Thread: Restoring a Jones and Shipman 520 cylindrical grinder II

Give him a piece of S**t and out comes a Rolls Royce. Excellent workmanship as usual, Michael.

Originally Posted by .RC.

Next up you will need some steadies made up.

Yes - already thinking about that one.
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In the meantime - the work done on the tailstock so far has been mainly cosmetic. Today I bit the bullet and started on the functional stuff. The tail stock has a slide inside it that is lever operated to quickly withdraw the centre. There is also a spring to apply pressure to the centre and (I assume) if the part being ground expands, allow some float.
This is one that a fellow J&S owner kindly took apart for me.
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The lever that you can see on the top of the tailstock (which is upside down in the picture turns a shaft through around 50 to 60 degrees, rotating a clevis that brackets the 5 sided piece.
After drilling the through hole, I mounted the tailstock on it's dummy base, skimmed the rear surface to get it parallel with the front edge and then put in the pocket that would have been cast in the original. The twin vice thing is not something I do often but once again it is something that comes in handy every so often for things like this or long slender stuff. The Vertex anglock vice used to be around $250, so a good buy for the money (now around $350 - wait for the sale?)
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Once the pocket was in it was then time for the V groove. Positioning of this is critical - the datum edge of the grinder is that front lip, so every thing gets measured from that. To get a 90 degree squre cut at 45 degrees I tilted the mill head over, but how to check for the right angle? I put my lathe test shaft in and reasoned that if I went up 100mm and across 100mm I should get 45 degrees so a clock should show the same reading at both points. It was fiddly because of the head weight but I got there.
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One of the perils of a universal table is that it may not be exactly square to the column, so I clocked the dummy base datum edge to ensure that the prismatic slide will move parallel to the edge of the grinder table. The cutter shown is a 3/4" one slowly cutting the V. To get the distances from the datums right I put the existing headstock on the mock base, measured it and then tried to get the same dimensions on my tail stock. Vertical was done with a height gauge on the mill table, so not as good as it could have been (the mill is ex-training college so 30 to 40 years of student dings are present. Unfortunately they weren't stoned when they made the dings). Horizontal was done using a cylindrical square and large micrometer (second photo). Typically I did a small cut, held a ground dowel in the v and checked my height to that. When I was happy-ish with vertical it was just a matter of feeding in until the horizontal distance was correct - for that I used the prismatic element
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The results? Well, the first photo is from overhead and looks to be pretty much spot on back to front. The second photo is from the front and shows that the tailstock centre is around 0.6mm high (The centres are a MT0 - the part behind the cone is 9.2mm diameter). While I would have liked it to be closer (say 0.2mm), the primary aim was to be on the high side so I can skim/ grind/ scrape a little off the base and it should be good. The final removal will wait until I have a test bar to put between centres as with no on-machine adjustment I intend to get it closer than that.
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Michael

I hadn't meant to make up the 3 point steady for some time as I did not see it as vital and did not have the material available but decided to draw it up anyway. While drawing it up I looked at the size and saw that if I flipped things around a bit it would just fit in that lump of material left over from doing the tailstock. Rather than having it just sit around...
I started by milling out the shape of the base with a fin on top. In keeping with the casting theme, the based needed to have some draft on it as well a slight curve. The radius worked out to around 200mm, so just for Ray, another lashed together arrangement -
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So, the R/T provides the radius, the sine plate gives a 3 degree draft and the angle & 1-2-3 block push the radius out to where they need to be. There is a stop bolted to the underside of the 1-2-3 block and a clamp on the far side of the block to secure it (as well as an additional clamp from the collection. As you can see, it worked although because of the extended nature of the cutting I needed to have the clamps on the R/T half secured to provide some anti-chatter drag. DOC was around 0.5mm for the same reason.

Once roughed out, the blank was marked out with a centre on both sides. The R/T was centred on the mill and then the blank clamped to the top with the 2 centres coinciding. One side had some half round bumps on it so I used a spreadsheet to calculate the coordinates for the passes. After putting this detail in, the space between the bumps was cleared and the profile put on the rear piece.
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The blank was then flipped over, recentred and the process repeated - this time it was 3 pairs of ribs, clear between and then put on the profile.
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There was no direct line up between the two sides except that centre mark. I did wonder a few times if I was going to get it horribly misaligned. In this next photo I've trimmed up the outside and cut out the centre. As the centre was the key datum, that was left until the very end.
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It all co-incided and with some clean up should compare favorably with the original. Part weight as shown is around 420g - from a 4kg block of CI (although I did get some usable offcuts)
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Michael

3 things of note have happened with respect to the J&S since my last post -

• I've had two people contact me with the bases of 520 grinders interested in knowing how to get them back and running;
• My special order grinding wheels arrived mid January, so when I have things running I have something to run with;
• I've started on the workhead drive drum;

The drum started off as a length of extra heavy wall pipe which then had to be prepped, have solid plugs welded into each end and then cleaned up -

