Saturday, February 16, 2008

Thursday 14. Medellin – Miami - Boston

I am back. Yes I did it again, I dropped off. Hey, this isn’t easy building this machine for the first time so quickly - it can drive someone crazy. By the way, don’t leave your cell phone behind in a Colombian airport. It is almost impossible to get back because you can’t leave the terminal boarding area once you are in!! Ok I didn’t try hard enough. My brother managed to convince someone to bring it in for me.

Fabrication has moved along very nicely. This week it seems not much progress happened but it did. We completed the welding on the base, lots of hours went into that. I’d say about 30 hours. We cleaned off and rust proof/primed the base by Wednesday afternoon. Now we have a working surface off which to start referencing all the linear motion components.

We also made some time to dive into castings. Initially I did not want to consider it, but I think it makes sense for smaller parts. We called around and indeed we found plenty of local suppliers that range from 2 to 5 dollar a kg for gray cast iron class 30. Currently we are having the support for the motors cast so that one piece holds the motor and the drive end of the linear screws. We also have a design for a T-slot table, which we will execute if we have time. We have to make the molds, which is not all that difficult. I guess casting will work for people that have access to small casting operations. They can spend a few weekends making the part replica and then take it in for a pour.

Now looking back at this week I feel confident the project will pull through. There is still a ton of work to do but we have the horse power to pull it off. Here is why. I found a great local supplier of motors and electrical components. Their prices are quite good. I just bough a 6.6 hp GE general-purpose motor (made in Colombia) for approx $350 USD with a two year warranty. With the supplier close by I know I can get plenty of support. Then there are the people. The project has a great staff now. Let me start with Jesid, he is our tech. Sometimes he works part-time for the university but for now he is full time with us. He is a funny guy, he has is own quail eggs business. When I asked him how many quails he had he said it’s a small operation but I make a living. He has 6000 quails and pack about a 100 boxes a day. The whole operation takes him a few hours a day so the rest of the time he gets bored out of his mind. His dad used to own a hardware store so he grew up being quite a handy man. Jesid has great work ethic, and he works hard. We don’t have to supervise him and he is always asking for more.

There are the dLaC guys –Estaban, Juan and Pedro. They have taken the roll off leading fabrication. In contrast to their design office in the most trendy square in Medellin, these guys now spend their day in jump suits, working with Jesid and chasing everything that needs to be made. I sit most of the time in the garage with them, working on my laptop and we call on each other for question and ideas. It’s been productive to work this way.


There are Lina and Camilo. I decided to hire help on the CAD side out of concern with the amount of work that preparing the document will take precisely at the time when we are doing the most testing on the machine. Lina started first on Wednesday and she quickly got up to speed with SW2008 and got started on the castings. (This gave me the time to chase down that motor supplier.) Seeing that this was quite a good idea and the fact the Jesid and the dLaC guys where running out of work and the fact that I could not continue to relay on all nighters to design them parts. (Design after a few night of little sleep is not recommend to anyone…not good.) I asked Lina if she new anybody. She said - I know just the right person and he is sort of available. Should I call him? She did and two hours later, Camilo came in. Camilo and Lina have been friends for a while and they graduated this December. Camilo is freelancing partime with the city on science museum project and Lina is waiting to go to France in the Fall to start her masters. Anyways, Camilo took on the enclosures for the machine and in an afternoon he had modeled a significant portion of it. I am so happy to have them helping out!

Then there is Hans Ley, a retired German machine designer that fell in love with Colombia and is now working as a professor. Hans is quite busy with his own stuff but from time to time he throws me a bone. This week he pointed me to a PC base CNC control board that I have been looking for. This was great the holdback in the motion control design so it just leaped forward. Plus he has three students that we are trying to convince to jump on board. They are CS/EE guys. They where initially intimidated because they had to pick the hardware but now that that is done they can focus on getting CNC Linux to run the machine.

And finally there is the staff at the university: Gabriell - CNC machinist; Jorge – Master welder; Juan, who runs the CNC plasma cutter; Jairo, who runs the place; and “The Beast” – he’s like Jesid but I actually don’t know his real name. Everybody calls him “La Fiera.” He is super cool and always willing to lend a hand. They are all very excited about the project and they are doing their part. They all have quirks of their own. For starters, there is Plasma Juan. He is an EE major the prefers to work the CNC plasma machine than graduate. He works part time for the university while he finishes his degree. He is the kind of person that would fit at MIT - he wears his welding hood while he bikes. Most people in a rush to cut something would rather not go through him since he likes to explain in detail what we will need to do. But people like him can teach you a thing or two, plus he is totally into the project and has delivered beautifully cut pieces very quickly. Plus, he can’t wait till we are done and pitch the idea of an Open Source CNC plasma cutter.

