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mattm82
23rd Apr 2019, 11:20 PM
Please note:

The following posts have been moved from METALWORK - Machinery, Equipment, MARKET thread Waldown NH and are from Post #8 on.....

You don't happen to have a 'b' set pulley on your other drill do you??

Cheers,

Matt


I forgot to mention it does work. But the eagled eyed will have noticed I have another one in single phase which is more convenient for me.

lamestllama
24th Apr 2019, 12:03 AM
You don't happen to have a 'b' set pulley on your other drill do you??

Cheers,

Matt

Afraid not. Neither of them had the B set. So 12000rpm was max.

mattm82
24th Apr 2019, 09:06 PM
Afraid not. Neither of them had the B set. So 12000rpm was max.

Fair enough, I've never come across anyone with one! I'd love to find one to measure so I could fabricate one. I've had two NH drills and neither had a b set but both were labeled for them.

Cheers

jhovel
25th Apr 2019, 12:10 AM
Hi Matt,
RayG has an NH drill with ONLY the B set of pulleys. He hasn't been active here for a while, but send him a PM. I'm sure he could help you with dimensions.

mattm82
25th Apr 2019, 10:01 AM
Hi Matt,
RayG has an NH drill with ONLY the B set of pulleys. He hasn't been active here for a while, but send him a PM. I'm sure he could help you with dimensions.

Greatly appreciated, thankyou. I’ll send him a PM now [emoji106]

RayG
25th Apr 2019, 12:40 PM
Greatly appreciated, thankyou. I’ll send him a PM now [emoji106]


Hi Matt,

I got your PM via an email from tapatalk, but I don't have that installed anymore.

I'll measure up that pulley and get back to you.

Regards
Ray

mattm82
25th Apr 2019, 02:16 PM
Hi Matt,

I got your PM via an email from tapatalk, but I don't have that installed anymore.

I'll measure up that pulley and get back to you.

Regards
Ray

Greatly appreciated Ray,

Thank you.

lamestllama
25th Apr 2019, 11:10 PM
Greatly appreciated Ray,

Thank you.

Matt,

Can you post the dimensions somewhere that I can have them too?

Eric

mattm82
26th Apr 2019, 01:29 AM
Matt,

Can you post the dimensions somewhere that I can have them too?

Eric

Sure can

RayG
26th Apr 2019, 11:18 AM
The original thread is here... http://metalworkforums.com/f65/t175815-waldown-speed the pulley dimensions I have are for the 12000/6000 rpm speeds. Note that it's not 20,000 NH model B as in the Brobo catalogue

The front measures 1 1/2" and 2 3/4 the motor pulley measures 6" so that's motor_rpm * 4, and motor_rpm * 2.18 So if the motor is 2880, that's 11,520 and 6,278...

The motor pulley flips upside down to get the other ratio.

However, this model doesn't appear to be the same speeds as the NH model, a similar unit is shown in McPherson's catalogue, the V85 model but that's a 6 speed. So the long story short, if you are chasing 20,000 rpm you would need to crank up the motor with a VFD to get there, or machine the front pulley to a smaller diameter. Mine only goes to 12,000 with this pulley set.
If you changed the smaller diameter to 0.869" instead of 1.5" that would give a ratio of 6/0.869= 6.94, 6.94*2880 = 20,000

379195379196379197

See earlier thread here
http://metalworkforums.com/f65/t175815-waldown-speed/latest/post1691893#post1691893

Hope that helps.

Regards
Ray

Michael G
26th Apr 2019, 12:55 PM
Nice to here from you again Ray.

I did a bit of playing on Excel with respect to the ratios I have (3k to 12k) and what the corresponding ratios for 15k and 18k would be. The minimum for the spindle pulley seems to be around 34mm. Based on that for 18k, a motor pulley of around 206mm would be needed. That of course means a new belt as the existing has a belt of a length for the same size smaller pulley and a smaller motor pulley too. I don't have the time now but could possibly try and calculate out what the pulley sizes for the same size belt would be.

Having said that, do you really need 18k rpm? That is not a very big drill bit in anyone's language...

Michael

RayG
26th Apr 2019, 05:12 PM
Nice to here from you again Ray.

I did a bit of playing on Excel with respect to the ratios I have (3k to 12k) and what the corresponding ratios for 15k and 18k would be. The minimum for the spindle pulley seems to be around 34mm. Based on that for 18k, a motor pulley of around 206mm would be needed. That of course means a new belt as the existing has a belt of a length for the same size smaller pulley and a smaller motor pulley too. I don't have the time now but could possibly try and calculate out what the pulley sizes for the same size belt would be.

Having said that, do you really need 18k rpm? That is not a very big drill bit in anyone's language...

Michael

Hi Michael,

Good to drop back for a visit. Still busy and too many unfinished projects. I'm not the one looking for higher speeds, that's mattm82.

But since you asked, there appears to be plenty of room for belt length adjustment. There must be a minimum diameter for that flat belt material however, that might ultimately be the limiting factor.

If it was me doing it, I'd probably go with a variable speed drive, those motors usually run quite happily at 100 Hz. That would get 24,000 + rpm

After all those considerations it ultimately depends on the part being made, sometimes it's easier to drill small sizes in the lathe with the drill bit mounted in the tool holder.
If you follow Stefan Gotteswinter on Youtube he does a lot of drilling small holes in parts using that method. https://www.youtube.com/channel/UCY8gSLTqvs38bR9X061jFWw

Ray

mattm82
27th Apr 2019, 10:38 AM
Ray,

Thank you for your reply. I do have the higher speed machine, so I’ll have to look at your your calculations, along with how it matches up to my machine.

I have a single phase model and would like to keep it intact so a vfd is not an option.

To answer Michael’s question. I don’t need those speeds, I just want to have a complete system.

I use it a lot, but have another two Waldowns, have likely acquired another, and have some waldown vices to go with them. I love these drills so it’s more a want than a need!

Thanks again for your assistance.

Matt