Gallery, Projects and General > How to's
Making a flywheel
Brass_Machine:
John...
This is a great 'how to'. Muchly appreciate the info!
Eric
shoey51:
a very informative thread but for me I think I will leave it to the experts.
trying to convince swmbo that I need a mill is another thing entirely
Bernd:
--- Quote from: shoey51 on March 23, 2009, 03:10:11 PM ---trying to convince swmbo that I need a mill is another thing entirely
--- End quote ---
:lol: :lol: :lol: :lol: :lol: :lol: :lol: :lol:
I've been trying to convince mine I need a bigger lathe, but haven't figgured out how to make a food processor out one yet.
Bernd
bogstandard:
This was going to be the last post, but is now the penultimate one. I just didn't feel like getting filthy, polishing up the wheel today, so that is the pleasure I have to look forwards to tomorrow.
On the last post I left it in limbo, deciding whether to go for the grub screw or the taper lock. The hub size was a little small for putting a taper lock into it, but decided, if I could keep things tight on measurements, I just might be able to squeeze it in. So that is what this post is about.
First off though, before going any further, the flywheel needs certain areas blending in. Even when machined to very tight tolerances, you will always get slight mismatches. On this pic, #1 shows where it is on this job, where the sides of the spokes blend into the inside hole. By using a combination of smooth files, a scraper and emery cloth I got all 12 areas blended in, #2.
Now that all the blending was finished, I could concentrate on the job in hand.
First off. I made the flange for one side with a core plug attached, this was a nice tight fit in the 11mm centre hole, and once it had a touch of loctite on it, it was going nowhere.
The plug went right the way thru, and was flushed off level with the ali.
I need this hub to have a tapered bore, starting at 8mm on the flange side, ending up at 9.5mm where the plug is flush with the ali. I got these figures out of my head, and a little mental calculation at this time showed me I could squeeze in a couple of 2mm cap screws for locking the taper. A quickie calculation gave me 3.5 degrees for the angle. In fact it was just a tiny bit larger, so I rounded it down.
To save me having to swing the topslide over twice, and matching up the tapers. If I could cut from small to large on the internal taper, then I wouldn't have to move the topslide to do the external one, and the tapers would automatically have a perfect match.
The flywheel was again mounted in the soft jaws, with the small hole sized flange on the outside. By coming up gradually thru a range of drills, I ended up putting a 7.9mm thru.
The topslide was swung over 3.5 degrees in the correct direction.
Everything was locked up, and the boring feed was done manually by using the topslide handle. I gradually came out until the bore was at my 7.9mm hole edge. A cut of 0.05mm was put on, and the bore given the final cut. This would be close enough for me.
This was how the internal tapered bore turned out.
The tooling was swapped over for external cutting, and still using the same topslide setover and feed, I started to cut the external taper.
When it was starting to get close to size, the flywheel was tried for fit after each cut. You only have to remove a very small amount each time, and it is very easy to take too much off.
I eventually got to where I wanted to be, a gap of about 0.25mm (0.010").
Before I parted this bit off, I put a hole up the centre, for when I start to bore for the shaft.
Internal and external tapers.
The two were tightly pushed together and a bit of old superglue smeared on the back of the joint. This will hold the parts together while I do a bit of drilling, but I will easily be able to break the joint apart.
The wheel was remounted onto the RT, which was still in the zeroed position.
By using my mental arithmetic, I drilled holes for the clamp down screws, complete with head recesses and the two jacking screw holes to get the bits apart.
The glue joint was broken and all old glue cleaned off. The four holes were tapped 2mm course thread, and the whole lot screwed up tight. It was a very tight clearance fits all round for bolt heads and threads, but there were no compromises, everything fit just right.
First off, the topslide was put back to zero. The wheel was again mounted onto the lathe, this time with the screwed bit on the inside. The excess of the taper was faced off, and the thru hole bored for a nice sliding fit on the shaft.
The last job before final assembly was to put a hacksaw cut along the length of the removeable part until the cut reached the centre bore. What this does is allow the taper to collapse down the central bore, and so grip the shaft, very accurately.
Here it is finished, you can just see the saw cut.
The back side.
This really was a tight squeeze getting it to fit into such a small area, but it works, and that is all that matters.
Get you sunglasses ready for the next post. Bling time.
Bogs
Darren:
Never seen that method before, how so neat :clap:
As usual, a very tidy job, looks very mechanical. I like that.... :thumbup:
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