Then there is Gabriel. He is the most excited and vociferous. He was the one that pushed for us to do castings and got us some initial quotes. He is also inviting all the local vendors of CNC related stuff to come in case we need something or they can be of some assistance. But what cracks me up about Gabriel is his obsession with the New York Yankees. He’s been begging me to bring him back a jersey from the States. The only problem is that I live in Boston, and I tell him I don’t think they sell Yankees stuff in Boston - it may be against the law or just plain stupid. So I tell him that I will have to order it online and that I will have to charge him for the shipping. He doesn’t like paying for the shipping for parts. I’ll get him the jersey anyway, but will not give it to him until the end. I’ll make him work for it.

Then there is Jorge, the welder. He’s the first Jorge I have ever worked with. Jorge is a perfectionist and initially he wasn’t too happy about our not-so-refined approach to welding. It took some time to convince him that a regular Joe in the countryside with a stick welder should be able to do this. Plus stick welding is ideal for thick gage structural welding and is more forgiving. Sure it doesn’t look as nice as what he can deliver but having Jesid do it is like 5 times cheaper, the university rate for Jorge is relatively high. He is happy now with fact he is only going to get the really important parts. The closer we get to the spindle, the more I am going to need his skills. I tell him, but not far away at the base, which is the first phase of the project. Jorge has his own quirk – he is obsessed with his helmet. Well, he has the only auto-darkening helmet around which the university purchased for ~$500 USD five years ago. He treasures this helmet. It is in remarkable condition – no, seriously. And he doesn’t like when others - especially students - use it. I asked him why and he showed me the scratches they have put on it. It’s a fire red Miller Elite helmet with flame detail. He constantly puts it away and even hides it but they find it anyway. Jorge asked me if I could find out what it costs to get one states side. It was only too simple to Google to find out the his helmet went for ~$350 USD, twice as much as other brands with the same specification. I haven’t told him but when I get back I’ll tell him that for 150 he can get something as good with flames and skulls.

As you can see, they are quite the crowd. I am starting to feel like Santa, who instead of returning to the North Pole returns to Boston. I don’t mind as long as it is not imposing, and although Colombia’s economy is in rapid growth (~7%), hardware is still expensive, especially if it is imported. It is one of the easiest ways for the government to ensure tax revenues. Colombia examines 50% of the containers that enter the county. Everything has a tax code or something like it, and when you compare the selection state side tagged with a 30% off sale at places like Travers - hands down the US is the most affordable place to buy tools and gear. This should say something about our ability to compete in manufacturing but does not seem to correlate. I am sure this topic needs a much larger discussion.

Now back in Miami waiting to connect. I am sending my last orders behind. I left my laptop behind for lina to continue the design and tomorrow she will be visiting a few foundries to show them what we need. Camilo has a new Dell Inspiron loaded with SW2007. It’s super fast and smooth. It makes my hp NW series look slow. Now I want to update my PC - bad news, because a fully loaded hp mobile work station will cost about $2,600 USD.

While I am in Boston, I will focus on the electrical diagrams for the machine to ensure that I have enough time to order everything. I also have to ship the spindle and ballscrews and some other gear. Juan and Esteban will be cutting the x and y axis and drilling the hundred or so holes that support the rails. Now, making these holes with modern machinery should by no problem. The problem is that we are not using any machine that is in working principle bigger or better than what we are building. If we manage to do this, then truly anybody can build this machine. So making the holes will take some time. I have to remind them to take some pictures.

There is one aspect that is starting to worry me, and that is implementation of a tool holder. I am not sure what I will be getting from SKF. Too much to worry about and I have not paid attention to this. Will call them tomorrow to find out.

Now to end this very long post. I have to say that this would’ve not been possible with out the incredible support that I have been getting from everybody my family, specially my brother and everybody in Medellin. I bring this up because I do not have this kind of support network in Boston. Most of my friends have come and gone and some have even moved back to Colombia. So although logistics and ordering would of been a lot easier state side, I feel very encouraged by everybody around me to put in the extra long hours that the project has demanded. Plus, you can beat the climate – it helps when you don’t have to worry about the snow.

1 comment:

bruce said...

Enclosuresare more important for such high speed CNC machines.