Harig Spin Fixture

First test of the Harig spin fixture.

[@charlieromeo7663]

I just picked up the Atco version recently. This video is very informative. Now I have to watch the center video. Thanks for the info

[@SolidRockMachineShopInc]

Thanks for watching! Glad you enjoyed it.

[@bcbloc02]

I agree with the advantages to the ball centers. I also think a lot of that movement in the test indicator is coming from the vibration caused by the drive end not running true. The wiggle in that pulley is moving the drive dog point and no doubt that translates to the part.

[@SolidRockMachineShopInc]

You are correct Brian. Check out my latest Instagram post where I fixed this. Steve

[@DK-vx1zc]

Very interesting, thanks for sharing... Hope all is well with you and your family!!

[@SolidRockMachineShopInc]

Thank you! You too! Steve

[@josephlovell6951]

Nice tool and nice to see you guys back at it ...

[@SolidRockMachineShopInc]

Thanks 👍 Steve

[@hereticswissery9010]

Hi Steve love the video! I never been a fan of that harig fixture for it's adjustable tail stock and spring loaded head stock, but look like you got it all figure out with the tooling ball mount, I love grinding between center it's so much fun and when you nail every detail you really need a electronic gauge to inspect what is going on. Also just to had up to your commentary on not having the center perfectly align, you can grind pretty round even if there are off... but if you need to turn the part end for end you will get TIR error because as you said the center will ride on the opposite side of the center. Happy to see you back and safe.

[@SolidRockMachineShopInc]

Thanks Simon, I plan on reworking many of the parts on this in the future to make it much better. Steve

[@shannonsears3496]

Nice addition. Even though we have 4 external grinders, i still use harig centers often. The tail center pivoting is really a non problem. Once its adjusted to make part true centers are in line very close. I always put wheel on center of part. I am usally grinding some shoulder so i just tap the fixture in square. I used harig centers this week to make tooling balls. The tail is solid unlike every OD grinder. It allowed me to use reverse center on tail and hold all dims from the ball end.

[@SolidRockMachineShopInc]

These unit come in handy and the precision with a few tweaks is amazing. Sounds like you like them as much as I do.

[@shannonsears3496]

i would not be happy in a shop without a set. I have a myford and 2 chinese Od grinders that i can use but still need the Harig centers often.@@SolidRockMachineShopInc

[@turningpoint6643]

Nice shop addition Steve. While it was about taper turning on a lathe with the tail stock off set, George Thomas in one of his books had a very good illustration of the need for using in his example female cup centers at both the head and tail stock and small ball bearings between them and the part centers. With your much smaller vertical adjustments required to remove any taper, that would still apply just as you pointed out. He also mentioned using what are known as bell center drills that cut an internal radius as a center. I honestly don't know enough about high precision radial grinding to know if they'd be accurate enough to help or not. They would provide slightly more support than the line contact a 60 degree center drill provides on a ball. Your idea of shop made carbide tooling balls might be even better than his separate hardened ball bearings. Much more wear resistant and durable for sure.

[@SolidRockMachineShopInc]

Thanks, a female ball center would have to be the exact same size as the tooling ball to to have full contact also, it would limit you to one size tooling ball. If any particles were to get in between the the contact surfaces it will cause problems that you wont have with the female angle shape. Steve

[@turningpoint6643]

@@SolidRockMachineShopInc Nope I know what you mean about matching the male / female ball sizes and having that full contact Steve. A perfect match to say Moore Tool levels would be almost impossible.That wasn't Georges intent or point. Try drawing it out by at least 10X size. The male ball with a female radiused center allows it to work more like a ball joint universal. The ball size and the internal radius doesn't have to exactly match or even be close to work.Would it make enough difference to matter? I'm unsure. It does make a large difference with an off set tail stock while taper turning. With a standard 60 degree male point and a standard 60 degree female center and with any misalignment you have only a two point contact within that female center where the male point touches depending on the direction of that misalignment just like you described. As I said, that radiused female center and a male ball tip allows it to act like a ball joint. If there were no advantage they wouldn't make ball joints :-) At this small scale and very light grinding loads? Maybe worth trying, or maybe there's no or not enough there to make it worth the effort? Visualizing it I suspect no matter how good the bell center drill is it's still going to leave measurable ridges on that internal radius.They make 60 degree center laps for I would think that exact reason and to true up those centers after hardening.

