What engineering plastic to use for a quadcopter frame?

What engineering plastic to use for a quadcopter frame?

I want to CNC route a drone frame from plastic and need to k ow which type is best. It needs to be lightweight, impact resistant, and rigid. I've tried hdpe, but it's too flexible. Any ideas what type of plastic would fit these needs best?

Submitted August 31, 2017 at 06:08PM by Jdog131313
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What engineering plastic to use for a quadcopter frame?

I accepted a job and then later got another job that i like better

I accepted a job and then later got another job that i like better

I start Monday at the first job.

The recruiter that helped me get this other position which pays a lot more and has better benefits, has told me I got the job. She said that I would have an offer letter today, but she called me and said I would get it next week. She assured me "you got the job", but I have yet to receive an official email or anything.

Well should I work for a couple weeks, full well knowing that I might leave? Or should I give my 2-3 days notice right now, for a position I am not sure I got.

Submitted August 31, 2017 at 06:02PM by Rintarou_Okabe
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I accepted a job and then later got another job that i like better

French drain redone – not sure the job is good

French drain redone – not sure the job is good


I'm posting here seeking advice and help. I've engage a contrator to repair my french drain. I had bad water infiltration in my house (1960s original drain). Here is the story of everything. This will be a photo story using my album at: http://ift.tt/2iK6Dt6. Also, sorry for my english, it isn't my main language. It's also very long.

Everything start with water infiltration in the basement. The first pictures shows the water infiltration at various state. This is right under the outside back door. Many person came to my house checking it and they all said it's water infiltration because of defective french drain. I decided to look for a contractor that would do that and, at the same time, change my sanitary exit one because it has roots cloging it every years.

The next picture is the beginning of the work. The guy with a blue jacket is the man I talk to and sign contract with. The big orange excavator is a man he engage himself to do the digging because his team were busy somewhere else. Needless to say, this guy is an expert with his excavator, precise and no damage anywhere. The other guy in the blue shirt and a shovel is the plumber I contracted to do the work. As far as the sanitary replacement goes, everything is a success.

As you can see in the photos already, the earth that are excavated is deposed directly on good unprotected ground. This will do damage and we'll see that later.

Continuing on, the engage man with the orange excavator continue to dig around the house since he was contracted for 6 hours of work. Everything he did was perfectly executed, no damage to anything except the fact that no ground was protected of the excavation (not his fault, he did ask the guy I contracted).

Continuing on, we can see at some point, before the picture showing my backyard with the pool, that some walls already have some fondation tape seal (soprema). Probably the old owner made some repairs himself at some point. While we are at the backyard, we can see the paving stone. I ask my contractor to remove them because they are broken, uneven and only cause trouble. He said no problem. While removing them, we found a surprise, there is 4 slab of cement in the ground! The old owner probably laid down cement as a base for his paving stone. He removed 2 of the 4 slabe, leaving 2 of them in the ground. As we can see, everything is again layed down on an unprotected ground.

The following picture show more of the plumber doing his work. Nothing special to see here.

After that, we can see a small excavator. This is the small one my contractor own. While using it, it broke down where it is right now. They dug the remaining (that the other guy with the big excavator didn't dug) with this one and a medium one. But, with both excavator, they were pure amateur. They scratch the house fondation, bump hard on it, it even left some mark on it. I'm unsure if I have picture of that though, we'll see on the way.

Next is a picture of one side of my house after the small excavator tried to dig. Was too small so he left it like that. We can see some styrofoam on the wall and the ground, plus the same fondation tape sceal and the fondation slab.

After is a picture of the isolofoam HD I made him bought to install. It was recommanded by the compagny selling those thing and said it was made to go underground.

The pictures after that show an underground tube where a power cable goes from my house to my garage. I had already said many time to my contractor that such a cable existed somewhere so he dug by hand to find it. But then, once they find it, the guy with the excavator did such a good job that he broke the piping and, as we can see on the wall, the protecting case of the main power cable on the house.

After that, we can see more of the excaved walls with some protection and styrofoam on it, then pile of dirt all around my house, on unprotected good ground. As we can see in the pictures, there's an old patch under my door in the backyard, right where water enter. There's also a lot of water reaching the footing. They also taped temporary the stuff they broke to prevent dirt and water entering. By the way, the underground piping going to my garage goes straight into my basement wall right next to my electric panel.

The next pictures are various view of the excaved ground. We can see sometime the old french drain (orange piping, in ceramic). We can also see it goes under my chimney. Then more picture of them, excaving the remaining where my parking his. As you can see, they freely roll the excavator on my neiboor grass without any protection. Needless to say, they scrap his perfect grass.

