Building a bed turret
Building a bed turret
I thought I would start a thread about a bed turret I am going to start building. I figure with the amount of small repetitive parts I make it only makes sense to have one. I bought plans from Downriver Tools but had to modify them drastically to accommodate my lathe. The plans call for cast grey iron for the main components so I am having rough castings poured. Once I have them I'll start posting pics of the progression.
In the mean time I have a question - is it easier to mill grey cast iron then say cold rolled steel? Last year I machined a riser for the mill from grey cast on the lathe but I can't remember if it was harder to work with then CRS or not.
In the mean time I have a question - is it easier to mill grey cast iron then say cold rolled steel? Last year I machined a riser for the mill from grey cast on the lathe but I can't remember if it was harder to work with then CRS or not.
Vision is not seeing things as they are, but as they will be.
Re: Building a bed turret
Assuming the iron isn't chilled, it is easier to machine by far than mild steel. The one serious drawback is it's extremely dirty to machine. Also, depending on the sand used for the molds, it can have sand included in the skin, making the first cut difficult. The use of carbide (make sure it's the proper grade---C2 works well) is a good idea for the first cut, where you penetrate the skin of the casting.
If you have a choice of iron, ductile is a better choice than gray. They are virtually identical, with ductile offering the quality of being ductile. It is greater in tensile strength, yet displays all of the desirable qualities of gray iron, including the free machining, lubricity and dampening for which gray iron is respected.
Back to machining---both gray and ductile machine without creating ribbons. Ductile has a tendency to form longer chips, but they are extremely fragile and do not constitute a hazard in the same way steel chips do. The dust created from both gray and ductile is a real nuisance, and will blacken your entire shop in due time. I highly recommend the use of a shop vac to control the dust. If you are doing a boring operation with a through hole in the work piece, placing the vacuum at the rear of the spindle works exceedingly well.
That's a great project. I have a bed turret that was produced for Enco, which I purchased in the late 60's. It was improperly machined in pretty much every way, so it requires a rebuild before it could be put back in service. Improper indexing resulted in wear, so the turret no longer aligns properly. If I live long enough, I'll cast a new turret and correct the indexing problem.
Please do keep us up to date with this project. Very cool!
H
If you have a choice of iron, ductile is a better choice than gray. They are virtually identical, with ductile offering the quality of being ductile. It is greater in tensile strength, yet displays all of the desirable qualities of gray iron, including the free machining, lubricity and dampening for which gray iron is respected.
Back to machining---both gray and ductile machine without creating ribbons. Ductile has a tendency to form longer chips, but they are extremely fragile and do not constitute a hazard in the same way steel chips do. The dust created from both gray and ductile is a real nuisance, and will blacken your entire shop in due time. I highly recommend the use of a shop vac to control the dust. If you are doing a boring operation with a through hole in the work piece, placing the vacuum at the rear of the spindle works exceedingly well.
That's a great project. I have a bed turret that was produced for Enco, which I purchased in the late 60's. It was improperly machined in pretty much every way, so it requires a rebuild before it could be put back in service. Improper indexing resulted in wear, so the turret no longer aligns properly. If I live long enough, I'll cast a new turret and correct the indexing problem.
Please do keep us up to date with this project. Very cool!
H
Wise people talk because they have something to say. Fools talk because they have to say something.
Re: Building a bed turret
Harold, thanks for the in-depth reply, I always appreciate your responses. I will have to ask the foundry if Ductile Iron casting is available. He mentioned something last time I was there about a different material but said it was much harder to machine so I'll see.
As for the first cut to square up the slugs can I use a surface mill with carbide insets or should I stick to a smaller cutter like 3/4" endmill?
As for the first cut to square up the slugs can I use a surface mill with carbide insets or should I stick to a smaller cutter like 3/4" endmill?
Vision is not seeing things as they are, but as they will be.
Re: Building a bed turret
Looks like a great project!
Squaring up cast iron bar.
Face mill worked for me!
Squaring up cast iron bar.
Face mill worked for me!
Glenn
Operating machines is perfectly safe......until you forget how dangerous it really is!
Operating machines is perfectly safe......until you forget how dangerous it really is!
Re: Building a bed turret
I'll be glued to this thread RSG. Fwiw something I was looking at not 5 minutes ago. A link to a pair of links about the use and tooling https://www.practicalmachinist.com/vb/a ... ts-379889/
Re: Building a bed turret
Thanks Glenn, I have a nice face mill I got from a friend that should work great for this.
Pete, thanks for the link, I wish I could open it but it seems flawed. I'll try to go in from the front end and see if I can find it then.
Pete, thanks for the link, I wish I could open it but it seems flawed. I'll try to go in from the front end and see if I can find it then.
