Integrated WCD "Warp drive" chassis

[mman1506]

Originally Posted by Gregor

With a CNC Plasma, I would consider doing drivetrains similar to 610. They have very nifty flat plate drivetrains, and is probably much easier to access and service. They cut their's on a CNC router.

http://www.chiefdelphi.com/forums/sh...&highlight=610
http://www.chiefdelphi.com/forums/sh...&highlight=610

I would but sheet metal is really expensive, I'm not sure if its just Canada but two 6061 6x37 .125 sheets would be double what the 3x3x37 .120 box tube costs. Plasma cut metal also takes a long time to finish and isn't as precise. Does anyone know how 610 hold's there sheetmetal in place on there router? I cant think of a way to do it without using wood as a relief material but it looks like there using something else in there pictures.

[CENTURION]

Originally Posted by mman1506

I would but sheet metal is really expensive, I'm not sure if its just Canada but two 6061 6x37 .125 sheets would be double what the 3x3x37 .120 box tube costs. Plasma cut metal also takes a long time to finish and isn't as precise. Does anyone know how 610 hold's there sheetmetal in place on there router? I cant think of a way to do it without using wood as a relief material but it looks like there using something else in there pictures.

Can you link to the photos of them cutting it?

A wood panel under the workpiece is one of the easiest ways to do it, plastic is a good substitute, but a bit more expensive. For accuracy, it's common to have the router face a small amount of material off of the top to true it to the spindle.

You can also get a vacuum table, but that is also more expensive.

[mman1506]

You can see it in one of the images of there pdf http://team610.com/wordpress/wp-cont...-Edition-4.pdf it's a small picture though. It looks like some sort of a vacuum table with plastic relief?

[CENTURION]

Not a vacuum table, those strap clamps are definitely doing the holding. I think they just have a sheet of plastic (the black part) as a backing.

[Gregor]

Originally Posted by mman1506

I would but sheet metal is really expensive, I'm not sure if its just Canada but two 6061 6x37 .125 sheets would be double what the 3x3x37 .120 box tube costs. Plasma cut metal also takes a long time to finish and isn't as precise. Does anyone know how 610 hold's there sheetmetal in place on there router? I cant think of a way to do it without using wood as a relief material but it looks like there using something else in there pictures.

The team I was on had a CNC router. We used a big piece of plywood and wood screws to hold the metal down.

At Metal Supermarkets a 6x37 sheet of 6061 0.125 would be $30, and a 6x37 sheet of 5052 would be $24. That is pretty cheap to me, considering you only need 4 sheets. Why 37", and what is your source?

[mman1506]

Originally Posted by Gregor

The team I was on had a CNC router. We used a big piece of plywood and wood screws to hold the metal down.

At Metal Supermarkets a 6x37 sheet of 6061 0.125 would be $30, and a 6x37 sheet of 5052 would be $24. That is pretty cheap to me, considering you only need 4 sheets. Why 37", and what is your source?

The more I think about it the more I want to build it that way.. Anyway It still doubles the metal cost. I'll see if I can get the funding, my teachers are picky. I'm building it off of 2011 size specs

[Mr. Lim]

Originally Posted by mman1506

I would but sheet metal is really expensive, I'm not sure if its just Canada but two 6061 6x37 .125 sheets would be double what the 3x3x37 .120 box tube costs. Plasma cut metal also takes a long time to finish and isn't as precise. Does anyone know how 610 hold's there sheetmetal in place on there router? I cant think of a way to do it without using wood as a relief material but it looks like there using something else in there pictures.

We use hold-down setup clamps, step blocks, studs and t-nuts. Similar to this set found on McMaster: http://www.mcmaster.com/#fixture-clamps/=mc62a5

The top of our router's table has t-slots running down the length.

In between the t-slots, the top surface has black Sintra strips glued to the surface. These came with our router, and we replace them around once a year. When we replace the strips, we face them down with the router to make sure the working surface is level.

Whenever we cut a part on the router, the cutter goes through the part, and barely scratches the surface of the Sintra strips beneath. This does leave scratch marks on the Sintra, but not enough to warrant replacing them more than once a year.

In hindsight, a vacuum hold-down table would've been a nice addition, but we've been able to do without. Cutting COMPLETELY THROUGH plate is easy. Cutting partially through thinner plate is an issue, because the middle section tends to lift off the surface of the table when clamped using the hardware above.

[mman1506]

Originally Posted by Mr. Lim

We use hold-down setup clamps, step blocks, studs and t-nuts. Similar to this set found on McMaster: http://www.mcmaster.com/#fixture-clamps/=mc62a5

The top of our router's table has t-slots running down the length.

In between the t-slots, the top surface has black Sintra strips glued to the surface. These came with our router, and we replace them around once a year. When we replace the strips, we face them down with the router to make sure the working surface is level.

Whenever we cut a part on the router, the cutter goes through the part, and barely scratches the surface of the Sintra strips beneath. This does leave scratch marks on the Sintra, but not enough to warrant replacing them more than once a year.

