Sourcing belts/pulleys?

[Lognic04]

Hi all, :hi:
I soon plan to make a mirror -o matic machine! This is a mirror grinding polishing machine, and it needs belts, pulleys, shafts, collars etc, but i cant really find any of these parts around? I know i can make the pulleys out of plywood, but not anything else.
If anyone knows where to get these bits your help would be greatly appreciated!!! :thanx::thumbsup:

[Merlin66]

I get all by pulleys and belts from mini bearings in Queensland. Great crowd to deal with.

[LewisM]

You could pull apart a CGEM for some bits...

Just sayin' :P

[Imme]

Ebay

[The_bluester]

If oyu get away from Melbourne a bit (Yarra Glen maybe) you might find that sort of stuff showing up at agricultural supply places, depending how big you need to go.

[bojan]

Ebay, Banggood....

(Also car scrapyard)

[Lognic04]

Just saw that repco sells belts and pulleys? Are these good for my purpose?

[billdan]

Repco will sell fan belts or alternator belts, which may or may not be the right length you need.
Check out ride on mower repair shops they have a large range of belts and pulleys you may be able to use.

Or machinery shops that sell short belts and variable speed pulleys for Lathes.

[Saturnine]

Hi Logan
You probably have already, but if not, you first need to work out the design of the machine. Plenty of on-line designs out there. What motor, gearbox, reduction box to achieve the speeds you want determines what pulley diameters you will need.
"V" belt drives seem to be the way to go and probably cheaper than Timing Belt systems and will give a positive enough drive, with the correct tension on the belt
http://www.artinso.com/astronomy/mirror-o-matic.htmlhttp://www.mirrorgrindingmachine.com/

A few examples in case you hadn't seen them yet. As you are on Cloudy Nights , you know that they are an excellent resource for links an help as well.

Have Fun
Jeff

[Saturnine]

Plenty of V belt pulleys on Ebay, just need to know what diameters and shaft sizes and whether to use taper locks or just grub screws on to the shafts.
V belts come in many cross section sizes, "A" section belts and pulleys should be fine for your needs.

[xelasnave]

Logan you may be able to use bike bits...plently of gears etc. And often they are available around the place...
Alex

[Lognic04]

That was what david campbell suggesed too!
I actually have a few bikes unused in the garage, though people are saying still use the belts and pulleys?

[Bart]

Belting Online


https://www.beltingonline.com/

[Lognic04]

Thanks for your input everyone!
Anyone know whether cutting my own pulleys with a hardwood disc and a rebate bit is practical for this project? This cheapens it a lot!

[RyanJones]

Hi Logan,

I'm a mechanic in Melbourne so I'm quite often after belts and pulleys etc. Try Frankston Bearings. They're a great group of guys and if thy don't stick what you need, they'll probably be able to get them for you. Theyre pretty good on price too. Dayco are a company that make a lot of his stuff that you can get through Burson auto parts. You can look through their catalogue online and pick what you need and get them to order it if they don't have it. Again at a pretty good price. I would suggest belt over chain drive for this application. You can adjust the tension so if for what ever reason something goes south, the belt has slip in it to avoid gouging deep grooves. It will also be heaps quieter and also belts won't require lubrication that could spray off and contaminate your work.

[Lognic04]

Thanks Ryan, i will have a look!
Anyone know where to get 1" shafts and collars locally too?

[Saturnine]

Try Williamstown metals, have an online store on Ebay.
Mouse over image to zoom
Have one to sell? Sell it yourself
STEEL ROUND MACHINING BAR 25.4mm x 300mm LATHE, MILLING, CNC

[Saturnine]

Also check if there are any scrap metal dealers or OneSteel stores in your area.

[xelasnave]

Logan if you were to make pulleys out of wood consider layers of ply with a soak in coating of resin...and throw in fibre glass and you can get great units.
Did you mention how you will power this unit and the rev range and how you seek to achieve it.
Alex

[Lognic04]

Thanks Jeff!
Alex, i will use a 0.5hp motor that is pre-geared down to 35rpm, so it makes speed adjustment easier (id only want slower for hand polishing, maybe 8rpm?) but 35 is fine for grinding.

