As mentioned in the previous post in this thread from March 9th, 2012, I would put a few hundred feet of material through the new Jessem Mast-R lift II, a prototype with an aluminum tool plate table top. Well, here we are a few months later and I have some developments to report. When I did the assembly of the router, carriage and top, I did an initial check of the aluminum top out of the box for flatness using a Starrett straightedge. It was flat. When I assembled the table and placed the aluminum tracks on each side that guide the fence, I also used the straightedge, and nothing seemed awry.
However, while template-routing some parts recently, I discovered that the cut was not perpendicular to the table top. Puzzled, I began checking some things out and found that not only was the perpendicularity of the cutter to the top seriously out of whack, but the entire tabletop was slightly sagged down in the middle – exactly the same issue I had found found with the phenolic top I had previously used. This was not a pleasing discovery to say the least. Besides the router-cut part being ruined, I now had to take time away from a project and figure out what was wrong with the router table and lift. I use the router table a fair amount and having it down was not a welcome state of affairs. A further problem had cropped up as well: the digital read-out, DRO, for the table was acting quite oddly. When I would apply the carriage ‘parking brake’ after moving the carriage to the desired setting, and then turn the router on, the setting would scroll on the read out a few hundredths of an inch. This rendered the DRO pretty much useless.
Sorting the router table out has taken the better part of a month, given the vacation I took, along with a recent 4-day trip down to NYC, and vacations also happening with key people at Jessem. One of the facts of life when it comes to testing prototype products is that glitches may be discovered and a step or two back must be taken. As a consumer, on the one hand, and product tester on the other, I was concerned with both getting the problem resolved and interested to see how Jessem would respond. There is no shortage of companies out there who will happily sell you a product and then ignore you – or even blame you – if there are any problems with that product. Some will simply ship you a new replacement, which, if the defect was unique is an acceptable solution, but if the defect was in every product they made then simply shipping a new one to you doesn’t help improve anything for anyone.
In any manufactured item there will be the occasional problem- I’m sure even Rolls Royce has the odd defect. The issue is not that defects occur, but it is how the company deals with the matter and moves forward. Does this spur them to improve the product or not?
I know in my own business that if I produced something which was found to have a problem of any kind by one of my clients, I would be on it right away and would certainly take any lessons learned forward with me in terms of how I would construct the same piece the next time. To this date I have never had a call-back from a customer mind you, and I remain committed to continuous improvement in my work in any case.
Once the problem with the aluminum top and non-perpendicularity of the router spindle had been discovered, it was a matter of tracking down the cause. Since I had checked the top for flatness prior to assembly of the lift carriage to the top and assembly of the top to the table stand, it followed that the top had either warped from some latent stresses working themselves out in the aluminum (an unlikely possibility I thought), or the top had become warped from stresses introduced after the carriage and/or stand were connected. Tracking this down was more or less a process of elimination.
First off I considered the matter of how the Jessem table stand might induce stress in the table top and it didn’t take long to rule that out as a cause. I even tried shimming the interface between stand and top in certain spots to see if I could obtain a flatter top. It made little to no difference.
Then I stripped the whole works down and re-checked the top. It was dead flat! So, that left really only one thing – something relevant to the carriage, which bolted to the top and held the router. I tried loosening the carriage and shifting the router slug position slightly to improve perpendicularity, however that resulted in no real improvement. After speaking with Darrin Smith, owner of Jessem, on the phone and explaining in detail what was occurring, he decided to send me an entirely new lift. Jessem would be sending me a new DRO as well, thinking that there might be slightly more play in the unit’s linear slide than it should have – a minor manufacturing defect.
The new parts arrived in fairly short order and I commenced the reassembly. The process is one of fitting the carriage to the top, then opening the carriage up using a central bolt which slightly spreads the carriage, and sliding the router slug into position. Once the router slug is at the correct depth relative to the carriage, the central bolt is turned the other way until, releasing the load on the carriage’s aluminum chassis and at the same time fastening it tightly onto the slug. Right away I discovered something strange – the new router carriage, having been mounted in the aluminum table top, wouldn’t spread open far enough to allow the router slug to slide in. This was a curious difference from the original carriage.