In hindsight, a vacuum hold-down table would've been a nice addition, but we've been able to do without. Cutting COMPLETELY THROUGH plate is easy. Cutting partially through thinner plate is an issue, because the middle section tends to lift off the surface of the table when clamped using the hardware above.

Thanks, is there any advantage using the sintra over wood and other plastics?

[Mr. Lim]

Originally Posted by mman1506

Thanks, is there any advantage using the sintra over wood and other plastics?

Yes. Because our router has a Unist mister on it, the coolant it sprays could absorb into wood. Depending on the wood you use, it could maybe even cause it to swell? I'm not 100% sure as I've never let coolant sit around on wood to see if this happens, but I would be concerned.

Over other plastics - yes - it turns out Sintra can be had for quite cheap, and we've started using it for some of our in-class projects and prototypes. Its surface properties are grippy enough to provide a nice clamping surface.

Now we don't see the Sintra as a "sacrificial material" as we barely scratch the surface of it when we cut parts. As I mentioned before, these strips last us about a year before they get scratched up badly enough to be replaced.

If you were considering using it for a true sacrificial material, where you're trashing the Sintra sheet every time you cut parts, then it's probably not going to be very cost-effective.

[CENTURION]

Originally Posted by Mr. Lim

Yes. Because our router has a Unist mister on it, the coolant it sprays could absorb into wood. Depending on the wood you use, it could maybe even cause it to swell? I'm not 100% sure as I've never let coolant sit around on wood to see if this happens, but I would be concerned.

Over other plastics - yes - it turns out Sintra can be had for quite cheap, and we've started using it for some of our in-class projects and prototypes. Its surface properties are grippy enough to provide a nice clamping surface.

Now we don't see the Sintra as a "sacrificial material" as we barely scratch the surface of it when we cut parts. As I mentioned before, these strips last us about a year before they get scratched up badly enough to be replaced.

If you were considering using it for a true sacrificial material, where you're trashing the Sintra sheet every time you cut parts, then it's probably not going to be very cost-effective.

IIRC, a good hardwood impregnated with oil actually gets harder and stronger, but I'm no carpenter.

[mman1506]

Originally Posted by Mr. Lim

Yes. Because our router has a Unist mister on it, the coolant it sprays could absorb into wood. Depending on the wood you use, it could maybe even cause it to swell? I'm not 100% sure as I've never let coolant sit around on wood to see if this happens, but I would be concerned.

Over other plastics - yes - it turns out Sintra can be had for quite cheap, and we've started using it for some of our in-class projects and prototypes. Its surface properties are grippy enough to provide a nice clamping surface.

Now we don't see the Sintra as a "sacrificial material" as we barely scratch the surface of it when we cut parts. As I mentioned before, these strips last us about a year before they get scratched up badly enough to be replaced.

If you were considering using it for a true sacrificial material, where you're trashing the Sintra sheet every time you cut parts, then it's probably not going to be very cost-effective.

Wow, I never thought about that. Are "brute force" coolant pump would destroy the wood. I'll have to see if I can get my hands on some sintra.

[DampRobot]

Originally Posted by Mr. Lim

Depending on the wood you use, it could maybe even cause it to swell?.

We've definitely had this issue. Especially with very long pieces (eg long tubing), if the piece is being clamped with MDF underneath, swelling from absorbed coolent can cause some misalignment in the part. Plywood is even worse; because it isn't informally packed like MDF, it doesn't swell evenly and is very often not flat to begin with.

I can't remember any specific issues with sacrificial backing swelling, but I'm pretty sure we've had issues with it in the past. Don't read this the wrong way, coolant (especially mist coolant) is awesome, just swelling in the MDF backing can sometimes mess up milled parts.

Also, that film of MDF dust and coolant mixed together that forms after a long day of milling is really gross...

[sgreco]

Kind of reminds me of some 233 drivetrains of the past.

http://www.chiefdelphi.com/media/photos/33366

http://www.chiefdelphi.com/media/photos/31472

(The second one doesn't have wheels, but you can see from the bearings where they'd go).

[mman1506]

I've been a little busy lately but here is the latest update:

I've modified the modules to the plate design with 4 wheels. It is properly dead spaced now (Thanks, that saved me a lot of headache). Unfortunately there is not a lot of room for spacers but hopefully the addition of a tire will add some rigidity. I could always add some plasma cut spacers if strength becomes a issue.

We also learned how to use our bridgeport CNC with CAM software. Are last team "wave" didn't like using any computerized tools. Now we just have to buy endmills that aren't 0.02" off (It might have been a non standard endmill but we rarely buy those)

If someone is interested I will post the CAD files here.

[CENTURION]

Very nice! Looks like it will be a lot easier to work with the chains now.

I assume you're going to be adding some lightening in there?

Also, why can't you add more spacers in there? It looks like there's plenty of room