49cc Huasheng straight shaft clutch replacement

[Otto Neumann]

I love the thought you've put into this. Perhaps you could include a mount for a stepper motor in your backing plate. How much would it cost you to have this made?

I dunno honestly, two pulleys are to be CNC machined and the aluminium plate laser cut; considering which a CNC machinist won't do the job for any less than 2 grands, it's gonna be pricey, unless I somehow manage to find two suitable pulleys, everything should be relatively cheap.

I'm eyeballing it, 400-500 bucks; but the CNC machined pulleys would be dynamically balanced, the bearing would be bomb proof, the plate would be sturdy, it'd be built to last; if a larger engine could be implemented, instead of a Nema 17, something like a small Kubota alternator could be implemented

 

[Gordy]

I know this is an American company, but could you use one of these for the bearing?

Front Hub Single Mount, 6202 Bearings

The Front Hub Single Mount with 6202 Bearings is a high-quality replacement part designed to provide efficient performance and durability. This front hub is made of sturdy materials that ensure long-lasting use and reliability. It features 6202 bearings that offer smooth rotation and better load...

www.gopowersports.com

And I'm not sure if this company would ship to Italy. But I'd think it's worth a shot.

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Online sheet metal fabrication service. Get custom parts delivered in just a few days—upload STEP or DXF files for instant pricing!

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[Otto Neumann]

I know this is an American company, but could you use one of these for the bearing?

Front Hub Single Mount, 6202 Bearings

The Front Hub Single Mount with 6202 Bearings is a high-quality replacement part designed to provide efficient performance and durability. This front hub is made of sturdy materials that ensure long-lasting use and reliability. It features 6202 bearings that offer smooth rotation and better load...

www.gopowersports.com

And I'm not sure if this company would ship to Italy. But I'd think it's worth a shot.

SendCutSend: Custom Sheet Metal Fabrication

Online sheet metal fabrication service. Get custom parts delivered in just a few days—upload STEP or DXF files for instant pricing!

sendcutsend.com

I could indeed; I was planning the flanged bearing because of the greasing port, and the easy accessibility, but that would be much lighter, as the SKF bearing is encapsulated on a cast iron flange.

My main concern are the pulleys at this point, I should attempt to keep that 1:5 ratio; as the larger is the reduction pulley's radius, the greater the surface on which the belt will grip, and the less will be the chances of the belt slipping, and more generally, lesser wear and tear

 

[Gordy]

I could indeed; I was planning the flanged bearing because of the greasing port, and the easy accessibility, but that would be much lighter, as the SKF bearing is encapsulated on a cast iron flange.

My main concern are the pulleys at this point, I should attempt to keep that 1:5 ratio; as the larger is the reduction pulley's radius, the greater the surface on which the belt will grip, and the less will be the chances of the belt slipping, and more generally, lesser wear and tear

If you have any farm or tractor supply companies near you you can get steel V belt pulleys. I know it won't be as nice as a machined aluminum pulley, but it will get the job done, at least for temporary.

 

[Otto Neumann]

If you have any farm or tractor supply companies near you you can get steel V belt pulleys. I know it won't be as nice as a machined aluminum pulley, but it will get the job done, at least for temporary.

You can find them on Aliexpress, I dunno if I can get them to make the right ratio; nothing that the mighty power of filler, primer and matte finish paint can't handle, matte black looks great on everything

 

[cloakedvillain]

You can pick bore size. https://www.grainger.com/product/FENNER-DRIVES-Standard-V-Belt-Pulley-Fixed-6VPG1

https://www.grainger.com/product/5RHY4

 

[ImpulseRocket]

I dunno honestly, two pulleys are to be CNC machined and the aluminium plate laser cut; considering which a CNC machinist won't do the job for any less than 2 grands, it's gonna be pricey, unless I somehow manage to find two suitable pulleys, everything should be relatively cheap.