On the next picture, we see a man in a hole with a grey and black wall. He his currently putting some fondation seal. I took some picture of the stuff, it's the green and black bucket "resisto seal". The preparation before putting this? They brushed the wall with a big brush. Nothing was shoot on the wall to clean it, no pressure washing, drying, just removed the rough with the brush. Also, as you can see, they didn't pump out the water, thus everytime they walked there, splash came on the wall and on the footing. We can clearly see the end of the footing unproteted. Also, they didn't check if the old patch on the fondation at that place was ok, they just cut the extra that wasn't sticking on the wall.

Moving on, we reach the chimney with the resisto seal. I you recall on other picture, they was an old fondation tape seal on the wall that wasn't sticking properly. Instead of cleaning the hole wall by removing it, they simply cut loose part and sprayed it over. Again, without cleaning anything. You can clearly see it on other picture where there's resisto seal on the left of the chimney and the old soprema patch still there.

After is some picture of the isolofoam I had to take for tax credit.

Later, we see a "completed" wall. We see the resisto seal, then the isolofoam and the delta-ms covering. As you can see, the delta-ms isn't thigh on the installation as it should. It's also dripping in water all around the house (mostly). Nothing was dried out, they just put it there. Looking at the picture were we see the basement windows and door, we can see 4 nail to hold the delta-ms and one directly in the corner. Needless to say, that's not how it suppose to be done if we check on the delta website. Also, we see clearly all the water going under the delta-ms at the bottom and the bottom of the delta-ms roughly cut at many place, both horizontaly and verticaly.

The following picture are more photo of the installation on the back, right side and a bit of the front.

Next up is picture from the left side (parking) with 2 window and an orange BMW GTR RC in the window We can see how dirty the wall is and the remaining of the old fondation tape seal still on (the corner is right next to the backyard window). There's also a second chimney there for an old oil furnace. Other picture showing the said corner. The other 2 picture with the silofoam is the front and right side. We can see on both how dirty the wall is just in front of the resisto seal. On the front one, we can clearly see even the fondation isn't cleared and how undeep the ground is around the footing.

After it's more picture of everything installed, then how dirty everything is around my house. At one time, we can see that the grass of my neighboor was protected (after damage). I put that there myself to try to minimize the remaining of the damage.

After, we can see a part of the installation. I had to go out for 3 hours, I asked for them to not fill anything while I was gone, but they didn't listen. When I came back, I found out they already had fill the hole with 3/4 rocks, the drain and fill it up. As we can see on the forst picture showing the right side of the house partially filled, the drain sit on top of the delta MS way above the footing. In fact, it's sitting on the footing (on it's side with some rocks between him and the delta-ms). The next picture show the same installation on the left side of the house (with the water exit on the wall). We can clearly see how high the drain is compared to the footing on the bottom left. We can also see two other thing: There is nearly no rock on the side and top of the drain but also, where is the geotextile wrapping that's suppose to be there (and on contract)? They told me there is one under the rock and on the wall near the dirt, but not on top (even if that was on contract). They told me they forgot it, will credit me and put it on the remaining of the drain. I also ask them about the drain installation since, by my research on the RBQ website and NRC-CNRC (construction code for canada), that's not how it's suppose to be installed. They told me they always do it like that without any problem. I argue, told them by any logic, there's no way this will protect any water infiltration since, first, the water coming from under will rise, attack the footing first then, after sometime, reach the drain, while the drain is suppose to be reached first. And second, since the footing is wrapped with delta-ms and the drain sit on top of the delta-ms, the water coming from under the house and on the side will reach the delta-ms, be pushed inside to the footing and never reach the drain, making it more useless. But they refused to listen.

As for the chimney, instead of removing the old drain under it, they left it there and wrap the drain around the chimney (that is higher then the footing). They told me they won't go under risking to collapse the chimney. This mean the portion of the footing under the chimney is not protected.

The next picture show how well they prep the wall for the seal and the isolofoam installation, removing nearly nothing of the old tape seal, spreading the seal on a wet and dirty wall.

After, we see the Delta-MS around my fireplace chimey. They didn't knew how to do it so they wrapped some sheet on the corner, clearly against maker recommandation. We after see the left corner in my backyard with a ripped delta-ms sheet on top and on ground. We also see at this place that the delta-ms was cut to high thus not reaching properly the footing (and it's also ripped at the footing).

Little birdy feeding her children…

The next picture show them trying to fix the broken piping. At first, they wanted to just put a new one with a cut side close shut with electric tape. I strongly refused, electric tape isn't water seal and not made to be burried underground. I told them the juice is off and we just have to fish the cable out. They did that and badly installed the new piping. The curbed near the house is too tigh, putting a lot of pressure on the joint. We'll see the result of that later. While wee see that, we can see on the wall without the isolofoam the old fondation tape seal around the corner going under the isolofoam. We also see it's not very sticky, full of dirt and the wall is so clean….

