Drilling and Tapping Questions - Machine Choice

[lucas_jude]

Hello Canadian Hobby Metal Workers,

I am curious to pick experienced brains on a project that I am working on. I've recently grown my small business of assembling small custom hydraulic parts and am looking to get into porting some cast parts in house. I have some cast iron pieces that I would be looking to drill and port in sizes ranging from 1' NPT thread to 1-1/2" NPT thread. My question to you, what would be a smart cost effective way into entering this type of production challenge? Would I be looking at a radial drill and tapping manually or with the drill? Would I be looking at a milling machine? Any guidance would be appreciated as I am new to machining.

Regards,

Lucas

 

[Janger]

I thought we had a thread on this.... I can't seem to find it though. Maybe it's just in my head. Anybody see it?
We've had a bunch of discussion on tapping with:

• JSN, Procunier, or Tapamatic tapping heads for a drill press etc.
• Tapping in the milling machine slow and just hitting power on and off. Tom Lipton has a video on doing this kind of thing.
• Tapping with a pneumatic arm and powered head. Anybody have one of these?
• Tapping with the grizzly manual tapping station thing, @PeterT has one.
• Tapping in the mill with a formed cutter and CNC control, need a very good CNC mill to make this work
• Tapping in the mill with a floating tapping head and a more typical CNC mill but still a pretty good one. @Alexander can you comment?
• Tapping in the lathe using a sliding die holder. @Jimbojones did you buy one? Post pics?
• What about one of those gas pipe threading machines?
• What else?

Lucas post some pictures of what you want to tap - that should help.

 

[Alexander]

Hey John. In a modern CNC most company's rigid tap in a collet chuck. The floating tapping head is old technology not used anymore unless there is a serious problem with the mill spindle encoder. That being said my milltronics VMC won't even tap with a floating tapping head it is however able to treadmill easily so that is the way I'll do it. As a side note depending on the material form tapping is better than using a cutting tap because the tap lasts longer and the thread is on average 30% stronger. You do need a rigid tapping mill spindle to accomplish this as far as I know. The tapping arms with an air tool for tapping work very Well. The small ones will only be able to turn a cutting tap up to 3/8".

 

[Alexander]

Lucas I just read your post after making that last post. I'm happy to weigh in on your project the biggest factor is going to be volume. I think you will be looking for a cnc milling machine from what you described. The start up cost with these type of machine shop assets will be high. but the resale value of the machine will be quite good so the cost to own and run the machine shouldn't be a problem as long as your quantitys are up over about 90 parts a month. I am over simplifying things but without knowing the scope of your parts run all I can do is guess.

 

[PeterT]

Tapping with the grizzly manual tapping station thing, @PeterT has one..

Nope not me. Maybe the other Peter?

That is a much bigger thread size than I have ever used so cant offer anything useful to say other than it looks to be outside the range of typical clutch tapping heads, so presumably trying to direct feed something that big & coarse into CI sounds like a lot of torque & stress.
http://www.tapmatic.com/product_line_self_reversing_manually_controlled_tapping_heads.ydev

For sure taps exist that size & for CI but just wondering if its the tap in & partial back out progression that makes this possible (as opposed to direct feed to depth?)
http://www.discount-tools.com/rfn-120gci.cfm

 

[Janger]

Nope not me. Maybe the other Peter?

Oh yes sorry that’s right it’s @CalgaryPT

 

[CalgaryPT]

Always the bridesmaid...never the bride....

 

[Janger]

Not but you’re certainly the fab man.

 

[CalgaryPT]

I like that. Thanks John.