Grinder Arbor/Shaft Extenders/Adapters > Buffer

First - this is a feasibility study. Does it make sense to have adapters machined?

Several members have said they might be interested in thread-on extenders/adapters for grinder arbors/shafts.

The purpose is to allow using a grinder as buffer.

Purpose built buffers have no wheel guards/covers and longer arbors, which provides plenty of room for buffing large, odd-shaped pieces.

The adapters available use set screws to secure the adapter to the grinder's shaft; which can damage the shaft/threads and cause uneven rotation.

Kevin54 has offered to do a run of adapters, but first needs to know the quantity before a price can be given.

I'll act as the order & distribution point; IF this is a go project.

I will run the poll until Friday, May 02 at 9:00 PM Eastern DST.

I will let Kevin know the results.

After he gets back with his cost, I will post the prices including USPS priority mailing. At that point, I will ask for a commitment and $.

Once I receive PayPal payment sufficient to proceed, I will give Kevin the green light.

I will ship within 2 days of receiving the adapters from Kevin.

NOTE: The adapters/extenders are for Craftsman Block Grinders. See pictures for thread specifications. Please verify your application.

This is the first time I have done this kind of thing, so bear with me. Check back here for updates.

Any suggestion, recommendations, or cautions - feel free to let me know.

Below is a copy of the stats on the Block grinders I have had the pleasure of meeting.







Thanks.
Mike

TM: first and formost thank you for putting in the effort to contact Kevin and make those awesome drawings.

i have a couple questions before i can commit. do you know which size HP the arbor changed to 5/8 from the 1/2 inch of the quarter HP version? if you can state that in your ad you might get a quicker response from the guys that would want any. i won't have time to go to the shop today, but if you and Kevin are involved if i can afford it i'd take a pair for my 1/2 HP commercial block and my newly acquired 1/3 HP with a "brake".

since you have both machines or i think all 1/2 HP are the same can you post which size to use?

thanks again TM and you too Kevin for your willingness to help again.

Are you talking tapered spindles for pinhole wheels?



I would be interested in a threaded set of those. Those set screws do kind of ****.

My replies in Blue, below.

drivesitfar said:

TM: first and formost thank you for putting in the effort to contact Kevin and make those awesome drawings.

i have a couple questions before i can commit. do you know which size HP the arbor changed to 5/8 from the 1/2 inch of the quarter HP version? if you can state that in your ad you might get a quicker response from the guys that would want any. i won't have time to go to the shop today, but if you and Kevin are involved if i can afford it i'd take a pair for my 1/2 HP commercial block and my newly acquired 1/3 HP with a "brake".

since you have both machines or i think all 1/2 HP are the same can you post which size to use? I added a spread sheet with stats. I can update it with additions, if that will help also.
From my small sample, it looks like:
1/4 - 1/2 HP = 1/2" arbor
3/4 HP = 1/2" or 5/8" arbor
1.0 HP = 5/8" arbor

thanks again TM and you too Kevin for your willingness to help again. You are welcome!

Click to expand...

91bronc300 said:

Are you talking tapered spindles for pinhole wheels?

I would be interested in a threaded set of those. Those set screws do kind of ****.

Click to expand...

Good idea.

Can you take some measurements, so Kevin has something to work from?

If I knew how to modify the Poll to add those as an option, I'd be glad to include them.

Any ideas? I've tried 'Modify' but it allows change of the post, but not the actual Poll attributes.

torqueman2002 said:

Can you take some measurements, so Kevin has something to work from?

Click to expand...

Sure. The collar is 1.500" long with a diameter of 0.875". The bore in the collar is 1.300" deep with a diameter of 0.625". The shoulder is 0.640" in diameter and 0.200" long. And the spindle tapers from 0.640" to 0.200" over a length of 2.650" and has 20 TPI. Total length is about 4 1/4 inches.

Problem is the shafts on my grinder AKA buffer are 5/8" but neither 11 or 18 TPI they are more like 13 TPI. Some damn proprietary thing maybe? I already tried to thread on a normal 5/8" x 11 nut and no go and it's definitely not a fine thread.