[xelasnave]

Thats easy to gear from up to five to one is easy with pulleys bike gears or wood ...depends what you have on hand.
Have you a design in mind.
Fram motor mounting turntable...maybe temperature control?
Do you need to watch temp with prolonged polishing or grinding?
The glass much pick up heat ...build in a peltie device in the turntable☺
Must be a concideration in final finishing..you would polish to suit a temp that you will image at I expect ...I dont know but I would polish at that temp..what do others think who know what they are talking about☺
Alex

[xelasnave]

I have been thinking of doing a 2.8 in anticipation of getting one of those curved sensors some how..should ask zwo if they have in mind this arrangement...but those sensors should make a hand made mirror more viable you could think.
Alex

[xelasnave]

I would love to try fitting a curved piece of glass straight on the sensor of a old dslr and see if that could work inconjunction with a hand made mirror.
You could probably test this with a lens flat one side and concave on the other...sit it on and you could get an idea but making a lens to cover the whole sensor would be a challenge...a square lens...but could coma correction for a short fl be made that simple ... be fun playing around if you could get a round lens from surplus shed...are they still selling?
Alex

[xelasnave]

Another idea Logan.
Build the frame onto an old fridge or something you can use to capture water etc...U assume there could be times where a waste management could make life more pleasant.
Alex

[xelasnave]

Canon apparently have a curved sensor to suit 1.2 fl and they are seeking folk to test it...try a letter...I will put up my 12 inch for a blank...imagine a 12 inch like that...short tube for a start☺
Alex

[Lognic04]

You know what would be cool, configurable curve, like the sensor detects the lens or you input it manually and it automatically curves - now that would be awesome!!
Yeah, waste management is gonna be tricky!!!
I have been working with the awesome David Campbell who had lended some of his engineering skill to help :)
I have started learning CAD to aid in design!

[xelasnave]

That is an original idea.
A great idea ..it really is...and I suspect it will come to pass and when it does be silently content that you had that idea.

I think the problem these curved sensors may present is a need to be made to match a specific fl.
Not a problem so much for astro photography but in other areas that could be a major problem.
I am not up to date they may have a way around the prblem but your idea if they could do that ....mmm nice challenge for us...how to make a sensor that will comply to a command for it to curve...how to do that...I know..you get that wire that grows with current...a very small web an the well suspended somehow...first problem is how to make it flexible...maybe the material ...only way around is a round sensor as if round you could possibly distort it to various fls.

If you had a pressurised chamber you could geometricly distort it I think.

Alex

[xelasnave]

Heres one☺
It does work apparently ...simeone said they use it with exray scopes when I ran the idea some place years ago.

But draw a parabola on paper so you get a wine glass extent.
Say our glass on the paper 150mm high...at the top "rim" of our wine glass we cut say from the top down 50 mm could be bigger...but to get the idea...takw our ring and work outchow to collect the light not bouncing off and back from the mirror but glacing at a fine angle...the idea is that it may be better☺
I wonder..
Alex

[Lognic04]

Hmm, I wonder if having a lens simply the opposite curvature of the mirror would correct curvature? This is your number one enemy at fast speeds

[xelasnave]

Thinking more the curved sensors would have to dish out whereas what they are working with is dished in...need to think about it.
Just trying to avoid dragging all my gear upstairs and actually doing something.
I wonder could you grab a sensor out of and old dslr and heat it and bend it☺
Microwave should do it☺
I still think a piece of glass to shape could be fitted to a sensor and maybe work.

Alex

[xelasnave]

And with a curved sensor a sperical mirror may be better...
Thats something to think about...but should be much easier to get right ...
.mmmm
And all this from some one who hasnt adjusted their reflector since purchase☺
Ask your helper what he thinks about building a vacuum chamber and mirroring set up.
Alex