Belts or Screws Why

[willyinaus]

Just checking in to see how the new belts are going have you had a chance to play as yet.
I have started work on the Y axis mounted two surplus rails on some aluminium extrusion lengthways and its is going to be 1260mm long approx 49inches in your language.

I was thinking of using
PART NUMBER, A 6Z16-C025 0.08( MXL )1/4"
for the belt does that sound right?

Then I just need to pick out the correct pulleys.

Willy

[bdring]

I think that is the belt I have. I have not used it yet, but I am happy with the look and feel of it. It is quite strong. My workshop is normally not heated and we have had a long cold spell 0F-10F. I don't like to fire up the shop heater below about 25F. I have my controller ready to test, so I am quite annoyed with the weather.

With that length you might consider some sort of support for the belt. It will sag quite a bit.

You sholud post some pictures of your build.

[lasersafe1]

I bought the 0.200" pitch timing belts. They were way overkill in size and strength. I just bought some 0.080" pitch belts to try out. I wanted to get a little more resolution. They are due on Monday. I will compare and let you know my thoughts Monday night.

Every time I read this I keep wondering what you actually meant. The pitch of the belt has nothing to do with resolution, unless there is some rule that more teeth gives a tighter engagement to the pulley. But even in this case the word would be "less backlash". Resolution is purely a matter of steps per inch and the ratio of the pulley sizes.

[willyinaus]

So this is a pic of the Y axis Rail and block its two Rails joined to together and whilst joining two rails together isn't ideal as you get the train track sound I don't seem to be getting an notable problems moving it with my hand and at a later date I will replace it with a single rail.

I have used a lightweight 25mm 1.6 SHS extrusion that I had left over from a set of shelves that I made for a cupboard over xmas tapping and screwing it was a bit of a challenge though, I also thought this would bend under the weight of the rail but adding the rail has stiffened it even further so it may actually work as the gantry only has to support its own weight after all, I can always add some angle if need but I think it will be fine.

I am trying to keep the Gantry as light weight as possible and this was a cheap idea I will upgrade down the track as the need arises.

Willy

[buildsomething]

Joining two linear rails is an industry standard practice providing you can square up the ends.
I was able to join two rails together grinding the ends of each rail using small milling machine. I machined up a small mandrel to hold a 6" grinding wheel and then trued up the ends using this technique. This worked for me.

As for using timing belts, I am using them in my machine a span of over 54" with no problems as of yet. Since there are effectively very low loads on the type mass that we are moving, timing belts can be used without any issues. We have used them at work in many robotic applications with a repeatibility of .001" with no problems at all.

Richard

[willyinaus]

Thanks build something wish I had a mill that I could do that on , I think it will be fine the worst it can do is damage a block over time and I have another 3 spare also if I get to that point that the laser is doing some much work and making $$ then I will just replace it with a full length rail.