large washers

Washers for 1" and 2" bolts will not be too common but at this size will be easy to make from sheet metal

2" bore washer will be about 4" OD. using 5mm steel this will weigh about 250g.

Getting under the 250 g requirement for a 1" bore washer is not a problem.

2" OD, 1" bore 5mm thick will weigh about 60g.

Please forgive the mixed units but you started it!

Bob

Lol cheers bob, I'm not into engineering as you can probably tell,

What type of company should I look for to get a price on these?

Phil

A laser cutting company would be your best bet. regards,Mark.

In article , " snipped-for-privacy@ems-fife.co.uk" writes

John Stevenson knows one well, if I recall correctly.

Does anyone make anything similar for spacing milling cutters on a 1" arbor, that could suit the dumb belle job.

This is why i'm asking, its hard to get small weight plates,

A company called platemate does magnetics but they're expensive.

So i was looking for something hopefully off the shelf which could be used instead. Perhaps a spacer of some type.

Phil

Margnor ( my favourite supplier of hard to find fasteners ) list M24 and M48

1" and 2" also. they will post small orders. call 01483 536 800, they are even open on Saturday

Thanks, will give them a ring on Monday :)

Phil

Got a friend of mine to plan something out for the engineering shop,

he's calculated the size of the plates so they add up to as near as 125g as possible, theres two sizes, 1" and 2" bore

Clever isn't he lol

Sizes Diameter (mm) Radius (M) Thk (M) Weight (Kg)

1" Bore 25.4 0.0127 0.01 0.039550951 Outside Dia 51.8 0.0259 0.01 0.164493604 Total Weight 0.1249

Sizes Diameter (mm) Radius (M) Thk (M) Weight (Kg)

2" Bore 50.8 0.0254 0.01 0.158203804 Outside Dia 68 0.034 0.01 0.283470143 Total Weight 0.1253

Phil

Probably not that clever! Where are you going to get a supply of

51.8mm bar from which to manufacture these. Lot of turning, lot of waste.

Surely it is better to tune the thickness dimension.

Have you thought of making them slightly overweight, and then drilling to lighten to exact requirement?

Mike

Thanks for pointing that out Mike, will see what the local engineering company relies with.

Assuming you buy steel rods in certain sizes, what size diameter should I start with to reduce machining and waste like you say? I want to get them with a 25.4 and 50.8 bore. weighing 125g and 250g?

What width would the rod have to be cut to supply the plates in those weights?

Phil

Purely by calculation using Steel with an SG of 7.9 . . . . . .

50.8 OD (2") 25.4 ID (1") Thickness = 10.4088mm = 125gm 76.2 OD (3") 50.8 ID (2") Thickness = 12.4906mm = 250gm

The problem is that this assumes absolute accuracy in all dimensions, if the bore were to be 25.41 instead of 25.4 then the weight would be

124.967gm. It really depends on how much tolerance you can give to the weight.

I would take Mike's advice, making the 1" 11mm or 7/16" thick, the 2"

12.5mm or ½" thick and fine tune the weight by drilling holes in one face.

JG

I think that JG has said it all. I was just about to put some more calculations on here, but it would be to little avail.

The point that he makes about minor variations in dimension is well made, and indeed the whole thing then depends on the specific gravity of the particular piece of steel.

In answer to your other question, you should be able to obtain steel bar at both 2" (50.8) and 3" (26.2) diameters without difficulty.

Mike

Correction of typo................

In answer to your other question, you should be able to obtain steel bar >at both 2" (50.8) and 3" (76.2) diameters without difficulty.

Sorry about that,

Mike