In the same photo, we can see the bottom of the hole is now full of rocks, there's no more water and we can't see the footing anymore. The drain isn't installed yet. Also, the rock is installed, but not the delta-MS, meaning the remaining here won't have any covering from the delta-MS.

Next picture, we see he was out of Delta-MS so he installed something else, without asking me. Even if it's equivalent, I paid for Delta-MS and it's my contract. It suppose to be the samething all the way. The picture also show how he fixed both covering. He filled the gap between them with tar. We can clearly see that it doesn't hold in place.

After, we can see the drain installed on the last remaining side. It's cleary way up and not covered with either rocks or geotextile, only dirt.

The remaning picture show how he filled the hole he dug. As you can see, he filled the hole with everything he dug and found, which mean: dirt, rocks, paved stone, old ceramic drain, old ceramic plastic drain (don't know where's it's coming from), styrofoam… He didn't removed the ther 2 slab of cement in the ground (while I did ask for it). He removed a lot of big stone (and make me paid for the removing of them because he dumped them at a place for that he said).

Next stop is the installation of the window edge. At first, he was installing the drain for the edge directly connected to the fondation drain. I showed to him it's not a good installation and per code, he isn't suppose to do that. That's why he finally installed me two other piping for inspection (he said normally he use the edge for that). There are the two left most on the left window (yeah, installed at the same place). Even this, at first, he was installing them in reverse. Instead of making a U connection at the botton, it was goung opposite side. We can also see that the Delta-MS isn't properly fixed on the wall, there's a lot of place where's it's not tight on the wall.

The other two picture are a light he broke and the fence he broke. He did replace the light and repaired the fence.

Next picture show the parking and the side of my neighboor. The grass was partially replaced with new one.

After we see the filling. The filling is flush with the house, meaning that once it has collapse, it's not leveled at all. He told me because he removed. The ground was partially leveled, but the ground is filled with old ceramic drain piping, extra materials, metal materials, paving stone, styrofoam, etc. This is all around the filled hole and on the ground. They also make me a small place with rocks so it's easier to get to my pool.

After we see the edge installed and the inspection chimney.

The next 3 picture show the water infiltration starting the next day after a rain.

I decided to make a test. I started pooring water over the ground so water would go to the drain and check if it's working. After about an hour, I found out my basement was full of water (see next 2 pictures). The water was coming from somewhere else so I panic (nothing from where there was water infiltration before). I found out the water was coming from the underground piping. On my wall (forgot to take picture…) there was water, mud and insect coming from the ground through my wall. I called my contractor to told them it was broken.

The next picture show a bit of the floor that fall because of the water. It was expected. They told me that when that happened, it broke the piping. They came back, excaved the ground around the piping to find it broken. They recap it the same way while I was telling them it will broke again is not made properly. They told me to wait a day, then fill a bit, water it down, then fill (etc.) to remove the change of big wait break everything. The next picture show the ground after they filled it back after repairing the broken pipe. At the sametime, they also put some cement at the joint of the fondation and the footing, telling me it would solved the problem. The owner of the compagny keep telling me the problem was the chimney, not the drain. They wanted to ciment a footing on the chimney. The chimney is kind of far though. When digging the whole to do all of that, they didn't protect anything (why protect something they scrapped) and they filled without leveling. Now, all of the 3/4 rock I had between my house and pool is gone underground.

I had holded the last payment because I was saying the job was badly done and nothing was fixed. After this day, they told me I would get sued over so I decided to pay. While talking with one of the guy, he told me that if I want the job done like i want (correctly), I would have to pay another 5000-6000$ for the time. I refused, arguing it's stupid since it's job is badly done. I paid the last part of the job. The owner of the shop told me he give me a 25 years warranty for the job. A week after, I got another water infiltration and he told me the problem is the chimney and that i'll cost me to repair it, refusing to say the problem is the drain installation.

We had after that about 1 month without any rain. After that, we had some shitty weather with lots of heavy rain falling without any water infiltration. I asked him if the problem was with water infiltration from the chimney up or under, never had any information. For me, since we are in summer, water under the house have lowered and the rain isn't enough to raise above the footing, thus why I'm not getting anything inside. For me, the problem come when the water under the house rise, and the next time I'll be able to check that is next spring.

We can also see that the "Delta-MS" (black stuff on the wall) is hold in place with a resisto-seal tape. This, didn't hold. They did that everywhere there was a joint or a crack on the delta-ms. Nothing hold.

The next pictures show how they made the joint. They installed the molding strip that came with the Delta-MS (I think) and put some tar on top of it. But, as the picture show, the wall wasn't cleaned before applying the tar. Because of that, the tar cracked and didn't hold at vaious place. They came many time to fix this, as some other picture show with some strip of tar applied with a gun in the crack showed, but it never hold.

