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Polishing buffer arbor issue

Seeking the Orchid wisdom once again!

I just purchased this 8” buffing motor on sale from my local Princess Auto (the Canadian version of Harbor Freight for you Americans :smile: ). It was a great deal, the only issue with making it my jewelry polisher are the gigantic 5/8” threaded arbors.

Ideally I would like some tapered spindles for the majority of my buffs and also an adapter to use wheels with 1/2” holes like the Cratex wheels/grinding wheels to grind down my casting sprues.

The current 5/8” arbors are straight and have about an inch and a quarter of threading on the ends. I’ve looked at tapered spindles and 5/8” to 1/2” arbor converters online and a lot of them seem quite short which means the set screws that hold them on would hit where the threading is (like the one I purchased with the motor that I’ll be returning - see pic).

Has anyone converted a buffer with this size/type or arbors to fit the typical jewelry buffs and wheels? Can anyone point me to the right products?

Thanks in advance!

If you can’t find what you need, you might cultivate a relationship with a good local machinist to help you make what you need. When you get done, you may wish that you had bought a decent Baldor, Red Wing or other jewelry specific polishing lathe. In 47 years I have only needed to buy two…Rob

Geez Rachel Pelling, and/or any other Orchid Member, if more people would concentrate on purchasing Made in USA products as opposed to made in India or any other foreign country, maybe issues like this could be avoided, and at the same time, keeping sales in the USA. Thank you for your time, Regards, Lucas Dental Company… www.LucasDentalCompany.com

put a piece of brass rod in the set screw hole in between the set screw
and the shaft, the brass will form to the threads and protect them. You
may find that the combination of taper over threaded shaft is slightly
out of round, should be ok for a belt buff, not ok for a grinding
wheel

Thanks for your suggestion Rob. Unfortunately a better motor really wasn’t in my budget right now but I do enjoy dreaming of new tools! I’ll look into a local machinist who might be able to help me.

Hi Richard,

I’ll point out that I’m actually in Canada, not the United States, so technically “buying USA” is buying from a foreign country for me, and is not actually supporting my local communities.

However I do take into account the place of manufacture of my purchases and buy made in Canada, made in USA, and made in Europe (generally in that order) when possible, primarily because these areas have superior worker and environmental protections in place so my purchase is hopefully not contributing to undue exploitation of people or our planet.

The place of manufacture isn’t the cause of the shaft/arbor issue I’m having though. Baldor itself makes buffers like these with large threaded shafts as “industrial buffers”. It’s not that it’s Chinese/Indian/etc made that’s the problem, it’s that this style of buffer is not primarily intended for jewelry manufacture and doesn’t fit the jewelry industry’s typical spindles and attachments.

Finally, I simply do not have the funds at the moment to buy a pricier “made in USA”, jewelry-specific motor. Advice on converting this one is appreciated, but a lecture on buying American made doesn’t much help me at this time.

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Racheal…We aren’t trying to give you a hard time. A polishing lathe is one of those few things in my shop that I would just go into debt to replace if I had to. The others include my torch, flex shaft, and probably rolling mill. I can get along without other tools temporarily or with less than quality until I can buy a good replacement. A good polishing lathe for typical jewelry work is at least 1/2 hp with a tapered shaft that will allow you to mount brass tapered spindles. They often times come with both right and left hand spindles. I never use the left hand, so my. current lathe is a right hand only. It is a Baldor with a lot of clearance because I polish larger pieces. Regarding a machinist. It is good to find one because you will find all kinds of reason to use them once you know what they can do. I had a little extra money a while ago and bought my own small metal lathe. I still use my machinist for precision work. I have done a search to see if there is an off the shelf solution for you, but can’t find one. If I do, I will let you know. Good luck…Robemphasized text

Hi Mark,

So if I have this right you’re suggesting a little “plug” of brass rod to be sandwiched between the bottom of the set screw and the threads on the shaft. This should deform against the threads and give the bottom of the set screw something flat to grip without crushing the threads?

I’m imagining such a set up might be less secure than a direct set screw to flat, solid metal connection. I’ve heard of a sort of glue (locktite?) that can be used to keep screws from backing out, maybe some of that added would help hold it together?

Thanks for your suggestion!

Rob,

I know you’re not trying to give me a hard time. My reply to Richard was pre-morning coffee and was probably snippier than necessary, I apologize for sounding ungrateful for your suggestions. I understand the value of investing in good tools, and generally I do, though financial constraints being what they are I do have to make choices about where my limited money goes. I’m a just a hobbyist so I’m not going to go into debt for any piece of equipment.

This plan for this (cheap) buffer is to grind down sprues with a grinding wheel faster than I can on my flex shaft (I hate grinding sprues!) and speedy polishing of a few larger pieces that are very cumbersome to polish on my flexshaft (my current main polishing tool).

If the buffer were to become an integral part of my workflow I would definitely consider upgrading at some point, but as it’s a new process for me I’m not willing to shell out more cash for a piece of equipment that might not get a lot of use.

