect seal can be hard through all the fittings/used bags. I run my pumps continuously without a hitch, but some will overheat. The TAP system mentioned earlier is hand pump so obviously not continuous. If you can, keep it running, but be aware of the temperature. always disconnect it when off, they will leak.

agreed. I try to keep mine on for a while, but without getting a perfect seal, it leaks and you lose vacuum pretty quickly. I cycle mine on occasionally.

I figure as i get better sealing them up i might be able to hold vacuum for a while - but i never quit get it just right and it always leaks...

 

[chaka]

You can get a pressure switch to monitor the vacuum for you if you have a reservoir tank, I use a similar setup in my pneumatic press. I think you can pick one up for around 25 bucks.

 

[okp]

thanks, with a low budget aspect, is the vaccuum gauge mandatory? I can just vaccum the air out and just stop the pump when no more air is inside, no need to get the bars measured right?

 

[sl33py]

thanks, with a low budget aspect, is the vaccuum gauge mandatory? I can just vaccum the air out and just stop the pump when no more air is inside, no need to get the bars measured right?

correct. You can see when it's fully under vacuum, and as it relaxes (loses vacuum) it's obvious as well. I don't think my level of skill or use needs super high precision (to get to *exactly* 28 inches of vacuum). If it goes to 25 or 28 - it just works...

I like seeing the gauge for keeping an eye on how badly the seal is leaking as it shows minor fluctuations better, but definitely not needed. Last - they aren't super expensive and the ones i use are about 10-15$ and grabbed them on amazon when gathering hose barbs.

GL!

 

[Hummina Shadeeba]

Roarocket sells a bag with a hand pump that they told me in the phone will hit 28.5 or 29 inches of mercury. I forget which. Comes with the bag (get the big one). People get good results with their stuff but I still haven't used it. I also have two vacuum pumps that I put in series. To do carbon laminations I don't think you'll need too much suck. The hand pump they sell sounds good but slow. use a slow epoxy.
I had similar plans with a board: cut it up and carbon it to reinforce later. I cut up a nice newboard .. then changed my mind and it went in the trash, but since then, and after talking to roarocket guy on the phone about all kinds of stuff ( really nice and interested in whatever you're doing),decided using a finer weave will make it much easier to get into the nooks and crannies. And he said people have made boards simply using matting as the core. I can't find it on tap plastics website but they sell "matting" that's used with carbon or fiberglass and it's very like a 1/4 inch thick mat that feels a cross between wool and foam. It's cheap and what I like most is you'd only need to make a simple concave to lay it in and add resin to harden it. And then start doing laminates onto that. I'd have thought you'd need fiberglass inserts where the trucks mount but he said no need. In tap plastics they have a demo piece with just one pretty thin carbon layer on both sides and the foam weave core stuff in the middle.. I can't break it and they encouraged me to try. Come pay day some day. After the other project . I routed the board too and it took a long time.