Was that these? https://www.ebay.co.uk/itm/20PCS-50...var=592088523871&_trksid=p2060353.m1438.l2649
No, the rods I used weren't fluxed. They're some sort of alloy I think (aluminium and zinc??) that melts before the aluminium. They came off ebay a while ago and weren't very expensive. They just require the metal to be wire brushed with a stainless brush.
Haven't got anything balanced yet. I've just been getting it functional rather than refining it too much yet as there's a fair amount left to do.
As for speed, the motor is 2850rpm at full load according to the data plate. It drives a 3 1/2" OD pulley, with a 3" OD pulley on the spindle. The pitch diameters will be a bit smaller than the OD, but assuming 3.5:3 the spindle speed should be about 3300rpm.
Right. Its just i never thought about the dynamic balancing of the spindle on grinders, until i dismantled mine and seen the pulley, while small had balancing holes drilled into the web. Yes mine spins at 3,000 rpm give or take too. You are doing a good job, looking forwards to seeing it finished and running.
TBH the pulley needs balancing, the spindle not so much. A turned plain spindle will be balanced well enough.
@RobCox Great thread, thanks for taking the time to document all your work.
You're welcome. Besides contributing to the reading material on here, its a great way to document what I've done to refer to in the future.
Can't wait to see it up and running. Mind you its the same with my 540, just waiting for warmer weather to paint it.
Bit more progress this weekend. I'd used up all the "aluminium brazing" rods I got cheap off ebay. After looking around to make sure I bought the right thing this time, I'm convinced they were just aluminium/silicon rods with a melting point about 80 degrees C below aluminium, hence the difficulty I had getting them to melt without cooking the whole workpiece (that, and the fact that I'm not the best at brazing). Anyway, I ended up buying some durafix rods from OWS... night and day compared to the fleabay cheapies. They melt way before the aluminium turns to mush and once the workpiece is up to temperature I don't need to continuously cook it with the propane torch to get it to carry on melting onto the job.
Couple of pictures of my efforts to repair the wheel guard. First go with the cheapie rods. The bit on the right didn't take properly and pinged off on the mill:
Second go with the durafix rods :
I built up the sides of the slot to make the guard a better fit on the bracket. After tidying it up on the mill I was quite happy with the result:
I liberated a couple of oil cups that were hiding in some lengths of brass bar. These replace the original "Kingfisher" oilers that had been drilled and bodged before I got hold of the machine. Having made these, they do look a bit like I popped down the DIY for some plumbing fittings!
wont be long before its grinding
I'd like to think not. I started work today on a mounting plate for the motor. The one it came with has the look of a hasty bodge. I've also got some steel plate coming to make some new panels to fill the access holes in the base. Then I guess it's electrics, bushes for the grinding wheel, oil cups for the table and sort out the cover for the table screw.
I'm planning on getting it done, then stripping it down and painting all the bits that need paint, because if it doesn't happen now it never will!
Finally got the motor mounted in properly. I didn't like the arrangment that came with the kit of parts. It consisted of a couple of bits of L section with several holes to be secured to the inside of the base and used the threaded part of two bolts as the pivots for the motor mounting plate. Since I only want to be fixing this once, not sometime in the future when I'd rather be grinding with the machine, I decided to over engineer the whole thing and make a new mounting arrangement.
This is the baseplate that the motor bolts to. The bronze bushes are evidence of the over engineering. They slide into bored holes in a couple of bits of 3/4 x 1 1/2 x 2" bar, which also has threaded holes to accept the bolts that secure them to the inside of the base. No more faffing with nuts inside the base where you can't see them and need to be a contortionist to hold them while doing up the bolts from the outside:
These are the mounting bolts on the outside. Whether they're original or not I don't know, but there's no other evidence of how the motor might have been fixed originally.
I replaced the rusty bent bracket that used to hold the belt in tension with another over engineered arrangement:
The motor wires were hitched up to the VFD and the motor run for a while:
After 5+ minutes of running, the front of the spindle is warm to the touch. The pulley on the motor is also warm. I'm assuming this is running OK.
Next job is to turn the bits of metal stood in the packaging behind the grinder into some panels to cover the access holes in the base. The VFD will get bolted to the side one as it saves butchering the base casting any more and access for any future VFD setup changes will be easier. The chunks of 2x4 that I used to support the motor at the right height to get the mounting bolts in will have to move too!