So, I removed the carriage from the top and spread it with the clamping bolt until the router could be slid in place, then released the bolt tension until the router was held firmly in the carriage. Then I went to re-attach the carriage to the top. And there we had a problem, as it wouldn’t fit back on! It seemed that the mounting points for the carriage, once the router was mounted, had become spread slightly too far apart and the holes in the top weren’t lining up. I fiddled around a bit and managed to actually get the machine screws started into the carriage mounting points, however once I had them tightened up, and had re-attached the cranking handle for the lift, the lift was binding excessively when I tried to raise or lower it. Clearly something was wrong with the picture. So I took it apart again. Something was clearly different in specs between the new carriage and the old one, however given that the parts are CNC-cut in aluminum, I was puzzled as to how the lifts could vary significantly from one another, short of a programming of cutter change. I checked and re-checked the new carriage, and even attempted a second re-assembly of lift, slug, and top, all to no avail.
I then reassembled the old carriage to the router slug and the top. As it had done before, these two parts went together perfectly. ‘Perfectly’ that is, until I looked at the table flatness and spindle perpendicularity, both of which were as far askew as I had seen previously. At this point I wasn’t able to do much more, so I called Darrin at Jessem and made an arrangement to have the top, carriage, and lift picked up by UPS and shipped back, on Jessem’s dime, to Ontario so they could investigate the matter further.
I was intrigued to see what they would discover, and hoped that this would lead to improvements in the product. Upon return from vacation I received the following email from Darrin:
Hi Chris,I did figure out some of the issues you were having. We have only made the aluminium Excel top one time and it was for a special request for one of our important dealers. When these aluminium tops were machined the clearance around the screw holes that attach the carriage shafts to the top was less than we use on our Mast-R-Lift II and less than we use on our phenolic top Excel. That shouldn’t be an issue but it actually is because it leaves no room to take the pressure off the shafts if the four clamping blocks are a little tighter. I checked the clamping blocks on the first carriage you had and the second one we sent and they both worked perfect on a phenolic Excel and on a Mast-R-Lift II but were both too tight on your aluminium Excel. The second set was way too tight. We are only talking a few thousands of an inch difference in the hole locations on the clamping blocks but that is enough to make a huge difference when there is no way to compensate for this when the clearance holes are too tight on the holes that the shaft screws go through.We modified the specs on the clamping blocks and machined a new set to try on your Excel, the phenolic Excel and the Mast-R-Lift II. They now work on all three units with no issues. I checked the squareness of the shaft mounts from your Excel as well and they were pretty close but we faced them in the lathe anyway. The change in the hole locations on the clamping blocks which removed the pressure from the shafts and the facing of the shaft mounts seems to have taken care of the issue with flatness on the top but to make sure I had a set of beefed up reinforcements machined as well to make sure.The clamping blocks went out for anodizing yesterday and are expected back here tomorrow. We should be able to get your Excel shipped back to you tomorrow.The squareness issue with the bit to the table I think is a product of the clamping blocks being too tight and no means of relieving the pressure on the shafts. I checked your Excel with the new clamping blocks and it was square to within a couple of thou per inch.I actually learned a lot from this exercise, we want our products to be the best available so it was well worth the effort to get to the bottom of this. I am planning on making an aluminium top Excel part of our regular line up and I am working on making it even better. When we do produce these I’ll send you a new top to replace this one. You should have the best for all the trouble this has been for you.I hope you had a great vacation and I’ll give you a call once you have your Excel back at your place.All the best,Darrin
This was looking good – Jessem had been completely receptive to my concerns and proactive in dealing with the issue in a prompt manner. It shows a lot about the character and culture of the company. Despite the inconveniences and frustrations, this has been a good process, even a rewarding one for me personally.
I was keen to see the return of the table and get it bolted back together and then get back to some productivity. The parts are now back in my hands and in tomorrow’s post I’ll detail the re-assembly of the router table and check out the function and flatness of the machine. I hope you’ll stay tuned. Thanks for coming by the Carpentry Way. On to the follow-up. ☜☜ link