Problems with 20/20

[HannahtB]

On Wednesday our team received a shipment of 20/20 to build the frame of our robot. This is a normal thing for our team. This year our shipment came on time but the measurements were off. The diameter of the channel was .5 millimeters too small. Which would be usable except for the fact that the inner channel is also .5 millimeters too small. This means our sliders won't fit. We decided that we needed more sliders anyway and looked into getting more. They don't make any for the channel we got. Is anyone else having this problem or one similar?

[Lil' Lavery]

I'm assuming you mean 80/20? What did you order? What did you receive? What sliders are you using?

[notmattlythgoe]

Originally Posted by HannahtB

On Wednesday our team received a shipment of 20/20 to build the frame of our robot. This is a normal thing for our team. This year our shipment came on time but the measurements were off. The diameter of the channel was .5 millimeters too small. Which would be usable except for the fact that the inner channel is also .5 millimeters too small. This means our sliders won't fit. We decided that we needed more sliders anyway and looked into getting more. They don't make any for the channel we got. Is anyone else having this problem or one similar?

Were you expecting metric 80/20 or fractional 80/20? If you usually use fractional and got metric that could be the issue.

Here are what the 2 profiles look like.

[HannahtB]

We are meeting this afternoon. I will post the pictures. The company said that whatever we got in the 20 series should work with the sliders. The rep I was speaking to plans to call us back today. When we ordered it there was only one option I believe.

[Andrew Duerner]

If your talking about the standard 1 inch profile, I have seen a thickness change also. The gearbox we make is designed with a snug fit that slides into the channel of the 80/20. This is sized to channel ordered from McMaster about 3 months ago. Some channel that was ordered from McMaster about 9 months ago shows a visible difference in the thickness of the extrusions. I haven't measured it but I think your about right on the change, about .010" - .020" decrease in thickness on the newer channel. One question, with thinner channel, why would your slide not work, besides being a little loose?

[HannahtB]

The sliders are too big. We had everything for the larger size.

[HannahtB]

I have attached a picture that a team member sent me. I will get more detailed pictures in a few hours.

[lcoreyl]

Originally Posted by HannahtB

I have attached a picture that a team member sent me. I will get more detailed pictures in a few hours.

you probably just purchased 20-2020 (metric) series t-slot from 80/20.



I don't know what the one on the right is, but it looks a little different than 1010 (standard) series t-slot from 80/20, you might need to investigate where your previous t-slot came from?

[artdutra04]

Originally Posted by lcoreyl

you probably just purchased 20-2020 (metric) series t-slot from 80/20.



I don't know what the one on the right is, but it looks a little different than 1010 (standard) series t-slot from 80/20, you might need to investigate where your previous t-slot came from?

Based on their photo, it's more like that they have 25mm 80/20 extrusion:
http://www.mscdirect.com/product/det...S_010=01547645

1 inch = 25.4mm, so that would likely explain a ~0.5mm measured difference.

[Lil' Lavery]

Both items in the photo show the metric-style hole pattern in the center of the piece.

[orangemoore]

I don't think those pieces came from the same manufacturer. Is that a possibility?

[HannahtB]

We ordered them both from 80/20. I will take exact measurements and get better pictures in an hour and a half.

[notmattlythgoe]

Originally Posted by HannahtB

We ordered them both from 80/20. I will take exact measurements and get better pictures in an hour and a half.

These are all different extrusions that 80/20 offers.

[notmattlythgoe]

Originally Posted by Lil' Lavery

Both items in the photo show the metric-style hole pattern in the center of the piece.

Yeah, and the only other one that has the same hole pattern is the 3030, interesting.

[lcoreyl]

Originally Posted by artdutra04

Based on their photo, it's more like that they have 25mm 80/20 extrusion:
http://www.mscdirect.com/product/det...S_010=01547645

1 inch = 25.4mm, so that would likely explain a ~0.5mm measured difference.

the OP is calling what they just got 2020, which is why I make the assumption they have 80/20's 20-2020 series.

80/20's 25-2525 actually claims to have a slot max width difference of only about 1um from the 1010 series:

is 80/20 trying to slowly trick us ('Murica) into giving up our fractions??