Bit more progress today. Time to make the panels to cover the access holes in the base.
Started off with some 2mm sheet steel that was a bit bigger than I needed, so I used the mill as a saw to get some straight clean cuts, not having any other tools that will deal with a piece this large. Here's the first setup:
Notice it's firmly clamped down at the edges and the cutter is rotating in an anti-clockwise direction. It started making a bit of noise and by pressing on the sheet with my hand (well away from the cutter) I could quieten it down. I wondered how it would be without me pressing down on it .... BANG. The cutter lifted the sheet, bent it a bit and dragged it out from under the clamps by the time I'd managed to stop it. What a numpty, should have seen that coming. Oh, and to remind myself not to be a bell end and do it again, I've ordered one of @doubleboost's slot cleaners!
And so on to setup number 2:
This time a piece of 1 1/2 x 3/4 bar stops any possibility of it lifting. I did try climb cutting but the mill won't take it in horizontal mode - too much slop in the table drive, so conventional cutting it was.
I got to use my hoist to shift the grinder out from the wall so I could get access to the back. Doesn't get used often, but when you need it it makes life so simple:
After some drilling and manual milling (on the corners), here;'s the end result:
I drilled and tapped four holes for the rear plate rather than use the two existing holes. The casting is far from flat and I didn't want sheet metal rattling whilst the grinder's being used.
And while I had the grinder shifted out, a different angle on the motor mount inside:
@RobCox At least your safe and sound. I concur Looking good
Small amount of progress since the last update. I'm on to the finishing touches now. Got the bellows fitted to the ways in front and behind the saddle:
I also fitted the knee height screw guard. This was a pain to fit at this stage. The side panel on the base had to be removed to slacken the motor belt, then the bolts securing the head removed so the head could be rotated 90 deg. Then the knee had to be wound up as far as poss and raised further with the hoist to get enough clearance under the screw to remove the nut and refit it with the guard fitted.
I'm not happy with it though as the tubes don't slide easily over one another and came apart at one point. Squeezing the swaged sections back together wasn't easy. I might replace it with some hoover pipe. It won't be original, but it can join the rest of the modern modifications (including BSW, UNC, and metric screws - not all my doing!).
Are those original bellows covers??? If they're replacements, where did you find them, all I've been able to spot are the flat ones without the turn-down at the sides?
Dave H. (the other one)
Original bellows covers - I'd be lucky! Most of this grinder was missing/worn out/needed fixing, so I had to source some bellows. I got them from Arceurotrade. They're Chinese made (what isn't?) but at least there's some quality control gone in to them. Cloth top, perforated plastic backing. Nice quality, but not cheap. Trouble was I couldn't find anything suitable and much cheaper on ebay.
The knee ways are covered with the 200x40mm version, split in half as I don't need the 800mm they'll open up to! I've also bought one of the 240x50mm ones for the vertical ways as the slide there is wider. Both need extensive tweaking to the plastic fingers to get them to fit and a whole lot of aluminium plates and brackets to sandwich the cut ends to secure them to the grinder and make sure there are no weak spots where they'll pull away.
Nearly done now. I machined up some oilers from some brass stock. The threads are a mixture of M6 and 1/4-20. I added some felt in the resevoir to transfer the oil onto the table ways:
I also have mounted the bellows over the column ways. Another slightly unconventional milling setup to cut a curve in the top mounting plate to clear the spindle head. The curve has a 4" radius and was cut with a boring bar in the horizontal spindle on the mill:
Here's the bellows assembled on the grinder:
And this is the grinder as it stands now:
All that's left to do now is to make some bushes for the grinding wheel and a locknut for the end of the spindle, some hardware to attach the magnetic chuck to the table, and finally do the electrics - an on and off switch mounted in an aluminium box on the front of the base and secure the VFD onto the inside of the side panel. Then strip it to bits and paint everything that needs painting.
Superlative work Rob, I especially like the quality of your scraping especially for a self-taught person you don't expect to see it that good.
Does your spindle nut also pre-load the bearings? Mine does. The bearings have a tiny bit of wear and I'm trying to think of a way to shim it out. I'm looking at some shims probably 0.0002"-0.0005" thick. Can't think what to use.
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