Author Topic: Engine Test Bench (Read 7446 times)

b.lindsey · « **on:** June 30, 2014, 02:30:42 AM »

Don had asked about the engine test bench the little radial was sitting on over on the build log. I have attached a few pictures below. There are plans for this along with a bill of materials for the purchased components and brass fittings, etc. On mine, the sides are 3/4 thick solid oak (yeah I know, I am in a rut with oak) and the bottom, top, and angled piece where the gage is are oak veneer plywood, all of which I got at the local big box store. I will need to convert the plans to .pdf format but will do so and post them in the morning if anyone is interested.

Bill

Don1966 · « **Reply #1 on:** June 30, 2014, 03:19:50 AM »

Bill I love it. Perfect setup for running in an engine. I'll be looking for the plans. Thanks buddy.

Don

Bearcar1 · « **Reply #2 on:** June 30, 2014, 04:36:10 AM »

Looks pretty interesting to me Bill. Nice work (as per your usual)

BC1
Jim

Arbalest · « **Reply #3 on:** June 30, 2014, 11:17:15 AM »

That looks really nice!

Must say though I may have been tempted to put some extra dials and switches on it for effect!

Ian S C · « **Reply #4 on:** June 30, 2014, 02:30:41 PM »

Nice work there Bill. Here I go asking silly questions. What sort of fixings have you used ie., screws etc. brass, or steel, Oak tends to corrode steel, something to do with tannin in the wood. Ian S C

sshire · « **Reply #5 on:** June 30, 2014, 03:15:55 PM »

Half-blind dovetails

b.lindsey · « **Reply #6 on:** June 30, 2014, 04:05:38 PM »

Ian, I used brass screws and the joints are glued as well. Haven't noticed any problem after many years.

Bill

smfr · « **Reply #7 on:** June 30, 2014, 04:20:03 PM »

That looks really handy, Bill

I wonder if some wooden clamps on the top side wouldn't go amiss to hold down the base of the engine being tested (since I noticed you had to have a finger on the base of your rotary engine while testing).

Simon

b.lindsey · « **Reply #8 on:** June 30, 2014, 05:12:18 PM »

I hope these will come through ok..it is a .pdf file with 13 pages. Please note that the air filter, regulator, and lubricator I used were obtained from WW Grainger. I think the SKU #'s shown on the purchased components sheet are still good but I haven't checked them lately. If you don't have access to Grainger I suspect McMaster may have similar "miniature" size air line components. Same for the gage. Other components may require some modifications to the mounting plate and/or brass fittings. If nothing else you can use this as a starting point.

Simon, I like your suggestion a lot...just not sure how to do that in wood and make it flexible enough at the same time for various sized engine bases.

Bill

philjoe5 · « **Reply #9 on:** June 30, 2014, 06:01:19 PM »

Very nice Bill. Thanks for sharing your work.

Cheers,
Phil

sshire · « **Reply #10 on:** June 30, 2014, 06:32:36 PM »

Thanks for posting that Bill.
Re: clamps. Threaded brass inserts in the top would work with some brass clamps.
I've also had good luck with wobblers that love to walk off the table by using the pads made to keep cell phones, etc. from sliding off the dashboard

b.lindsey · « **Reply #11 on:** June 30, 2014, 06:55:03 PM »

Dang, you guys are gonna make me go back and do some mods now re: clamps

I could make some 1/4-20 flanged bushings glued or press fit from the underside and placed in various strategic places to add as much flexibility as possible. Simon...where were you 9 years ago when I drew these up

Guess I have my next mini-project decided now!!

Bill

mklotz · « **Reply #12 on:** June 30, 2014, 07:12:56 PM »

You're aware that they make (machine) threaded inserts with exterior knife-like threads that screw into wood? Simply drill a hole, screw in the insert with a flat blade screwdriver and voila, you have threads.

http://www.amazon.com/E-Z-Threaded-Stainless-Internal-Threads/dp/B00AGIE8DG/ref=sr_1_9?ie=UTF8&qid=1404151941&sr=8-9&keywords=thread+inserts

b.lindsey · « **Reply #13 on:** June 30, 2014, 07:47:35 PM »

Yes, I have seen those too Marv, just wonder if they would be as secure in plywood. I'm sure gluing would help too. But for the purposes stated, simply holding down a model, it wouldn't take a lot of force anyway...not like clamping for machining.