[@TheKnacklersWorkshop]

Hi Steve, A very interesting bit of kit... What you said regard using a ball fit rather than the traditional taper makes a lot of sense. I will look forward to seeing more videos on the Harig... Take care Paul,,

[@SolidRockMachineShopInc]

I have plans to build a sine plate spin fixture in the future that will replace this unit. Steve

[@CraigLYoung]

A new toy! Thanks for sharing!

[@SolidRockMachineShopInc]

You bet! Steve

[@outsidescrewball]

Enjoyed the discussions...great lessons

[@SolidRockMachineShopInc]

Thanks Chuck.

[@ROBRENZ]

Looking real Good Steve! ATB, Robin

[@SolidRockMachineShopInc]

Thanks Robin, I have made a lot of improvements since this video, Steve

[@t.d.mich.7064]

Another good reason to start at the end you did, the wheel wear will work in your favor and give you a nicer wheel condition as you move off the part. Going the opposite direction, the wheel breaks down, and if the wheel doesn't completely leave the work because of travel limitations, one end of the work will not match the other. On another issue, the straight lines created by a lapped internal center, mated to a perfectly round tooling ball, would give the best alignment and rigidity on any setup. As you stated, your centers are always in complete contact. Nice tutorial!

[@SolidRockMachineShopInc]

Very true!

[@billchiasson2019]

Great video!! Very interesting, I alway Learn something new! Thanks for making these videos!.

[@SolidRockMachineShopInc]

Glad you like them! Steve

[@sharkrivermachine]

I like that design, giving me some ideas to build my own thanks for sharing,

[@SolidRockMachineShopInc]

You're welcome Steve. I plan on building a sine plate version in the near future that we will be posting videos of. I already have it modeled and the base plates squared up. Steve

[@jimtaylor6979]

the shed dweller just built one on

[@RRINTHESHOP]

Nice setup Steve. That will be a great rig, when your done with it.

[@SolidRockMachineShopInc]

Thanks Randy, I started the improvements today. Steve

[@CapeCodCNC]

The smooth idler on a toothed belt may be inducing vibration and the large driven pulley seems a bit loose. Cool video!

[@SolidRockMachineShopInc]

I already fixed it, you can check it out on our Instagram page. It works real nice now. Steve

[@toolbox-gua]

Very interesting and always educational.

[@SolidRockMachineShopInc]

Thanks. Steve

[@frederickstidman1502]

You mentioned it is only one speed. You could go old school and use a Variac ( variable voltage transformer) which you can plug into. I use one I built about 5 Amp size to control my foredom Flex shaft unit. This looks like a low amp motor on your spin fixture and not much back EMF on start up (I.E. not much load on start up) . Easy to find plans on internet or purchase on Ebay etc. Can then use it on multiple small Amp motors in shop. Plug it into wall socket between Motor and wall socket.

[@SolidRockMachineShopInc]

Thanks for the info. I will have to check that out. Steve

[@TBJK07Jeep]

I would like to see you make tool ball’s as well. I’d like to see how its done & the technique used.

[@SolidRockMachineShopInc]

Should be coming in the near future. You will be surprised at how simple it is. Steve

[@SuperAWaC]

Would a standard V pulley with vertical flanges shield a larger, softer O-ring from coolant splash?

[@SolidRockMachineShopInc]

I would think so. I plan on fixing this in the near future. Steve

[@Steve_Just_Steve]

Like the intro WAY better!

[@SolidRockMachineShopInc]

Thanks for watching.

[@AmateurRedneckWorkshop]

That certainly looks like a handy tool. Now to see the tool balls.

[@SolidRockMachineShopInc]

Hopefully in the near future we will do a video on it. Steve

[@ShadonHKW]

Nice tool, love mine, let me know how the ball trick runs. Also the drive dog pin creates a "lope" on the drive end, I tried a rubber band on the actual part to drive the part and the "lope" went away.

