Hole enlarging on a lathe

[tvrulesme]

I had to replace the motor on my wacker plate compactor. I stupidly didn't check the spindle size. My old motor had a 19mm spindle and the new one has a 20mm spindle.

I need to put a pulley wheel with centrifugal clutch on the new motor so will need to enlarge the bore to fit the new motor (pictures below).

I don't really have space for a lathe to buy one. Does anyone know which kind of business I would look for locally to machine this for me and how much I'd be looking to pay? The wacker plate was super cheap so I can't really justify spending a lot on this. As you can see from the picture I had a bash with a 20mm drill bit with zero success

 

[guineafowl21]

Local engineering firm, the sort who does engine rebuilds, might be your best bet.

19mm is a standard motor shaft size, so I’d be inclined to leave the pulley wheel alone and get the motor shaft machined down to 19mm.

20mm drill bit will make a very rough hole, likely over size.

 

[Phill05]

Buy another motor with 19mm shaft and sell the 20mm one, or maybe ask to part exchange.

 

[ChaiLatte]

...get the motor shaft machined down to 19mm.

The motor shaft is the crankshaft of the engine, So you would need to pull the crank from the motor.

I wonder whether if you gripped the flywheel in the chuck, removed the sparkplug and blocked up the engine off the bed of the lathe you could turn it in situ with a revolving centre in the other end.

Start the engine up and machine the shaft down with a file. Make a wooden split lap (like a pair of nutcrackers lined with 120 grit) to finesse it when you get close.

 

[redhunter350]

TVRULESME -- Look for local machine shops in Yell.com or local model engineer's who may help. Possibly someone who repairs/services lawn mowers ?
If you were close I would be happy to assist sadly we are 260 miles apart !
You said motor -- is this an electric whacker or did you mean engine as in petrol engine ?
John

 

[Inspector]

I think he is talking about a soil compactor.

Like these. https://multiquip.co.uk/product-cat...plication/compaction/mikasa-compaction-plate/

Maybe an electric one but similar.

Pete

 

[ChaiLatte]

You said motor -- is this an electric whacker or did you mean engine as in petrol engine ?

Please consider how a centrifugal clutch might not work well on an electric motor that is either off (zero rpm) or on (100% rpm). On an IC engine, the clutch allows the motor to tick over (many thousands of Suffolk Punch lawnmowers).

 

[MorrisWoodman12]

A drill is the wrong tool for this job. I'd use an expanding reamer until the hole diameter was close and either a fixed 20mm reamer to finish it off or just increment it very very slowly until I got the fit I wanted. This was the route I took when I had to re-motor my old bandsaw.

 

[guineafowl21]

Oh, motor = engine down there? Makes more sense to have a clutch on an engine, I suppose. Thought it was to allow the motor to run up to speed unloaded, or to slip rather than stall.

Looking at what the drill bit did to it, that pulley centre is hard material. Might need grinding if normal HSS or carbide won’t touch it.

This would be a good job for Doubleboost on youtube.

 

[duke]

I think he is talking about a soil compactor.

Like these. https://multiquip.co.uk/product-cat...plication/compaction/mikasa-compaction-plate/

Maybe an electric one but similar.

Pete

Maybe aggregate compactor?

 

[guineafowl21]

This is what I would call a wacker plate:

 

[tvrulesme]

Buy another motor with 19mm shaft and sell the 20mm one, or maybe ask to part exchange.

Probably the right answer but a very expensive one for a very cheap machine

 

[tvrulesme]

TVRULESME -- Look for local machine shops in Yell.com or local model engineer's who may help. Possibly someone who repairs/services lawn mowers ?
If you were close I would be happy to assist sadly we are 260 miles apart !
You said motor -- is this an electric whacker or did you mean engine as in petrol engine ?
John

Thank you, it's a petrol wacker, picture below. I bought it for next to nothing on eBay so keen to spend as little as possible

 

[tvrulesme]

Thanks all for the replies. Just an update, I managed to find a clutch with the right bore on Aliexpress for ~£10. Going to try this route first before modifying the original clutch.

The wacker plate was an ebay punt which was very cheap so I don't really want to spend a lot on new engines or even a reamer for a lathe if I can help it.

I found a few machinists on eBay who will do this for around £10 + postage which sounds reasonable so I will probably go down this path if the aliexpress one doesn't work out.