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The stepped part on the base is for a braking. Not sure how well that will work at the moment as it could need a bit of development but that's the story behind a lot of this build really.
The process is rather unremarkable except that I've not used a 3 point steady in anger so it was interesting setting it up. The steady is actually a 10EE one but fits the CVA. As you can see, the drum diameter is right on the limits of the steady. I bored the small end first then flipped the drum to do the large end. I left the flange on the end thick so I'd have something decent to hold in the chuck; of course the result was that the material then had to come off as the last step. I found a pipe centre was very handy for helping stop the drum shaking around and being pulled out of the chuck while doing this

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Below is the large end bored and bushed. I'll need to put in a grease nipple to maintain lubrication I think. Shafting is 19.96mm. The bushes were reamed with an adjustable reamer (sadly the pair were a smidge too far apart for the pilot to work) out to 20.00 so about 1.5 thou clearance which rotates nicely on the shaft.
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After doing all that I did of course have to try on the grinder. It looks the part but as can be seen in the second photo I have what could be considered a "clearance issue". I have a note on my sketch telling me 100mm maximum diameter and that is what it is - the drum still rotates but the clearance is too slight for comfort. More frame mods required...

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Michael

Has this project come to a standstill, or is the adjustable angle plate a tool needed to finish this?
Kryn

I've been a little busy lately, but it's still there. I need to mod the frame and then make up the clutch piece. I have a blank cut and bored; it just needs the cone cut and a groove for engaging/ disengaging. After that there are the idler rollers to make and then theoretically I should be able to drive the workhead.
I made up a B&S 10 to MT2 adaptor the other day and while turning it thought that it was the sort of thing a cylindrical grinder would be handy for.

Michael

I had a go at my cone clutch today.
Nothing too tricky although matching up the taper to the drum took a couple of goes with a whiteboard pen. I had a momentary revelation when I realised that a clutch did not need (or want) a smooth polished surface . Made it a lot quicker/ easier.
First photo is the drum showing the whiteboard pen removal. Second photo is the cone, complete with groove for the clutch lever (yet to be devised - a couple of Phos Bronze shoes perhaps or maybe some ball bearings). The clutch can wait though, as the spring will keep everything engaged so the grinder will be usable although not fully controllable.
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Fitted it now looks like this. I still need to mod the frame and make up the idler rollers, as well as secure the fixed parts to the shaft. I'd like to use taper pins but if one works loose it will flick out. Perhaps a drop of loctite on the end to help secure, or should I use dog point screws instead? Thoughts?
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The spring clears the flat belt pulley by just over 1/4". The drawing said it would be close so I expected that but even so I hope no shaft position adjustment is needed.

Michael

Originally Posted by Michael G

I still need to mod the frame and make up the idler rollers, as well as secure the fixed parts to the shaft. I'd like to use taper pins but if one works loose it will flick out. Perhaps a drop of loctite on the end to help secure, or should I use dog point screws instead? Thoughts?

Depends how much wall thickness you have. If sufficient you could use a taper pin with the big end sunk below the surface and a short grub screw on top to stop the pin backing out.

Make sure you mark the thing so disassembly doesn't turn into a nightmare some time in the future. I recently made a locking wedge for my HBM spindle' the big end of the wedge is stamped 'BIG' just so I don't try to drive it deeper.

PDW

The other option I've seen Michael is the small end of the taper pin turned parallel for a short distance (the bit that will stick out plus a little) and thread it. That way you can put a nut on it to pull it in and keep it there. A bit like the way cotter pins used to work on bicycles.

Motivation is a hard to find thing at the moment due to other issues, but I did do a little bit on the J&S this weekend to try to move things along.

The tailstock is one of those things critical to machine operation so I did a bit of fiddling with that. The sliding piece that holds the T/S centre in the T/S is held in with a plate. As assembled, there was around 7 thou clearance which could be potentially 7 thou of movement, so first order of the day was to remove that by grinding the spacing pieces on the back of the T/S.
Everything needs to be relative to the front of the bed so the T/S was clamped to the dummy bed section, that section put on spacers and presented to the grinder. (Not seen in the picture is a magnetic extension block, keeping things square and attached to the table). I find ground dowel pins come in really handy for this sort of thing.

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Once I had decent clearance (just under a thou I think), I then was in a position to try and get the centres co-axial. To do this I made up a basic test bar around 150mm long between centres on the lathe, put it between the existing headstock and the new tailstock, and then ran it back and forth against an indicator. The indicator has a large foot on it to negate any misalignment in 'the other axis' The first pass showed 21 thou in the vertical and 3 thou horizontal. The 3 thou was not an immediate concern but I did want to reduce the 21 thou before I went too much further.

