Weighted Follow Rest

[urbanrifleman]

I was thinking of making a simple, belcrank style weighted follow rest. Instead of using springs or pnuematics, just a simple pivoted bellcrank with lead weights to back up the tool. That way it will work on contouring tapers. Not exactly like this, but sort of.. Has anyone ever seen anyone use something like this? I hear that it is not that uncommon.

.

 

[Greg Y]

I made one that used a block of wood to contact the barrel. What I found is paying for a barrel taper is worth 4x whatever they charge.

 

[urbanrifleman]

I made one that used a block of wood to contact the barrel. What I found is paying for a barrel taper is worth 4x whatever they charge.

Kind of you can't get there from here... I am assuming this is because of cycle time?

 

[urbanrifleman]

Let's just say "pay for contouring" is not an option, and work from there...

 

[Greg Y]

Anything can be done. Imagine that you have a spaghetti noodle on centers that doesn't want to spin all that fast while taking a cut.....and you want to counteract the force the tool has on the noodle. Centerline seems to change because it is a noodle and wants to climb the tool.

So...you take shallow cuts and wait the eternity for it to reach the end and repeat.....a lot.

Now you have half your day gone and something resembling a hammerforged barrel.....so out comes the belt sander and you burn on it for a couple of hours and it resembles something presentable.

A few hours of scrubbing grit off the ways, your face and hooking the coolant pump back up. (You didn't want to run that grit through the pump did you?)

Now you have one less day in your life, hopefully not bent the barrel, 43 bux in belts can be thrown out.....but hey, you saved $80.00.

 

[Dusty Stevens]

I think for $80 you can get 2 done

 

[55fairlane]

I saw one like this but it had a bearing on it that contacted the work....

 

[urbanrifleman]

Anything can be done. Imagine that you have a spaghetti noodle on centers that doesn't want to spin all that fast while taking a cut.....and you want to counteract the force the tool has on the noodle. Centerline seems to change because it is a noodle and wants to climb the tool.

So...you take shallow cuts and wait the eternity for it to reach the end and repeat.....a lot.

Now you have half your day gone and something resembling a hammerforged barrel.....so out comes the belt sander and you burn on it for a couple of hours and it resembles something presentable.

A few hours of scrubbing grit off the ways, your face and hooking the coolant pump back up. (You didn't want to run that grit through the pump did you?)

Now you have one less day in your life, hopefully not bent the barrel, 43 bux in belts can be thrown out.....but hey, you saved $80.00.

A bit overdramatic don't you think?

I would not suggest doing it the way you described. Which I had no intention of doing it like that. Thanks.

Btw, The noodle can be easily caught in the steady and spilt into two halves. Not really that dramatic. I was just trying to eliminate that step.

 

[urbanrifleman]

I saw one like this but it had a bearing on it that contacted the work....

Yes a bearing (or even two bearings) would be most ideal.

 

[gme]

https://www.ebay.com/itm/Maxnovo-Profilomatic-Gun-Barrel-Profiling-lathe-/224195690931

 

[urbanrifleman]

https://www.ebay.com/itm/Maxnovo-Profilomatic-Gun-Barrel-Profiling-lathe-/224195690931

Wow that's a big sucker!!!

 

[gme]

 

[gme]

 

[Greg Y]

Not mine, but another very simple pneumatic that would make the job tolerable.

 

[urbanrifleman]

View attachment 1247916

That is actually very simple and elegant. There must be a bottom roller.

 

[urbanrifleman]

Not mine, but another very simple pneumatic that would make the job tolerable.

I could make that one easy. Those cylinders are cheap too. I am a mechanical engineer and I have designed a fair amount of fixtures and lift assists.

 

[urbanrifleman]

I think for $80 you can get 2 done

Who does this for $40 now?

Shipping on two barrels both ways is what? Another $50?

 

[Dusty Stevens]

Barrels ship for $18-20

 

[Greg Y]

The problem with the design you have is that it doesn't fight the "climb" of the barrel....which is dynamic based on the diameter and distance between centers.

I suggest chucking up a tube and spinning it up, try to counteract the chatter and see how you can skin the cat.

Short of a grinder, a pneumatic rest is about the only frustration free way to even consider this.

It can be done without, but you WILL spend a lot of time on it.

 

[Dusty Stevens]

If you can find this book it shows how to make a pneumatic follow rest for tapering barrels. Its pretty expensive but has good info in it.

Tricks of the Trade. Stratton

Tricks of the Trade. Stratton One of the great current, out of print or rare titles available from Bunduki Books

www.bundukibooks.com.au