I’ll have to send out feelers for machinists in my area, they sound like handy people to know!

Think about an expansion wheel with a 5/8" center. You could use various grit size silicon belts belts to remove metal. I use one on an arbor all the time. You would have to run water to it. You can collect the swarf and send it to the refiners.

If it was me and I was doing blacksmith, etc. and I got this on the cheap, I would take a big file or hand held grinder, turn your machine on, and grind both shafts to a point while it was running. Not the best way, not even preferred, but you will be where you want to be by poor-boying it.

Hi all. Orchid is an international group and we have to buy often where we live. I looked at purchasing an item from the USA at $19 but the shipping was $48 plus clearance charges and UK tax at 20% on the total. Orchid was originally operated from Thailand so does not just have USA following and many of us also feel our locally made equipment is as good as those in US especially as us is 110 volts and most others are 230volts. The usa does produce good material but not exclusively. Rant over🙂

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Hi Rachel, well it is actually slightly more secure as the brass deforms
into the threads holdign it into place, but more than adequate for your
purpose. i would not use it for, say, a main drive shaft keyway on a 50
hp motor, but I used this exact trick to correct a design oversight on a
set of quick change tools I use on my milling machine and have clocked
about13,000 hours on this quick fix and it is still holding up quite
well; I imagine your total polishing time will be, perhaps, 16 to 20
hours a year, so it should be worth trying.

If you want to use locktite (sometimes I will use a small piece of paper
towel in the threads of the setscrew in place of locktite, to take up any
‘slack’) make sure that everything fits together, then put a drop of
locktite; it can make it hard to disassemble.

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I’m going to chime in here…I have a buffer which was made from a Chinese grinder. I don’t think it matters whether the shaft is solid or threaded if you can find the appropriate diameter LH and RH spindles, they will fit well enough to spin on polishing buffs. The grinding wheel adapters can likewise be rigged. If you are on a low budget and can stand switching the adapters out, the motor can serve for both buffing and grinding. I find these old Chinese grinders for sale used for about $30, so you might be able to afford both a grinder and a polishing “lathe.” I have to disagree with the idea that this motor has to be expensive. It doesn’t really matter if the grinding wheel or buffing wheel runs out a little or not. You can grind and polish a lot of stuff on your $30 motor, certainly enough to pay for it and then move up if you choose. -royjohn

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Okay Rachel Pelling, so now I know your Canadian.

I am with Rob in this discussion. I can still do all I would need to do with a plumbers torch if I had too. But I would go into debt for a good polishing motor and a rolling mill. They are a necessity for the level of work I do right now. All the rest in my shop is the best I could get at the time. Luckily it’s all pretty good.

Now I can afford to buy the equipment I need. The hard part is determining if a I really need it or do I just want it. Then the Boatyard Mechanic in me says, “You got this Donnie, It can’t be that hard to build.” That’s where I get into trouble.

I am a fan of the whole idea of “Making Do”. It is really about getting from point A to point B after all. Early on I would look up the price of a Baldor motor but continue on using the polisher Dad used for as long as I can remember. And at 69 I can remember a lot. Maybe Rob remembers when Dad got that polisher motor but I don’t. It still turns true with a ½ horsepower and 3250 rpm’s. I don’t know the name of the manufacturer because of how it is located in the cabinet but it is stern stuff.

Years ago If what I had available to me was a grinder motor from Harbor Freight and there was a way to make it work as a polisher I would do it in a heartbeat. The jewelry and the customer doesn’t care what polished the work. And as soon as the money came in to go to the next level of equipment I would buy the new American Made (Canadian Made) polisher and not look back.

Don Meixner

If it was my motor I would cut the threads off (with my angle grinder or hack saw) and file a small flat key on the remaining shaft for the arbor set screws to seat. Long shafts and a dis-aligned arbor will invite excess vibration and some danger… But first I would carefully measure the shaft with a caliper to make sure it is in fact 5/8". If it is slightly larger you can sand it smaller with emery cloth, if too small add thin brass shims…I have been using a re-purposed 1/2" dual shafted washing machine motor for decades. Probably easily available at your neighborhood appliance repair shop for nearly nothing.
Finally, and seeing that you already have this motor and (unless you are thinking that you are going to use the threads for a grind stone or wire wheel) you can just crank down on the set screws and mash the threads to get a seat.

E.g. this motor (used of course)

Gesswein has tapered spindles for 5/8" threaded arbors.
https://www.gesswein.com/p-4510-tapered-spindles.aspx

Take a look at Arbe Machine. They manufacture and sell to a lot of the people we buy from like Rio, Gesswein and others. They are located on Long Island and, last I knew, you could call them up and ask to stop by, look at what you want and buy it if you like it. USA made, sorry Canada, but I am sure that there is great stuff made in Canada. For that matter, we all have or crave a Durston mill (UK), PUKs come from Germany, I buy all of my files from Switzerland and the list goes on. We are part of a world economy, at least for now, but who knows what Dangerous Don has in mind. There, I said it…Rob

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