Vision is not seeing things as they are, but as they will be.
Re: Building a bed turret
Ok try this one for 1940's Warner & Swasey Turret Tools http://www.vintagemachinery.org/pubs/de ... x?id=22350
And 1920's Barnes & Oliver Turret Tools http://www.vintagemachinery.org/pubs/de ... x?id=22761
Both links work at my end so they should work for you. But oddly that Practical Machinist link also works as a direct thread link for me.
And 1920's Barnes & Oliver Turret Tools http://www.vintagemachinery.org/pubs/de ... x?id=22761
Both links work at my end so they should work for you. But oddly that Practical Machinist link also works as a direct thread link for me.
Re: Building a bed turret
Thanks Pete! Both links work.
There sure is no shortage of tool configurations available. That's actually the more daunting part of this project, knowing what type of tool holders that will be needed and then having to take the time to make them There's no mention in any of the literature from DWT on how to adjust the tools to the correct dimension when setting everything up for a given part. I assume that's a simple cut measure, adjust, cut measure adjust and so on. The thing that seems lacking about this process is you have to unscrew bolts or undo tool holders and slide them around until you get the dims you want. Doesn't seem very accurate to me. I'd like some sort of screw slide like a boring head has or something similar.
There sure is no shortage of tool configurations available. That's actually the more daunting part of this project, knowing what type of tool holders that will be needed and then having to take the time to make them There's no mention in any of the literature from DWT on how to adjust the tools to the correct dimension when setting everything up for a given part. I assume that's a simple cut measure, adjust, cut measure adjust and so on. The thing that seems lacking about this process is you have to unscrew bolts or undo tool holders and slide them around until you get the dims you want. Doesn't seem very accurate to me. I'd like some sort of screw slide like a boring head has or something similar.
Vision is not seeing things as they are, but as they will be.
Re: Building a bed turret
So far I've never used a turret RSG but have thought a few times about picking up the drawings from Downriver Tools. Like yourself they wouldn't directly apply to my lathe so at least some re-design would be required. That's why I'll be very much glued to this thread.
Randy Richard on YT has shown a few set ups with his bed mounted turret and also mentioned that doing the initial set up is what takes the most time. But gaining some experience will help speed that up. Plus your limited to the turret's fixed stroke length and at what point it does the indexing. Apparently having screw length drills can be very helpful for most parts. The little I've managed to pick up about screw machines indicates there a lot like the much simpler turret's and that set up is everything. Using dial indicators to measure tool movement during that set up and adjustment was from what I've gathered the preferred method on those screw machines. I haven't checked yet, but if there's any scanned information about B & S screw machines on that Vintage Machinery website that might be helpful since a lot of the tooling and methods would apply to both. Since the B & S screw machines were the most common then if there's any scanned information it's likely it will be for them. It might be worth researching what size the more common screw machine and turret's used for tooling before deciding on the bore size's for your turret. For lathe turret's Hardinge was probably one of the more common so there might be some information about them on that Vintage Machinery web site as well.
Randy Richard on YT has shown a few set ups with his bed mounted turret and also mentioned that doing the initial set up is what takes the most time. But gaining some experience will help speed that up. Plus your limited to the turret's fixed stroke length and at what point it does the indexing. Apparently having screw length drills can be very helpful for most parts. The little I've managed to pick up about screw machines indicates there a lot like the much simpler turret's and that set up is everything. Using dial indicators to measure tool movement during that set up and adjustment was from what I've gathered the preferred method on those screw machines. I haven't checked yet, but if there's any scanned information about B & S screw machines on that Vintage Machinery website that might be helpful since a lot of the tooling and methods would apply to both. Since the B & S screw machines were the most common then if there's any scanned information it's likely it will be for them. It might be worth researching what size the more common screw machine and turret's used for tooling before deciding on the bore size's for your turret. For lathe turret's Hardinge was probably one of the more common so there might be some information about them on that Vintage Machinery web site as well.
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Re: Building a bed turret
There are loads of tooling on ebay, since that type of machine is no longer used in most shops.
Re: Building a bed turret
I would never try to steer someone away from a project building a tool. I was able to pick up a schaublin turret some years back and made an adapter plate to match it to the bed did the lathe I used it on. I've only used it one other time, but it paid for itself on the job it was purchased for.
Dave
Dave
Re: Building a bed turret
Oh, yeah! For those who have never used one, you may not understand just how good they are.
Imagine a project where you must set stock length, center drill, drill, ream, then run a thread on the OD. With stops set, the operations happen in seconds. Indexing takes about a second, and proper setup of the die head allows for it to cock again without operator intervention.
The only real negative of a turret is they're pretty much useless for one-off parts.
H
Wise people talk because they have something to say. Fools talk because they have to say something.