[rx7vt]

Apologies if this isn't the right forum - I'm looking at a benchtop vs. a Bridgeport. Forum for each. What's a newbie to do?

I have an older Bridgeport in decent shape - belt drive spindle, 2 axis DRO. I do light machining, mostly prototypes and replacement parts.

I need to make dozens (and perhaps hundreds) of enclosures with various cutouts. Most are plastic, some are light gauge steel. I've wanted to move to CNC anyway, so this is a good catalyst. My budget for ALL expenses is $10k.

After tons of lurking and research, I think I have two basic choices:

1) Do a CNC retrofit to my Bridgeport

2) Sell the Bridgeport and get an IH machine with the CNC kit

The work envelope that I need rules out most benchtop CNC systems. I won't be running full production so I don't think I need a full-blown VMC, and I don't have time to deal with too much uncertainty about when I'll be able to start making chips. I can deal with the IH kit, but an unknown used machine scares me.

My understanding of pros and cons:

Bridgeport is a beefier machine. Parts are easy to find and cheap. Most Bridgeport CNC retrofits seem to be heavier, stronger, and faster than the IH.

IH gives me variable speed spindle, and new machine with support and no worries.

IH would be easier to enclose to catch coolant.

Neither one gives me the spindle speeds I wish I had for plastic - I think I'll do some sort of engraver attachment to the head if that becomes a problem.

I think costs are pretty near a wash.

Any thoughts and collective wisdom that I can shamelessly take advantage of?

[SCzEngrgGroup]

IH no longer sells "kits", just assembled machines, starting at $10K, and that does not include a variable speed motor. So, from a purely cost standpoint, I think you'd probably come out cheaper doing a conversion on the BP, albeit with a lot more of your time going into the conversion. Functionally, either machine will do what you need, since you won't be doing anything that requires heavy milling. Any differences in stiffness will be lost int he noise just doing panels. I did a conversion on my BP clone, and the parts alone probably cost me about $3-4K, and I've long since lost count of the hours that've gone into the design and fab of all the parts.

Regards,
Ray L.

[rx7vt]

IH no longer sells "kits", just assembled machines, starting at $10K, and that does not include a variable speed motor. So, from a purely cost standpoint, I think you'd probably come out cheaper doing a conversion on the BP, albeit with a lot more of your time going into the conversion. Functionally, either machine will do what you need, since you won't be doing anything that requires heavy milling. Any differences in stiffness will be lost int he noise just doing panels. I did a conversion on my BP clone, and the parts alone probably cost me about $3-4K, and I've long since lost count of the hours that've gone into the design and fab of all the parts.

Regards,
Ray L.

Thanks for your post. The IH kit situation must have changed recently. I just talked to Tommy at IH two days ago. The kit is on their site and he spent some time explaining the difference between th kit and the turnkey package. One significant difference is that the turnkey package has oiling built into it. The price puts it out of reach for me, but the kit could work. Wiring and mechanical work doesn't bother me at all. Hence my opportunity to agonize over the decision. I'm a little bit worried about the time and uncertainty involved in a BP conversion, but the machine has been good to me. If I sold it and got the manual IH plus the kit plus the variable speed motor, I'd still be well under my 10K mark.

[SCzEngrgGroup]

Thanks for your post. The IH kit situation must have changed recently. I just talked to Tommy at IH two days ago. The kit is on their site and he spent some time explaining the difference between th kit and the turnkey package. One significant difference is that the turnkey package has oiling built into it. The price puts it out of reach for me, but the kit could work. Wiring and mechanical work doesn't bother me at all. Hence my opportunity to agonize over the decision. I'm a little bit worried about the time and uncertainty involved in a BP conversion, but the machine has been good to me. If I sold it and got the manual IH plus the kit plus the variable speed motor, I'd still be well under my 10K mark.

If you can still get the IH kit, then I'd go for it. I thought I had read that they no longer sold kits, and I couldn't find them on the website (which it not very well organized....) They're very good machines, and their support is as good as you'll ever find. I think the only limitation on the IH, even with the variable speed option, is the low spindle speed. You might consider sinking some of your "savings" (about $1K) into a true high-speed spindle (see www.homeshopcnc.com for one). Seller linearmotionbearings2008 on E-Bay also has several, starting at about $500. They'll make a HUGE difference in your throughput with small tools, and work MUCH better than a little handheld tool fastened to the head.

Regards,
Ray L.

[BobWarfield]

You sound like you want to be making parts sooner rather than later. I'd go with the kit, either IH, or find one for your Bridgeport. If it were me, I'd go the IH Kit and leave the Bridgeport unmolested. You can either sell it, or you may use it later.

Cheers,

BW

PS Looks like Tommy decided to make the kit available again. Good for him!

[Neal.R2E3]

Definatly do the retro you just can't beat the old iron for the conversion cost you cant even get close to that kind of solid structure in a new machine for under $20,000. If you alreay have the machine get a 3 axis kit from ajaxcnc you'll be suprised on how cheap the retro will end up and how moderenized that willl make your machine. I have a friend that has a machine that has been retroed and it's awesome the difference from old to new and i bought a bp r2e3 and i'm in the process of retroing it as we speak.

[pete from TN]

I have an RF45 cnc mill, it is real nice and I am having a lot of fun with it and learning to use it more everyday. I also have a knee mill here that mostly just sits and collects dust now. I built my own cnc conversion and with a little help from some nice fellows I built the control unit. I have not had nor do I now have $10K dollars for a cnc mill. IF I had anywhere near $10k for a cnc mill I would definitely be looking for a nice used small VMC. If you have any aspirations of making parts in a production environment or for any real amount of time I think you might be real surprised at how cheap you can get a decent used VMC for these days. Check on ebay lately? The IH machine is a real nice machine it seems and is very similar to my LAthemaster machine and now that my machine is cnc and in a full flood coolant environment and enclosure I really enjoy it. It has taken me some considerable time to get it where it is and no small amount of cash. I do intend to make money with this machine as soon as it is optimized and I feel ready for production. If I had that kind of money to put toward a cnc mill and needed to make parts on any sort of permanent basis I would be definitely looking for a great deal on something like a used Cincinatti arrow, fadal, or hurco smaller vmc that would fit in my shop. Not saying that you would not be happy with the IH or cncing the BP just that these machines are MADE for this and designed to run all day long, most have rapid toolchangers, full flood coolant, full or adequate enclosures and higher speed spindles. There really is no comparison to these other machines when you get down to it. Just a humble opinion here.... peace

[lumberjack_jeff]

Don't rule out a gantry router.

A well built mechmate can cut steel for far less than your $10k budget

http://www.mechmate.com/forums/showt...7&postcount=55