Milling:Holding a plate

Hi, I started to mill manually a lid(With 6mm glass see through) for my lathe.

Measurements are roughly 340x 400 x 25mm. Milled it square all sided, them drilled the 4x holes to bolt it down, now busy milling the 6mm depth to accept the glass to see what going on. I have a prototype working, but want to make this out of one piece, no moving parts to catch the oil and deliver it to the spindle bearings.
-I have to mill from both sides to get 3x catch areas made up, in lid.
-Now nothing is exactly precise, but I need to mill at various angles, from 3-10 degrees to get the effects of the oil catch & flow going.

What is the best way clamping down and holding a 340x 400 x 25mm piece of aliminium on the mill bed and mill it at angles in certain sections.
Whejn finished there will be no oving parts, no biolts inside, and you will be able to see the gears run, where the oil splash, how its caught, and where its delivered.

How would you hold this secure, any suggestions. A lot of material will be removed.

Some carefully calculated and placed packing will allow the who part to be set like a sine table to the various angles needed.

That's assuming you don't have a mill the size of a Bridgeport and the large sine tables that fit them or a mill where the table can be inclined.

Another option if your 4 holes are in the corners is to make two strips of say 20 x 20 that can be screwed to the back of the plate so they are parallel at each end. You can then use two vices, one to hold each strip and just set the plate to your angle and tighten the vices.

Edited By JasonB on 07/10/2022 20:13:47

Chris, you don't say what sort of mill - can you tilt the head ?

Use a tilting table ?

Another approach would be to bolt the plate flat on the mill and get some tapered endmills as shown on the attached link to make the angled oilways. The link is to a US site but I expect you can get them in the UK also, at suppliers to the injection mould making industry. Many angles of taper are available.

https://www.mcmaster.com/draft-angle-endmills/high-speed-steel-tapered-square-end-mills/

I think me and Speedy were thinking that the plate only needs tilting 1-10deg from horizontal which would be for shallow areas that slope and drain, the taper cutters would be more 1-10deg from vertical. Maybe Chris can post an image

Thinking a bit more about using the 4 corner holes if you bolted round stock on then the whole thing just becomes a big sine plate, pack as required and clamp it down

I guess I misinterpreted the OP's statement "but I need to mill at various angles, from 3-10 degrees to get the effects of the oil catch & flow going."

When someone says "I need to mill at an angle" I envision angling the head, or using angled cutters, to make a milled feature with walls angled to the Z axis.

If they say "I need to mill a sloping surface" then I envision a sine plate type setup as Jason sketched.

Just based on my experience over the years in many shops. Your mileage may vary.

Thanks for the advice, I was thinking too complicated.

I think I can get it done just like its clamped now flat to the table with front side to the right .
By tilting the head & moving in the Y-Axis(Short one towards the head, I can get my angles). I can also get a slight angle by swivelling the bed. The catch areas to be milled out is at a slight horizontal angle, apart from two other angles with number of holes in each, with a 6mm groove in the center, directing the oil caught towards the main groove between the two spindle bearings and this is where the oil ends up going.

The trick to get splashes in lower gears is I overfill the gearboc with 68(20 weight) oil to splash high enough at lower gears(No extra gear on input shaft sitting high).. In higher gears to splash is very good and the surplus oil is overflowing into a small thank(Plastic) in gearbox with 3x 4mm holes(68 Oil) to drain.This method keeps the extra oil in suspension(Tank stays full but drains at same time so oil level is normal and dont drag the gears at speed) while running in higher gears, I thought about this for a few days initially.

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Heres another question:The holes shape(Top)
The oil is splashed through holes and in lower gears my catching is not 100% possible, but enough. The holes are tapered(Like reamed) from the botton, but have a sharp protruding corner on top, so oil lands there, but rather flow over than back and thats how it is catched. So by milling, I can ream a hole from the bottom, but how do I mill the top of the hole that it have a sharp corner, something like a valvestem sticking out-?
-I was looking at a woodwork cutter cutting like dowls....
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I found how oil wants to flow interesting(Surface tention etc) and that I can make it happen without moving parts or bolts in lid that can come loose and fall in gearbox, so if lid is removed, the idea is removed, except tank.

---Just want to mention any good lathe will not have a problem I imagine, although one will only know for sure looking at it through a glass window, I was surprised at what I saw in this case, therefore this attempt.

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That sounds good to me, Chris

Watchmakers’ lathes feature a similar idea, called a Rose Cutter… it should only be a matter of making something along those lines, with a big hole where the pilot would be, and the right scale and proportions for your purpose

[ of course if you have some exotic CNC machine, you just program it to whizz around everywhere ]

MichaelG.

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Credit: http://www.lathes.co.uk/watchmaker/page2.html

Put the plate on a rotary table, ctr each hole and then offset and mill around the hole. Or just counterbore the hole and Loctite in a "collar"

Other option would be to use an "aircraft" counterbore without it's pilot or a hollow endmill

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[ref. your first option] Does Craig have a very big mill ?

[quote] Measurements are roughly 340x 400 x 25mm [/quote]

MichaelG.

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Edit: __ ‘very big’ by my standards 

Edited By Michael Gilligan on 08/10/2022 07:53:06

A picture saves a thousand miss interpretations.

Regards Ian.

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You could try this one: **LINK**

https://www.model-engineer.co.uk/albums/member_photo.asp?a=56455&p=901582

… but it may not be the only Mill that Chris has access to.

MichaelG.

I recently saw the use of Blue multi surface masking tape for holding down an aluminium plate on a mill.

Tape the underside of Al plate, tape the top side of potentially sacrificial mountiing surface, superglue the two taped surfaces together using a weight. Then mill

When finished, split the two tapes with a chisel. Not tried it yet but it worked OK

What a beautiful picture of a milling machine MG but can't quite see the component the O/P is trying to copy.?

Regards Ian.

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Sorry … I thought your comment related to my immediately-preceding post

MichaelG.

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Edited By Michael Gilligan on 08/10/2022 10:59:27

Hi, I basicly will try to mill from a piece of aliminium as described before a one piece lid & functional oil catch plate, so the lid becomes a see through catchplate one piece with a manual mill.

Before this I used/made a wooden square like lid with a 6mm glass fitted to see through what happenes.
-Then I watch through the gears how the oil splash, and noticed mainly 3 patterns of splash through all the gears.
-I then made a contraption of 3x catchplates from 3mm thick aliminium strips. I then experimented over few weeks with hole sizes & angle of fitment relative to gear shafts, not to a right angle, I catch more oil if at angle.
-I then assemble this contraption and it rest below the wooden lid with 3x contact points over the gearbox and it deliver oil catched to a horizontal channel leading to both spindle bearings, there holes in the gearbox castings above the spindle bearings, so now the oil positively flow trough the spindle bearings back into gearbox.

So instead of having various pieces doing a job(s), which could be a risk if a 3mm bolt comes loose etc, I am attempting to make all function in one piece. Nothing has to be critically accurate, but I will have to think carefully about each next step milling from both sides of the blank thick plate.

If I had a CNC machine was knowledgeable about say Fusion 360, I assume it would have been easy.

-So this may take some time to do. Where I need to I will make some experiments on seperate aliminium piece, like hole shapes.
-An interesting aspect of catching oil like I do, is your very catch hardware is allso a barrier except for the holes and, hole size also matters, I think 12mm is a good size, too large you have too much hole for too little hard surfaces, too small and the oil will not go through it well. So its a best effort hit and miss affair with no moving parts like a extra pump.

I will post a photo when I get to the angles, at moment its just straight forward milling basic shape.

 

Edited By Chris Mate on 08/10/2022 20:22:55