Help Please for Moving Gantry

[Nr1madman]

Okey :)

I think fixed gantry will be a good choice.
Maybe something like this.
https://m.youtube.com/watch?v=K9UA9ZRFwWU

I also think it's a good choice to go up in size for the steel frame.. as you have planned now!

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[endlasuresh]

Thanks for the Video and I watched it long back, planned to mAke similar one with less in size because of grinding and milling can need on z axis.
anyway here are some questions
I need size of rails and screws

For z axis 20mm linear rails can be ok?
and lead screw how much size should i take?

sample one here https://www.ebay.com/itm/Z-Axis-Line...wwW4n38Qfo6T7g


for x and y axis should i increase 20 to 40mm?
also the same lead screw sizes as the weight would be more sometimes.

First i am going to buy these two things then build the base since these are available in Our local stores.

Waiting for your answer and the size of the base would be 31 inches into 31 or 35 inches sine I dont need the biggest onE presently.

[Nr1madman]

Thanks for the Video and I watched it long back, planned to mAke similar one with less in size because of grinding and milling can need on z axis.
anyway here are some questions
I need size of rails and screws

For z axis 20mm linear rails can be ok?
and lead screw how much size should i take?

sample one here https://www.ebay.com/itm/Z-Axis-Line...wwW4n38Qfo6T7g


for x and y axis should i increase 20 to 40mm?
also the same lead screw sizes as the weight would be more sometimes.

First i am going to buy these two things then build the base since these are available in Our local stores.

Waiting for your answer and the size of the base would be 31 inches into 31 or 35 inches sine I dont need the biggest onE presently.

Hello again!

That ebay link is for a lead screw with 8mm thickness.. it's not nearly enough.
It probably would work for a machine made in MDF for sole purpose of machining plastic or something like that.
Not for steel construction with high weight.

Most people use ballscrews with 16mm diameter with your size machine.
Leadscrews have bigger backlash and more wear that ballscrews. And they require bigger motors.

When you say 20mm rail. What type of rail are you looking at ?

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[endlasuresh]

That lead screw was posted as sample, yes it is very small. can I use 16mm or above with ball screws.

For rails someone suggested long back linear rails. let me know the best one and sizes so i can search in market as they are available here.

thanks again,

[routercnc]

Hi Endlasuresh,

You are only getting answers to some of your questions because what you want to do is not the usual DIY machine.

The requirements of your machine are to be able to machine tool steel (?) to create accurate dies for a plastic injection molding machine. I assume on a fairly regular / daily basis as part of a small business. This is quite an ask for a simple DIY machine and is one of the reasons you are not get a direct answer.

So, lets put it another way. No-one is going to give you plans or CAD drawings for a machine ready for you to put it together and start machining.
Instead, if I was doing what you were doing I would look at how the commercial machines go about doing it, ask yourself why they did that, and design in some of those features as best you can. For example, here is the inside of a Mori Seki machining centre with a moving gantry.





If you go to their website it will most likely tell you the interior cutting area and from that you can approximate the scale of the ballscrews (I would estimate at least 20 mm) and linear profile rails (estimate at least 25 mm possible larger), aligned to a reference edge and stiffened using side load 'fingers', with cast main assemblies, and a very powerful spindle, plus servos motors to drive it all. Given you started looking at machines in 2010 these sorts of features should be familiar to you.

Alternatively there you can convert a reasonably sized milling machine to CNC / buy an aftermarket kit for a milling machine. This gives you a fixed head and moving table.

Hope this helps you decide what to do - I don't think anyone on this forum is 'holding out on you' if that is the sub-text of your posts.

[endlasuresh]

@routErcnC
I know no one is going to give cad or whole Help, but just needed some help, the rest will be done By ourselves.

thanks for your suggestions

ill go with 20mm ball S Crews and 30mm linear rails.

ill search In the market and post the images, until that i Put hold.

well all people design first and then Look for the materials, but i am Trying to find these two t Hings Offline and then design it.

the One video posted by nr i madman is easier to build so ill go with that one.

i Understand what you said, but i Want to do Once in My Life.