Ingar-RT618 Surface Grinder (Boyar Schultz clone)

[Joco]

Been a while since I last posted but I have (for me) an exciting new addition to the home workshop.  I'm going to try and be more diligent on this one and take pics and videos as I go. I do not (at this stage) plan to do a full  rebuild/refurb.  This is more of a clean up, checking what I have and noting down where I  might want to  get more into it a later time (e.g. if things need scraping or the like).  And probably a little bit of me starting the beginning steps on the long road to learning surface grinding to some small degree.

I have struggled to find much mention of Ingar's as a specific machine online and so have been relying quite a lot on the Boyar Schultz info.  So as I  go  along this journey, anyone who has experience/advice based on either Ingar or Boyar Schultz experiences would be greatly appreciated.

Cheers,
James.

[Joco]

Set the SG up with a VFD to get the 3-phase motor running.  Trued up a wheel and had a crack at some mild steel.   From what I can gather getting a good finish on mild steel is a bit tricky.  I picked a wheel from the collection I got that seems to fit the bill.  Ring tested it and mounted up.  No I do NOT yet have a way to balance wheels so all that has been done is to dress this wheel. Nothing more.

Images inlude the wheel used and the result on a section of mild steel.  The surface feel is silky smooth so its not a bad start for a first ever use of an SG.

[ShopShoe]

Joco,

I'm sure you are aware of these videos, but you may find them interesting about surface grinding in general. My apologies if I'm digressig from your requests.

Suburban Tool makes precision tooling and has some really good videos on YouTube about precision grinding and measuring: Search for "Suburban Tool videos."

Shadon HKW on YouTube covers lots of subjects, but includes some very good videos on "correcting" tooling with a surface grinder.

Keith Rucker (vintage machinery.org), also on YouTube, covers lots of subjects, but among them is his build-out of his large shop which included a surface grinder that needed lots of TLC to get operating efficiently. He has been building up his skills of machine restoration and scraping over the last few years.

Keep posting your progress. I would love to have a surface grinder, but don't have the space for one.

--ShopShoe

[nj111]

Very nice addition to any workshop. I'm in no way an expert on surface grinding and I don't use my Jones & Shipman commercially, but one thing that has given me better results over the last 15 years or so is to use the technique of a relatively deep cut (up to 0.002") but a narrow index across the wheel. (i.e. index say 1/4 to 1/3 way across the wheel for each pass).  This is rather than taking a shallow cut of a couple of tenths of a thou and wide index almost the width of the wheel.  I found this only wears one edge of the wheel, the wheel doesn't need such frequent dressing and the surface finish remains good across the entire part.  I also found something like a cool blue 46 grit wheel much better for most jobs.  46 grit sounded coarse to try, but the finish is very good (to my old eyes). That's just what I have settled upon as it has worked very well for me over the years!

[Joco]

Cheers.  I’ve been devouring videos from Keith, Shadon, Solid Rock and others. Shadon’s were very useful as he has a Boyer Schultz that (other than being hydraulic) is very similar to my Ingar.  Also from these videos have taken the 46 grit advice.

One of the parts I seem to have missed from their videos is what, if anything, they have done to remove looseness due to wear in the spindle “saddle” assembly that rides in the column. The Boyer Schultz style machines have no gibs that I can see and no other signs of adjustment available.  Any insights there welcome.

I’m also finding that the spindle resists then clocks over. This is with it connect to the motor. It is almost  like the motor has perm magnets.  Pretty sure that is not right? So about to start pulling that assemble apart so can check motor and spindles independently.  The motor absolutely runs and when running seems very stable.  But I’m suspicious about this “clocking” effect.

I have attached the machine drawing for a reference as well. Just so you can all see what I’m referring to. (Hopefully)

Here is a link to a much higher resolution version of the schematic.  2.4MB compared to the 1MB limit of the forum:  https://drive.google.com/file/d/1bikXg8WTbOfz4q0keuQnAlYu1LrycESW/view?usp=sharing

[Joco]

Some more cleaning work tonight.  Just checking out what I have so I know what things I will eventially look to deal with.
So going down the attachments list in numerical order:
[1] chuck taken off and started to clean.  Poor girl is starting to look a bit bare

[2] Chuck off and what do i find ... shims!  The previous owner shimed the chuck true.   I guess you could do that but I think the "correct" way is to have ground the table, then grind the chuck base, then grind the chuck top.

[3] Table off and the ways look pristene.

[4] The ways the table sits in have a turcite like compund on them.  That probably explains why the table's running surfgaces are looking so good.  There a bit of were here but hard to tell if it will effect anything.  The really nice thing about this discovery is that reconditioning should be relatively straight forward (when the time comes).  Strip this stuff and replace. The rescrap in the surfaces to be true.  "When you say it fast it sounds so simple.   

[5] On the left side the "turcite" is delaminating  a little.  Not ideal but under the weight of the table I wonder if that is really going to be a problem.  Initial thoughts is to not do anything unless it is proven to be influencing things.   Given how much weight is in that table I doubt it is. But time will tell.

So the adventure continues. But learning more and more about the wee SG.

Cheers,
James.

[Joco]

Continuing the strip down.   Tonight got the motor off and the spindle carraige assembly and vertical leadscrew all removed.
Shown by attachemnts #2 and #3.

I think I have discovered what was causing the "clocking" effect on the spindle I described a few posts ago. Link to video below.  But the gist of it is the pully on the motor is bent.  That is about the only way to describe it.  Its got so much wobble that when turning it will be causing a change in belt tension results in resistance being felt until you get just past the worst point then as the wobble comes back in the spindle "clocks" forward as the belt tension pulls everything back into its lowest tension state. This can not be good for vibration into the spindle or for the wear on the spindle bearings. Think I am going to have to fix this one before putting it all back together.
https://drive.google.com/file/d/1HMs0xMlY4jww1PxU3K6hZ6iuC5Bio0Ox/view?usp=sharing

Cheers,
James.

