CS-88 rebate clamp effectiveness

[Not your average framer]

Recently I began offering 13mm wide oak mouldings and this has become popular with my customer, but being narrower that the most narrow hardwood moulding we had offered offered previously, there is not sufficient width of wood to set the wedges far enough from the back (outside edge) of the moulding to fully prevent the tendancy for the corners to open slightly as the wedges are inserted.

Therefore it did occur to me to discuss this and ask if anyone else is trying to join such narrow oak mouldings with a CS-88 and ask if they are encountering the same problem. I suspect that a more effective rebate clamp may significantly improve this by preventing the corners from being able to open while inserting the wedges.

Therefore I am wondering is whether my rebate clamp might have been more effective when the machine was new, compared to what it is like now, or if anyone has found a way to improve the effectiveness of the rebate clamp on the CS-88. Since the rebate clamp is operated by a cable and spring, it did occur to me that a new spring might increase the available rebate clamp pressure. This would only work if the spring has lost some of this force since it was new.

My current solutions to this are either to fill and sand the corners, or to make a right angled spacer faced with a suitable friction material and to locate this between the frame and the normal underpinner fences. Both solutions work, but if possible I would prefer to manage without any extra effort, fiddling about.

Any comments please?

[prospero]

All things considered, I think you are stuck with filling Mark.

Even if you had a mega-strong clamp, the wood might still splay the moment you released it.

[Roboframer]

Plenty of glue and a band clamp after pinning may get better results, still a pain though.

Even with a pneumatic rebate clamp, narrow hardwoods, especially deep-rebated ones like Simons Oak 9, can be a pain.

[stcstc]

i found the clamps rubbish on my cs88, anything remotely hardbut narrow just couldnt get tight joins

changed to a 199xl and man soooooo much difference


I thought you have a fancy pnuematic underpinner to be installed?

[Not your average framer]

I have had a good measure of success with just a right angle spacer made of wood and faced with very fine sandpaper and I can get really tight joints this way, but it's not easy to get perfect alignment of the sandpaper pieces where the two bits of sandpaper join together.

Any gap can affect the way the two pieces of moulding align themselves before being joined. I can easily fix this by cutting the wood spacer on the morso after the sandpaper has been glued in place, but I don't fancy cutting sandpaper on my morso and blunting the blades.

I mention this because this has proven that being able to prevent movement between the fences and the two pieces of moulding substancially reduces the gaps in joints with these small hardwood mouldings. I would like to find another way of doing this without using the sandpaper, so that I can apply the same method to other mouldings, without worrying about the sandpaper marking the mouldings.

Quote stcstc,

"I thought you have a fancy pnuematic underpinner to be installed?"

Hi Stephen,

Yes, I do have a Pneumatic underpinner waiting to be installed and this will happen very soon now, but things like this are on the back burner right now, due to my own health problems and my having to nurse my wife who is recovering from an abdominal operation for an umbilical hernia. Niether of us are completely well at this time.

[stcstc]

sorry to hear about your health,

what about using something like neoprene type rubber, but maybe a bit harder.it should grip cos of the rubber type properties

tell you what though get the pnuematic installed, it will actually help with you health, its much easier on the hands and knees etc

[Not your average framer]

tell you what though get the pnuematic installed, it will actually help with you health, its much easier on the hands and knees etc

Hi Stephen,

Thanks for the kind words. I've been looking forward to getting the underpinner installed for some time now. What you say about the hands and the knees is becoming an important consideration for me, as my arthiritis is becoming quite uncomfortable in colder weather and anything which makes this any easier will be very welcome.

The existing rebate clamp on the Gielli is a bit basic, but I'm planning to replace it with the spring claw rebate clamp used on the minigraph. It will require a bit of adapting to make it fit, but it should result in an excellent underpinner.

[Not your average framer]

what about using something like neoprene type rubber, but maybe a bit harder.it should grip cos of the rubber type properties

It would not need to be particularly hard, in fact a softer neoprene would be quite grippy and if it was quite thin then the neopene would not act like it was too squishy.

Thin cork would be another interesting possibility. Cork used to be used as a brake, or clutch linning material and still is in some applications, so it might work for something like this.

[ChrisG]

When I had my CS88 I used to glue and Bessey the frame to start with and leave overnight underpinning the following morning. As long as care was taken to ensure the mitres were all tight and even in the band clamp and a good glue was used the underpinning didn't affect the joins just reinforced them.

[AllFramed]

I do as ChrisG with oak and use a polyurethane glue.

Mark, do you use the fences on their own or do you use the hinged spacer bar? Also do you find the rebate clamp makes much difference ? I hardly ever use it as I don't notice any difference in the outcome.

[Not your average framer]

Hi Tim,

I don't have a hinged spacer bar, so I have made my own right angled spacers out of wood and they seem to work just as well. The original rubber inserts on my CS-88 rebate clamp were largely ineffective, (possibly due to age and wear with usage), so I bought some new inserts from Lion.

The new ones were made from a completely different design and material, which was a transparent green material, very similar to the material used by Cassesse for their round top clamp bungs. The results were noticably improved after fitting the new inserts.

With the new inserts fitted, I find the CS-88 rebate clamp is still worth using, but I think that Cassesse could have chosen a much more effective design than the one they incorporated into this machine, as I often find that the degree of clamping force provided by the CS-88 rebate clamp is not really enough.

The CS-88 is a rugged and reliable machine, but I think that the Minigraph "Alpha 1/M Super" is probably the better manual underpinner of the two and the Alpha 1/N Super has a more effective rebate clamp.

[AllFramed]

Thanks Mark. Perhaps I will have a look at doing some maintenance!