Aren't grinders normally ~1800 rpm and buffers are ~3600?

Think ideally it's reversed, but I've seen both speeds on both types of machines.

doan said:

Aren't grinders normally ~1800 rpm and buffers are ~3600?

Click to expand...

TP Tools site specs "1800 rpm for plastics and 3600 rpm for metals and nonferrous materials."

I'm waiting on a 2-speed buffer from them.

91bronc300 said:

Sure. The collar is 1.500" long with a diameter of 0.875". The bore in the collar is 1.300" deep with a diameter of 0.625". The shoulder is 0.640" in diameter and 0.200" long. And the spindle tapers from 0.640" to 0.200" over a length of 2.650" and has 20 TPI. Total length is about 4 1/4 inches.

Problem is the shafts on my grinder AKA buffer are 5/8" but neither 11 or 18 TPI they are more like 13 TPI. Some damn proprietary thing maybe? I already tried to thread on a normal 5/8" x 11 nut and no go and it's definitely not a fine thread.

Click to expand...

Thanks Bronc.

What grinder/buffer do you have?

It's a Wilton 17205 8" 3600 RPM grinder with those set screw type spindles on it. I guess I'm probably out of luck though with some oddball thread on the shafts like that. Stupid.

91bronc300 said:

It's a Wilton 17205 8" 3600 RPM grinder with those set screw type spindles on it. I guess I'm probably out of luck though with some oddball thread on the shafts like that. Stupid.

Click to expand...

Someone on the OWWM site might be familiar with that grinder.

I have read they are a quality grinder supplied by another manufacturer. Wish I could recall which one.

Update - Monday, 5/12/14 10:00 AM Eastern DLST

I apologize for letting the deadline pass without an update. I made a trip back East to visit an ailing relative, who is well on the recovery road now!

Anyway, I eMailed Kevin a few moments ago. So, when I hear back, I'll post prices, including USPS lowest cost rate.

Mike

I did find RH thread adaptors

Busch Enterprises has pinhole tapered buff arbors
http://www.buschshineproducts.com/t...spiral-threads-mounts-pinhole-buffs-p-59.html


Supergrit has 1/2" male threaded shaft adapters
https://www.supergrit.com/products/products_hardware

I thought in the past I found tapered thread on LH and RH arbors but can't find it now.

bluebolt said:

I did find RH thread adaptors

Busch Enterprises has pinhole tapered buff arbors
http://www.buschshineproducts.com/t...spiral-threads-mounts-pinhole-buffs-p-59.html


Supergrit has 1/2" male threaded shaft adapters
https://www.supergrit.com/products/products_hardware

I thought in the past I found tapered thread on LH and RH arbors but can't find it now.

Click to expand...

Thanks. I bookmarked them.

91bronc300 said:

Sure. The collar is 1.500" long with a diameter of 0.875". The bore in the collar is 1.300" deep with a diameter of 0.625". The shoulder is 0.640" in diameter and 0.200" long. And the spindle tapers from 0.640" to 0.200" over a length of 2.650" and has 20 TPI. Total length is about 4 1/4 inches.

Problem is the shafts on my grinder AKA buffer are 5/8" but neither 11 or 18 TPI they are more like 13 TPI. Some damn proprietary thing maybe? I already tried to thread on a normal 5/8" x 11 nut and no go and it's definitely not a fine thread.

Click to expand...

Any chance the threading on the arbor is 14 TPI?

5/8" BSF (British Standard Fine) is 14 TPI. Outside would be .625".

I have a small Makita Grinder that uses 1/2" Whitworth threads with 12 TPI. My understanding is 1/2" whitworth is the standard threading on a number of small Asian grinders.

The threads on BSF would also be slightly rounded on the peaks and in the valleys.

Here is the latest update on the Arbor adapters for using Blocks as buffers.
Kevin54 PM'd me with a final few questions and I replied a few moments ago.

