SingAstro

Hi! I'm new to this.. And I would just like to find out why we need to use a dovetail rail? Why can't we directly attach the telescope to the mount without the dovetail bar instead? Can anyone help?

Help12345,

What you mean by a dovetail rail?
Can you explain how you mount your telescope to the mount (what mount) without a dovetail bar?

i mean dovetail bar not rail… hmmm.. I have no idea but I have seen some really cheap and lousy telescopes online which don't appear to use a dovetail bar. so i was just wondering if it is at all possible to attach the telescope on the mount without a dovetail bar.

http://davetrott.com/wp-content/uploads ... heapo1.jpg

those cheap telescopes are light. very light. even good camera mounts can hold them very steadily

dovetail is a very stable structure it prevents telescopes of weight in excess of 10kg to be slided onto the mount without falling out due to the wedge design. and it allows easy mounting sliding onto the mount.

Essentially dovetail bars are a universal means of convenient quick attach and release, with the ability to balance the scope. Without them, each telescope must be manufactured to fit a particular mount, which is much like saying each camera has its own specific model of tripod.
Yes you can attach your telescope to a mount without a dovetail but this will usually involve drilling a hole of the appropriate size in the tube of the telescope and bolting that directly to the bolt hole of the mount, which would make it difficult to disassemble and impossible to rebalance.

The dovetail shape does have industrial usage, not just limited to astro purpose.