[@SolidRockMachineShopInc]

Hi Stan, I plan on rebuilding a lot of things on this unit and the drive train is one of the first things I plan on redoing. Also, I plan on making a sine plate version of a unit like this. I been working on it for awhile now and have it modeled and the base plates squared up. Plan on doing video series of the build. Steve

[@grumpyoldman5368]

@@SolidRockMachineShopInc Looking forward to that build series. I have been planning to do something similar, so would be interested in the decisions that go into yours.

[@robc2536]

Looks like a nice addition to the shop Steve. What is the HP and RPM of the drive motor?

[@SolidRockMachineShopInc]

Not sure. Maybe Harig's website might have the info.

[@roeng1368]

Are these fixtures expensive ? I just bought a surface grinder and would like to be able to do small cylindrical jobs too.

[@SolidRockMachineShopInc]

Yes, Harig list them for about 3.5k. Steve

[@HybridiHippo]

I have feeling that toothed belt driver makes noise in to grind. Round continues o-ring belt for it. My inside grinder spindle use flat belt and sounds great even in 15K speed

[@HaraldFinster]

Agreed. I had the same feeling. The wobbly bearings of the drive wheel might also introduce some vibration. Anyways the spin fixture looks like an excellent tool. Question: I have seen people lapping conical centers. Would you do the same with the "ball-bearings" shown here? Last but not least: very enjoyable and informative video. Thank you for sharing your experience.

[@SolidRockMachineShopInc]

I plan on making a different drive system for it in the future. Steve

[@SolidRockMachineShopInc]

@@HaraldFinster That is one of the advantages is that I would not need to do any lapping. Steve

[@warrenjones744]

That looks like a cool tool Steve. Is the motor the kind you can use a speed control on? Or is to really necessary? Lately I have been learning about tooling balls. Joe Pi did a couple vids on em, I am going to incorporate them into my work when the time comes for sure. Tooling Ball grinding centers seem like a great idea especially if you are intentionally grinding a taper. Robin sold me on that same lube several years back. (it is excellent for flaring hydraulic tubing BTW) He is a wealth of information and gives it freely. Personally I feel we the audience are so lucky to have not only YOU but Robin, Stefan, Joe Pi and Tom Lipton to take the time to share your experience and knowledge and show us those techniques that are so important to reach that next decimal point of precision.(Well with Robin and Stefan by the nature of their work maybe two decimal points😀) Cheers

[@SolidRockMachineShopInc]

Thanks Warren, I believe you could hook one up. I agree there is a lot of great guys on KZbin sharing their knowledge. I learn a lot from them too. Steve

[@ericrichards5862]

Nice spin fixture Steve, Thanks for the demonstration. Tooling balls soon?

[@SolidRockMachineShopInc]

Hopefully the next video. Steve

[@wileecoyoti]

Great video as always! At the end you talked about the drive system causing problems: is that the influence of the belt teeth engaging or entirely the lobing weight from the drive dog/pin? Great idea with the tooling balls too, I might have to use that on something! Also how insane would it be for someone to try and build their own to a level of precision that harig or atco did? (I know I'm probably the guy that would try it even if it's crazy haha)

[@SolidRockMachineShopInc]

It could be both. I have been working on a unit that is similar but it will be a combo Sine Plate, Sine Vise and Sine Spin Fixture all in one. I have it modeled in CAD and the base plates squared up. We plan on doing KZbin Videos of the build. Steve

[@wileecoyoti]

@@SolidRockMachineShopInc that sounds awesome, I can't wait to see you build that!

[@MrJzplastic]

Please forgive my newbie question, you want the work piece to be offset left of the wheel centerline?

[@SolidRockMachineShopInc]

It depends on the rotation of the wheel. My wheel turns clockwise so I want to be on the left of center line. This way if I mess up and feed into the part hard it will move the table away from the wheel. If you are on the other side then it will pull the table toward the wheel and possibly do a lot of damage.

[@SimonPEdwards63]

I suspect the extra run-out is coming from the belt drive. I suggest you replace the bearing and ideally move from a toothed belt to a flat or round belt.

