large washers

I've been scouring google for ages looking for some large washers,
thought I'd ask here because I've came up with nothing.
I'm looking for large washers that will fit onto a 1" diameter bar and
2" diameter bar, I want to use them as micro dumbell plates.
Tricky thing is i want them to weight around 250g or less
Or is there a product I could pour into a mould,
250g flat magnets would be ideal cos i could just stick em on.
Phil
Reply to
bunnykilla
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bunnykilla wrote in message ...
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
Reply to
Bob Minchin
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
Reply to
bunnykilla
A laser cutting company would be your best bet. regards,Mark.
Reply to
mark
In article , " snipped-for-privacy@ems-fife.co.uk" writes
John Stevenson knows one well, if I recall correctly.
Reply to
Nigel Eaton
Does anyone make anything similar for spacing milling cutters on a 1" arbor, that could suit the dumb belle job.
Reply to
Bill H
This is why i'm asking, its hard to get small weight plates,
A company called platemate does magnetics but they're expensive.
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So i was looking for something hopefully off the shelf which could be used instead. Perhaps a spacer of some type.
Phil
Reply to
bunnykilla
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
Reply to
Jonathan Barnes
Thanks, will give them a ring on Monday :)
Phil
Reply to
bunnykilla
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
Reply to
bunnykilla
In message , bunnykilla writes
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
Reply to
Mike Whittome
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
Reply to
bunnykilla
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
Reply to
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
Reply to
Mike Whittome
Correction of typo................
In answer to your other question, you should be able to obtain steel bar
Sorry about that,
Mike
Reply to
Mike Whittome

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