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I was not sure how to hold the T/S to grind the base but then realised that the plate mentioned above could act as a clamp plate for a piece of bright bar - so 1/2" bar through the back and supported on some mag V blocks. Tilt was governed by the third mag block supporting the outer edge. A bit of fiddling with a dial indicator but I managed to get it parallel.
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I'm now down to around 6 thou vertical. I'm going to leave it at that until I can grind the test bar on the machine and check both the diameters and the indicated deviation (same method as has been done). That of course requires me to get on with the overhead bit. The literature says that the grinder can grind to 1/10th of a thou so it should be a matter of doing a grind and then adjusting until I have something parallel within that range.
Just like on a lathe if the cutting point is not in the same plane as the work axis, the diameter can vary but it's a sine thing so any vertical mis-match between centres is not always going to be measurable - for example a 1 thou change in height on a 0.4" diameter bar (so roughly 10.2mm) only changes the diameter by 25/10,000 of a thou. However, 6 thou vertical with the same bar is 1/10 thou in diameter*.

Michael

*This does assume that my maths is correct - no guarantees on that at the moment

Tail stock looks great beautiful work ! Just for some extra benefit add a diamond dresser location to the back of tailstock if possible but maybe too late not enough material there now ?

Thanks Steve and welcome to the forum. On these machines the dresser was a separate piece and that was the first 'accessory' that I made (back in post 1 of this thread). I partly hold Kryn responsible as he was the one who gave me the slug of CI that I made that from and kicked off all the rest.

Michael

As pictures are now back I guess there is not much excuse for more progress
Nothing terribly exciting but first I got rid of that pulley/ frame clash. The easy way would have been to reduce the flange diameter a little, but I might want it there some day so after covering everything up, I did a cut and shut. Welding is improving.
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After that I started doing the two front tensioning rolls. Raw material was some 2" hollow bar that I had for some long forgotten (and never started) project. The ID was 1 1/4 but the bearings were 30mm OD, so after cleaning up the 'as rusted' exterior I bored the ends for some solid plugs.
The first photo shows a slip on pipe centre I made - only partly successful as the ID was not quite round, although it did the job.
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End clean up and reboring to a uniform diameter for the plug was done with the fixed steady. I still have trouble adjusting the fingers so things don't bind up (especially after some heat build up) but managed.
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After clean up some plugs were turned, welded in and then a uniform OD applied. The idea of these is that as the workhead traverses the belt will travel along the length of the roller so they need to be parallel otherwise the belt may pull off to one side.
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I'd like to say that my boring was spot on and all the bearings press in without any bearing glue. I got two ends that way but the other ends of the roller will need some help.. My main issue seems to be judging the amount of heat in the metal so that when it cools it contracts down to the target size.

Michael

A bit more today -
First the rollers had to be mounted. I'm not at all sure about how well this bit is going to work, so most of it is just tacked. The theory is that once I have things running (that is, I know it all works) I will then dismantle it all to paint the frame and while that is happening I'll inspect each weld, grind out the the defects then fully weld or otherwise tidy them up. Yesterday was one of those 'can't weld to save his life' days, followed by today where the metal went right where it was wanted almost by itself. Grrr!
Anyway, the bottom roller bracket was tacked into place without great drama
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Then the tensioning arrangement for the belt via the top roller. By mounting that roller on bellcranks I can have a belt length variation of around 90mm, so that should be enough to allow for adjustments as well as assembly/ disassembly. The original unit has the two rollers paired on a mount that can move up and down - the tilt is minimal (that is, the up and down is for the movement). The down side of my method is that I lose wrap angle - not sure that will matter as much with the grippier belt.
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As my nod towards recycling, the material for those cranks came from a cut out piece for some of the bracing used elsewhere on the frame. The next step is to get a belt made up so I can see what the tracking is like - some of the rollers may have to be moved/ realigned to avoid jumping off the pulleys. I've noticed that when the tensioning roller is pressed into the wheel head drive belt that happens but I need to do some investigation to work out what to move.

Also added to the frame was the overhead bar in the third photo. That will have the tensioning spring fitted to one end with the other on the bellcrank assembly as well as to support the clutch mechanism. I was surprised as when I turned it over under power today (I do after adding bits to the frame, just to remind myself that it works) the work head drum is happy to rotate and even without the clutch springs pinned in place will provide some torque before slipping. If I can do it without displacing anything else or casting shadows I'd also like to put one of the spare LED light fittings I have on there - wired in parallel with the supply so it is always on if the VFD has power.

I've also been starting to look at the coolant supply & drain. I was very fortunate to snag several BSPP taps and dies the other day on ebay (NOS Goliath) so I should be able to make some of the fittings that will be required. I would like to be able to use the same reservoir and pump on the surface grinder (around a metre away) but that would require some form of quick disconnect. I may have a look at the brass hose fittings in the garden section of the hardware shop but it will depend on how fluid tight they are - a dribble of water on the garden path can be tolerated but I don't want coolant leaks spraying anywhere. There is a quick connect on my Enerpac ram but every time I break that connection a teaspoon or so of oil dribbles out. I guess if the line drains back it may not matter.

Michael

Originally Posted by Michael G

The next step is to get a belt made up so I can see what the tracking is like - some of the rollers may have to be moved/ realigned to avoid jumping off the pulleys.

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I got a belt today and could not wait to try it out, so jury rigged up a tension spring mount and powered up. Even without the clutch completed it tracks along the drum like a bought one. Not that I'm chuffed or anything...

Michael