Where to buy spindle

[HipoPapi]

Hi Jezz and thanks for the reply.

The gentry is made of 100x100x4 mild steel mainly and 20mm aluminum plate.

The estimated weight of the gantry excluding the steppers/HIWIN rails and blocks/ ballscrews and mounts is:

Y + Z = 135 kg (including 5.5 kw ER32 spindle)

Z = 46 kg (including 5.5 kw ER 32 spindle)

In terms of speed I have no idea to be honest . I was told by someone who used to machine ice that I can push it as fast as I can as is really easy to machine. I guess experimentation will tell.

I was thinking of servos as well, but they need gearing and since planetary gears are expensive and belts aren't an option in the freezer I think I am going to stay with the closed loop hybrid servos.

I have seen your video review of the similar system from zapp and was quite impressed.

Please see the attached pictures for sizes.

Light Grey = 100 x 100 x 4
Dark Grey = 150 x 100 x 4
Orange = 10 mm steel plate
White = 20 mm aluminum plate
Blue = ice
Purple = removable module to be replaceable with 4th axes module in future
20mm HIWIN rails an all axes


Thanks for taking the time to comment.
Vass

[JAZZCNC]

Ok well given the fact you will be running a resonably heavy gantry at higher feeds then I may be inclined to go with servo's due to linear torque.

Other option is to use higher pitch screws 2020 so you can get the same speed at lower motor RPM. Obviously you will lose some resolution but do you need more than 0.01mm.? I think you won't for ice.
20mm will put the motor in a 450 RPM range where torque is strong for the same speed as 10mm pitch. Where with 10mm at 9M/min you will be in the 900rpm range where torque starts to drop away.

Also I think if you contact belt manufactures there will be belts than can handle the cold so you could either use servo's or steppers with higher pitch screws to increase torque with a ratio.

[EddyCurrent]

Looking at the side view, it strikes me that things would be stronger if the cutter was further back so it was 'inside' the footprint of the two bearing blocks supporting the end frame. At the moment it is cantilevered out in front of them both.

[HipoPapi]

Hi Jazz,

Thanks for the quick reply.
That is a great suggestion as you are absolutely right that I dont need better resolution than 0.01. In fact I dont need better resolution than 0.5. I know it sounds ridiculous when I see what people are aiming for in this forum but realistically everything I do melts.
Ice blocks come in standard sizes of 1000 x 500 x 250 and they are not perfect so essentially here I need precision is the edges to make them match each other to glue them together with water. The cnc would do just the sides the top and bottom will be done on a band saw.

Thanks again I will definitely consider the 2020 screws.

Vass

[HipoPapi]

Silyavsky thanks for the hearts :) feeling much better now.

You and Eddy are absolutely right in your assumption. The design has changed since than. Instead of the 50x100 pieces I have used 100x100 ones all round and now the vertical bit is all the way to the back.Originally I have brought it forward to leave access to the HIWIN blocks but with the 100x100 profile it is no longer necessary.
It looks like this at the moment:


I have tried to design it in a way to have the blocks fixed and the rail moving, but the gentry become a lot taller.
The reason for that is the fact that the lowest position of the spindle is different from what you have seen.
You can see it better in the following picture.


Thanks again Silyavsky and Eddy.

[JAZZCNC]

Ice blocks come in standard sizes of 1000 x 500 x 250 and they are not perfect so essentially here I need precision is the edges to make them match each other to glue them together with water. The cnc would do just the sides the top and bottom will be done on a band saw.

So what you need is a surface planner not a CNC router.? Have you considered building a four sided planer on linear axis.?

This would be very easy to build and wouldn't need expensive spindles, tools, or controller and drives, ballscrews etc.

Because you know the linear movement you can just use programable drives that don't even need a PC. Use planner blocks and blades with normal motors for the cutting heads. For linear movement the simple chain drive could be used as you don't need precision just to move a set distance.

If you wanted to automate the process so each blade moves in sequence then a simple arduino could do this.

Just a thought.??

[HipoPapi]

Hi Jazz,

That is an interesting thought, but I intend the use the capabilities of the cnc as well actually quite a bit including 3d roughing and as mentioned earlier would like to add a 4th axes later if this works out alright.

Here are a couple of pictures of similar machines that I have used as reference. The one on the picture is a rack and pinion system and has been working for the past 9 years generally for about 6 hours a day. And it has a surprising setup that blew my mind and in a way made me confident in my design. It has only three HIWIN blocks on the y and also just three on the z. On the Y there are 2 on the front and one on the top and on the z two on one side and one on the other :)

I do a lot of logos in ice which would be done with the cnc. At the moment I do them by hand and it was ok until now, but now that I know that I am designing a cnc I cant stop thinking about how easy it would be :)


Thanks again for the great advice.

Cheers,
Vass

[JAZZCNC]

Ahh ok well you do need CNC then. . Lol

Something I was going to suggest regards the design was moving the top rail onto top of gantry beam and using the bearing plate to support the rear plate due to it's height and I see they have done this on this machine. This would be a good design change and if you notice they have triangle plates supporting the tall back plate which will resonate while cutting. Now surface finish won't be an issue for you but anything that resonates for long enough is going to have a negative affect on components etc so reducing it doesn't hurt.

[HipoPapi]

I will definitely consider the triangle plates as my z is higher hence I have the two beams. Mine is higher because I dont want the removable front plate to preposition the spindle all the time when I want to work an a thinner sheet of ice.
I have been thinking of placing one of the rails on the top, but It seems to me that it would be a lot harder to get them parallel, but steel I think that is the right way to go and will do a redesign on that.
Just to give you an idea of what they have got away with on the machine pictured earlier the gantry beam is a 150 x 110 aluminum box section, held by 100 x 50 x 3 aluminum box sections (the vertical bits and bottom bits) and the side plates and z axes plates are 13mm aluminum plates. This hopefully gives you a better idea of what forces are needed for Ice.

Thanks again