Kevin54
Torqueman2002
Quote" I haven't forgot you and am working on some prices right now. The last you said was that most likely you want 7 sets. How long to you want the adapters to be? This will be on top of the 3" dimension of the arbor already sticking out of the grinder motors.

For instance, on my buffer, the total shaft length is 7" from motor housing to the end of the shaft, but I have 3/4" shafts. 7" total length is OK.

Do you know what diameter of buff wheels you will be running? The grinder wheels you have listed are 6", 7", and 8". Eastwood, has about the best selection of buff wheels. They carry the diameters of 4", 6", 8", and 10". The 10" fits a 3/4" shaft, and requires a 1 horse minimum motor. the others fit 1/2"-5/8" shafts and run a smaller motor. Not certain what others will be running, but I will post your comments and recommendations.

Would you want me to just make the buff wheel end a 5/8" thread for all of the sets just for simplicity on buffing wheels. Maybe some people wouldn't want Eastwoods buff wheels, but 5/8" should work for all. I know that if a buff pad had a 1/2" hole, it will still go over a 5/8" shaft. There is enough wiggle room in the pads. Then I can make up all of the blanks for the adapters the same size, and the only thing I would need to do is change up the mounting ends for the grinder motor. Executive decision ahead - 5/8" on ALL to keep cost down.

In doing that, it will be easier to turn everything the same size. And if that sounds alright, then all I need is a length that you and the others would prefer. 7" total length, I think these Blocks should handle the extra forces. If it's too close to the motor, then you won't have a lot of pivot room for parts if you need it. And if it's too far, you have to remember that it is an adapter, and not like a complete shaft running through the motor. And as said, mineshaft is 7", but the pad is at 4" away unless i add another spacer to move the pad out more. Also, you will need four large washers for each pair of adapters. The washers on my 10" buff pads are 4" in diameter. If some of the people buy 6" pads....if you put 4" on each side of the pad, it will make the pad stiffer than normal. So maybe something like 3" diameter washers for all of the shafts maybe? I agree - 3" washers should be good.

Along with that, what about spacers. My buffer has 2 spacers on the inside area towards the motor. One spacer is 1" and the other spacer is 2" in length. If I had another spacer, I could add a secondary buff wheel on the shaft and run it with a different compound, depending on what I was doing. Let’s go with 1" spacers. Do you recommend 2/side - 4/pair?

So do you want me to figure in some spacers also? If I make all of the shafts at say 5/8" diameter outside of the mounting area that goes on the motor shaft, I may be able to find some tubing with a 5/8" or a tad larger and just lob off some in the lathe at a couple different lengths. Yes, please make-up spacers for each pair. " End quote.

So, the project is still alive. If you haven't given me your contact information and which choice you voted for, please let me know by posting here.

BTW - I might be able to accommodate add-ons. Post in this thread, Polling is closed, but you can still post.

Thanks. Mike

neophyte said:

Any chance the threading on the arbor is 14 TPI?

5/8" BSF (British Standard Fine) is 14 TPI. Outside would be .625".

I have a small Makita Grinder that uses 1/2" Whitworth threads with 12 TPI. My understanding is 1/2" whitworth is the standard threading on a number of small Asian grinders.

The threads on BSF would also be slightly rounded on the peaks and in the valleys.

Click to expand...

Oops, sorry neophyte, I didn't subscribe to this thread.

I went and measured again and it's definitely .625 on the outside but it really seems to be 6.5 threads per half inch (I can't measure a full inch). I didn't know whitworth threads were still around, I'd only heard about them in a historical context.

Oh well, those spindle adapters aren't the kind Kevin is making anyway....

91bronc300 said:

... Oh well, those spindle adapters aren't the kind Kevin is making anyway....

Click to expand...

Might be worth dropping him a line and see what he could help you with.

I heard back from Kevin. Seems he was waiting for me to respond, while I was waiting for him to do the same.

Sorry for the delay; I was about to ping him to see where we were, when I got his PM.