Bill

mklotz · « **Reply #14 on:** June 30, 2014, 10:14:38 PM »

Quote from: b.lindsey on June 30, 2014, 07:47:35 PM

Yes, I have seen those too Marv, just wonder if they would be as secure in plywood. I'm sure gluing would help too. But for the purposes stated, simply holding down a model, it wouldn't take a lot of force anyway...not like clamping for machining.

If you manage to pull those out clamping a model engine, I'll pay for the repairs.

b.lindsey · « **Reply #15 on:** July 01, 2014, 12:07:44 AM »

Deal Marv...but a pretty safe on I would say too

Bill

PStechPaul · « **Reply #16 on:** July 01, 2014, 11:26:01 PM »

Something I think would be useful on a test bench would be a tachometer and a DC generator with variable pulleys and an adjustable resistance load so you can do dynamometer testing to see how she runs under various load conditions and RPMs. You could also add a lamp on an adjustable arm, and also a camera mount, so you can take good pictures and video.

Maybe instead of a resitive load and just generating heat (unless you are in a cold workshop and it may be welcome), you could rig up a battery charger and at least recoup some of the energy. You might even be able to get an Energy Star rating for your gasoline powered battery charger. One was awarded for a gas powered alarm clock!

sshire · « **Reply #17 on:** July 02, 2014, 12:48:20 AM »

IIRC, Bill had his students' engines on some type of test bench

b.lindsey · « **Reply #18 on:** July 02, 2014, 12:58:03 AM »

You are correct Stan, but it was a different bench and will require some improvements before next year. Paul, those are also nice ideas. Maybe someone will take the plans and improve on them. Meanwhile, I like the clamp idea and have ordered some of the knife edge inserts Marv suggested along with some thumb screws. I will make the clamps myself. More on that to follow.

Bill

b.lindsey · « **Reply #19 on:** July 07, 2014, 01:10:29 AM »

Brief update on this mod to the test bench. The inserts worked well and anchor very securely. The only problem was that the oak veneer on the plywood top is so thin...maybe like 1/64" that it still wanted to splinter some even using tape. A little putty helped but looked bad I though so I cut out some .009" brass washers and epoxied them over the inserts then polished them and added a couple of coats of brushed on gloss urethane. The last photo shows the little radial 5 being held down by one clamp which I made. The spacer at the back of the clamp should have been the exact same height as the engine base, but I had added some felt pads to the bottom of the engine base so needed a makeshift shim to keep the clamp level of pointed down just slightly to the base. All in all its functional but could have been executed better. I'll live with it for a while and make additional changes later if needed.

Bill

Don1966 · « **Reply #20 on:** July 07, 2014, 01:34:54 AM »

I like it Bill, maybe a clamp from Delrin or something coated with felt so it doesn't scratch your fine work. Not being critical mind you just suggesting buddy.

Don

b.lindsey · « **Reply #21 on:** July 07, 2014, 01:55:03 AM »

I don't disagree Don, just didn't have any delrin or UHMW handy to try. Would be much easier to machine them too...something like an "L" shape with the toe clamp and riser made as one piece. I will give that a try too just wanted to have something to take with me to the beach the end of this week and had to use what was handy

Bill

mklotz · « **Reply #22 on:** July 07, 2014, 03:36:12 PM »

I'm pleased to hear that the thread inserts worked and that I won't have to be paying for any repairs.

If you have some plastic tubing you could make clamps like the ones shown in this photo...

No spacer block required and they self-adjust to a variety of heights.

b.lindsey · « **Reply #23 on:** July 07, 2014, 04:18:13 PM »

Thanks Marv, I like that idea and will give it a try. As Don noted already, plastic will be easier on the wood finish too.

Bill

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Author Topic: Engine Test Bench (Read 7446 times)

Arbalest