I'm eyeballing it, 400-500 bucks; but the CNC machined pulleys would be dynamically balanced, the bearing would be bomb proof, the plate would be sturdy, it'd be built to last; if a larger engine could be implemented, instead of a Nema 17, something like a small Kubota alternator could be implemented

If you have cad drawings you could always get quotes through PCBWay for cnc work. I am not sure if it would be any cheaper, but there is the potential there.

 

[Otto Neumann]

You can pick bore size. https://www.grainger.com/product/FENNER-DRIVES-Standard-V-Belt-Pulley-Fixed-6VPG1

https://www.grainger.com/product/5RHY4

If you have cad drawings you could always get quotes through PCBWay for cnc work. I am not sure if it would be any cheaper, but there is the potential there.

Hey guys, extra good news: I found the pulleys on Aliexpress!
40 and 200mm in diameter, both with a 15mm bore and with a keyway, they would cost me 60-70 euro; they looks decently made too, could potentially act as a permanent solution.

https://www.aliexpress.com/item/1005007150409564.html?spm=a2g0o.cart.0.0.202b18fcagIvS1&mp=1&gatewayAdapt=glo2ita

https://www.aliexpress.com/item/1005006632742856.html?spm=a2g0o.cart.0.0.202b18fcagIvS1&mp=1&gatewayAdapt=glo2ita

Without the need of getting two custom machined pulleys, the cost is going to significantly drop; I'll just have to get a laser cut frame; even if I don't think which any natural curvature in a 6 by 250mm long plate would afflict the alignment of the belts, I can request at worse a surface milling on both sizes to ensure it's flat.

Given the saving, I may consider to invest into a steel plate rather than into 6063, because should I require to weld something, 6063 looses about half of its mechanical strength and becomes brittle; should the clutch arm snap off, the clutch would become inoperable.

 

[Gordy]

Hey guys, extra good news: I found the pulleys on Aliexpress!
40 and 200mm in diameter, both with a 15mm bore and with a keyway, they would cost me 60-70 euro; they looks decently made too, could potentially act as a permanent solution.

https://www.aliexpress.com/item/1005007150409564.html?spm=a2g0o.cart.0.0.202b18fcagIvS1&mp=1&gatewayAdapt=glo2ita

https://www.aliexpress.com/item/1005006632742856.html?spm=a2g0o.cart.0.0.202b18fcagIvS1&mp=1&gatewayAdapt=glo2ita

Without the need of getting two custom machined pulleys, the cost is going to significantly drop; I'll just have to get a laser cut frame; even if I don't think which any natural curvature in a 6 by 250mm long plate would afflict the alignment of the belts, I can request at worse a surface milling on both sizes to ensure it's flat.

Given the saving, I may consider to invest into a steel plate rather than into 6063, because should I require to weld something, 6063 looses about half of its mechanical strength and becomes brittle; should the clutch arm snap off, the clutch would become inoperable.

You could use much thinner steel plate, so it wouldn't weigh too much more.

 

[Otto Neumann]

You could use much thinner steel plate, so it wouldn't weigh too much more.

I wouldn't dare going any thinner than 4 mm; 6 is purely indicative, as it gives plenty of space for milling, it would make the whole thing more forgiving during welding too, should I need to weld something, I'm trying design this thing to make as less use of the TIG machine as possible.

I considered to opt for a transmission that's normally in gear, by spring loading the swinging arm, because I didn't considered a key factor:
When the belt would be tensioned, it will constantly fight against the idler, and all of that constantly varying tension, would be fought by the clutch cable and the lever, they wouldn't handle such forces for long before falling apart.

I've been thinking to use the china girl's clutch spring, but as there's no space for it, I'd use it as reference; it would be great to know how much force it exerts when the clutch is popped in gear, so that I could find a similar and physically smaller spring.

At this point, it would be a good idea to start a new thread for this belt clutch prototype, should I get something out of Staton Inc, I'd update here.