Anyway below quote-box is the exchange we had today.

Kevin's price will be: $60.00 + postage/set.
(more on postage when I have Kevin's cost to send the order to me & the weight/set for price to send them from me to members)

Total members postage = (Kevins total postage/# total sets * total # of sets the member orders) + postage form Torqueman's 48334 ZIP.

Each set includes:

• LH and RH adapter shaft @ 7" long
• two nuts [1 LH, 1 RH]
• 4 washers
• 2 - 1" spacers
• 2 - 2" spacers

If you have not voted in the now closed Poll, here is a chance to join in and get a set or sets.

What needs to happen next.

Post a reply in this thread with the style and quantity of Extenders/Adapters you want. 3 choices are listed below.

• LH & RH 1/2" to 1/2" (grinder to buffer - 1/2x20 TPI)
• LH & RH 5/8" to 1/2" (grinder to buffer - 5/8x18 to 1/2x20 TPI)
• LH & RH 5/8" to 5/8" (grinder to buffer - 5/8x18 TPI)

PM me with your shipping and payment method.
Note: PayPal is preferred, it allows more time for you. Postal MOs are OK, but I need them by Friday, June 13.

Check back here for additional postage details, before sending me $.

Send payment to me. I need the $$ by next Friday, June 13. I know, it'll be OK.

Order and $$ will be sent to Kevin on Saturday, Jun 14.

I will send out the Adapters/Extenders/Adapters as soon as I receive them, or on or about June 24 should they arrive before my return. I am, as some may be aware, going to search the far off waters to the East.

That ^^ is NOT Abe Lincoln!

torqueman2002 said:

Hmmmm, more to this project than I imagined. Good thing you're helping me.

Let's go with 1-2" & 1-1" per side; like your set up.

I will post up the latest information and ask for commitments and $$ before Saturday, June 14.

I should be able to get you a finalized order, with sizes, and have $$ to send you.

How would you like the $$ ? I have PayPal, if that helps.

Do you have a rough idea how much the cheapest postal rate will be [MI 48334], for 7 sets?

How much will 1 set weigh?

What's the next price point in terms of quantity? Should more than 7 people want 'in'?

BTW - what sort of run-out tolerance (if that is the correct term - or wobble at the far end of the adapter) will there be, assuming the arbor is dead-on accurate.

Forgive me if I am expressing this wrong. But I am thinking an extra 7" spinning at ~ 3,600 RPM will have some off center variation.

Mike

Kevin54 said:

I know that on my buffer I have a 2" and a 1" on each side, but I can make them all 1" and supply 3 per side, or however you want them. Basically all the spacers are is just a piece of pipe cut into lengths. So however you would want them, it would make no difference to me as far as machine work.

Kevin54 said:

Hi Mike,
I'm not exactly sure, but I think I have been waiting on you for something as far as an answer, but then going through my PM's, I'm now thinking that you may have been waiting on me to get back to you. If so, you have my sincere apologies.

I did do some figuring, and I can make the adapter shafts for $60/set, or pair. Shipping would be on top of that.

If per chance I can find the material cheaper, and I will check down to out local Fastenal if I can, then it would drop the price a couple of dollars per set. Each set would be complete, with a left hand and right hand adapter shaft @ 7" long, two nuts, and 4 washers.

If this sounds doable from your end, let me know, and I can get the material ordered, and we can get the timeframe finalized along with going over the sizes one more time to make sure we are on the same page.

And again, I am sorry if you were waiting on me. That is a mistake on my part.

Kevin

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No replies.

Looking like this maybe still born.

Too slow from concept to proto-type?

Too few choices?

Too much $$?

Too ... ??



Ryan offered and I agreed he will make one each of the 1/2"x5/8" and 5/8"x5/8" and send them to me for evaluation.

I'll take pictures and post them here for consideration.

One detail not clear, is if he is waiting on exact final number. To allow a 1 time purchase of material.

Mike

Are the screw on spindles or couplers available? My motor shaft is a 1/2" 12 threads to the inch one.