The remaining picture are photo I took about 2 months after showing the ground. We can see on these pictures all the stuff they left on the ground (and in if we don't count what we don't see). Orange stuff are ceramic piping from old drain, black stuff are flexible black drain, plastic drain tubbing, nails, geotextile remainings…

After we can see the corner of the chimey. As you can see, the corner is ripped and a resisto seal tape was used to "fix" it. They finally put nail in the molding on top of the delta-ms, as we can see on the next tw picture. But still, the molding and the delta-ms isn't tight to the wall and the tar doesn't hold.

The next picture show another big patch of resisto seal tape used to cover a ripped delta-ms.

Next pictures show other place here the tar doesn't hold or were they patched with resisto seal tape delta-ms again.

Remaining picture show stuff I found in the grass, like metal rod that was holding old antenna (that they removed), wood, ceramic (Etc.). The front of the house, like the back, is full of rocks too and not flatted/leveled like it should (the level was nearly just ok the first time but when they got back to repair the back, they didn't level anything). Because of that, no way I can cut the weeds (no more grass everywhere), that's why it's looking like that.

There's another picture in there showing the edge on the fron Window. We can clearly see that the edge is not close to the wall and have rocks stuck between it and the wall. Also, this specific edge doesn't even have nail on the bottom.

The last picture show how the terrain look like right now. It doesn't seems that bad because of the weed, but it's very hazardous. I denied my kid to go there and in the backyard because one of them already hurt himself walking on a ceramic piping. Nothing serious, but still, I don't take any chance.

As for the pile of woodscrap in the front, the city cut the tree in front and didn't clean the place. They are suppose to come finish the job.

I sent them a formal notice requesting them to either reimburse me or pay the bill for the remaking of the installation and cleaning of the ground. They told me I was making false accusation and they'll do the drain again.

I've replied saying that if they wan't to redo the job, while I'm not very open to the idea, they have to respect a list of criteria and stuff to do. This inclued to redo the whole resisto seal (liquid one) with a proper cleaning and removal of old seal tape, installing new isolofoam (can use the same if undamaged or unsoak), installing properly while using recommendation from maker of the dela-ms covering while replacing teared sheet, installing properly the drain on the side of the footing, under the level of it so it drain the water before reaching the footing, installing the missing geotextile, putting the 18" of 3/4 rocks properly on top and bottom, cleaning excaved ground so the filling doesn't contain any bad stuff like ceramic tubbing, styrofoam (etc.), cleaning the ground where they didn't excaved and didn't protect so it's on clear black top soil and grass with everything leveled. I'm 5 days out of 10 in the countdown, I'm pretty sure he won't accept.

Now, this hole big post is about: Am I right that this installion, when checking these picutre, is a big mess badly done? I'm probably going to court against the contractor and I'd like some input on that job. He says everything is right done by the code and laws, but that's not what I read. Right now I wanted to have an engineer to come to my house and verify, but they quote me about 2000$ and I'm running short on cash. Before wasting money on an engineer, would be great to be sure.

Thank you

Submitted August 31, 2017 at 11:16AM by nodiaque
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French drain redone – not sure the job is good

Lets talk about Tooling Design!

Lets talk about Tooling Design!

Hi engineers! I have been in the special assembly tooling industry for about 16 years designing, building and providing field support for automotive assembly. (Think lift assists and other ergonomic related tools…) One of the biggest challenges that I have seen is developing a robust "Zero-G" control scheme that is easily applied to various tooling designs. (Zero-G is a term used by Tooling ME's and EH&S peeps to designate a tools up & down movement as perfectly balanced and requiring very little effort by an operator to manipulate.) There are many different ways to accomplish this but they all have unique elements that make them a PITA. What caveats exist in the equipment you design? What would be the best solution to your issue?

Submitted August 31, 2017 at 10:04AM by nippletumor
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Lets talk about Tooling Design!

Need reading Material, Manufacturing and meterials (aluminum, Steel, etc) related

Need reading Material, Manufacturing and meterials (aluminum, Steel, etc) related

I am a new Manufacturing Engineer at a 3rd party manufacturer in the aerospace industry. We do Phosphoric Acid Anodization, layup and bonding of fiberglass panels that may or may not use some type of aluminum panel, and chemical etching.

I have search google for books on these subjects and there are many. I am looking for recommendations from people who may be in the aerospace industry or are familiar with these practices as they pertain to the aerospace industry or are at least a good lead.

I am interested in finding out more about the types of metals that might be used, how they are designated and the material properties. I am also interested in learning more about how the Phosphoric Acid Anodize works. Maybe some in depth papers, publications etc on the subject.

Submitted August 31, 2017 at 09:42AM by tool2508
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Need reading Material, Manufacturing and meterials (aluminum, Steel, etc) related