Metcal SP440 - repair or upgrade to MFR 1350? - Page 1
Forum section: electronics / general

author: dfnr2
author_rank: Regular Contributor
timestamp: February 12, 2017, 07:39:12 pm
content: I have an SP440 I picked up on Ebay more than 10 years ago, and it's been working great since then, only requiring a couple of inline filter changes, and periodic maintenance of the collection chamber paper and pads.I've recently noticed more clogging, with the evacuated solder hardening around the coil assembly seal. I assume this is an air leak with inrushing air prematurely cooling the solder, since the manual indicates the seal can fail over time.No problem--I'll just buy a new seal. But of course, this model was discontinued years ago and no parts are available. I see that OKI has replaced this with the MFR-1350, which looks nice. I like the idea of the convertible handpiece. However, I have a modest investment in consumables for the SP440 (tips, paper, filters, etc.) and would like to keep it running as long as possible.If anyone has used both, I'm curious to hear the comparison. Some questions:- One marketing video (below) claims the SP440 had a "lackluster suction pump." The SP440 manual indicates 12 inches Hg, no reservoir. However, when I measure the vacuum pulled by the SP440, it's -10 PSI in steady state, just about the same as the "21 inches Hg" touted for the MFR 1350.- I think both units operate at 450 kHz. How compatible are the handpieces? At the right time, a new handpiece at USD$200 is cheaper than a whole new unit. The SP440 has a 5-pin DIN connector, which I think is not directly compatible with the MFR handpiece, but I'm wondering if a simple connector change might do the trick.- I already know throughthis threadthat the tips are not compatible. However, the overall handpiece design seems similar to the SP440 handpiece. I wonder if the seal or the internals of the coil assembly might be compatible. Can anyone compare them?I think it would be possible to supplement the failing seal with some high-temp o-rings, which is what I will try next. I don't want to turn this into a project, though. Too much real project work at the moment :-)Thanks,Dave

author: dfnr2
author_rank: Regular Contributor
timestamp: February 12, 2017, 09:23:17 pm
content: I should mention that I also have a metcal MX-500 system on each bench, and a couple of DS1 handpieces with maintenance parts, but no shop air. An alternative would be to get a compressor and use these handpieces, but that could get more expensive. Plus, I like the pencil grip of the SP440.

author: dfnr2
author_rank: Regular Contributor
timestamp: February 16, 2017, 07:23:46 am
content: I went ahead and ordered the MFR-1350, so I can make a comparison.First, I can confirm that the tips aren't compatible--they are a bit smaller diameter. The newer CxP tips have a shorter stem for sucking up solder, which means less chance of cooling in the stem. Perhaps this is intended to reduce clogging? The newer tips are less of a tight fit than the SP440 tips. They slide on easily and with a bit of force snap into place--much easier to switch out than the SP440.The new cardboard collection chambers don't fit the older SP440.But, the silicone seal between the coil assembly and collection chamber is identical between the SP440 and MFR-1350. A set of 2 seals is $10. I just ordered a set from Mouser, and will report back if that fixes the SP440.The suction on the base unit is not much different from the SP440. I read a suction of about -10.5 PSI, about 21 inch Hg, compared with -10 PSI on the SP440.The device is very much like the SP440, but seems to have been reingineered for lower cost. The handpiece feels cheaper and less solid, and is a bit smaller.The handpiece feels hotter to the touch than the SP440 when used like a pencil. This may be due to thinner plastic and smaller diameter.The pencil is advertised as "ergonomic" but doesn't really feel optimized for use in a pencil grip configuration. The pencil seems like whatever is left when the removable pistol grip is off. in order to control the vacuum with your index finger, you have to hold the pencil in what looks and feels upside-down. The vacuum button is smaller and requires a more specific hand position than the SP440 button.All in all, I prefer the older SP440. Hopefully the replacement seal will give a few more years of life until either the coil assembly or all the tips wear out.

author: rachaelp
author_rank: Unknown
timestamp: February 16, 2017, 07:50:49 am
content: Quote from: dfnr2 on February 16, 2017, 07:23:46 amThey used to have the older Metcal desoldering stations where I worked about 10 years ago, they were great. When I was setting up my own home lab a couple of years back there was no question that I would get the latest Metcal kit for my bench. The MX-5000 rework station itself and the main hand piece are great but.... The MFR-1530 is definitely a lot more "flimsy" feeling than the older gear. I don't use it as a pencil, I keep the handle on it and use it as a desoldering gun but unfortunately because it's designed to be convertible and its made of fairly thin plastic the handle it annoyingly wobbly. Also in the not as solid feeling as I would like category are the tweezers for the MX-5000. It's easy to make the tips not line up quite right if you aren't careful and don't have the right tongue angle when using them....Quote from: dfnr2 on February 16, 2017, 07:23:46 amFingers crossed it works for you. I'm wondering if the older more substantial desoldering hand piece could be made to fit on the MFR-1350 main unit if I can find the hand piece in good working order somewhere?Bests Regards,Rachael

author: dfnr2
author_rank: Regular Contributor
timestamp: February 16, 2017, 04:20:38 pm
content: Quote from: rachaelp on February 16, 2017, 07:50:49 amI'm sure the older handpiece can be made to work with the new unit, by swapping out the connector on the handpiece. But the SP440 base units are now very cheap on Ebay ($75USD) and seem to work the same as the new MFR base.The main issue with the older handpiece is the eventual scarcity of tips. I believe it would be possible to modify the old handpiece to accept the newer coil assembly, which would solve that problem. The filter materials should be easy to improvise. My plan is to repair the SP440 and use it until I'm out of tips, or the coil assembly gives out, then try to modify it.The other option is to come up with some kind of silicone grip for the MFR pencil unit to make the grip more comfortable and less hot.After using both the pencil and pistol grip configurations, I do prefer the pencil grip.Dave