+x

 

quinn - 1/20/2019 4:05:44 PM

+x

 

Steve Broad - 1/20/2019 9:30:05 AM

Photographic evidence? :-)

Here it is. The fan I got on Amazon for pretty cheap. It's a blower fan made for fireplaces so figured it's probably designed to handle some heat. Handled one cycle so far, we'll see if it holds up. Temp controller also on amazon for pretty cheap. I just had it set to a basic mode that holds one temp, but once I figure out the terrible chinglish manual, it can go through up to 12 difference temperature profiles with specific amounts of time. Should be great for a full ramp up, soak, ramp down cycle. The temp sensor on it is a bit slow to react though. That other little temp sensor I bought sitting next to the controller seems much better. I'll try moving the controllers sensor in front of fan air to see if it reads quicker. One thing that's bugging me a bit, the oven puts off a smell, not like burning, but I think it's from the mdf getting hot. Mdf combusts at like double my my max temp, so not worried about it, but hopefully the smell will get better after a couple cycles. Probably wouldn't notice it if I didn't open the door while running a cycle.

Edit: running into a slight issue. My oven is too efficient lol. Ran another cycle this morning with my aluminum molds in it. Ramp up of mold temp was slower but not too bad, with probe placed inside a bored hole in the mold, it took a bit over an hour to go from 20c to 120c. Ramping down is the issue. This mold stores some serious energy. Without the mold in there, the oven would drop a couple degrees per minute with bulbs off, with mold in there, it has now been over an hour since bulbs turned off and it has only dropped to 108c. The mold is like a big heating element in the oven and doesn't want to ramp down with the insulation containing all the energy in the oven. Easy solution would be to just open the door, but I'd like to have a full cycle of ramp up/ramp down programmed without having to touch the oven. My temp controller does have an outlet for cooling, just need to figure out what to power with it. Somehow need to set it up to vent the oven without losing insulation during ramp up. 

+x

 

Steve Broad - 1/20/2019 9:30:05 AM

Photographic evidence? :-)

+x

 

quinn - 1/17/2019 7:32:00 PM

Molds are done. not bad for a home built cnc.

+x

 

quinn - 1/9/2019 1:19:56 AM

+x

 

Steve Broad - 1/9/2019 1:03:44 AM

+x

 

quinn - 1/8/2019 3:08:57 PM

+x

 

Hanaldo - 1/8/2019 1:40:39 AM

Depends on the pre-preg. But it should stay put well enough. 

Sounds good. After watching a few more videos, it looks like +/-45 is great for getting into corners so that should work to my advantage. 
Couple more questions before I order prepreg. I'm still a bit unclear on whether or not it's an advantage to use single sided prepreg for first layer. I see that easy composites sells a prepreg that is optimized for the surface layer and it's single sided. I'm in the US so can't order their stuff, but should I pick a single sided for my first layer, or is it gonna make much difference? The part will not be getting clear coat or paint so I want it to come out of the mold with good finish. If 2 sided is not much of a disadvantage for surface layer, I'd rather use it since I need it for other areas. My other question is the bagging technique. Eventually I want to try a silicone plug if I go into production, but for prototyping I'm just gonna vacuum bag it. I'll make a tube out of bagging material that is slightly larger than the inside of my part.  This will be fed through the middle once mold is closed, then I'll bag the whole mold and seal the outside of the ends of that inner tube to the outer bag. Before closing the mold I will apply release film to the laminate, leaving a strip of laminate exposed for the overlap, then close mold and push overlaps down. Question is, do I need a breather between the release film and the bagging material? In most videos I watch, they use breather, but in the tutorial on this forum they bag straight onto the release film, only using breather on outside of mold. It will be much easier for me if I can do it the same way and only wrap breather around the outside. Will this work well in my case?

When we made a hockey stick out of a carbon/aramid mix, we just used a balloon lightly coated with a release agent and connected to a pressure pump, no bagging required. This way you can improve on 1 atmosphere if you so desire :-)

Good to know. Sounds like balloons work fine as a bladder. Just curious, did you paint the name on afterwards, or did you do that in the mold before lay up? 

+x

 

Steve Broad - 1/9/2019 1:03:44 AM

+x

 

quinn - 1/8/2019 3:08:57 PM

+x

 

Hanaldo - 1/8/2019 1:40:39 AM

Depends on the pre-preg. But it should stay put well enough. 

Sounds good. After watching a few more videos, it looks like +/-45 is great for getting into corners so that should work to my advantage. 
Couple more questions before I order prepreg. I'm still a bit unclear on whether or not it's an advantage to use single sided prepreg for first layer. I see that easy composites sells a prepreg that is optimized for the surface layer and it's single sided. I'm in the US so can't order their stuff, but should I pick a single sided for my first layer, or is it gonna make much difference? The part will not be getting clear coat or paint so I want it to come out of the mold with good finish. If 2 sided is not much of a disadvantage for surface layer, I'd rather use it since I need it for other areas. My other question is the bagging technique. Eventually I want to try a silicone plug if I go into production, but for prototyping I'm just gonna vacuum bag it. I'll make a tube out of bagging material that is slightly larger than the inside of my part.  This will be fed through the middle once mold is closed, then I'll bag the whole mold and seal the outside of the ends of that inner tube to the outer bag. Before closing the mold I will apply release film to the laminate, leaving a strip of laminate exposed for the overlap, then close mold and push overlaps down. Question is, do I need a breather between the release film and the bagging material? In most videos I watch, they use breather, but in the tutorial on this forum they bag straight onto the release film, only using breather on outside of mold. It will be much easier for me if I can do it the same way and only wrap breather around the outside. Will this work well in my case?

When we made a hockey stick out of a carbon/aramid mix, we just used a balloon lightly coated with a release agent and connected to a pressure pump, no bagging required. This way you can improve on 1 atmosphere if you so desire :-)

+x

 

quinn - 1/8/2019 3:08:57 PM

+x

 

Hanaldo - 1/8/2019 1:40:39 AM

Depends on the pre-preg. But it should stay put well enough. 

Sounds good. After watching a few more videos, it looks like +/-45 is great for getting into corners so that should work to my advantage. 
Couple more questions before I order prepreg. I'm still a bit unclear on whether or not it's an advantage to use single sided prepreg for first layer. I see that easy composites sells a prepreg that is optimized for the surface layer and it's single sided. I'm in the US so can't order their stuff, but should I pick a single sided for my first layer, or is it gonna make much difference? The part will not be getting clear coat or paint so I want it to come out of the mold with good finish. If 2 sided is not much of a disadvantage for surface layer, I'd rather use it since I need it for other areas. My other question is the bagging technique. Eventually I want to try a silicone plug if I go into production, but for prototyping I'm just gonna vacuum bag it. I'll make a tube out of bagging material that is slightly larger than the inside of my part.  This will be fed through the middle once mold is closed, then I'll bag the whole mold and seal the outside of the ends of that inner tube to the outer bag. Before closing the mold I will apply release film to the laminate, leaving a strip of laminate exposed for the overlap, then close mold and push overlaps down. Question is, do I need a breather between the release film and the bagging material? In most videos I watch, they use breather, but in the tutorial on this forum they bag straight onto the release film, only using breather on outside of mold. It will be much easier for me if I can do it the same way and only wrap breather around the outside. Will this work well in my case?