Built on a foundation of past mistakes.

[Moondog]

Hey Guru....(Benny).

it is amazing that you completed it so quickly. great achievement. Thanks for posting all of the details, warts and all.... we can all learn from our mistakes. Anyone who says that they didn't make a mistake is either a Liar.. or hasn't done anything. Hopefully when mine is finished I too can share my mistakes and reflect on how I would have done things differently.

Hopefully all of the 'New' buidlers can take inspiration and know it is all worth it in the end when you see your little 'baby' take its first steps....

cheers

[c_bakey]

Enjoyed your post. I am getting ready to do my first machine and I had been thinking about using many of your techniques, so it was most reassuring (you know how some of your bright ideas just don't seem to work as planned!). While I found your discussion of the gear ratios interisting, I am curious to know what speed motors you used/would use next, and if your measured the breakaway torque on the axis'.

[ViperTX]

Benny...that was pretty fast....great job!

I'm still working on mine....darn designing and machining ballscrew journals has really slowed progress. Got the machining under control after annealing the end of the ballscrew.

I finally broke down and ordered some bearing blocks from Mitsumi, so I can move forward.

[Jason Marsha]

Benny,
I am in the process of building a 5X10 router and I would like to know if you had any problems with the belt stretching.

Is there a special grade of belt to purchase?

Have you replaced your belt due to wear?

http://www.cnczone.com/forums/showth...253#post159253

Jason

[ynneb]

Jason, my belts have not stretched yet and are still like guitar stings if plucked. The belts plastic with steel impregnated cables in them. They are perfect for cnc routers, but probably would stand up to machinists standards when working in the 100th on a mm catagory. Not only this the belts have zero backlash due to the nature of how they are etnsioned on the pulleys, and the way they interlock with the pully. I guess in real terms there is a minute momentary stretch when triyng to get the weight of the gantry moving. But in practical use this is immeasureable and make no difference to the quality of the cut.

[Jason Marsha]

Thanks Benny,

It seems I have a lot of choices of belt material and configurations to choose from. I am partial to the GT2 series , 5 mm pitch belts from SDP/SI but these are neoprene - nylon covered fiberglass reinforced only. The HTD and T series are available with the additional option of polyurethahe-translucent reinforced with steel tensile cords which I assume is stronger but the minimum diameter of the pulley to be used is larger than that of the neoprene belt due to flexibility.

What is the diameter as well as the number of grooves used in the pulley that your long belt runs on?

Jason

[turmite]

Hi Benny,

I'm curious if you would have an opinion about a light weight machine running belts in an axis length of say 24 ft? Could this be done or would it be better to rack and pinion?

Mike

[Netjams]

That is one cool machine!

[ynneb]

Mike, I really have no idea what would be better over 24 foot lenght, other than I selected belts for cost saving over Rack and pinion. I do expect you would need very wide belts in order to compensate momentary stretch. You wouldnt have that problem with R&P.

Thanks Netjams, you are easily impressed. I would rate my machine amongst the lowest compared to other members machines, in terms of build quality. But thanks anyhow

[Jason Marsha]

Benny, I think you rate your machine to low as I have not seen many who have a working router that big complete with supporting table and is reliable enough for you to source outside jobs. I am sure your machine does what a lot of much more expensive machines do and just as well, shopbot,ezcnc etc. I know of an AXYZ machine that just cuts plastics and mdf for signs, I am sure if they had the knowledge they would have tried to build one themselves.

After Spalm linked me to your thread I decided to use belts for my long axis when I saw what you did with yours, which now makes my task a little more simple.
One great thing about designing and building a machine yourself, you know how to fix it yourself.

Jason

[ynneb]

think you rate your machine to low

Probably I do. But you know when you build something yourself, you know of all the mistakes and flaws. The other thing is, if you rag something, you dont dissapoint anyone when they see it. I recon its better to undervalue something with the chance that others think better of it, than overrate it and pople thinking what you have done is crap.

[4nak8or]

ynneb, you have to give yourself credit for building a working machine at least,especially in the time that you completed it in, I'm building a 4 x 4 router at the moment and its work like yours that inspires and helps the rest of us. I'm considering using belt drive on my x axis now after finding out about the success youve had with your machine, keep up the good work.