开云体育

ctrl + shift + ? for shortcuts
© 2025 开云体育

Re: Depth of cuts


 

开云体育

Do you have the setup with the V belt pulley on the motor and a large flat pulley on the countershaft? Looks strange but this was standard.

I'm a great fan of the link belts for V-belt pulleys. I've had one long time no problem on a wood lathe. Link belt on a flat pulley sounds like a problem to me but I have no direct experience.

A V belt in a V groove wedges in and gets good traction. A regular V belt works well enough on that big, flat, pulley because there is so much surface area in contact.

So yes, changing that belt sounds to me like a reasonable thing to try.

On 6/25/23 16:13, Steven Schlegel wrote:

Wow. Lots of questions. One fact is really obvious. My machine operator pair should take cuts 10x deeper than I am.

The lathe head and all associated gearing is good. It was recently rebuilt and all pins, etc. were replaced correctly. Of that I am pretty certain. The drive unit moves freely, was also rebuilt, and operates correctly.?

Speeds are from the ebay chart I bought. The HSS tools I grind are based upon lots of videos I watch. I bought a jig to help get the angles correct. My carbide are inserts, many are still the original chinesium, but are being replaced by higher quality as they die. I use a Boxer quick change toolpost.

Now, here is where I feel the problem lies since I do not have the power to make deep cuts:?

I use a link belt on the motor. It slips especially as oil gets on it. The bearing in the drive unit slings oil. The drive belt to the lathe head is a serpentine auto belt. It seems to transfer power efficiently. The drive unit is mounted on channel so it's adjustable.??

I am wondering about switching to an auto v-belt for the motor. Next, could the channel be flexing? It is the kind used to support conduit.

Thanks,
Steven

Get

From: [email protected] <[email protected]> on behalf of Davis Johnson <davis@...>
Sent: Sunday, June 25, 2023 12:04:57 PM
To: [email protected] <[email protected]>
Subject: Re: [SouthBendLathe] Depth of cuts
?

What sort of carbide are you using? I've never had good luck with the 0 degree rake brazed carbide. I hear that it wants to run really fast.

On 6/25/23 14:24, Brandon Corey wrote:
0.002” is way too low. ?I run 0.015”-0.020” at a minimum for the hardest materials. ?Material? ?Speeds? ?What size is your motor?

Brandon

On Jun 24, 2023, at 8:20 PM, Steven Schlegel <sc.schlegel@...> wrote:

I have a simple question. How deep of cuts do you normally make?

I have a 1949 vintage SB9C, with 6 speeds. I replaced the 1/4 hp motor with a 1/2 HP one. I use carbide a lot, but HSS still gets used some. Many of the videos say I should take at least a 0.005" cut for the best finish. I usually cannot take more than 0.002" with dragging down, or stopping, the spindle.

What's reasonable for me?
Thanks, Steven

Join [email protected] to automatically receive all group messages.