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Prokop
01-04-2011, 05:47 AM
I want to swap the electric motor on my new to me Walker Turner table saw for something stronger.

The original motor had a pulley with 3/4" bore and a keyway of course. I looked at motors available at local TSC and all the motors have diferrent shafts, typically 7/8".

Now I am thinking to just make a new pulley. I would buy a chunk of cold rolled bar O.D. 3", sharpen a HSS bit the way I just found here (http://bbs.homeshopmachinist.net/showthread.php?t=45253&highlight=pulley) and make one.

The only thing I dont know how to make is the keyway. I believe in English it is called broaching - and of course, I dont have a broaching machine.

Any tips/advices for the lathe part or how to make the keyway?

Thank you.

Black_Moons
01-04-2011, 06:55 AM
You can use your lathe as a shaper, taking tiny cuts using the carrage for feed, and cross slide for DOC. (Lathe spindle off), Mount the shaper bit in a boring bar.

Prokop
01-04-2011, 07:33 AM
You are right, I heard of that method for making shaft splines.

Now I have a different idea. I will buy pulley (http://www.surpluscenter.com/item.asp?item=1-2BK36-D&catname=) with the right bore and turn what I need from it. That pulley is cast iron, will make it easy enough to turn too.

Opinions, please?

Ian B
01-04-2011, 08:00 AM
If I understand, you want to buy a 2 groove pulley and remachine it as a 3 groove, with the OD of the 3 groove being about the root diameter of the original 2 groove?

Two other suggestions:

1. Buy a 3 groove pulley of the right diameter.

2. Use a 2 belt drive system, and replace the standard belts with more modern, higher grip, higher strength belts.

Ian

gary350
01-04-2011, 08:35 AM
If it were me I would buy a pully the correct diameter and bore. Why work on day on something you can buy for $20.

Surface area belt contact is what makes the belt grip if your having a slipping problem use a larger diameter pully.

lodcomm
01-04-2011, 12:35 PM
I make pulleys all the time, - Usually make them out of Aluminum scrap
the easiest way I have found is to follow this:

http://www.google.com/url?sa=t&source=web&cd=1&sqi=2&ved=0CBwQFjAA&url=http%3A%2F%2Fwww.green-trust.org%2Fjunkyardprojects%2FFreeHomeWorkshopPla ns%2FMakingV-BeltPulleys.pdf&rct=j&q=tool%20for%20machining%20a%20pulley&ei=bFkjTa7bDYe4sAOqhOmDDw&usg=AFQjCNHFL9HgddLQ497iw8H5sud5SQgj7A

MotorradMike
01-04-2011, 01:34 PM
I got a used pulley for $5. It has 2 identical sheaves. I plan to bore the center out to fit my new motor and maybe turn one sheave down if I want Hi/Lo.

gnm109
01-04-2011, 01:35 PM
If it were me I would buy a pully the correct diameter and bore. Why work on day on something you can buy for $20.

Surface area belt contact is what makes the belt grip if your having a slipping problem use a larger diameter pully.


I would definitely buy a pulley if only to save time and money. In fact I did when I recently added a third pulley to my old Craftsman drill press.

I'm sure I could make one like the one I bought but I actually checked and just the material alone (5" round X 3" 6061) was almost the cost of the pulley. (Chicago Die Casting, 4 step pulley, $22.00 delivered)

Just my opinion, however.

http://i144.photobucket.com/albums/r188/gnm109/Machinery/Craftsman3.jpg

Prokop
01-04-2011, 01:43 PM
I would love to just buy a new pulley, but so far I was not able to find it. The belts are 11/32 wide and 5/16" thick - worn out maybe a bit but thats the best I can measure it.

I am open to all suggestions, that's why I am here:D

Thank you, gentlemen.

MotorradMike
01-04-2011, 02:30 PM
I could be wrong but I'd guess you have an 'A' size belt and may be looking for an odd sheave size.

I found belt info here (http://www.engineersedge.com/xbelt_size.htm).

rohart
01-04-2011, 02:31 PM
If your belt is non-standard, then you'll be making a pulley, and you won't be able to replace the belt when it goes.

