[nivlek]

Hello all

I'm hoping that someone could assist me on a how to, "set up and machine a six sided toy car“

I'm using V25 and have a 4 axis set up.

I have a 3D model of a toy car.

Basically I can machine 4 sides (top,bottom, left hand side and right hand side) but miss the front and back.

How can I then re-position the toy car to machine the other 2 sides (front and back)

awaiting your advice
Kel

[RAF.]

A picture of the toy would help if your unable to post the solid.

These are always fun challenges.

RAF.

[RAF.]

POSTED TWICE

HAD TO REFRESH BEFORE FIRST POST SHOWED UP.

Is the zone having problems again?

[magicniner]

One option is to extract the geometry from your model and use it to model and machine a pair of fixture plates with a partial negatives of the car's top and bottom shapes. You could use these to sandwich and securely hold your car without damage, whilst leaving the ends exposed. With the fixture held in a vice you can position the front or rear of the car upwards for finishing.
Careful planning of material left on the ends and zero for the end operations should make it reasonably easy to position for machining,
Regards,
Nick

P.S. This was far harder to post than to compose, some features of the site still appear T.F.BUNDY

[nivlek]

This was the 6 sided car that I would like to machine

Kel

[ger21]

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Is the zone having problems again?

It did the other day.
Clear your cache, or logout and log back in.

[aldepoalo]

Have you watched this video:

[aldepoalo]

And this one?

[nivlek]

Thank you Al, That video is what I used to get to where I am now. I can index to four sides of the F1 by using your video. But, how do I re-position the F1 to machine the front and rear of the F1. (the 5th and 6th sides)

I am using a 4 axis machine and I hold the F1 at the front and read positions. I then machine the LHS, RHS, roof and the undercarriage by indexing and final finishing cut by using the rotation 360 degree.

I expect, that I would then have to remove the F1, from the 4th axis and hold the F1 in a vice, to machine the front. But this would have to be a very accurate re-position so everything machines within tolerance and lines up.

Kel

[BurrMan]

I am using a 4 axis machine and I hold the F1 at the front and read positions. I then machine the LHS, RHS, roof and the undercarriage by indexing and final finishing cut by using the rotation 360 degree.

I expect, that I would then have to remove the F1, from the 4th axis and hold the F1 in a vice, to machine the front. But this would have to be a very accurate re-position so everything machines within tolerance and lines up.

Kel

I would say you can do it, but the sixth cut will be setup as a hand job.

So your stock is setup precisely (not just random stock, so your reposition will be precise). You will make a solid in the front and back that will represent the amount of material you determine "needs" to be there to hold it stable during the rotation ops (Preferably a round pole of some size).

You can then flip the stock to cut some detail in the "front grill" with a 5th op. Then cut the pole off the rear window by hand and sand/grind that small area smooth.

braininskull - YouTube

If you really need a sixth cut, you will have to cut a jig/negative of one of the ends to hold it, as mentioned.

You may possibly be able to leave some poles in the roof and undercarriage to rechuck the 4th axis and do the 5th and 6th cuts, then hand cut/grind/sand those areas last, but that just becomes method.

Anytime your removing and resetting stock though, is opening the doors for inaccuracies.

[jrmach]

You could drill,then bore dowel pin holes to use as "Datum" points.From there you can get creative with clamping and fixturing.When you are done, fill the holes with appropriate material (wood putty,???) and sand and blend smooth.

[nivlek]

Thank you BurrMan for the suggest. Your explanation is basically what I was suggesting. A maunal re-position, by hand, focusing on been very accurate.Because the brain in the video is round,the position can be a little off, but with the front of the car, head lights, grill etc, you really need to re-position precisely.

Thank you also to JRMACH. I have made up a simple adapter that I screw to the material and then hold it in the 3 jaw chuck and tail stock.

Kel

[BurrMan]

The position is with the model and its relation to the origin and rotation of the toolpath ops. This is precise and is easily obtained. The imprecision comes in resetting the actual stock.

I would think you can get better precision from "leaving some known portion" of the original stock to use for re fixturing, rather than attaching something after the fact.

[jrmach]

"I would think you can get better precision from "leaving some known portion" of the original stock to use for re fixturing,"




YES,or you can put in your own feature/features (dowel pins) and remove them when done.I am not talking dowel pins to hold in the lathe or whatever,just as Burr is saying,it is establishing an EXACT point (Datum Point.)

[magicniner]

Thank you BurrMan for the suggest. Your explanation is basically what I was suggesting. A maunal re-position, by hand, focusing on been very accurate.Because the brain in the video is round,the position can be a little off, but with the front of the car, head lights, grill etc, you really need to re-position precisely.

You can build cuboid blocks which you add to the front & rear of the model for the 4-axis cuts which then give you very precise datum surfaces for aligning your final two manually aligned cuts,

- Nick

[nivlek]

Nick
sorry to trouble you, but could you please explain cuboid blocks ?

Kel

[RAF.]

Nick
sorry to trouble you, but could you please explain cuboid blocks ?

Kel

This is what I think cuboid blocks might be. And if not this type of set up still works for holding and indexing ends. indexing does take some time but works

RAF..

[magicniner]

Nick
sorry to trouble you, but could you please explain cuboid blocks ?

Kel

Kell,
I just thought you could leave a cube (or rectangular cross section solid [cuboid]) on the front & back of the car, giving you four edges and a face for setting your zero for machining each end.
Since you'll be adding the blocks in specific positions they could offer you an excelent datum for setup,
Regards,
Nick

[RAF.]

Has any body tried a set up like this?

While job is still in the forth axis / spray part and mandrel grip areas with release agent and hold upper mandrel in spindle at desired coordinates and use epoxy or even hot glue to form the female cavity. After cured or cooled put in to forth axis index and finish ends.

[nivlek]

Nick and RAF
Thank you for your advise.

These models maybe one off's. So I'm a little concerned that the cuboid blocks would be very time consuming to make.

The only way that I thought of was how you have explained it, leave a section of square at the end. (front and rear.) Then hold it on the underside. After machining, fill the hole in the underside by wood filling.
The only problem is the precise location, and that is where the cuboid blocks come in.

On the other hand maybe I should try 5 sides rather then 6 sides. Secure the underside to the A axis and maybe rotate it to do the front, LHS, RHS & back. With the cutters that I have, maybe they will cut the roof line. Maybe !!!!!

Kel