[@SolidRockMachineShopInc]

You are correct. I already made many improvements and now it is near zero run out. instagram.com/p/CO_XhtKpEQA/ Steve

[@SimonPEdwards63]

@@SolidRockMachineShopInc excellent

[@f.hababorbitz]

Don't know if you'll see my comment Steve, but you indicated you ground the reverse centers, what angle? 45 seems viable, but looks like your tooling ball is deeper then the radius of the ball into the center. I looked for tooling balls, found McMaster Carr has small ones with a shoulder and adjustable ones with a long shaft, either for slip fit. My current project is to correct ER collet runout, using a similar jig and a sine plate. I don't know if I can fix the runout grinding on the outside of the collet. We shall see. I was planning on starting with the large one, making an arbor shaft, then machine it down as I step through the sizes of the collets.

[@SolidRockMachineShopInc]

Went with a 60 degree inclusive angle. Used a center drill to rough it in while soft. I bought the ceramic ball bearings from Amazon.

[@f.hababorbitz]

@@SolidRockMachineShopInc If I would have looked I would have found your video; kzbin.info/www/bejne/nqmpiXh3j96rqdE I didn't thing I heard you say the size, but I think they are 1/4" diameter bearings given you say the center drill is a 1/4" body diameter.

[@SolidRockMachineShopInc]

@@f.hababorbitz Yes, they are 1/4" ceramic balls. I bought some off Amazon.

[@duanedickey7043]

I suppose you could flip the bar and see if you get the same pattern.

[@SolidRockMachineShopInc]

I am sure it would be the same. I am quite sure the noise is coming from the drive system. Steve

[@RyanWeishalla]

Nice new tool for the shop. Pretty good for right out of the sellers hands and you not giving it some TLC.

[@SolidRockMachineShopInc]

Hi Ryan, Checkout the latest Instagram post. I already made improvements and working on some more. Steve

[@RyanWeishalla]

@@SolidRockMachineShopInc Thanks, Steve. I'm not an Instagram user.

[@bruceanderson9461]

Time to switch to rumble!🇺🇸🇺🇸🇺🇸🇺🇸🇺🇸🇺🇸

[@SolidRockMachineShopInc]

I been checking out Bitchute.

[@bruceanderson9461]

@@SolidRockMachineShopInc Keith Fenner just switched to Rumble and it worked well for his first video. Trying to keep us free. Bitchute may be great also. I will follow you wherever ever.

[@donepearce]

The difference between the two ends may be to do with the fact that you are relying on a bearing at the driven end. Not the accuracy - between centres takes care of that - but any radial slop. That may be worth checking. Oops - just as I hit send, you make exactly the same point.

[@SolidRockMachineShopInc]

I already made a few modifications and it and it works a lot better. I have an Instagram post showing this. I have more modifications to do yet. Steve

[@donepearce]

@@SolidRockMachineShopInc Just a thought. Whenever I turn between centres I turn the point of the support cone in the collet, and then I don't move it. It is guaranteed centred. You don't have that luxury here. You are relying on the accuracy of the hole that is already there. The fixed end, of course, just needs to be still.

[@ReinoGoo]

The wheel does not running true. That can give you some vibrations.

[@SolidRockMachineShopInc]

Yes it can if not properly dressed. Steve

[@mikeputnam4230]

From a machine design stand point clogged belts are a problematic choice when vibration reduction is of primary importance. This is most likely one of the reasons a round belt is typically selected for this type of application. There are ways to minimize the vibration, this article ( www.researchgate.net/publication/319300848_Periodic_Response_of_a_Timing_Belt_Drive_System_With_an_Oval_Cogged_Pulley_and_Optimal_Design_of_the_Pitch_Profile_for_Vibration_Reduction) discusses the vibration problems using cogged belts and analyzes some approaches to minimizing it.

[@SolidRockMachineShopInc]

Thanks for the info. I already made improvements that you can see on out Instagram page. Steve

[@davidl.579]

Dump the belt and go with an oring won't even be able to hear it

[@SolidRockMachineShopInc]

This unit has been greatly modified. Already using o-ring like you suggest, using ceramic ball bearing instead of centers and modified the spring tension of the adjustable center. The unit with modifications is fantastic and extremely accurate.

[@mashed-out]

Dude you gotta fix that wobbly ass cog wheel...I'm gonna freekout watching it...that wobble has to transfer to part in some manner.

[@SolidRockMachineShopInc]

Fixed a long time ago.