Find the nearest standard size of belt to what you have, and replace all the pulleys commercially to match the kind of belt you can source successfully.

I agree that using pulleys with double belts will give a much smoother drive.

There's plenty of scope for making your own pulleys, but make sure the belt size you use is easily obtainable. Pulley drives are not such a high precision system as to require non-standard sizes.

Non-standard sizes are designed into machines to save pennies in manufacture, and cause users grief.

wooleybooger
01-04-2011, 09:39 PM
While Ive not yet made a pulley from scratch i have modified a few. not terribly hard to do. just follow the instructions in the link lodcomm posted. its the same info i use. i got lucky and got one of those old tools in a box of e-bay stuff.too big for my lathe but i keep it around to impress the unknowing.

Mcgyver
01-04-2011, 09:52 PM
If your belt is non-standard, then you'll be making a pulley, and you won't be able to replace the belt when it goes.


yeah but good belts on a multi belt drive might last another 40 years if in good shape...I had mine off recently on my lathe, its got a 4 belt set up, and after 40 years they look perfect ....bet they go another 40 so why spend all the money changing unless the belts look iffy?

'Duplex's advice in the link is good, cut each side, if the lathe is light. I've done them a side at a time with a form tool but if its a decent sized belt its a very wide cut and prone to chatter, the way in the link is foolproof

wierdscience
01-04-2011, 10:43 PM
I would love to just buy a new pulley, but so far I was not able to find it. The belts are 11/32 wide and 5/16" thick - worn out maybe a bit but thats the best I can measure it.

I am open to all suggestions, that's why I am here:D

Thank you, gentlemen.

Sounds like you have a 3V wedge belt pulley.Pretty common,made to carry higher HP in a smaller package.Look at the 3VX coss section here-

http://www.maurey.com/prod_ihp.php

http://www.maurey.com/pdfs/QD_SHV_WEDGE_3V_GR_2004.pdf

jkilroy
01-04-2011, 10:54 PM
How about you just bore out and cut a new keyway in the pullies you already have?

Frank Ford
01-05-2011, 02:43 AM
I enjoy making pulleys, too. I made a replacement for this broken one:

http://www.frets.com/HomeShopTech/AtTechShop/StepPulley/steppulley01.jpg

To cut the grooves, I simply used a stout parting tool and set the compound appropriately. For the keyway, I used a simple shop made tool and the mill.

Here's the full deal:

http://www.frets.com/HomeShopTech/AtTechShop/StepPulley/steppulley.html

Prokop
01-05-2011, 05:10 AM
Thank you, gentlemen:)

ega
01-05-2011, 10:04 AM
I had to do this recently and hit on the idea of mounting the tool in a boring head in the lathe tailstock, putting on cut with the feed screw in the boring head and reciprocating the tool with my lever feed tailstock. Surprisingly effective if slow to do.

Prokop
01-19-2011, 09:58 AM
Well I got the keyway cut, it was fairly doable even I never done it before. Now I am trying to cut deep groves with a parting tool and it is like giving birth to a hedgehog:mad: I bought cold rolled steel to make this pulley and now I feel it was a mistake.

I use a normal parting HSS blade and the work piece eats it right up. I tried to grind a piece of cobalt, it held little but better but still very slow and painful process. Should I get a carbide parting tool? What do you think? Or toss the piece and buy normal construction steel since the cold rolled is too much for me?

Opinions and encouragement highly appreciated.

Thank you

Duffy
01-19-2011, 11:04 AM
I am late into this discussion, but did it not occur to anyone to turn the end of the motor shaft down to 3/4"? I doubt very much that the loadswill affect the motor function.

Prokop
01-19-2011, 01:24 PM
I thought about it, but I am not sure I will keep the motor yet - $200 from TSC - I am not going to alternate it.

