[Einars]

Hi,
I am looking for a drive of axis. My router will be ~2m long and ~1.4m wide. ACME rods are too expensive for me (total length of the rod ~4m), expensive bearings, nuts, etc. That why I am looking to belt drive. Where can I find pulleys for NEMA34 and open belt? It would be great from Europa UK/Germany..
In eBay has only for reprap belts.

Thanks.
Sorry for my English. :violin:

[John_B]

Look up Nexxen, they make a highly accurate rail and "gear" system.



Sent from my DROID RAZR

[rbraeking]

McMaster-Carr has power transmission parts. They are much more reasonable than grainger and their online catalog is easier to navigate.

FWIW I used #25 roller chain. It has a working pressure of 114#. My x runs off of a single motor close coupled to a transverse shaft. My y runs directly off of the motor.

[louieatienza]

Look up Nexxen, they make a highly accurate rail and "gear" system.

If the OP thinks ACME rod is too expensive, wait till he sees the prices on the Nexen system!

You might want to look into rack and pinion.

[harryn]

I am not sure about EU suppliers, but there is a lot of excellent information at BRECOflex CO., L.L.C. - High Precision Drive Components.

The OP probably cannot buy from McMaster. I was in Germany in Sept, and it was difficult to use their web site from there - partial IP blocking of some kind.

Belts can be used, but it is easy to underestimate the required width. A length to width ratio of approx. 10:1 will be needed for a fast wood router, and maybe you can back down to 15:1 for a hobby grade one, but not really much further.

Timing pulleys are usually supplied with a "pilot hole". You drill them to the final size locally so you can get the exact fit needed.

Rack and pinion is a good option. The challenge in Europe is that metric rack there tends to be made to a tighter tolerance than conventional US rack, so the price is a bit higher, at least that is what I have found so far.

[rbraeking]

I beg to differ with harryn. To buy from McMaster one merely needs to register on the site. He is probably thinking of Grainger which requires a buyer to be affiliated with a business. This is also easily gone around with a DBA filed at the county courthouse.....a cost of which is $10 in Texas.

The advantage of belt over roller chain is the amount of sag that can be removed with tension. As chain has more mass than belting it will have a tendency to sag more. One can overcome this by supporting the chain along its length. I intended to fabricate a wood rail with a slot for the protruding sprocket teeth but I found that this was not necessary. Chain sag is not a significant accuracy issue. It causes slight backlash but that can be overcome within Mach3. The chain is tensioned at the ends of the axis and utilizes one drive sprocket and two idler sprockets. I am running a chain on either side of my x axis and the tension mechanism also is used to square the gantry. The system works great and was the most economical of any of the alternatives.

Bob

[harryn]

Hi Bob, I use McMaster all of the time - in the US. The challenge I had was trying to use it when I was in Germany. I have a C corp, so that was not the issue.

[gualalasmooth]

Ya Bob I highly recomend chains I have them spaning 10' on my x
and have had no problems with any backlash adjusters are very easy with
the idler sprockets but I hardly ever have to adjust them. Also the cost of
chain and sprockets was great @ mcmaster and carr.

happy with chains - Tom