[Joco]

After discovering the wobbly pulley I decided to make a new one.   First time making a polly-v pulley, actually a pulley of any form.

So had a look at what I had to replace (attachment #1). And started making it. I thought "no need for that reduced neck" so kept it simple.

Looking down the attachement list ...
#2 - blank machined and groove cut lines scratched on the blue

#3 - checking things against the belt.  Looking good.

#4 - V's cut and the belt fits very nicely. Next the hole was drilled and bored to 16.01mm for a snug tapped fit and by keeping it all in the same setup bore and pulley grooves are all perfectly concentric.

#5 - internal keyway has been cut (thanks to Bruce's clever lathe mounted broching tool). Set screws all in place and a tightish tap fit onto the 16mm shaft.

#6 - but a bit of a disaster on fitting. The thick body of the pully was interfering with the vertical leadscrew! Should have copied the original shape.  Ah well, back to the lathe and using a button insert contoured things into shape.

Finally got it all installed and did a test run done.  Seems to be pretty good and there is definately no clocking any more.  Sorry about the camera shake and my rubbish commentary.   
https://drive.google.com/file/d/1ub_B4fQoBLiYEwi7ORNbgbit3N6-4G4v/view?usp=sharing

Cheers,
James.

[Joco]

Did a test run with a wheel last night.  Runs super quiet but there is definately a vibration coming through with a wheel on as compared to no wheel.  So that probably means my wheel needs balancing.

I have been reading about static balancing and also dynamic balancing.  I'm going to give the later a go and see if it works.  I'm most definatley not the first to do this and its not exactly clever or new, basic physics by all accounts.
I'm following this example  http://nwnative.us/Grant/shop%20articles/autobalancer/ and I have also watched a youtube video on the principle as implemented to dynamically balance truck wheels.  https://www.youtube.com/watch?v=ullnFQD4F1I

In essence it appears that the balls migrate around the tunnel (torus) to points that balance out the inherent heavy side weights in the wheel/holder assemnbly. Its no doubt due to some clever physics stuff that I might understand if I had paid more attention to high-school physics classes about 35+ years ago.

Anyway, once I source some 5mm chrome balls I'll get this moving as well.

Cheers,
James.

[nj111]

Good that you are making progress, in my experience a static balance should be just fine for the surface grinding we need to do in the home workshop. Always used my J&S balancing stand and moved the little weights around in the wheel mounts and always had good results.  BUT!  that autobalancer is something I have never seen and is amazing!  The truck wheel video really shows how well it works. It's given me ideas of various applications. Interesting and thanks for putting that up here!

[Joco]

Cheers Nick.

I'm actually being a little lazy.  I don't have a static balancing rig, the grinder didn't come with any of that gear. The wheel mounts are plan ones, no weights and from what I can see none of the wheels have been "drilled" to remove weight to balance them.  In short the previous owner didnt seem to bother.  I've decided if I'm going to do this surface grindng lark I will at least try and do it well.  And it will be MUCH faster for me to make a proof dynamic balancer than it will be to make the arbor, make the balancing jig and then static balance wheels using the drilling method.

Cheers,
J.

[nj111]

The same author - at his site - has another (earlier) article as he made a similar dynamic balancer previously for a bench grinder with mixed results. (It seems the ball bearings must not be allowed to get stuck, so grease etc is a no no), I'll be very interested to see how you get on with this, if it works reliably I shall be making a few!

[Joco]

Nick - balls ordered. So fingers crossed they will be here for the weekend.  The article talks in terms of 7/32" balls and doing the count in the pics he had 8.  For me sourcing 5mm is easier and significantly cheaper.  In NZ you pay Imperial tax if it's not metric, that is the only way to explain the prices.  Anyway I think having 9 x 5mm balls should give me similar weight.   I will also use M3 flathead screws instead of pins.  That way I can add in or remove balls on this prototype more easily than if it is pinned.

Re the bench grinder balancing article, yes grease is clearly a no-go.  Once he cleaned that out he had success and it was all go.

[Joco]

After putting in the new pulley on the motor and getting the grinder back into a testable (if not really working) condition I decided to put the mag chuck back on and do a test grind.  Just to see if there was some improvement.

Here are two links to high res images.  You need to look at the hi res to be able to see the differences.
Image 1:
https://drive.google.com/file/d/1LSMNgkG6u7G8s85xcAzDxfoAzoWYnfOk/view?usp=sharing
This is the origina grind.  You should be able to make out by looking at the shapes around the light reflections that there is a ripple. I suspect this was caused by the orginal pulley being bent. It would have been creating a cyclic tension change on the belt which would be generating a vibration or harmonic through the spindle.

Image 2:
https://drive.google.com/file/d/1L5gu8hqx9m7ovGqb5esdzP8pzzAUmjLh/view?usp=sharing
This is with the new pulley in place.  You can see the texture of the grinding grits of the A46J8 wheel in the mild steel.  But there is no ripple.  This will be more about having the right wheel for mild steel and/or me still learning to get a good dress for clean cutting.

BUT an improvement.  It will be interesting to see if the dynamic balancing ring also improves things in some way.

Cheers,
J.

[nj111]

Another thing I've learnt:  I get a better wheel dress and grinding finish with a smaller  (say 1/4 carat) single point diamond dresser.  I don't know why, it's tempting to purchase a larger one for longevity but the results have been inferior.  Obviously that is with regular turning of the diamond for both sizes.