As far as the pulley - I am done. First and main reason for my problems, I am an idiot. I took a brake and realized I am running it too high - changing cutting speed did the trick no problem. Took less than three hours to cut all three grooves and angle all grooves out to match the old pulley.

jungle_geo
01-19-2011, 01:45 PM
As suggested above, why not bore-out the old pulley from 3/4 to 7/8 and then cut the key-way deeper? Saves you burning up new stock, but then again sometimes thats the goal. :D
Almost all pulleys have a place where you can grab them in a 4-jaw chuck and then bore it. Should only take a few minutes to chuck it up and true it and another 10 minutes or so to bore it. Sounds like you have a way to slot the pulley, so that is covered.
Over the years I've converted a number of 19mm pulleys (about 0.002" under 3/4) to the more common 7/8 shaft when the 3rd world motor burned out and I replaced it with a domestic model.

But then again making a pulley from scratch is a good learning experience.

Highpower
01-19-2011, 05:00 PM
I just bought the size of pulleys I needed, and did a cut & paste. :D

http://img.photobucket.com/albums/v82/Highpwr/Lathe%20modifications/th_Pulleyset.jpg (http://smg.photobucket.com/albums/v82/Highpwr/Lathe%20modifications/?action=view&current=Pulleyset.jpg) http://img.photobucket.com/albums/v82/Highpwr/Lathe%20modifications/th_Recessed.jpg (http://smg.photobucket.com/albums/v82/Highpwr/Lathe%20modifications/?action=view&current=Recessed.jpg) http://img.photobucket.com/albums/v82/Highpwr/Lathe%20modifications/th_Doublepulley.jpg (http://smg.photobucket.com/albums/v82/Highpwr/Lathe%20modifications/?action=view&current=Doublepulley.jpg)

Alistair Hosie
01-19-2011, 05:20 PM
I am not sure why people or some people here are so frightened of parting off.
I am no expert but Although last year I bought all new tools from kennametal inc a new parting system I have never had a problem yet and this is even with the HSS old parting tool and holder I made myself from a used wood thicknesss planer blade.
As I see it/find it as long as you take it easy and don't get too tight and bind up leaving a twice the tool thickness groove size cut for this reason you should be ok,but I hear guys all the time telling me their dead frightened of this procedure why?
Am I just lucky or stupid what? Alistair

jack3140
01-19-2011, 05:25 PM
I enjoy making pulleys, too. I made a replacement for this broken one:

http://www.frets.com/HomeShopTech/AtTechShop/StepPulley/steppulley01.jpg

To cut the grooves, I simply used a stout parting tool and set the compound appropriately. For the keyway, I used a simple shop made tool and the mill.

Here's the full deal:

http://www.frets.com/HomeShopTech/AtTechShop/StepPulley/steppulley.html
frank this may be a real dumb question but could you tell me how you keep the spindle from turning when you use the mill for broaching a keyway ? i am a newbie so please bear with me thanks jack

Prokop
01-19-2011, 06:42 PM
One of the first decisions I made was to keep the original setup - i.e. no pulley or motor alterations. That said and looking back, to make the pulley was an experience and overall easy enough to say I would do it again.

That said, there are bushings available in TSC I could turn down and bore the original pulley and weld the whole shibank together - I but all I need to do now is to drill and tap two 1/4-20 threads in the pulley and the saw is ready to go. Imagine Tim Allen here: "More power, ho ho ho!!!"

Prokop
01-24-2011, 08:16 AM
Well, here it is. My first pulley http://www.tractorbynet.com/forums/attachments/related-topics/196603d1295874619-wiring-saw-240v-img00072.jpg mounted on the motor.

I looked up older threads here and learned a lot about pulley making - using a pin to mount it to the lathe, using the parting tool to cut grooves and also how to broach it.

Thank you, guys.

wierdscience
01-24-2011, 09:20 AM
That pulley looks just like a little red x

Prokop
01-24-2011, 09:47 AM
I dont follow.

dp
01-24-2011, 09:54 AM
A red X means the image didn't load for him and his browser placed a red X where the image would be. I see it fine - nice job!

Prokop
01-24-2011, 09:59 AM
I see, thank you, here is a link:

http://www.tractorbynet.com/forums/related-topics/192942-wiring-saw-240v-3.html